diff --git a/CMakeLists.txt b/CMakeLists.txt
index 354a98dc9..8735e88da 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -554,6 +554,7 @@ set(ENGINE_SOURCES
 src/log.cpp
 src/baseutils.cpp
 src/fileutils.cpp
+src/timeutils.cpp
 src/utfutils.cpp
 
 extern/itcompress/compression.c
@@ -791,6 +792,7 @@ src/engine/export.cpp
 src/engine/exportDef.cpp
 src/engine/fileOpsIns.cpp
 src/engine/fileOpsSample.cpp
+src/engine/filePlayer.cpp
 src/engine/filter.cpp
 src/engine/instrument.cpp
 src/engine/macroInt.cpp
@@ -994,6 +996,7 @@ src/gui/patManager.cpp
 src/gui/pattern.cpp
 src/gui/piano.cpp
 src/gui/presets.cpp
+src/gui/refPlayer.cpp
 src/gui/regView.cpp
 src/gui/sampleEdit.cpp
 src/gui/scaling.cpp
diff --git a/papers/format.md b/papers/format.md
index 196f8078c..c92c7da3f 100644
--- a/papers/format.md
+++ b/papers/format.md
@@ -432,6 +432,7 @@ reserved input portsets:
 
 reserved output portsets:
 - `000` through `01F`: chip outputs
+- `FFC`: reference file/music player (>=238)
 - `FFD`: wave/sample preview
 - `FFE`: metronome
 - `FFF`: "null" portset
diff --git a/po/de.po b/po/de.po
index 312af88b6..19da48295 100644
--- a/po/de.po
+++ b/po/de.po
@@ -3763,19 +3763,19 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
 msgstr ""
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
+msgid "01xx: Pitch slide up (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
+msgid "02xx: Pitch slide down (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:60
diff --git a/po/es.po b/po/es.po
index 075592dd9..bb1a06239 100644
--- a/po/es.po
+++ b/po/es.po
@@ -4023,20 +4023,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "un sistema diseñado para propósitos de prueba."
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy: Arpegio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: Arpegio (x: semitonos; y: semitonos)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: Deslizamiento de tono hacia arriba"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: Deslizamiento de tono hacia arriba (xx: velocidad)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: Deslizamiento de tono hacia abajo"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: Deslizamiento de tono hacia abajo (xx: velocidad)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: Portamento (xx: velocidad)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/fi.po b/po/fi.po
index 0164e5345..65e57b90f 100644
--- a/po/fi.po
+++ b/po/fi.po
@@ -3763,19 +3763,19 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
 msgstr ""
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
+msgid "01xx: Pitch slide up (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
+msgid "02xx: Pitch slide down (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:60
diff --git a/po/fr.po b/po/fr.po
index 6a8c24c99..62e0a910c 100644
--- a/po/fr.po
+++ b/po/fr.po
@@ -3763,20 +3763,20 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy: Arpège"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: Arpège (x: demi-tons; y: demi-tons)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: Glissement d'hauteur vers le haut"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: Glissement d'hauteur vers le haut (xx: vitesse)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: Glissement d'hauteur vers le bas"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: Glissement d'hauteur vers le bas (xx: vitesse)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: Palier"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: Palier (xx: vitesse)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/furnace.pot b/po/furnace.pot
index 3bdce21b5..3e00f8225 100644
--- a/po/furnace.pot
+++ b/po/furnace.pot
@@ -3759,19 +3759,19 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
 msgstr ""
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
+msgid "01xx: Pitch slide up (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
+msgid "02xx: Pitch slide down (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:60
diff --git a/po/hy.po b/po/hy.po
index e30f221aa..b47b87289 100644
--- a/po/hy.po
+++ b/po/hy.po
@@ -3767,19 +3767,19 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
 msgstr ""
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
+msgid "01xx: Pitch slide up (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
+msgid "02xx: Pitch slide down (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:60
diff --git a/po/id.po b/po/id.po
index b5a68e00a..fd66c1066 100644
--- a/po/id.po
+++ b/po/id.po
@@ -3768,20 +3768,20 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy: Arpegio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: Arpegio (x: banyaknya semitone; y: banyaknya semitone)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: Geser nada ke atas"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: Geser nada ke atas (xx: kecepatan)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: Geser nada ke bawah"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: Geser nada ke bawah (xx: kecepatan)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: Portamento (xx: kecepatan)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/ja.po b/po/ja.po
index 4279d277b..bdced83ec 100644
--- a/po/ja.po
+++ b/po/ja.po
@@ -3763,19 +3763,19 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
 msgstr ""
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
+msgid "01xx: Pitch slide up (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
+msgid "02xx: Pitch slide down (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:60
diff --git a/po/ko.po b/po/ko.po
index ab6c2677b..c367af161 100644
--- a/po/ko.po
+++ b/po/ko.po
@@ -3981,20 +3981,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "테스트 목적으로 설계된 시스템입니다."
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy: 아르페지오"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: 아르페지오 (x: 반음 수; y: 반음 수)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: 피치 슬라이드 업"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: 피치 슬라이드 업 (xx: 속도)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: 피치 슬라이드 다운"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: 피치 슬라이드 다운 (xx: 속도)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: 포르타멘토"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: 포르타멘토 (xx: 속도)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/nl.po b/po/nl.po
index d321a1ecb..78fbd046f 100644
--- a/po/nl.po
+++ b/po/nl.po
@@ -3806,19 +3806,19 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
 msgstr ""
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
+msgid "01xx: Pitch slide up (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
+msgid "02xx: Pitch slide down (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:60
diff --git a/po/pl.po b/po/pl.po
index d171e93eb..92698817b 100644
--- a/po/pl.po
+++ b/po/pl.po
@@ -4091,20 +4091,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "ten system jest przeznaczony do testowania."
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: Arpeggio (x: półtony; y: półtony)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: Portamento w górę"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: Portamento w górę (xx: szybkość)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: Portamento w dół"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: Portamento w dół (xx: szybkość)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: Auto-portamento (do wskazanej nuty)"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: Auto-portamento (do wskazanej nuty; xx: szybkość)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/pt_BR.po b/po/pt_BR.po
index 5d7ee7dff..5751433e7 100644
--- a/po/pt_BR.po
+++ b/po/pt_BR.po
@@ -4145,20 +4145,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "este é um sistema desenvolvido para propósito de testes."
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy: Arpejo"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: Arpejo (x: semitons; y: semitons)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: Slide de tom para cima"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: Slide de tom para cima (xx: velocidade)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: Slide de tom para baixo"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: Slide de tom para baixo (xx: velocidade)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: Portamento (xx: velocidade)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/ru.po b/po/ru.po
index 61c30a61b..94d056dde 100644
--- a/po/ru.po
+++ b/po/ru.po
@@ -4080,20 +4080,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "это система, разработанная для тестирования."
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
 msgstr "00xy: Арпеджио"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: Портаменто вверх"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: Портаменто вверх (xx: скорость)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: Портаменто вниз"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: Портаменто вниз (xx: скорость)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: Авто-портаменто (до указ. ноты)"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: Авто-портаменто (до указ. ноты; xx: скорость)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/sk.po b/po/sk.po
index 72488a9fd..878729303 100644
--- a/po/sk.po
+++ b/po/sk.po
@@ -3767,20 +3767,20 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy Arpeggio (x: poltóny; y: poltóny)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx Tónovy šmyk nahor"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx Tónovy šmyk nahor (xx: rýchlosť)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx Tónovy šmyk nadol"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx Tónovy šmyk nadol (xx: rýchlosť)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx Portamento"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx Portamento (xx: rýchlosť)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/staging/ko-new.po b/po/staging/ko-new.po
index e80472c9d..b4037304e 100644
--- a/po/staging/ko-new.po
+++ b/po/staging/ko-new.po
@@ -3528,20 +3528,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "테스트 목적으로 설계된 시스템입니다."
 
 #: src/engine/engine.cpp:51
-msgid "00xy: Arpeggio"
-msgstr "00xy: 아르페지오"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: 아르페지오 (x: 반음 수; y: 반음 수)"
 
 #: src/engine/engine.cpp:53
-msgid "01xx: Pitch slide up"
-msgstr "01xx: 피치 슬라이드 업"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: 피치 슬라이드 업 (xx: 속도)"
 
 #: src/engine/engine.cpp:55
-msgid "02xx: Pitch slide down"
-msgstr "02xx: 피치 슬라이드 다운"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: 피치 슬라이드 다운 (xx: 속도)"
 
 #: src/engine/engine.cpp:57
-msgid "03xx: Portamento"
-msgstr "03xx: 포르타멘토"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: 포르타멘토 (xx: 속도)"
 
 #: src/engine/engine.cpp:59
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/staging/ko-old.po b/po/staging/ko-old.po
index dda06f041..d4507075a 100644
--- a/po/staging/ko-old.po
+++ b/po/staging/ko-old.po
@@ -3524,20 +3524,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "이것은 테스트 목적으로 설계된 시스템입니다."
 
 #: src/engine/engine.cpp:51
-msgid "00xy: Arpeggio"
-msgstr "00xy: 아르페지오"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: 아르페지오 (x: 반음; y: 반음)"
 
 #: src/engine/engine.cpp:53
-msgid "01xx: Pitch slide up"
-msgstr "01xx: 피치 슬라이드 업"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: 피치 슬라이드 업 (xx: 속도)"
 
 #: src/engine/engine.cpp:55
-msgid "02xx: Pitch slide down"
-msgstr "02xx: 피치 슬라이드 다운"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: 피치 슬라이드 다운 (xx: 속도)"
 
 #: src/engine/engine.cpp:57
-msgid "03xx: Portamento"
-msgstr "03xx: 포르타멘토"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: 포르타멘토 (xx: 속도)"
 
 #: src/engine/engine.cpp:59
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/staging/pt_BR-after.po b/po/staging/pt_BR-after.po
index 55f95a4cd..615419416 100644
--- a/po/staging/pt_BR-after.po
+++ b/po/staging/pt_BR-after.po
@@ -3558,20 +3558,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "este é um sistema desenvolvido para propósito de testes."
 
 #: src/engine/engine.cpp:51
-msgid "00xy: Arpeggio"
-msgstr "00xy: Arpejo"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: Arpejo (x: semitons; y: semitons)"
 
 #: src/engine/engine.cpp:53
-msgid "01xx: Pitch slide up"
-msgstr "01xx: Slide de tom para cima"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: Slide de tom para cima (xx: velocidade)"
 
 #: src/engine/engine.cpp:55
-msgid "02xx: Pitch slide down"
-msgstr "02xx: Slide de tom para baixo"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: Slide de tom para baixo (xx: velocidade)"
 
 #: src/engine/engine.cpp:57
-msgid "03xx: Portamento"
-msgstr "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: Portamento (xx: velocidade)"
 
 #: src/engine/engine.cpp:59
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/sv.po b/po/sv.po
index 9ba9c2779..d2006d3a2 100644
--- a/po/sv.po
+++ b/po/sv.po
@@ -4025,20 +4025,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "detta är ett system designat för teständamål."
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: Arpeggio (x: halvtoner; y: halvtoner)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: Tonhöjd glider upp"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: Tonhöjd glider upp (xx: hastighet)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: Tonhöjd glider ner"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: Tonhöjd glider ner (xx: hastighet)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: Portamento (xx: hastighet)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/th.po b/po/th.po
index 5e4d472cc..da428d75f 100644
--- a/po/th.po
+++ b/po/th.po
@@ -3762,20 +3762,20 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy: อาร์เปจโจ"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: อาร์เปจโจ (x: ครึ่งเสียง; y: ครึ่งเสียง)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: เลื่อนระดับเสียงขึ้น"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: เลื่อนระดับเสียงขึ้น (xx: ความเร็ว)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: เลื่อนระดับเสียงลง"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: เลื่อนระดับเสียงลง (xx: ความเร็ว)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: เสียงเลื่อนไหล"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: เสียงเลื่อนไหล (xx: ความเร็ว)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/tr.po b/po/tr.po
index fa1a2e797..0fdf208e0 100644
--- a/po/tr.po
+++ b/po/tr.po
@@ -3763,19 +3763,19 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
 msgstr ""
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
+msgid "01xx: Pitch slide up (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
+msgid "02xx: Pitch slide down (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:60
diff --git a/po/uk.po b/po/uk.po
index 6914bf909..a59fc5d77 100644
--- a/po/uk.po
+++ b/po/uk.po
@@ -3764,19 +3764,19 @@ msgid "this is a system designed for testing purposes."
 msgstr ""
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
 msgstr ""
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
+msgid "01xx: Pitch slide up (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
+msgid "02xx: Pitch slide down (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
+msgid "03xx: Portamento (xx: speed)"
 msgstr ""
 
 #: src/engine/engine.cpp:60
diff --git a/po/zh.po b/po/zh.po
index 6d7d48273..587db3936 100644
--- a/po/zh.po
+++ b/po/zh.po
@@ -3798,20 +3798,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "此系统只是为了测试"
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy: 琶音"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: 琶音 (x: 半音; y: 半音)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: 音高上滑"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: 音高上滑 (xx: 速率)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: 音高下滑"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: 音高下滑 (xx: 速率)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: 滑音"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: 滑音 (xx: 速率)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/po/zh_HK.po b/po/zh_HK.po
index 1cf342840..0832d1fe7 100644
--- a/po/zh_HK.po
+++ b/po/zh_HK.po
@@ -3798,20 +3798,20 @@ msgid "this is a system designed for testing purposes."
 msgstr "此系統只是為了測試"
 
 #: src/engine/engine.cpp:52
-msgid "00xy: Arpeggio"
-msgstr "00xy: 琶音"
+msgid "00xy: Arpeggio (x: semitones; y: semitones)"
+msgstr "00xy: 琶音 (x: 半音; y: 半音)"
 
 #: src/engine/engine.cpp:54
-msgid "01xx: Pitch slide up"
-msgstr "01xx: 音高上滑"
+msgid "01xx: Pitch slide up (xx: speed)"
+msgstr "01xx: 音高上滑 (xx: 速率)"
 
 #: src/engine/engine.cpp:56
-msgid "02xx: Pitch slide down"
-msgstr "02xx: 音高下滑"
+msgid "02xx: Pitch slide down (xx: speed)"
+msgstr "02xx: 音高下滑 (xx: 速率)"
 
 #: src/engine/engine.cpp:58
-msgid "03xx: Portamento"
-msgstr "03xx: 滑音"
+msgid "03xx: Portamento (xx: speed)"
+msgstr "03xx: 滑音 (xx: 速率)"
 
 #: src/engine/engine.cpp:60
 msgid "04xy: Vibrato (x: speed; y: depth)"
diff --git a/src/engine/cmdStreamOps.cpp b/src/engine/cmdStreamOps.cpp
index 4a7dc1718..51c47e020 100644
--- a/src/engine/cmdStreamOps.cpp
+++ b/src/engine/cmdStreamOps.cpp
@@ -1252,10 +1252,9 @@ SafeWriter* DivEngine::saveCommand(DivCSProgress* progress, DivCSOptions options
   setOrder(0);
   BUSY_BEGIN_SOFT;
   // determine loop point
-  int loopOrder=0;
-  int loopRow=0;
-  int loopEnd=0;
-  walkSong(loopOrder,loopRow,loopEnd);
+  calcSongTimestamps();
+  int loopOrder=curSubSong->ts.loopStart.order;
+  int loopRow=curSubSong->ts.loopStart.row;
   logI("loop point: %d %d",loopOrder,loopRow);
 
   int cmdPopularity[256];
diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 9503106f1..98b518456 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -52,13 +52,13 @@ void process(void* u, float** in, float** out, int inChans, int outChans, unsign
 const char* DivEngine::getEffectDesc(unsigned char effect, int chan, bool notNull) {
   switch (effect) {
     case 0x00:
-      return _("00xy: Arpeggio");
+      return _("00xy: Arpeggio (x: semitones; y: semitones)");
     case 0x01:
-      return _("01xx: Pitch slide up");
+      return _("01xx: Pitch slide up (xx: speed)");
     case 0x02:
-      return _("02xx: Pitch slide down");
+      return _("02xx: Pitch slide down (xx: speed)");
     case 0x03:
-      return _("03xx: Portamento");
+      return _("03xx: Portamento (xx: speed)");
     case 0x04:
       return _("04xy: Vibrato (x: speed; y: depth)");
     case 0x05:
@@ -201,15 +201,9 @@ const char* DivEngine::getEffectDesc(unsigned char effect, int chan, bool notNul
   return notNull?_("Invalid effect"):NULL;
 }
 
-void DivEngine::walkSong(int& loopOrder, int& loopRow, int& loopEnd) {
+void DivEngine::calcSongTimestamps() {
   if (curSubSong!=NULL) {
-    curSubSong->walk(loopOrder,loopRow,loopEnd,chans,song.jumpTreatment,song.ignoreJumpAtEnd);
-  }
-}
-
-void DivEngine::findSongLength(int loopOrder, int loopRow, double fadeoutLen, int& rowsForFadeout, bool& hasFFxx, std::vector<int>& orders, int& length) {
-  if (curSubSong!=NULL) {
-    curSubSong->findLength(loopOrder,loopRow,fadeoutLen,rowsForFadeout,hasFFxx,orders,song.grooves,length,chans,song.jumpTreatment,song.ignoreJumpAtEnd);
+    curSubSong->calcTimestamps(chans,song.grooves,song.jumpTreatment,song.ignoreJumpAtEnd,song.brokenSpeedSel,song.delayBehavior);
   }
 }
 
@@ -566,6 +560,7 @@ void DivEngine::createNew(const char* description, String sysName, bool inBase64
   BUSY_BEGIN;
   renderSamples();
   reset();
+  calcSongTimestamps();
   BUSY_END;
 }
 
@@ -603,6 +598,7 @@ void DivEngine::createNewFromDefaults() {
   BUSY_BEGIN;
   renderSamples();
   reset();
+  calcSongTimestamps();
   BUSY_END;
 }
 
@@ -1515,8 +1511,7 @@ String DivEngine::getPlaybackDebugInfo() {
     "midiTimeDrift: %f\n"
     "changeOrd: %d\n"
     "changePos: %d\n"
-    "totalSeconds: %d\n"
-    "totalTicks: %d\n"
+    "totalTime: %s\n"
     "totalTicksR: %d\n"
     "curMidiClock: %d\n"
     "curMidiTime: %d\n"
@@ -1528,7 +1523,7 @@ String DivEngine::getPlaybackDebugInfo() {
     "totalProcessed: %d\n"
     "bufferPos: %d\n",
     curOrder,prevOrder,curRow,prevRow,ticks,subticks,totalLoops,lastLoopPos,nextSpeed,divider,cycles,clockDrift,
-    midiClockCycles,midiClockDrift,midiTimeCycles,midiTimeDrift,changeOrd,changePos,totalSeconds,totalTicks,
+    midiClockCycles,midiClockDrift,midiTimeCycles,midiTimeDrift,changeOrd,changePos,totalTime.toString(),
     totalTicksR,curMidiClock,curMidiTime,totalCmds,lastCmds,cmdsPerSecond,
     (int)extValue,(int)tempoAccum,(int)totalProcessed,(int)bufferPos
   );
@@ -1648,6 +1643,37 @@ void DivEngine::getCommandStream(std::vector<DivCommand>& where) {
   BUSY_END;
 }
 
+DivFilePlayer* DivEngine::getFilePlayer() {
+  if (curFilePlayer==NULL) {
+    BUSY_BEGIN_SOFT;
+    curFilePlayer=new DivFilePlayer;
+    curFilePlayer->setOutputRate(got.rate);
+    BUSY_END;
+  }
+  return curFilePlayer;
+}
+
+bool DivEngine::getFilePlayerSync() {
+  return filePlayerSync;
+}
+
+void DivEngine::setFilePlayerSync(bool doSync) {
+  filePlayerSync=doSync;
+}
+
+TimeMicros DivEngine::getFilePlayerCue() {
+  return filePlayerCue;
+}
+
+void DivEngine::setFilePlayerCue(TimeMicros cue) {
+  filePlayerCue=cue;
+}
+
+void DivEngine::syncFilePlayer() {
+  if (curFilePlayer==NULL) return;
+  curFilePlayer->setPosSeconds(totalTime+filePlayerCue);
+}
+
 void DivEngine::playSub(bool preserveDrift, int goalRow) {
   logV("playSub() called");
   std::chrono::high_resolution_clock::time_point timeStart=std::chrono::high_resolution_clock::now();
@@ -1678,10 +1704,10 @@ void DivEngine::playSub(bool preserveDrift, int goalRow) {
   midiTimeDrift=0;
   if (!preserveDrift) {
     ticks=1;
+    subticks=0;
     tempoAccum=0;
-    totalTicks=0;
-    totalTicksOff=0;
-    totalSeconds=0;
+    totalTime=TimeMicros(0,0);
+    totalTimeDrift=0;
     totalTicksR=0;
     curMidiClock=0;
     curMidiTime=0;
@@ -1771,6 +1797,7 @@ void DivEngine::playSub(bool preserveDrift, int goalRow) {
   cmdStream.clear();
   std::chrono::high_resolution_clock::time_point timeEnd=std::chrono::high_resolution_clock::now();
   logV("playSub() took %dµs",std::chrono::duration_cast<std::chrono::microseconds>(timeEnd-timeStart).count());
+  logV("and landed us at %s (%d ticks, %d:%d.%d)",totalTime.toString(),totalTicksR,curOrder,curRow,ticks);
 }
 
 /*
@@ -1998,6 +2025,12 @@ bool DivEngine::play() {
     output->midiOut->send(TAMidiMessage(TA_MIDI_MACHINE_PLAY,0,0));
   }
   bool didItPlay=playing;
+  if (didItPlay) {
+    if (curFilePlayer && filePlayerSync) {
+      syncFilePlayer();
+      curFilePlayer->play();
+    }
+  }
   BUSY_END;
   return didItPlay;
 }
@@ -2014,15 +2047,28 @@ bool DivEngine::playToRow(int row) {
     keyHit[i]=false;
   }
   bool didItPlay=playing;
+  if (didItPlay) {
+    if (curFilePlayer && filePlayerSync) {
+      syncFilePlayer();
+      curFilePlayer->play();
+    }
+  }
   BUSY_END;
   return didItPlay;
 }
 
 void DivEngine::stepOne(int row) {
+  if (curFilePlayer && filePlayerSync) {
+    curFilePlayer->stop();
+  }
+
   if (!isPlaying()) {
     BUSY_BEGIN_SOFT;
     freelance=false;
     playSub(false,row);
+    if (curFilePlayer && filePlayerSync) {
+      syncFilePlayer();
+    }
     for (int i=0; i<DIV_MAX_CHANS; i++) {
       keyHit[i]=false;
     }
@@ -2069,6 +2115,10 @@ void DivEngine::stop() {
     }
   }
 
+  if (curFilePlayer && filePlayerSync) {
+    curFilePlayer->stop();
+  }
+
   // reset all chan oscs
   for (int i=0; i<chans; i++) {
     DivDispatchOscBuffer* buf=disCont[dispatchOfChan[i]].dispatch->getOscBuffer(dispatchChanOfChan[i]);
@@ -2507,12 +2557,8 @@ void DivEngine::virtualTempoChanged() {
   BUSY_END;
 }
 
-int DivEngine::getTotalSeconds() {
-  return totalSeconds;
-}
-
-int DivEngine::getTotalTicks() {
-  return totalTicks;
+TimeMicros DivEngine::getCurTime() {
+  return totalTime;
 }
 
 bool DivEngine::getRepeatPattern() {
@@ -3100,6 +3146,10 @@ void DivEngine::addOrder(int pos, bool duplicate, bool where) {
     prevOrder=curOrder;
     if (playing && !freelance) {
       playSub(false);
+      if (curFilePlayer && filePlayerSync) {
+        syncFilePlayer();
+        curFilePlayer->play();
+      }
     }
   }
   BUSY_END;
@@ -3152,6 +3202,10 @@ void DivEngine::deepCloneOrder(int pos, bool where) {
     if (pos<=curOrder) curOrder++;
     if (playing && !freelance) {
       playSub(false);
+      if (curFilePlayer && filePlayerSync) {
+        syncFilePlayer();
+        curFilePlayer->play();
+      }
     }
   }
   BUSY_END;
@@ -3172,6 +3226,10 @@ void DivEngine::deleteOrder(int pos) {
   if (curOrder>=curSubSong->ordersLen) curOrder=curSubSong->ordersLen-1;
   if (playing && !freelance) {
     playSub(false);
+    if (curFilePlayer && filePlayerSync) {
+      syncFilePlayer();
+      curFilePlayer->play();
+    }
   }
   BUSY_END;
 }
@@ -3195,6 +3253,10 @@ void DivEngine::moveOrderUp(int& pos) {
   pos--;
   if (playing && !freelance) {
     playSub(false);
+    if (curFilePlayer && filePlayerSync) {
+      syncFilePlayer();
+      curFilePlayer->play();
+    }
   }
   BUSY_END;
 }
@@ -3218,6 +3280,10 @@ void DivEngine::moveOrderDown(int& pos) {
   pos++;
   if (playing && !freelance) {
     playSub(false);
+    if (curFilePlayer && filePlayerSync) {
+      syncFilePlayer();
+      curFilePlayer->play();
+    }
   }
   BUSY_END;
 }
@@ -3419,6 +3485,12 @@ void DivEngine::autoPatchbay() {
     }
   }
 
+  // file player
+  song.patchbay.reserve(DIV_MAX_OUTPUTS);
+  for (unsigned int j=0; j<DIV_MAX_OUTPUTS; j++) {
+    song.patchbay.push_back(0xffc00000|j|(j<<16));
+  }
+
   // wave/sample preview
   song.patchbay.reserve(DIV_MAX_OUTPUTS);
   for (unsigned int j=0; j<DIV_MAX_OUTPUTS; j++) {
@@ -3526,6 +3598,73 @@ void DivEngine::noteOff(int chan) {
   BUSY_END;
 }
 
+int DivEngine::getViableChannel(int chan, int off, int ins) {
+  // if the offset is zero, we don't have to do anything
+  if (off==0) return chan;
+
+  // if there isn't an instrument, just offset chan by off
+  if (ins==-1) {
+    return (chan+off)%chans;
+  }
+  
+  bool isViable[DIV_MAX_CHANS];
+  bool isAtLeastOneViable=false;
+  int finalChan=chan;
+  int finalChanType=getChannelType(finalChan);
+
+  // this is a copy of the routine in autoNoteOn...... I am lazy
+  DivInstrument* insInst=getIns(ins);
+  for (int i=0; i<chans; i++) {
+    if (ins==-1 || ins>=song.insLen || getPreferInsType(i)==insInst->type || (getPreferInsType(i)==DIV_INS_NULL && finalChanType==DIV_CH_NOISE) || getPreferInsSecondType(i)==insInst->type) {
+      if (insInst->type==DIV_INS_OPL) {
+        if (insInst->fm.ops==2 || getChannelType(i)==DIV_CH_OP) {
+          isViable[i]=true;
+          isAtLeastOneViable=true;
+        } else {
+          isViable[i]=false;
+        }
+      } else {
+        isViable[i]=true;
+        isAtLeastOneViable=true;
+      }
+    } else {
+      isViable[i]=false;
+    }
+  }
+
+  // screw it if none of the channels are viable
+  if (!isAtLeastOneViable) {
+    return (chan+off)%chans;
+  }
+
+  // now offset (confined to viable channels)
+  int channelsCycled=0;
+  int i=(chan+1)%chans;
+  int attempts=0;
+  while (true) {
+    if (isViable[i]) {
+      channelsCycled++;
+      if (channelsCycled==off) {
+        // we found it
+        return i;
+      }
+    }
+
+    if (++i>=chans) {
+      i=0;
+    }
+
+    // fail-safe
+    if (++attempts>1024) {
+      logE("getViableChannel(): too many attempts!");
+      break;
+    }
+  }
+
+  // fail-safe
+  return (chan+off)%chans;
+}
+
 bool DivEngine::autoNoteOn(int ch, int ins, int note, int vol) {
   bool isViable[DIV_MAX_CHANS];
   bool canPlayAnyway=false;
@@ -3630,6 +3769,11 @@ void DivEngine::setOrder(unsigned char order) {
   prevOrder=curOrder;
   if (playing && !freelance) {
     playSub(false);
+
+    if (curFilePlayer && filePlayerSync) {
+      syncFilePlayer();
+      curFilePlayer->play();
+    }
   }
   BUSY_END;
 }
@@ -3650,6 +3794,10 @@ void DivEngine::updateSysFlags(int system, bool restart, bool render) {
   if (restart) {
     if (isPlaying()) {
       playSub(false);
+      if (curFilePlayer && filePlayerSync) {
+        syncFilePlayer();
+        curFilePlayer->play();
+      }
     } else if (freelance) {
       reset();
     }
@@ -3898,9 +4046,8 @@ void DivEngine::quitDispatch() {
   nextSpeed=3;
   changeOrd=-1;
   changePos=0;
-  totalTicks=0;
-  totalTicksOff=0;
-  totalSeconds=0;
+  totalTime=TimeMicros(0,0);
+  totalTimeDrift=0;
   totalTicksR=0;
   curMidiClock=0;
   curMidiTime=0;
@@ -3909,6 +4056,9 @@ void DivEngine::quitDispatch() {
   totalCmds=0;
   lastCmds=0;
   cmdsPerSecond=0;
+  if (filePlayerSync) {
+    if (curFilePlayer!=NULL) curFilePlayer->stop();
+  }
   for (int i=0; i<DIV_MAX_CHANS; i++) {
     isMuted[i]=0;
   }
@@ -4302,6 +4452,10 @@ bool DivEngine::quit(bool saveConfig) {
     metroBuf=NULL;
     metroBufLen=0;
   }
+  if (curFilePlayer!=NULL) {
+    delete curFilePlayer;
+    curFilePlayer=NULL;
+  }
   if (yrw801ROM!=NULL) delete[] yrw801ROM;
   if (tg100ROM!=NULL) delete[] tg100ROM;
   if (mu5ROM!=NULL) delete[] mu5ROM;
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 69ecf3a68..81698fdf6 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -28,6 +28,7 @@
 #include "dataErrors.h"
 #include "safeWriter.h"
 #include "cmdStream.h"
+#include "filePlayer.h"
 #include "../audio/taAudio.h"
 #include "blip_buf.h"
 #include <functional>
@@ -54,8 +55,8 @@ class DivWorkPool;
 
 #define DIV_UNSTABLE
 
-#define DIV_VERSION "dev237"
-#define DIV_ENGINE_VERSION 237
+#define DIV_VERSION "dev238"
+#define DIV_ENGINE_VERSION 238
 // for imports
 #define DIV_VERSION_MOD 0xff01
 #define DIV_VERSION_FC 0xff02
@@ -509,8 +510,9 @@ class DivEngine {
   int midiTimeCycles;
   double midiTimeDrift;
   int stepPlay;
-  int changeOrd, changePos, totalSeconds, totalTicks, totalTicksR, curMidiClock, curMidiTime, totalCmds, lastCmds, cmdsPerSecond;
-  double totalTicksOff;
+  int changeOrd, changePos, totalTicksR, curMidiClock, curMidiTime, totalCmds, lastCmds, cmdsPerSecond;
+  TimeMicros totalTime;
+  double totalTimeDrift;
   int curMidiTimePiece, curMidiTimeCode;
   unsigned char extValue, pendingMetroTick;
   DivGroovePattern speeds;
@@ -587,6 +589,7 @@ class DivEngine {
   int samp_temp, samp_prevSample;
   short* samp_bbIn;
   short* samp_bbOut;
+
   unsigned char* metroTick;
   size_t metroTickLen;
   float* metroBuf;
@@ -596,6 +599,14 @@ class DivEngine {
   float metroVol;
   float previewVol;
 
+  float* filePlayerBuf[DIV_MAX_OUTPUTS];
+  size_t filePlayerBufLen;
+  DivFilePlayer* curFilePlayer;
+  bool filePlayerSync;
+  TimeMicros filePlayerCue;
+  int filePlayerLoopTrail;
+  int curFilePlayerTrail;
+
   size_t totalProcessed;
 
   unsigned int renderPoolThreads;
@@ -738,12 +749,25 @@ class DivEngine {
     void createNewFromDefaults();
     // load a file.
     bool load(unsigned char* f, size_t length, const char* nameHint=NULL);
+
     // play a binary command stream.
     bool playStream(unsigned char* f, size_t length);
     // get the playing stream.
     DivCSPlayer* getStreamPlayer();
     // destroy command stream player.
     bool killStream();
+
+    // get the audio file player.
+    DivFilePlayer* getFilePlayer();
+    // get whether the player is synchronized with song playback.
+    bool getFilePlayerSync();
+    void setFilePlayerSync(bool doSync);
+    // get/set file player cue position.
+    TimeMicros getFilePlayerCue();
+    void setFilePlayerCue(TimeMicros cue);
+    // UNSAFE - sync file player to current playback position.
+    void syncFilePlayer();
+
     // save as .dmf.
     SafeWriter* saveDMF(unsigned char version);
     // save as .fur.
@@ -851,11 +875,8 @@ class DivEngine {
     int convertPanSplitToLinearLR(unsigned char left, unsigned char right, int range);
     unsigned int convertPanLinearToSplit(int val, unsigned char bits, int range);
 
-    // find song loop position
-    void walkSong(int& loopOrder, int& loopRow, int& loopEnd);
-
-    // find song length in rows (up to specified loop point), and find length of every order
-    void findSongLength(int loopOrder, int loopRow, double fadeoutLen, int& rowsForFadeout, bool& hasFFxx, std::vector<int>& orders, int& length);
+    // calculate all song timestamps
+    void calcSongTimestamps();
 
     // play (returns whether successful)
     bool play();
@@ -1028,8 +1049,7 @@ class DivEngine {
     void virtualTempoChanged();
 
     // get time
-    int getTotalTicks(); // 1/1000000th of a second
-    int getTotalSeconds();
+    TimeMicros getCurTime();
 
     // get repeat pattern
     bool getRepeatPattern();
@@ -1182,6 +1202,10 @@ class DivEngine {
     // set whether autoNoteIn is mono or poly
     void setAutoNotePoly(bool poly);
 
+    // get next viable channel with an offset
+    // chan is the base channel, off is the offset and ins is the instrument.
+    int getViableChannel(int chan, int off, int ins);
+
     // go to order
     void setOrder(unsigned char order);
 
@@ -1504,15 +1528,13 @@ class DivEngine {
       stepPlay(0),
       changeOrd(-1),
       changePos(0),
-      totalSeconds(0),
-      totalTicks(0),
       totalTicksR(0),
       curMidiClock(0),
       curMidiTime(0),
       totalCmds(0),
       lastCmds(0),
       cmdsPerSecond(0),
-      totalTicksOff(0.0),
+      totalTimeDrift(0.0),
       curMidiTimePiece(0),
       curMidiTimeCode(0),
       extValue(0),
@@ -1552,6 +1574,12 @@ class DivEngine {
       metroAmp(0.0f),
       metroVol(1.0f),
       previewVol(1.0f),
+      filePlayerBufLen(0),
+      curFilePlayer(NULL),
+      filePlayerSync(false),
+      filePlayerCue(0,0),
+      filePlayerLoopTrail(0),
+      curFilePlayerTrail(0),
       totalProcessed(0),
       renderPoolThreads(0),
       renderPool(NULL),
@@ -1584,6 +1612,7 @@ class DivEngine {
       memset(oscBuf,0,DIV_MAX_OUTPUTS*(sizeof(float*)));
       memset(exportChannelMask,1,DIV_MAX_CHANS*sizeof(bool));
       memset(chipPeak,0,DIV_MAX_CHIPS*DIV_MAX_OUTPUTS*sizeof(float));
+      memset(filePlayerBuf,0,DIV_MAX_OUTPUTS*sizeof(float));
 
       for (int i=0; i<DIV_MAX_CHIP_DEFS; i++) {
         sysFileMapFur[i]=DIV_SYSTEM_NULL;
diff --git a/src/engine/export/amigaValidation.cpp b/src/engine/export/amigaValidation.cpp
index b79694a51..30224e84f 100644
--- a/src/engine/export/amigaValidation.cpp
+++ b/src/engine/export/amigaValidation.cpp
@@ -55,10 +55,9 @@ void DivExportAmigaValidation::run() {
   EXTERN_BUSY_BEGIN_SOFT;
 
   // determine loop point
-  int loopOrder=0;
-  int loopRow=0;
-  int loopEnd=0;
-  e->walkSong(loopOrder,loopRow,loopEnd);
+  e->calcSongTimestamps();
+  int loopOrder=e->curSubSong->ts.loopStart.order;
+  int loopRow=e->curSubSong->ts.loopStart.row;
 
   e->curOrder=0;
   e->freelance=false;
diff --git a/src/engine/export/grub.cpp b/src/engine/export/grub.cpp
index fc8bf6b2f..e48ae5195 100644
--- a/src/engine/export/grub.cpp
+++ b/src/engine/export/grub.cpp
@@ -76,10 +76,9 @@ void DivExportGRUB::run() {
     e->got.rate=rate;
 
     // Determine loop point.
-    int loopOrder=0;
-    int loopRow=0;
-    int loopEnd=0;
-    e->walkSong(loopOrder,loopRow,loopEnd);
+    e->calcSongTimestamps();
+    int loopOrder=e->curSubSong->ts.loopStart.order;
+    int loopRow=e->curSubSong->ts.loopStart.row;
     logAppendf("loop point: %d %d",loopOrder,loopRow);
     e->warnings="";
 
diff --git a/src/engine/export/ipod.cpp b/src/engine/export/ipod.cpp
index 5ffe98970..e05d5c074 100644
--- a/src/engine/export/ipod.cpp
+++ b/src/engine/export/ipod.cpp
@@ -75,10 +75,9 @@ void DivExportiPod::run() {
     e->got.rate=rate;
 
     // Determine loop point.
-    int loopOrder=0;
-    int loopRow=0;
-    int loopEnd=0;
-    e->walkSong(loopOrder,loopRow,loopEnd);
+    e->calcSongTimestamps();
+    int loopOrder=e->curSubSong->ts.loopStart.order;
+    int loopRow=e->curSubSong->ts.loopStart.row;
     logAppendf("loop point: %d %d",loopOrder,loopRow);
     e->warnings="";
 
diff --git a/src/engine/export/sapr.cpp b/src/engine/export/sapr.cpp
index c99c1254e..f638cfaab 100644
--- a/src/engine/export/sapr.cpp
+++ b/src/engine/export/sapr.cpp
@@ -92,10 +92,9 @@ void DivExportSAPR::run() {
     e->got.rate=sapRate;
 
     // Determine loop point.
-    int loopOrder=0;
-    int loopRow=0;
-    int loopEnd=0;
-    e->walkSong(loopOrder,loopRow,loopEnd);
+    e->calcSongTimestamps();
+    int loopOrder=e->curSubSong->ts.loopStart.order;
+    int loopRow=e->curSubSong->ts.loopStart.row;
     logAppendf("loop point: %d %d",loopOrder,loopRow);
     e->warnings="";
 
diff --git a/src/engine/export/tiuna.cpp b/src/engine/export/tiuna.cpp
index 104c38193..6a212c23f 100644
--- a/src/engine/export/tiuna.cpp
+++ b/src/engine/export/tiuna.cpp
@@ -181,7 +181,7 @@ static void writeCmd(std::vector<TiunaBytes>& cmds, TiunaCmd& cmd, unsigned char
 }
 
 void DivExportTiuna::run() {
-  int loopOrder, loopOrderRow, loopEnd;
+  int loopOrder, loopOrderRow;
   int tick=0;
   SafeWriter* w;
   std::map<int,TiunaCmd> allCmds[2];
@@ -199,10 +199,9 @@ void DivExportTiuna::run() {
   e->synchronizedSoft([&]() {
     // determine loop point
     // bool stopped=false;
-    loopOrder=0;
-    loopOrderRow=0;
-    loopEnd=0;
-    e->walkSong(loopOrder,loopOrderRow,loopEnd);
+    e->calcSongTimestamps();
+    loopOrder=e->curSubSong->ts.loopStart.order;
+    loopOrderRow=e->curSubSong->ts.loopStart.row;
     logAppendf("loop point: %d %d",loopOrder,loopOrderRow);
 
     w=new SafeWriter;
diff --git a/src/engine/export/zsm.cpp b/src/engine/export/zsm.cpp
index 109e0e754..708340539 100644
--- a/src/engine/export/zsm.cpp
+++ b/src/engine/export/zsm.cpp
@@ -574,10 +574,9 @@ void DivExportZSM::run() {
     e->got.rate=zsmrate&0xffff;
 
     // determine loop point
-    int loopOrder=0;
-    int loopRow=0;
-    int loopEnd=0;
-    e->walkSong(loopOrder,loopRow,loopEnd);
+    e->calcSongTimestamps();
+    int loopOrder=e->curSubSong->ts.loopStart.order;
+    int loopRow=e->curSubSong->ts.loopStart.row;
     logAppendf("loop point: %d %d",loopOrder,loopRow);
 
     zsm.init(zsmrate);
diff --git a/src/engine/filePlayer.cpp b/src/engine/filePlayer.cpp
new file mode 100644
index 000000000..62dac52de
--- /dev/null
+++ b/src/engine/filePlayer.cpp
@@ -0,0 +1,556 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2025 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "filePlayer.h"
+#include "filter.h"
+#include "../ta-log.h"
+#include <inttypes.h>
+#include <chrono>
+
+#define DIV_FPCACHE_BLOCK_SHIFT 15
+#define DIV_FPCACHE_BLOCK_SIZE (1<<DIV_FPCACHE_BLOCK_SHIFT)
+#define DIV_FPCACHE_BLOCK_MASK (DIV_FPCACHE_BLOCK_SIZE-1)
+
+#define DIV_FPCACHE_BLOCKS_FROM_FILL 3
+#define DIV_FPCACHE_DISCARD_SIZE 4096
+
+// 5MB should be enough
+#define DIV_MAX_MEMORY (5<<20)
+
+#define DIV_NO_BLOCK (-10)
+
+void DivFilePlayer::fillBlocksNear(ssize_t pos) {
+  logV("DivFilePlayer: fillBlocksNear(%" PRIu64 ")",pos);
+
+  // don't if file isn't present
+  if (!blocks) return;
+
+  // don't if there was an I/O error
+  if (fileError) return;
+
+  // don't read anything if we cannot seek
+  // (if this is set the file is already read in its entirety)
+  if (!si.seekable) return;
+
+  ssize_t firstBlock=pos>>DIV_FPCACHE_BLOCK_SHIFT;
+  ssize_t lastBlock=firstBlock+DIV_FPCACHE_BLOCKS_FROM_FILL;
+  if (firstBlock<0) firstBlock=0;
+  if (firstBlock>=(ssize_t)numBlocks) firstBlock=numBlocks-1;
+  if (lastBlock<0) lastBlock=0;
+  if (lastBlock>=(ssize_t)numBlocks) lastBlock=numBlocks-1;
+
+  // don't read if we're after end of file
+  if (firstBlock>lastBlock) return;
+  
+  bool needToFill=false;
+  for (ssize_t i=firstBlock; i<=lastBlock; i++) {
+    if (i<0 || i>=(ssize_t)numBlocks) continue;
+    if (!blocks[i]) {
+      needToFill=true;
+      firstBlock=i;
+      break;
+    }
+  }
+
+  if (!needToFill) return;
+
+  // check whether we need to seek
+  sf_count_t curSeek=sf_seek(sf,0,SEEK_CUR);
+  if (curSeek==-1) {
+    // I/O error
+    fileError=true;
+    return;
+  }
+
+  if ((curSeek&DIV_FPCACHE_BLOCK_MASK)!=0 || (curSeek>>DIV_FPCACHE_BLOCK_SHIFT)!=firstBlock) {
+    // we need to seek
+    logV("- seeking");
+    // we seek to a previous position in order to compensate for possible decoding differences when seeking
+    // (usually in lossy codecs)
+    sf_count_t seekWhere=firstBlock<<DIV_FPCACHE_BLOCK_SHIFT;
+    if (seekWhere<DIV_FPCACHE_DISCARD_SIZE) {
+      curSeek=sf_seek(sf,0,SEEK_SET);
+      // discard
+      if (sf_readf_float(sf,discardBuf,seekWhere)!=seekWhere) {
+        // this is a problem
+      }
+    } else {
+      seekWhere-=DIV_FPCACHE_DISCARD_SIZE;
+      curSeek=sf_seek(sf,seekWhere,SEEK_SET);
+      // discard
+      if (sf_readf_float(sf,discardBuf,DIV_FPCACHE_DISCARD_SIZE)!=DIV_FPCACHE_DISCARD_SIZE) {
+        // this is a problem
+      }
+    }
+  }
+
+  // read blocks
+  for (ssize_t i=firstBlock; i<=lastBlock; i++) {
+    if (!blocks[i]) {
+      blocks[i]=new float[DIV_FPCACHE_BLOCK_SIZE*si.channels];
+      memset(blocks[i],0,DIV_FPCACHE_BLOCK_SIZE*si.channels*sizeof(float));
+    }
+    logV("- reading block %" PRIu64,i);
+    sf_count_t totalRead=sf_readf_float(sf,blocks[i],DIV_FPCACHE_BLOCK_SIZE);
+    if (totalRead<DIV_FPCACHE_BLOCK_SIZE) {
+      // we've reached end of file
+    }
+  }
+}
+
+void DivFilePlayer::collectGarbage(ssize_t pos) {
+  // don't if file isn't present
+  if (!blocks) return;
+
+  // don't if there was an I/O error
+  if (fileError) return;
+  
+  // don't if we cannot seek
+  if (!si.seekable) return;
+
+  size_t memUsage=getMemUsage();
+  if (memUsage<DIV_MAX_MEMORY) return;
+
+  pos>>=DIV_FPCACHE_BLOCK_SHIFT;
+  if (pos<0) pos=0;
+  if (pos>=(ssize_t)numBlocks) pos=numBlocks-1;
+
+  // collect garbage
+  // start with blocks before the given position
+  // then try with blocks after given position
+  // prioritize far away ones
+  // do not destroy priority blocks
+  for (ssize_t i=0; i<pos-2; i++) {
+    if (!blocks[i]) continue;
+    if (priorityBlock[i]) continue;
+    logV("erasing block %d",(int)i);
+    float* block=blocks[i];
+    blocks[i]=NULL;
+    delete[] block;
+
+    memUsage-=DIV_FPCACHE_BLOCK_SIZE*si.channels*sizeof(float);
+    if (memUsage<DIV_MAX_MEMORY) return;
+  }
+  for (ssize_t i=numBlocks-1; i>pos+DIV_FPCACHE_BLOCKS_FROM_FILL; i--) {
+    if (!blocks[i]) continue;
+    if (priorityBlock[i]) continue;
+    logV("erasing block %d",(int)i);
+    float* block=blocks[i];
+    blocks[i]=NULL;
+    delete[] block;
+
+    memUsage-=DIV_FPCACHE_BLOCK_SIZE*si.channels*sizeof(float);
+    if (memUsage<DIV_MAX_MEMORY) return;
+  }
+}
+
+void DivFilePlayer::runCacheThread() {
+  std::unique_lock<std::mutex> lock(cacheThreadLock);
+
+  while (!quitThread) {
+    ssize_t wantBlockC=wantBlock;
+    if (wantBlockC!=DIV_NO_BLOCK) {
+      wantBlock=DIV_NO_BLOCK;
+      logV("thread fill %" PRIu64,wantBlockC);
+      fillBlocksNear(wantBlockC);
+      collectGarbage(wantBlockC);
+    }
+    cacheCV.wait(lock);
+  }
+
+  threadHasQuit=true;
+  logV("DivFilePlayer: cache thread over.");
+}
+
+float DivFilePlayer::getSampleAt(ssize_t pos, int ch) {
+  if (blocks==NULL) return 0.0f;
+  ssize_t blockIndex=pos>>DIV_FPCACHE_BLOCK_SHIFT;
+  if (blockIndex<0 || blockIndex>=(ssize_t)numBlocks) return 0.0f;
+
+  float* block=blocks[blockIndex];
+  size_t posInBlock=(pos&DIV_FPCACHE_BLOCK_MASK)*si.channels+ch;
+  if (block==NULL) return 0.0f;
+
+  return block[posInBlock];
+}
+
+void DivFilePlayer::mix(float** buf, int chans, unsigned int size) {
+  // fill with zero if we don't have a file
+  if (sf==NULL) {
+    for (int i=0; i<chans; i++) {
+      memset(buf[i],0,size*sizeof(float));
+    }
+    return;
+  }
+
+  float actualVolume=volume+1.0f;
+  if (actualVolume<0.0f) actualVolume=0.0f;
+  if (actualVolume>1.0f) actualVolume=1.0f;
+
+  if (wantBlock!=DIV_NO_BLOCK) {
+    cacheCV.notify_one();
+  }
+
+  for (unsigned int i=0; i<size; i++) {
+    // acknowledge pending events
+    if (pendingPosOffset==i) {
+      pendingPosOffset=UINT_MAX;
+      playPos=pendingPos;
+      rateAccum=0;
+    }
+    if (pendingPlayOffset==i) {
+      playing=true;
+    }
+    if (pendingStopOffset==i) {
+      playing=false;
+    }
+
+    ssize_t blockIndex=playPos>>DIV_FPCACHE_BLOCK_SHIFT;
+    if (blockIndex!=lastWantBlock) {
+      wantBlock=playPos;
+      cacheCV.notify_one();
+      lastWantBlock=blockIndex;
+    }
+
+    if (playing) {
+      // sinc interpolation
+      float x[8];
+
+      unsigned int n=(8192*rateAccum)/outRate;
+      n&=8191;
+      float* t1=&sincTable[(8191-n)<<2];
+      float* t2=&sincTable[n<<2];
+      if (si.channels==1) {
+        // mono optimization
+        for (int k=0; k<8; k++) {
+          x[k]=getSampleAt(playPos+k-3,0);
+        }
+
+        float s=(
+          x[0]*t2[3]+
+          x[1]*t2[2]+
+          x[2]*t2[1]+
+          x[3]*t2[0]+
+          x[4]*t1[0]+
+          x[5]*t1[1]+
+          x[6]*t1[2]+
+          x[7]*t1[3]
+        )*actualVolume;
+
+        for (int j=0; j<chans; j++) {
+          buf[j][i]=s;
+        }
+      } else for (int j=0; j<chans; j++) {
+        if (j>=si.channels) {
+          buf[j][i]=0.0f;
+          continue;
+        }
+
+        for (int k=0; k<8; k++) {
+          x[k]=getSampleAt(playPos+k-3,j);
+        }
+        buf[j][i]=(
+          x[0]*t2[3]+
+          x[1]*t2[2]+
+          x[2]*t2[1]+
+          x[3]*t2[0]+
+          x[4]*t1[0]+
+          x[5]*t1[1]+
+          x[6]*t1[2]+
+          x[7]*t1[3]
+        )*actualVolume;
+      }
+
+      // advance
+      rateAccum+=si.samplerate;
+      while (rateAccum>=outRate) {
+        rateAccum-=outRate;
+        playPos++;
+        /*if (playPos>=(ssize_t)si.frames) {
+          playPos=0;
+        }*/
+      }
+    } else {
+      for (int j=0; j<chans; j++) {
+        buf[j][i]=0.0f;
+      }
+    }
+  }
+}
+
+ssize_t DivFilePlayer::getPos() {
+  return playPos;
+}
+
+TimeMicros DivFilePlayer::getPosSeconds() {
+  if (sf==NULL) {
+    return TimeMicros(0,0);
+  }
+  double microsD=playPos%si.samplerate;
+  return TimeMicros(
+    playPos/si.samplerate, // seconds
+    (int)((1000000.0*microsD)/(double)si.samplerate) // microseconds
+  );
+}
+
+ssize_t DivFilePlayer::setPos(ssize_t newPos, unsigned int offset) {
+  if (offset==UINT_MAX) {
+    playPos=newPos;
+    rateAccum=0;
+    wantBlock=playPos;
+    logD("DivFilePlayer: setPos(%" PRIi64 ")",newPos);
+    return playPos;
+  } else {
+    pendingPosOffset=offset;
+    pendingPos=newPos;
+    wantBlock=playPos;
+    logD("DivFilePlayer: offset %u setPos(%" PRIi64 ")",offset,newPos);
+    return newPos;
+  }
+}
+
+ssize_t DivFilePlayer::setPosSeconds(TimeMicros newTime, unsigned int offset) {
+  if (sf==NULL) return 0;
+  double microsD=(double)si.samplerate*((double)newTime.micros/1000000.0);
+  if (offset==UINT_MAX) {
+    playPos=(ssize_t)newTime.seconds*(ssize_t)si.samplerate+(int)microsD;
+    rateAccum=0;
+    wantBlock=playPos;
+    logD("DivFilePlayer: setPosSeconds(%s)",newTime.toString());
+    return playPos;
+  } else {
+    pendingPosOffset=offset;
+    pendingPos=(ssize_t)newTime.seconds*(ssize_t)si.samplerate+(int)microsD;
+    wantBlock=pendingPos;
+    logD("DivFilePlayer: offset %u setPosSeconds(%s)",offset,newTime.toString());
+    return pendingPos;
+  }
+}
+
+size_t DivFilePlayer::getMemUsage() {
+  if (blocks==NULL) return 0;
+  size_t ret=0;
+  for (size_t i=0; i<numBlocks; i++) {
+    if (blocks[i]) ret+=DIV_FPCACHE_BLOCK_SIZE*si.channels*sizeof(float);
+  }
+  return ret;
+}
+
+bool DivFilePlayer::isBlockPresent(ssize_t pos) {
+  if (blocks==NULL) return false;
+  ssize_t which=pos>>DIV_FPCACHE_BLOCK_SHIFT;
+  if (which<0 || which>=(ssize_t)numBlocks) return false;
+  return (blocks[which]!=NULL);
+}
+
+bool DivFilePlayer::setBlockPriority(ssize_t pos, bool priority) {
+  if (priorityBlock==NULL) return false;
+  ssize_t which=pos>>DIV_FPCACHE_BLOCK_SHIFT;
+  if (which<0 || which>=(ssize_t)numBlocks) return false;
+  priorityBlock[which]=priority;
+  return priority;
+}
+
+bool DivFilePlayer::isLoaded() {
+  return (sf!=NULL);
+}
+
+bool DivFilePlayer::isPlaying() {
+  return playing;
+}
+
+void DivFilePlayer::play(unsigned int offset) {
+  if (offset!=UINT_MAX) {
+    pendingPlayOffset=offset;
+    logV("DivFilePlayer: playing (offset: %u)",offset);
+  } else {
+    playing=true;
+    logV("DivFilePlayer: playing");
+  }
+}
+
+void DivFilePlayer::stop(unsigned int offset) {
+  if (offset!=UINT_MAX) {
+    pendingStopOffset=offset;
+    logV("DivFilePlayer: stopping (offset: %u)",offset);
+  } else {
+    playing=false;
+    logV("DivFilePlayer: stopping");
+  }
+}
+
+bool DivFilePlayer::closeFile() {
+  if (sf==NULL) return false;
+
+  logD("DivFilePlayer: closing file.");
+
+  if (cacheThread) {
+    quitThread=true;
+    while (!threadHasQuit) {
+      cacheCV.notify_one();
+      std::this_thread::yield();
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+    }
+    // this join is guaranteed to work
+    cacheThread->join();
+    delete cacheThread;
+    cacheThread=NULL;
+  }
+
+  sfw.doClose();
+  sf=NULL;
+  playing=false;
+  quitThread=false;
+  threadHasQuit=false;
+
+  for (size_t i=0; i<numBlocks; i++) {
+    if (blocks[i]) {
+      delete[] blocks[i];
+      blocks[i]=NULL;
+    }
+  }
+  numBlocks=0;
+  delete[] blocks;
+  blocks=NULL;
+
+  delete[] discardBuf;
+  discardBuf=NULL;
+
+  return true;
+}
+
+bool DivFilePlayer::loadFile(const char* path) {
+  if (sf!=NULL) closeFile();
+
+  logD("DivFilePlayer: opening file...");
+  sf=sfw.doOpen(path,SFM_READ,&si);
+  if (sf==NULL) {
+    logE("could not open file!");
+    return false;
+  }
+
+  logV("- samples: %d",si.frames);
+  logV("- channels: %d",si.channels);
+  logV("- rate: %d",si.samplerate);
+
+  numBlocks=(DIV_FPCACHE_BLOCK_MASK+si.frames)>>DIV_FPCACHE_BLOCK_SHIFT;
+  blocks=new float*[numBlocks];
+  priorityBlock=new bool[numBlocks];
+  memset(blocks,0,numBlocks*sizeof(void*));
+  memset(priorityBlock,0,numBlocks*sizeof(bool));
+
+  // mark the first blocks as important
+  for (size_t i=0; i<DIV_FPCACHE_BLOCKS_FROM_FILL; i++) {
+    if (i>=numBlocks) break;
+    priorityBlock[i]=true;
+  }
+
+  playPos=0;
+  lastWantBlock=DIV_NO_BLOCK;
+  rateAccum=0;
+  fileError=false;
+
+  // read the entire file if not seekable
+  if (!si.seekable) {
+    logV("file not seekable - reading...");
+    for (size_t i=0; i<numBlocks; i++) {
+      blocks[i]=new float[DIV_FPCACHE_BLOCK_SIZE*si.channels];
+    }
+    for (size_t i=0; i<numBlocks; i++) {
+      sf_count_t totalRead=sf_readf_float(sf,blocks[i],DIV_FPCACHE_BLOCK_SIZE);
+      if (totalRead<DIV_FPCACHE_BLOCK_SIZE) {
+        // we've reached end of file
+        break;
+      }
+    }
+  } else {
+    logV("file is seekable");
+    // read the first couple blocks
+    fillBlocksNear(0);
+  }
+
+  discardBuf=new float[DIV_FPCACHE_DISCARD_SIZE*si.channels];
+
+  // stsrt the block cache thread
+  if (cacheThread==NULL) {
+    quitThread=false;
+    threadHasQuit=false;
+    cacheThread=new std::thread(&DivFilePlayer::runCacheThread,this);
+  }
+  return true;
+}
+
+String DivFilePlayer::getLastError() {
+  return lastError;
+}
+
+const SF_INFO& DivFilePlayer::getFileInfo() {
+  return si;
+}
+
+void DivFilePlayer::setOutputRate(int rate) {
+  if (rate<1) return;
+  outRate=rate;
+}
+
+float DivFilePlayer::getVolume() {
+  return volume;
+}
+
+void DivFilePlayer::setVolume(float vol) {
+  volume=vol;
+}
+
+bool DivFilePlayer::getActive() {
+  return isActive;
+}
+
+void DivFilePlayer::setActive(bool active) {
+  isActive=active;
+}
+
+DivFilePlayer::DivFilePlayer():
+  discardBuf(NULL),
+  blocks(NULL),
+  priorityBlock(NULL),
+  numBlocks(0),
+  sf(NULL),
+  playPos(0),
+  lastWantBlock(DIV_NO_BLOCK),
+  wantBlock(DIV_NO_BLOCK),
+  outRate(44100),
+  rateAccum(0),
+  volume(0.0f),
+  playing(false),
+  fileError(false),
+  quitThread(false),
+  threadHasQuit(false),
+  isActive(false),
+  pendingPos(0),
+  pendingPosOffset(UINT_MAX),
+  pendingPlayOffset(UINT_MAX),
+  pendingStopOffset(UINT_MAX),
+  cacheThread(NULL) {
+  memset(&si,0,sizeof(SF_INFO));
+  sincTable=DivFilterTables::getSincTable8();
+}
+
+DivFilePlayer::~DivFilePlayer() {
+  closeFile();
+}
diff --git a/src/engine/filePlayer.h b/src/engine/filePlayer.h
new file mode 100644
index 000000000..50fac93ad
--- /dev/null
+++ b/src/engine/filePlayer.h
@@ -0,0 +1,107 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2025 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _FILEPLAYER_H
+#define _FILEPLAYER_H
+
+#include "../ta-utils.h"
+#include "../timeutils.h"
+#include <thread>
+#include <mutex>
+#include <condition_variable>
+
+#ifdef HAVE_SNDFILE
+#include "sfWrapper.h"
+#else
+typedef void SNDFILE;
+struct SF_INFO {
+  int invalid;
+};
+#endif
+
+class DivFilePlayer {
+  float* sincTable;
+  float* discardBuf;
+  float** blocks;
+  bool* priorityBlock;
+  size_t numBlocks;
+  String lastError;
+  SFWrapper sfw;
+  SNDFILE* sf;
+  SF_INFO si;
+
+  ssize_t playPos;
+  ssize_t lastWantBlock;
+  ssize_t wantBlock;
+  int outRate;
+  int rateAccum;
+  float volume;
+  bool playing;
+  bool fileError;
+  bool quitThread;
+  bool threadHasQuit;
+  bool isActive;
+
+  ssize_t pendingPos;
+  unsigned int pendingPosOffset;
+  unsigned int pendingPlayOffset;
+  unsigned int pendingStopOffset;
+
+  std::thread* cacheThread;
+  std::mutex cacheMutex;
+  std::mutex cacheThreadLock;
+  std::condition_variable cacheCV;
+
+  void fillBlocksNear(ssize_t pos);
+  void collectGarbage(ssize_t pos);
+  float getSampleAt(ssize_t pos, int ch);
+
+  public:
+    void runCacheThread();
+
+    size_t getMemUsage();
+
+    void mix(float** buf, int chans, unsigned int size);
+    ssize_t getPos();
+    TimeMicros getPosSeconds();
+    ssize_t setPos(ssize_t newPos, unsigned int offset=UINT_MAX);
+    ssize_t setPosSeconds(TimeMicros newTime, unsigned int offset=UINT_MAX);
+    
+    bool isBlockPresent(ssize_t pos);
+    bool setBlockPriority(ssize_t pos, bool priority);
+    bool isLoaded();
+    bool isPlaying();
+    void play(unsigned int offset=UINT_MAX);
+    void stop(unsigned int offset=UINT_MAX);
+    bool closeFile();
+    bool loadFile(const char* path);
+
+    String getLastError();
+    const SF_INFO& getFileInfo();
+    void setOutputRate(int rate);
+    float getVolume();
+    void setVolume(float vol);
+    bool getActive();
+    void setActive(bool active);
+
+    DivFilePlayer();
+    ~DivFilePlayer();
+};
+
+#endif
diff --git a/src/engine/filter.cpp b/src/engine/filter.cpp
index feac741aa..f0d60e7d5 100644
--- a/src/engine/filter.cpp
+++ b/src/engine/filter.cpp
@@ -128,4 +128,4 @@ float* DivFilterTables::getSincIntegralSmallTable() {
     }
   }
   return sincIntegralSmallTable;
-}
\ No newline at end of file
+}
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index bfd74f1f0..72852444d 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -2169,6 +2169,15 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
               prevOrder=curOrder;
               prevRow=curRow;
               playPosLock.unlock();
+
+              // also set the playback position and sync file player if necessary
+              TimeMicros rowTS=curSubSong->ts.getTimes(curOrder,curRow);
+              if (rowTS.seconds!=-1) {
+                totalTime=rowTS;
+              }
+              if (curFilePlayer && filePlayerSync) {
+                syncFilePlayer();
+              }
             }
             // ...and now process the next row!
             nextRow();
@@ -2572,30 +2581,28 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
     if (stepPlay!=1) {
       if (!noAccum) {
         double dt=divider*tickMult;
-        // TODO: is this responsible for timing differences when skipping?
-        if (skipping) {
-          dt*=(double)virtualTempoN/(double)MAX(1,virtualTempoD);
-        }
         totalTicksR++;
-        // despite the name, totalTicks is in microseconds...
-        totalTicks+=1000000/dt;
-        totalTicksOff+=fmod(1000000.0,dt);
-        while (totalTicksOff>=dt) {
-          totalTicksOff-=dt;
-          totalTicks++;
+        totalTime.micros+=1000000/dt;
+        totalTimeDrift+=fmod(1000000.0,dt);
+        while (totalTimeDrift>=dt) {
+          totalTimeDrift-=dt;
+          totalTime.micros++;
         }
       }
-      if (totalTicks>=1000000) {
-        totalTicks-=1000000;
+      if (totalTime.micros>=1000000) {
+        totalTime.micros-=1000000;
         // who's gonna play a song for 68 years?
-        if (totalSeconds<0x7fffffff) totalSeconds++;
+        if (totalTime.seconds<0x7fffffff) totalTime.seconds++;
         cmdsPerSecond=totalCmds-lastCmds;
         lastCmds=totalCmds;
       }
     }
 
     // print status in console mode
-    if (consoleMode && !disableStatusOut && subticks<=1 && !skipping) fprintf(stderr,"\x1b[2K> %d:%.2d:%.2d.%.2d  %.2x/%.2x:%.3d/%.3d  %4dcmd/s\x1b[G",totalSeconds/3600,(totalSeconds/60)%60,totalSeconds%60,totalTicks/10000,curOrder,curSubSong->ordersLen,curRow,curSubSong->patLen,cmdsPerSecond);
+    if (consoleMode && !disableStatusOut && subticks<=1 && !skipping) {
+      String timeFormatted=totalTime.toString(2,TA_TIME_FORMAT_HMS);
+      fprintf(stderr,"\x1b[2K> %s  %.2x/%.2x:%.3d/%.3d  %4dcmd/s\x1b[G",timeFormatted.c_str(),curOrder,curSubSong->ordersLen,curRow,curSubSong->patLen,cmdsPerSecond);
+    }
   }
 
   
@@ -3102,6 +3109,19 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
           // used by audio export to determine how many samples to write (otherwise it'll add silence at the end)
           lastLoopPos=size-runLeftG;
           logD("last loop pos: %d for a size of %d and runLeftG of %d",lastLoopPos,size,runLeftG);
+          // if file player is synchronized then set its position to that of the loop row
+          if (curFilePlayer && filePlayerSync) {
+            if (curFilePlayer->isPlaying()) {
+              TimeMicros rowTS=curSubSong->ts.loopStartTime;
+
+              if (rowTS.seconds==-1) {
+                logW("that row isn't supposed to play. report this now!");
+              }
+
+              curFilePlayer->setPosSeconds(rowTS+filePlayerCue,lastLoopPos);
+            }
+          }
+          // increase total loop count
           totalLoops++;
           // stop playing once we hit a specific number of loops (set during audio export)
           if (remainingLoops>0) {
@@ -3212,7 +3232,7 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
     // complain and stop playback if we believe the engine has stalled
     //logD("attempts: %d",attempts);
     if (attempts>=(int)(size+10)) {
-      logE("hang detected! stopping! at %d seconds %d micro (%d>=%d)",totalSeconds,totalTicks,attempts,(int)size);
+      logE("hang detected! stopping! at %s (%d>=%d)",totalTime.toString(),attempts,(int)size);
       freelance=false;
       playing=false;
       extValuePresent=false;
@@ -3237,6 +3257,23 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
     renderPool->wait();
   }
 
+  // process file player
+  // resize file player audio buffer if necessary
+  if (filePlayerBufLen<size) {
+    for (int i=0; i<DIV_MAX_OUTPUTS; i++) {
+      if (filePlayerBuf[i]!=NULL) delete[] filePlayerBuf[i];
+      filePlayerBuf[i]=new float[size];
+    }
+    filePlayerBufLen=size;
+  }
+  if (curFilePlayer!=NULL && !exporting) {
+    curFilePlayer->mix(filePlayerBuf,outChans,size);
+  } else {
+    for (int i=0; i<DIV_MAX_OUTPUTS; i++) {
+      memset(filePlayerBuf[i],0,size*sizeof(float));
+    }
+  }
+
   // process metronome
   // resize the metronome's audio buffer if necessary
   if (metroBufLen<size || metroBuf==NULL) {
@@ -3274,6 +3311,19 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
     }
   }
 
+  // calculate volume of reference file player (so we can attenuate the rest according to the mix slider)
+  // -1 to 0: player volume goes from 0% to 100%
+  // 0 to +1: tracker volume goes from 100% to 0%
+  float refPlayerVol=1.0f;
+  if (curFilePlayer!=NULL) {
+    // only if the player window is open
+    if (curFilePlayer->getActive()) {
+      refPlayerVol=1.0f-curFilePlayer->getVolume();
+      if (refPlayerVol<0.0f) refPlayerVol=0.0f;
+      if (refPlayerVol>1.0f) refPlayerVol=1.0f;
+    }
+  }
+
   // now mix everything (resolve patchbay)
   for (unsigned int i: song.patchbay) {
     // there are 4096 portsets. each portset may have up to 16 outputs (subports).
@@ -3295,7 +3345,7 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
       // chip outputs
       if (srcPortSet<song.systemLen && playing && !halted) {
         if (srcSubPort<disCont[srcPortSet].dispatch->getOutputCount()) {
-          float vol=song.systemVol[srcPortSet]*disCont[srcPortSet].dispatch->getPostAmp()*song.masterVol;
+          float vol=song.systemVol[srcPortSet]*disCont[srcPortSet].dispatch->getPostAmp()*song.masterVol*refPlayerVol;
 
           // apply volume and panning
           switch (destSubPort&3) {
@@ -3317,6 +3367,11 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
             out[destSubPort][j]+=((float)disCont[srcPortSet].bbOut[srcSubPort][j]/32768.0)*vol;
           }
         }
+      } else if (srcPortSet==0xffc) {
+        // file player
+        for (size_t j=0; j<size; j++) {
+          out[destSubPort][j]+=filePlayerBuf[srcSubPort][j];
+        }
       } else if (srcPortSet==0xffd) {
         // sample preview
         for (size_t j=0; j<size; j++) {
diff --git a/src/engine/song.cpp b/src/engine/song.cpp
index 05d402055..116815da7 100644
--- a/src/engine/song.cpp
+++ b/src/engine/song.cpp
@@ -19,254 +19,412 @@
 
 #include "song.h"
 #include "../ta-log.h"
+#include <chrono>
 
+TimeMicros DivSongTimestamps::getTimes(int order, int row) {
+  if (order<0 || order>=DIV_MAX_PATTERNS) return TimeMicros(-1,0);
+  if (row<0 || row>=DIV_MAX_ROWS) return TimeMicros(-1,0);
+  TimeMicros* t=orders[order];
+  if (t==NULL) return TimeMicros(-1,0);
+  return t[row];
+}
 
-bool DivSubSong::walk(int& loopOrder, int& loopRow, int& loopEnd, int chans, int jumpTreatment, int ignoreJumpAtEnd, int firstPat) {
-  loopOrder=0;
-  loopRow=0;
-  loopEnd=-1;
-  int nextOrder=-1;
-  int nextRow=0;
-  int effectVal=0;
-  int lastSuspectedLoopEnd=-1;
-  DivPattern* subPat[DIV_MAX_CHANS];
+DivSongTimestamps::DivSongTimestamps():
+  totalTime(0,0),
+  totalTicks(0),
+  totalRows(0),
+  isLoopDefined(false),
+  isLoopable(true) {
+  memset(orders,0,DIV_MAX_PATTERNS*sizeof(void*));
+  memset(maxRow,0,DIV_MAX_PATTERNS);
+}
+
+DivSongTimestamps::~DivSongTimestamps() {
+  for (int i=0; i<DIV_MAX_PATTERNS; i++) {
+    if (orders[i]) {
+      delete[] orders[i];
+      orders[i]=NULL;
+    }
+  }
+}
+
+void DivSubSong::calcTimestamps(int chans, std::vector<DivGroovePattern>& grooves, int jumpTreatment, int ignoreJumpAtEnd, int brokenSpeedSel, int delayBehavior, int firstPat) {
+  // reduced version of the playback routine for calculation.
+  std::chrono::high_resolution_clock::time_point timeStart=std::chrono::high_resolution_clock::now();
+
+  // reset state
+  ts.totalTime=TimeMicros(0,0);
+  ts.totalTicks=0;
+  ts.totalRows=0;
+  ts.isLoopDefined=true;
+  ts.isLoopable=true;
+
+  memset(ts.maxRow,0,DIV_MAX_PATTERNS);
+  
+  for (int i=0; i<DIV_MAX_PATTERNS; i++) {
+    if (ts.orders[i]) {
+      delete[] ts.orders[i];
+      ts.orders[i]=NULL;
+    }
+  }
+
+  // walking state
   unsigned char wsWalked[8192];
   memset(wsWalked,0,8192);
   if (firstPat>0) {
     memset(wsWalked,255,32*firstPat);
   }
-  for (int i=firstPat; i<ordersLen; i++) {
-    for (int j=0; j<chans; j++) {
-      subPat[j]=pat[j].getPattern(orders.ord[j][i],false);
-    }
-    if (i>lastSuspectedLoopEnd) {
-      lastSuspectedLoopEnd=i;
-    }
-    for (int j=nextRow; j<patLen; j++) {
-      nextRow=0;
-      bool changingOrder=false;
-      bool jumpingOrder=false;
-      if (wsWalked[((i<<5)+(j>>3))&8191]&(1<<(j&7))) {
-        loopOrder=i;
-        loopRow=j;
-        loopEnd=lastSuspectedLoopEnd;
-        return true;
-      }
-      for (int k=0; k<chans; k++) {
-        for (int l=0; l<pat[k].effectCols; l++) {
-          effectVal=subPat[k]->newData[j][DIV_PAT_FXVAL(l)];
-          if (effectVal<0) effectVal=0;
-          if (subPat[k]->newData[j][DIV_PAT_FX(l)]==0x0d) {
+  int curOrder=firstPat;
+  int curRow=0;
+  int prevOrder=firstPat;
+  int prevRow=0;
+  DivGroovePattern curSpeeds=speeds;
+  int curVirtualTempoN=virtualTempoN;
+  int curVirtualTempoD=virtualTempoD;
+  int nextSpeed=curSpeeds.val[0];
+  double divider=hz;
+  double totalMicrosOff=0.0;
+  int ticks=1;
+  int tempoAccum=0;
+  int curSpeed=0;
+  int changeOrd=-1;
+  int changePos=0;
+  unsigned char rowDelay[DIV_MAX_CHANS];
+  unsigned char delayOrder[DIV_MAX_CHANS];
+  unsigned char delayRow[DIV_MAX_CHANS];
+  bool shallStopSched=false;
+  bool shallStop=false;
+  bool songWillEnd=false;
+  bool endOfSong=false;
+  bool rowChanged=false;
+
+  memset(rowDelay,0,DIV_MAX_CHANS);
+  memset(delayOrder,0,DIV_MAX_CHANS);
+  memset(delayRow,0,DIV_MAX_CHANS);
+  if (divider<1) divider=1;
+
+  auto tinyProcessRow=[&,this](int i, bool afterDelay) {
+    // if this is after delay, use the order/row where delay occurred
+    int whatOrder=afterDelay?delayOrder[i]:curOrder;
+    int whatRow=afterDelay?delayRow[i]:curRow;
+    DivPattern* p=pat[i].getPattern(orders.ord[i][whatOrder],false);
+    // pre effects
+    if (!afterDelay) {
+      // set to true if we found an EDxx effect
+      bool returnAfterPre=false;
+      // check all effects
+      for (int j=0; j<pat[i].effectCols; j++) {
+        short effect=p->newData[whatRow][DIV_PAT_FX(j)];
+        short effectVal=p->newData[whatRow][DIV_PAT_FXVAL(j)];
+
+        // empty effect value is the same as zero
+        if (effectVal==-1) effectVal=0;
+        effectVal&=255;
+
+        switch (effect) {
+          case 0x09: // select groove pattern/speed 1
+            if (grooves.empty()) {
+              // special case: sets speed 1 if the song lacks groove patterns
+              if (effectVal>0) curSpeeds.val[0]=effectVal;
+            } else {
+              // sets the groove pattern and resets current speed index
+              if (effectVal<(short)grooves.size()) {
+                curSpeeds=grooves[effectVal];
+                curSpeed=0;
+              }
+            }
+            break;
+          case 0x0f: // speed 1/speed 2
+            // if the value is 0 then ignore it
+            if (curSpeeds.len==2 && grooves.empty()) {
+              // if there are two speeds and no groove patterns, set the second speed
+              if (effectVal>0) curSpeeds.val[1]=effectVal;
+            } else {
+              // otherwise set the first speed
+              if (effectVal>0) curSpeeds.val[0]=effectVal;
+            }
+            break;
+          case 0xfd: // virtual tempo num
+            if (effectVal>0) curVirtualTempoN=effectVal;
+            break;
+          case 0xfe: // virtual tempo den
+            if (effectVal>0) curVirtualTempoD=effectVal;
+            break;
+          case 0x0b: // change order
+            // this actually schedules an order change
+            // we perform this change at the end of nextRow()
+
+            // COMPAT FLAG: simultaneous jump treatment
+            if (changeOrd==-1 || jumpTreatment==0) {
+              changeOrd=effectVal;
+              if (jumpTreatment==1 || jumpTreatment==2) {
+                changePos=0;
+              }
+            }
+            break;
+          case 0x0d: // next order
+            // COMPAT FLAG: simultaneous jump treatment
             if (jumpTreatment==2) {
-              if ((i<ordersLen-1 || !ignoreJumpAtEnd)) {
-                nextOrder=i+1;
-                nextRow=effectVal;
-                jumpingOrder=true;
+              // - 2: DefleMask (jump to next order unless it is the last one and ignoreJumpAtEnd is on)
+              if ((curOrder<(ordersLen-1) || !ignoreJumpAtEnd)) {
+                // changeOrd -2 means increase order by 1
+                // it overrides a previous 0Bxx effect
+                changeOrd=-2;
+                changePos=effectVal;
               }
             } else if (jumpTreatment==1) {
-              if (nextOrder==-1 && (i<ordersLen-1 || !ignoreJumpAtEnd)) {
-                nextOrder=i+1;
-                nextRow=effectVal;
-                jumpingOrder=true;
+              // - 1: old Furnace (same as 2 but ignored if 0Bxx is present)
+              if (changeOrd<0 && (curOrder<(ordersLen-1) || !ignoreJumpAtEnd)) {
+                changeOrd=-2;
+                changePos=effectVal;
               }
             } else {
-              if ((i<ordersLen-1 || !ignoreJumpAtEnd)) {
-                if (!changingOrder) {
-                  nextOrder=i+1;
+              // - 0: normal
+              if (curOrder<(ordersLen-1) || !ignoreJumpAtEnd) {
+                // set the target order if not set, allowing you to use 0B and 0D regardless of position
+                if (changeOrd<0) {
+                  changeOrd=-2;
                 }
-                jumpingOrder=true;
-                nextRow=effectVal;
+                changePos=effectVal;
               }
             }
-          } else if (subPat[k]->newData[j][DIV_PAT_FX(l)]==0x0b) {
-            if (nextOrder==-1 || jumpTreatment==0) {
-              nextOrder=effectVal;
-              if (jumpTreatment==1 || jumpTreatment==2 || !jumpingOrder) {
-                nextRow=0;
+            break;
+          case 0xed: // delay
+            if (effectVal!=0) {
+              // COMPAT FLAG: cut/delay effect policy (delayBehavior)
+              // - 0: strict
+              //   - delays equal or greater to the speed * timeBase are ignored
+              // - 1: strict old
+              //   - delays equal or greater to the speed are ignored
+              // - 2: lax (default)
+              //   - no delay is ever ignored unless overridden by another
+              bool comparison=(delayBehavior==1)?(effectVal<=nextSpeed):(effectVal<(nextSpeed*(timeBase+1)));
+              if (delayBehavior==2) comparison=true;
+              if (comparison) {
+                // set the delay row, order and timer
+                rowDelay[i]=effectVal;
+                delayOrder[i]=whatOrder;
+                delayRow[i]=whatRow;
+
+                // once we're done with pre-effects, get out and don't process any further
+                returnAfterPre=true;
               }
-              changingOrder=true;
             }
-          }
+            break;
         }
       }
+      // stop processing if EDxx was found
+      if (returnAfterPre) return;
+    } else {
+      //logV("honoring delay at position %d",whatRow);
+    }
 
-      wsWalked[((i<<5)+(j>>3))&8191]|=1<<(j&7);
+
+    // effects
+    for (int j=0; j<pat[i].effectCols; j++) {
+      short effect=p->newData[whatRow][DIV_PAT_FX(j)];
+      short effectVal=p->newData[whatRow][DIV_PAT_FXVAL(j)];
+
+      // an empty effect value is treated as zero
+      if (effectVal==-1) effectVal=0;
+      effectVal&=255;
+
+      // tempo/tick rate effects
+      switch (effect) {
+        case 0xc0: case 0xc1: case 0xc2: case 0xc3: // set tick rate
+          // Cxxx, where `xxx` is between 1 and 1023
+          divider=(double)(((effect&0x3)<<8)|effectVal);
+          if (divider<1) divider=1;
+          break;
+        case 0xf0: // set tempo
+          divider=(double)effectVal*2.0/5.0;
+          if (divider<1) divider=1;
+          break;
+        case 0xff: // stop song
+          shallStopSched=true;
+          break;
+      }
+    }
+  };
+
+  auto tinyNextRow=[&,this]() {
+    // store the previous position
+    prevOrder=curOrder;
+    prevRow=curRow;
+
+    if (songWillEnd) {
+      endOfSong=true;
+    }
+
+    for (int i=0; i<chans; i++) {
+      tinyProcessRow(i,false);
+    }
+
+    // mark this row as "walked" over
+    wsWalked[((curOrder<<5)+(curRow>>3))&8191]|=1<<(curRow&7);
+
+    // commit a pending jump if there is one
+    // otherwise, advance row position
+    if (changeOrd!=-1) {
+      // jump to order and reset position
+      curRow=changePos;
+      changePos=0;
+      // jump to next order if it is -2
+      if (changeOrd==-2) changeOrd=curOrder+1;
+      curOrder=changeOrd;
+
+      // if we're out of bounds, return to the beginning
+      // if this happens we're guaranteed to loop
+      if (curOrder>=ordersLen) {
+        curOrder=0;
+        ts.isLoopDefined=false;
+        songWillEnd=true;
+        memset(wsWalked,0,8192);
+      }
+      changeOrd=-1;
+    } else if (++curRow>=patLen) {
+      // if we are here it means we reached the end of this pattern, so
+      // advance to next order unless the song is about to stop
+      if (shallStopSched) {
+        curRow=patLen-1;
+      } else {
+        // go to next order
+        curRow=0;
+        if (++curOrder>=ordersLen) {
+          logV("end of orders reached");
+          ts.isLoopDefined=false;
+          songWillEnd=true;
+          // the walked array is used for loop detection
+          // since we've reached the end, we are guaranteed to loop here, so
+          // just reset it.
+          memset(wsWalked,0,8192);
+          curOrder=0;
+        }
+      }
+    }
+    rowChanged=true;
+    ts.totalRows++;
+
+    // new loop detection routine
+    // if we're stepping on a row we've already walked over, we found loop
+    // if the song is going to stop though, don't do anything
+    if (!songWillEnd && wsWalked[((curOrder<<5)+(curRow>>3))&8191]&(1<<(curRow&7)) && !shallStopSched) {
+      logV("loop reached");
+      songWillEnd=true;
+      memset(wsWalked,0,8192);
+    }
+    // perform speed alternation
+    // COMPAT FLAG: broken speed alternation
+    if (brokenSpeedSel) {
+      unsigned char speed2=(curSpeeds.len>=2)?curSpeeds.val[1]:curSpeeds.val[0];
+      unsigned char speed1=curSpeeds.val[0];
       
-      if (nextOrder!=-1) {
-        i=nextOrder-1;
-        nextOrder=-1;
+      // if the pattern length is odd and the current order is odd, use speed 2 for even rows and speed 1 for odd ones
+      // we subtract firstPat from curOrder as firstPat is used by a function which finds sub-songs
+      // (the beginning of a new sub-song will be in order 0)
+      if ((patLen&1) && (curOrder-firstPat)&1) {
+        ticks=((curRow&1)?speed2:speed1)*(timeBase+1);
+        nextSpeed=(curRow&1)?speed1:speed2;
+      } else {
+        ticks=((curRow&1)?speed1:speed2)*(timeBase+1);
+        nextSpeed=(curRow&1)?speed2:speed1;
+      }
+    } else {
+      // normal speed alternation
+      // set the number of ticks and cycle to the next speed
+      ticks=curSpeeds.val[curSpeed]*(timeBase+1);
+      curSpeed++;
+      if (curSpeed>=curSpeeds.len) curSpeed=0;
+      // cache the next speed for future operations
+      nextSpeed=curSpeeds.val[curSpeed];
+    }
+
+    if (songWillEnd && !endOfSong) {
+      ts.loopEnd.order=prevOrder;
+      ts.loopEnd.row=prevRow;
+    }
+  };
+
+  // MAKE IT WORK
+  while (!endOfSong) {
+    // cycle channels to find a tick rate/tempo change effect after delay
+    // (unfortunately Cxxx and F0xx are not pre-effects and obey EDxx)
+    for (int i=0; i<chans; i++) {
+      if (rowDelay[i]>0) {
+        if (--rowDelay[i]==0) {
+          tinyProcessRow(i,true);
+        }
+      }
+    }
+
+    // run virtual tempo
+    tempoAccum+=curVirtualTempoN;
+    while (tempoAccum>=curVirtualTempoD) {
+      tempoAccum-=curVirtualTempoD;
+      // tick counter
+      if (--ticks<=0) {
+        if (shallStopSched) {
+          shallStop=true;
+          break;
+        } else if (endOfSong) {
+          break;
+        }
+
+        // next row
+        tinyNextRow();
         break;
       }
+
+      // limit tempo accumulator
+      if (tempoAccum>1023) tempoAccum=1023;
     }
-  }
-  return false;
-}
 
-double calcRowLenInSeconds(const DivGroovePattern& speeds, float hz, int vN, int vD, int timeBaseFromSong) {
-  double hl=1; //count for 1 row
-  if (hl<=0.0) hl=4.0;
-  double timeBase=timeBaseFromSong+1;
-  double speedSum=0;
-  for (int i=0; i<MIN(16,speeds.len); i++) {
-    speedSum+=speeds.val[i];
-  }
-  speedSum/=MAX(1,speeds.len);
-  if (timeBase<1.0) timeBase=1.0;
-  if (speedSum<1.0) speedSum=1.0;
-  if (vD<1) vD=1;
-  return 1.0/((60.0*hz/(timeBase*hl*speedSum))*(double)vN/(double)vD/60.0);
-}
-
-void DivSubSong::findLength(int loopOrder, int loopRow, double fadeoutLen, int& rowsForFadeout, bool& hasFFxx, std::vector<int>& orders_vec, std::vector<DivGroovePattern>& grooves, int& length, int chans, int jumpTreatment, int ignoreJumpAtEnd, int firstPat) {
-  length=0;
-  hasFFxx=false;
-  rowsForFadeout=0;
-
-  float secondsPerThisRow=0.0f;
-
-  DivGroovePattern curSpeeds=speeds; //simulate that we are playing the song, track all speed/BPM/tempo/engine rate changes
-  short curVirtualTempoN=virtualTempoN;
-  short curVirtualTempoD=virtualTempoD;
-  float curHz=hz;
-  double curDivider=(double)timeBase;
-
-  double curLen=0.0; //how many seconds passed since the start of song
-
-  int nextOrder=-1;
-  int nextRow=0;
-  int effectVal=0;
-  int lastSuspectedLoopEnd=-1;
-  DivPattern* subPat[DIV_MAX_CHANS];
-  unsigned char wsWalked[8192];
-  memset(wsWalked,0,8192);
-  if (firstPat>0) {
-    memset(wsWalked,255,32*firstPat);
-  }
-  for (int i=firstPat; i<ordersLen; i++) {
-    bool jumped=false;
-
-    for (int j=0; j<chans; j++) {
-      subPat[j]=pat[j].getPattern(orders.ord[j][i],false);
+    if (shallStop) {
+      // FFxx found - the song doesn't loop
+      ts.isLoopable=false;
+      ts.isLoopDefined=false;
+      break;
     }
-    if (i>lastSuspectedLoopEnd) {
-      lastSuspectedLoopEnd=i;
-    }
-    for (int j=nextRow; j<patLen; j++) {
-      nextRow=0;
-      bool changingOrder=false;
-      bool jumpingOrder=false;
-      if (wsWalked[((i<<5)+(j>>3))&8191]&(1<<(j&7))) {
-        return;
-      }
-      for (int k=0; k<chans; k++) {
-        for (int l=0; l<pat[k].effectCols; l++) {
-          effectVal=subPat[k]->newData[j][DIV_PAT_FXVAL(l)];
-          if (effectVal<0) effectVal=0;
 
-          if (subPat[k]->newData[j][DIV_PAT_FX(l)]==0xff) {
-            hasFFxx=true;
-
-            // FFxx makes YOU SHALL NOT PASS!!! move
-            orders_vec.push_back(j+1); // order len
-            length+=j+1; // add length of order to song length
-
-            return;
-          }
-
-          switch (subPat[k]->newData[j][DIV_PAT_FX(l)]) {
-            case 0x09: { // select groove pattern/speed 1
-              if (grooves.empty()) {
-                if (effectVal>0) curSpeeds.val[0]=effectVal;
-              } else {
-                if (effectVal<(short)grooves.size()) {
-                  curSpeeds=grooves[effectVal];
-                  //curSpeed=0;
-                }
-              }
-              break;
-            }
-            case 0x0f: { //  speed 1/speed 2
-              if (curSpeeds.len==2 && grooves.empty()) {
-                if (effectVal>0) curSpeeds.val[1]=effectVal;
-              } else {
-                if (effectVal>0) curSpeeds.val[0]=effectVal;
-              }
-              break;
-            }
-            case 0xfd: { //  virtual tempo num
-              if (effectVal>0) curVirtualTempoN=effectVal;
-              break;
-            }
-            case 0xfe: { //  virtual tempo den
-              if (effectVal>0) curVirtualTempoD=effectVal;
-              break;
-            }
-            case 0xf0: { //  set Hz by tempo (set bpm)
-              curDivider=(double)effectVal*2.0/5.0;
-              if (curDivider<1) curDivider=1;
-              break;
-            }
-          }
-
-          if (subPat[k]->newData[j][DIV_PAT_FX(l)]==0x0d) {
-            if (jumpTreatment==2) {
-              if ((i<ordersLen-1 || !ignoreJumpAtEnd)) {
-                nextOrder=i+1;
-                nextRow=effectVal;
-                jumpingOrder=true;
-              }
-            } else if (jumpTreatment==1) {
-              if (nextOrder==-1 && (i<ordersLen-1 || !ignoreJumpAtEnd)) {
-                nextOrder=i+1;
-                nextRow=effectVal;
-                jumpingOrder=true;
-              }
-            } else {
-              if ((i<ordersLen-1 || !ignoreJumpAtEnd)) {
-                if (!changingOrder) {
-                  nextOrder=i+1;
-                }
-                jumpingOrder=true;
-                nextRow=effectVal;
-              }
-            }
-          } else if (subPat[k]->newData[j][DIV_PAT_FX(l)]==0x0b) {
-            if (nextOrder==-1 || jumpTreatment==0) {
-              nextOrder=effectVal;
-              if (jumpTreatment==1 || jumpTreatment==2 || !jumpingOrder) {
-                nextRow=0;
-              }
-              changingOrder=true;
-            }
-          }
+    // log row time here
+    if (rowChanged && !endOfSong) {
+      if (ts.orders[prevOrder]==NULL) {
+        ts.orders[prevOrder]=new TimeMicros[DIV_MAX_ROWS];
+        for (int i=0; i<DIV_MAX_ROWS; i++) {
+          ts.orders[prevOrder][i].seconds=-1;
         }
       }
+      ts.orders[prevOrder][prevRow]=ts.totalTime;
+      rowChanged=false;
+    }
 
-      if (i>loopOrder || (i==loopOrder && j>loopRow)) {
-        //  we count each row fadeout lasts. When our time is greater than fadeout length we successfully counted the number of fadeout rows
-        if (curLen<=fadeoutLen && fadeoutLen>0.0) {
-          secondsPerThisRow=calcRowLenInSeconds(speeds,curHz,curVirtualTempoN,curVirtualTempoD,curDivider);
-          curLen+=secondsPerThisRow;
-          rowsForFadeout++;
-        }
+    if (!endOfSong) {
+      // update playback time
+      double dt=divider;//*((double)virtualTempoN/(double)MAX(1,virtualTempoD));
+      ts.totalTicks++;
+
+      ts.totalTime.micros+=1000000/dt;
+      totalMicrosOff+=fmod(1000000.0,dt);
+      while (totalMicrosOff>=dt) {
+        totalMicrosOff-=dt;
+        ts.totalTime.micros++;
       }
-
-      wsWalked[((i<<5)+(j>>3))&8191]|=1<<(j&7);
-      
-      if (nextOrder!=-1) {
-        i=nextOrder-1;
-        orders_vec.push_back(j+1); // order len
-        length+=j+1; // add length of order to song length
-        jumped=true;
-        nextOrder=-1;
-        break;
+      if (ts.totalTime.micros>=1000000) {
+        ts.totalTime.micros-=1000000;
+        // who's gonna play a song for 68 years?
+        if (ts.totalTime.seconds<0x7fffffff) ts.totalTime.seconds++;
       }
     }
-    if (!jumped) { // if no jump occured we add full pattern length
-      orders_vec.push_back(patLen); // order len
-      length+=patLen; // add length of order to song length
-    }
+    if (ts.maxRow[curOrder]<curRow) ts.maxRow[curOrder]=curRow;
   }
+
+  ts.totalRows--;
+  ts.loopStart.order=prevOrder;
+  ts.loopStart.row=prevRow;
+  ts.loopStartTime=ts.getTimes(ts.loopStart.order,ts.loopStart.row);
+
+  std::chrono::high_resolution_clock::time_point timeEnd=std::chrono::high_resolution_clock::now();
+  logV("calcTimestamps() took %dµs",std::chrono::duration_cast<std::chrono::microseconds>(timeEnd-timeStart).count());
 }
 
 void DivSubSong::clearData() {
@@ -400,24 +558,23 @@ void DivSong::findSubSongs(int chans) {
   for (DivSubSong* i: subsong) {
     std::vector<int> subSongStart;
     std::vector<int> subSongEnd;
-    int loopOrder=0;
-    int loopRow=0;
-    int loopEnd=-1;
     int curStart=-1;
 
     // find possible subsongs
     logD("finding subsongs...");
     while (++curStart<i->ordersLen) {
-      if (!i->walk(loopOrder,loopRow,loopEnd,chans,jumpTreatment,ignoreJumpAtEnd,curStart)) break;
+      i->calcTimestamps(chans,grooves,jumpTreatment,ignoreJumpAtEnd,brokenSpeedSel,delayBehavior,curStart);
+      if (!i->ts.isLoopable) break;
       
       // make sure we don't pick the same range twice
       if (!subSongEnd.empty()) {
-        if (subSongEnd.back()==loopEnd) continue;
+        if (subSongEnd.back()==i->ts.loopEnd.order) continue;
       }
 
-      logV("found a subsong: %d-%d",curStart,loopEnd);
+      logV("found a subsong: %d-%d",curStart,i->ts.loopEnd.order);
       subSongStart.push_back(curStart);
-      subSongEnd.push_back(loopEnd);
+      subSongEnd.push_back(i->ts.loopEnd.order);
+      curStart=i->ts.loopEnd.order;
     }
 
     // if this is the only song, quit
diff --git a/src/engine/song.h b/src/engine/song.h
index 30121a6ac..437e1159e 100644
--- a/src/engine/song.h
+++ b/src/engine/song.h
@@ -23,6 +23,7 @@
 #include "../pch.h"
 
 #include "defines.h"
+#include "../timeutils.h"
 #include "../ta-utils.h"
 #include "config.h"
 #include "orders.h"
@@ -167,6 +168,40 @@ struct DivGroovePattern {
     }
 };
 
+struct DivSongTimestamps {
+  // song duration (in seconds and microseconds)
+  TimeMicros totalTime;
+  int totalTicks;
+  int totalRows;
+
+  // loop region (order/row positions)
+  struct Position {
+    int order, row;
+    Position():
+      order(0), row(0) {}
+  } loopStart, loopEnd;
+  // set to true if a 0Bxx effect is found and it defines a loop region
+  bool isLoopDefined;
+  // set to false if FFxx is found
+  bool isLoopable;
+
+  // timestamp of a row
+  // DO NOT ACCESS DIRECTLY! use the functions instead.
+  // if seconds is -1, it means this row is not touched at all.
+  TimeMicros* orders[DIV_MAX_PATTERNS];
+  TimeMicros loopStartTime;
+
+  // the furthest row that the playhead goes through in an order.
+  unsigned char maxRow[DIV_MAX_PATTERNS];
+
+  // call this function to get the timestamp of a row.
+  TimeMicros getTimes(int order, int row);
+
+  DivSongTimestamps();
+  ~DivSongTimestamps();
+};
+
+
 struct DivSubSong {
   String name, notes;
   unsigned char hilightA, hilightB;
@@ -185,15 +220,13 @@ struct DivSubSong {
   String chanName[DIV_MAX_CHANS];
   String chanShortName[DIV_MAX_CHANS];
 
-  /**
-   * walk through the song and determine loop position.
-   */
-  bool walk(int& loopOrder, int& loopRow, int& loopEnd, int chans, int jumpTreatment, int ignoreJumpAtEnd, int firstPat=0);
+  // song timestamps
+  DivSongTimestamps ts;
 
   /**
-   * find song length in rows (up to specified loop point).
+   * calculate timestamps (loop position, song length and more).
    */
-  void findLength(int loopOrder, int loopRow, double fadeoutLen, int& rowsForFadeout, bool& hasFFxx, std::vector<int>& orders, std::vector<DivGroovePattern>& grooves, int& length, int chans, int jumpTreatment, int ignoreJumpAtEnd, int firstPat=0);
+  void calcTimestamps(int chans, std::vector<DivGroovePattern>& grooves, int jumpTreatment, int ignoreJumpAtEnd, int brokenSpeedSel, int delayBehavior, int firstPat=0);
 
   void clearData();
   void removeUnusedPatterns();
diff --git a/src/engine/vgmOps.cpp b/src/engine/vgmOps.cpp
index f48f2db7e..c7d1cbfde 100644
--- a/src/engine/vgmOps.cpp
+++ b/src/engine/vgmOps.cpp
@@ -1272,10 +1272,9 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version, bool p
   double origRate=got.rate;
   got.rate=correctedRate;
   // determine loop point
-  int loopOrder=0;
-  int loopRow=0;
-  int loopEnd=0;
-  walkSong(loopOrder,loopRow,loopEnd);
+  calcSongTimestamps();
+  int loopOrder=curSubSong->ts.loopStart.order;
+  int loopRow=curSubSong->ts.loopStart.row;
   logI("loop point: %d %d",loopOrder,loopRow);
   warnings="";
 
diff --git a/src/gui/clock.cpp b/src/gui/clock.cpp
index b02adf43b..1d5312738 100644
--- a/src/gui/clock.cpp
+++ b/src/gui/clock.cpp
@@ -104,10 +104,9 @@ void FurnaceGUI::drawClock() {
       }
     }
     if (clockShowTime) {
-      int totalTicks=e->getTotalTicks();
-      int totalSeconds=e->getTotalSeconds();
+      String timeFormatted=e->getCurTime().toString(2,TA_TIME_FORMAT_MS_ZERO);
       ImGui::PushFont(bigFont);
-      ImGui::Text("%.2d:%.2d.%.2d",(totalSeconds/60),totalSeconds%60,totalTicks/10000);
+      ImGui::TextUnformatted(timeFormatted.c_str());
       ImGui::PopFont();
     }
   }
diff --git a/src/gui/commandPalette.cpp b/src/gui/commandPalette.cpp
index f0586fe5f..f55673db8 100644
--- a/src/gui/commandPalette.cpp
+++ b/src/gui/commandPalette.cpp
@@ -381,6 +381,7 @@ void FurnaceGUI::drawPalette() {
               showError("cannot add chip! ("+e->getLastError()+")");
             } else {
               MARK_MODIFIED;
+              recalcTimestamps=true;
             }
             ImGui::CloseCurrentPopup();
             if (e->song.autoSystem) {
diff --git a/src/gui/debugWindow.cpp b/src/gui/debugWindow.cpp
index fc0d94f32..1b3ba9259 100644
--- a/src/gui/debugWindow.cpp
+++ b/src/gui/debugWindow.cpp
@@ -25,6 +25,7 @@
 #include <fmt/printf.h>
 #include "imgui.h"
 #include "imgui_internal.h"
+#include "misc/cpp/imgui_stdlib.h"
 
 PendingDrawOsc _debugDo;
 static float oscDebugData[2048];
@@ -199,6 +200,41 @@ void FurnaceGUI::drawDebug() {
       ImGui::Text("patScroll: %f",patScroll);
       ImGui::TreePop();
     }
+    if (ImGui::TreeNode("Song Timestamps")) {
+      if (ImGui::Button("Recalculate")) {
+        e->calcSongTimestamps();
+      }
+
+      DivSongTimestamps& ts=e->curSubSong->ts;
+
+      String timeFormatted=ts.totalTime.toString(-1,TA_TIME_FORMAT_AUTO);
+      ImGui::Text("song duration: %s (%d ticks; %d rows)",timeFormatted.c_str(),ts.totalTicks,ts.totalRows);
+      if (ts.isLoopDefined) {
+        ImGui::Text("loop region is defined");
+      } else {
+        ImGui::Text("no loop region");
+      }
+      if (ts.isLoopable) {
+        ImGui::Text("song can loop");
+      } else {
+        ImGui::Text("song will stop");
+      }
+
+      ImGui::Text("loop region: %d:%d - %d:%d",ts.loopStart.order,ts.loopStart.row,ts.loopEnd.order,ts.loopEnd.row);
+      timeFormatted=ts.loopStartTime.toString(-1,TA_TIME_FORMAT_AUTO);
+      ImGui::Text("loop start time: %s",timeFormatted.c_str());
+
+      if (ImGui::TreeNode("Maximum rows")) {
+        for (int i=0; i<e->curSubSong->ordersLen; i++) {
+          ImGui::Text("- Order %d: %d",i,ts.maxRow[i]);
+        }
+        ImGui::TreePop();
+      }
+
+      ImGui::Checkbox("Enable row timestamps (in pattern view)",&debugRowTimestamps);
+      
+      ImGui::TreePop();
+    }
     if (ImGui::TreeNode("Sample Debug")) {
       for (int i=0; i<e->song.sampleLen; i++) {
         DivSample* sample=e->getSample(i);
@@ -334,6 +370,25 @@ void FurnaceGUI::drawDebug() {
       ImGui::Unindent();
       ImGui::TreePop();
     }
+    if (ImGui::TreeNode("TimeMicros Test")) {
+      static TimeMicros testTS;
+      static String testTSIn;
+      String testTSFormatted=testTS.toString();
+      ImGui::Text("Current Value: %s",testTSFormatted.c_str());
+
+      if (ImGui::InputText("fromString",&testTSIn)) {
+        try {
+          testTS=TimeMicros::fromString(testTSIn);
+        } catch (std::invalid_argument& e) {
+          ImGui::Text("COULD NOT! (%s)",e.what());
+        }
+      }
+
+      ImGui::InputInt("seconds",&testTS.seconds);
+      ImGui::InputInt("micros",&testTS.micros);
+
+      ImGui::TreePop();
+    }
     if (ImGui::TreeNode("New File Picker Test")) {
       static bool check0, check1, check2, check3, check4, check5;
 
diff --git a/src/gui/doAction.cpp b/src/gui/doAction.cpp
index 2efc846d5..de578f833 100644
--- a/src/gui/doAction.cpp
+++ b/src/gui/doAction.cpp
@@ -363,6 +363,9 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_WINDOW_USER_PRESETS:
       nextWindow=GUI_WINDOW_USER_PRESETS;
       break;
+    case GUI_ACTION_WINDOW_REF_PLAYER:
+      nextWindow=GUI_WINDOW_REF_PLAYER;
+      break;
     
     case GUI_ACTION_COLLAPSE_WINDOW:
       collapseWindow=true;
@@ -471,6 +474,9 @@ void FurnaceGUI::doAction(int what) {
         case GUI_WINDOW_USER_PRESETS:
           userPresetsOpen=false;
           break;
+        case GUI_WINDOW_REF_PLAYER:
+          refPlayerOpen=false;
+          break;
         case GUI_WINDOW_TUNER:
           tunerOpen=false;
           break;
diff --git a/src/gui/editControls.cpp b/src/gui/editControls.cpp
index 1804b4b80..d0c0fd833 100644
--- a/src/gui/editControls.cpp
+++ b/src/gui/editControls.cpp
@@ -633,6 +633,10 @@ void FurnaceGUI::drawMobileControls() {
         if (ImGui::Button(_("EffectList"))) {
           effectListOpen=!effectListOpen;
         }
+        ImGui::SameLine();
+        if (ImGui::Button(_("RefPlayer"))) {
+          refPlayerOpen=!refPlayerOpen;
+        }
         if (ImGui::Button(_("Switch to Desktop Mode"))) {
           toggleMobileUI(!mobileUI);
         }
@@ -755,8 +759,18 @@ void FurnaceGUI::drawEditControls() {
 
         ImGui::SameLine();
         pushToggleColors(noteInputPoly);
-        if (ImGui::Button(noteInputPoly?(_("Poly##PolyInput")):(_("Mono##PolyInput")))) {
-          noteInputPoly=!noteInputPoly;
+        if (ImGui::Button(noteInputPoly?(noteInputChord?(_("Chord##PolyInput")):(_("Poly##PolyInput"))):(_("Mono##PolyInput")))) {
+          if (noteInputPoly) {
+            if (noteInputChord) {
+              noteInputPoly=false;
+              noteInputChord=false;
+            } else {
+              noteInputChord=true;
+            }
+          } else {
+            noteInputPoly=true;
+            noteInputChord=false;
+          }
           e->setAutoNotePoly(noteInputPoly);
         }
         if (ImGui::IsItemHovered()) {
@@ -885,8 +899,18 @@ void FurnaceGUI::drawEditControls() {
 
         ImGui::SameLine();
         pushToggleColors(noteInputPoly);
-        if (ImGui::Button(noteInputPoly?_("Poly##PolyInput"):_("Mono##PolyInput"))) {
-          noteInputPoly=!noteInputPoly;
+        if (ImGui::Button(noteInputPoly?(noteInputChord?(_("Chord##PolyInput")):(_("Poly##PolyInput"))):(_("Mono##PolyInput")))) {
+          if (noteInputPoly) {
+            if (noteInputChord) {
+              noteInputPoly=false;
+              noteInputChord=false;
+            } else {
+              noteInputChord=true;
+            }
+          } else {
+            noteInputPoly=true;
+            noteInputChord=false;
+          }
           e->setAutoNotePoly(noteInputPoly);
         }
         if (ImGui::IsItemHovered()) {
@@ -1023,8 +1047,18 @@ void FurnaceGUI::drawEditControls() {
         popToggleColors();
 
         pushToggleColors(noteInputPoly);
-        if (ImGui::Button(noteInputPoly?_("Poly##PolyInput"):_("Mono##PolyInput"))) {
-          noteInputPoly=!noteInputPoly;
+        if (ImGui::Button(noteInputPoly?(noteInputChord?(_("Chord##PolyInput")):(_("Poly##PolyInput"))):(_("Mono##PolyInput")))) {
+          if (noteInputPoly) {
+            if (noteInputChord) {
+              noteInputPoly=false;
+              noteInputChord=false;
+            } else {
+              noteInputChord=true;
+            }
+          } else {
+            noteInputPoly=true;
+            noteInputChord=false;
+          }
           e->setAutoNotePoly(noteInputPoly);
         }
         if (ImGui::IsItemHovered()) {
@@ -1123,8 +1157,18 @@ void FurnaceGUI::drawEditControls() {
 
         ImGui::SameLine();
         pushToggleColors(noteInputPoly);
-        if (ImGui::Button(noteInputPoly?_("Poly##PolyInput"):_("Mono##PolyInput"))) {
-          noteInputPoly=!noteInputPoly;
+        if (ImGui::Button(noteInputPoly?(noteInputChord?(_("Chord##PolyInput")):(_("Poly##PolyInput"))):(_("Mono##PolyInput")))) {
+          if (noteInputPoly) {
+            if (noteInputChord) {
+              noteInputPoly=false;
+              noteInputChord=false;
+            } else {
+              noteInputChord=true;
+            }
+          } else {
+            noteInputPoly=true;
+            noteInputChord=false;
+          }
           e->setAutoNotePoly(noteInputPoly);
         }
         if (ImGui::IsItemHovered()) {
diff --git a/src/gui/editing.cpp b/src/gui/editing.cpp
index 882506163..9df50c377 100644
--- a/src/gui/editing.cpp
+++ b/src/gui/editing.cpp
@@ -129,7 +129,6 @@ void FurnaceGUI::prepareUndo(ActionType action, UndoRegion region) {
 
 void FurnaceGUI::makeUndo(ActionType action, UndoRegion region) {
   bool doPush=false;
-  bool shallWalk=false;
   UndoStep s;
   s.type=action;
   s.oldCursor=undoCursor;
@@ -184,6 +183,7 @@ void FurnaceGUI::makeUndo(ActionType action, UndoRegion region) {
       if (!s.ord.empty()) {
         doPush=true;
       }
+      recalcTimestamps=true;
       break;
     case GUI_UNDO_PATTERN_EDIT:
     case GUI_UNDO_PATTERN_DELETE:
@@ -227,13 +227,29 @@ void FurnaceGUI::makeUndo(ActionType action, UndoRegion region) {
                 s.pat.push_back(UndoPatternData(subSong,i,e->curOrders->ord[i][h],j,k,op->newData[j][k],p->newData[j][k]));
 
                 if (k>=DIV_PAT_FX(0)) {
-                  if (op->newData[j][k&(~1)]==0x0b ||
-                      p->newData[j][k&(~1)]==0x0b ||
-                      op->newData[j][k&(~1)]==0x0d ||
-                      p->newData[j][k&(~1)]==0x0d ||
-                      op->newData[j][k&(~1)]==0xff ||
-                      p->newData[j][k&(~1)]==0xff) {
-                    shallWalk=true;
+                  int fxCol=(k&1)?k:(k-1);
+                  if (op->newData[j][fxCol]==0x09 ||
+                      op->newData[j][fxCol]==0x0b ||
+                      op->newData[j][fxCol]==0x0d ||
+                      op->newData[j][fxCol]==0x0f ||
+                      op->newData[j][fxCol]==0xc0 ||
+                      op->newData[j][fxCol]==0xc1 ||
+                      op->newData[j][fxCol]==0xc2 ||
+                      op->newData[j][fxCol]==0xc3 ||
+                      op->newData[j][fxCol]==0xf0 ||
+                      op->newData[j][fxCol]==0xff ||
+                      p->newData[j][fxCol]==0x09 ||
+                      p->newData[j][fxCol]==0x0b ||
+                      p->newData[j][fxCol]==0x0d ||
+                      p->newData[j][fxCol]==0x0f ||
+                      p->newData[j][fxCol]==0xc0 ||
+                      p->newData[j][fxCol]==0xc1 ||
+                      p->newData[j][fxCol]==0xc2 ||
+                      p->newData[j][fxCol]==0xc3 ||
+                      p->newData[j][fxCol]==0xf0 ||
+                      p->newData[j][fxCol]==0xff) {
+                    logV("recalcTimestamps due to speed effect.");
+                    recalcTimestamps=true;
                   }
                 }
 
@@ -258,9 +274,6 @@ void FurnaceGUI::makeUndo(ActionType action, UndoRegion region) {
     redoHist.clear();
     if (undoHist.size()>settings.maxUndoSteps) undoHist.pop_front();
   }
-  if (shallWalk) {
-    e->walkSong(loopOrder,loopRow,loopEnd);
-  }
 
   // garbage collection
   for (std::pair<unsigned short,DivPattern*> i: oldPatMap) {
@@ -1798,6 +1811,7 @@ void FurnaceGUI::doCollapseSong(int divider) {
     redoHist.clear();
     if (undoHist.size()>settings.maxUndoSteps) undoHist.pop_front();
   }
+  recalcTimestamps=true;
   
   if (e->isPlaying()) e->play();
 }
@@ -1874,6 +1888,7 @@ void FurnaceGUI::doExpandSong(int multiplier) {
     redoHist.clear();
     if (undoHist.size()>settings.maxUndoSteps) undoHist.pop_front();
   }
+  recalcTimestamps=true;
 
   if (e->isPlaying()) e->play();
 }
@@ -2065,6 +2080,7 @@ void FurnaceGUI::moveSelected(int x, int y) {
   // replace
   cursor=selStart;
   doPaste(GUI_PASTE_MODE_OVERFLOW,0,false,c);
+  recalcTimestamps=true;
 
   makeUndo(GUI_UNDO_PATTERN_DRAG,UndoRegion(firstOrder,0,0,lastOrder,e->getTotalChannelCount()-1,e->curSubSong->patLen-1));
 }
@@ -2119,10 +2135,11 @@ void FurnaceGUI::doUndo() {
           }
         }
       }
-      e->walkSong(loopOrder,loopRow,loopEnd);
       break;
   }
 
+  recalcTimestamps=true;
+
   bool shallReplay=false;
   for (UndoOtherData& i: us.other) {
     switch (i.target) {
@@ -2197,10 +2214,11 @@ void FurnaceGUI::doRedo() {
           }
         }
       }
-      e->walkSong(loopOrder,loopRow,loopEnd);
       break;
   }
 
+  recalcTimestamps=true;
+
   bool shallReplay=false;
   for (UndoOtherData& i: us.other) {
     switch (i.target) {
diff --git a/src/gui/findReplace.cpp b/src/gui/findReplace.cpp
index 2c595993d..d48567534 100644
--- a/src/gui/findReplace.cpp
+++ b/src/gui/findReplace.cpp
@@ -459,6 +459,7 @@ void FurnaceGUI::doReplace() {
   if (!curQueryResults.empty()) {
     MARK_MODIFIED;
   }
+  recalcTimestamps=true;
 
   if (!us.pat.empty()) {
     undoHist.push_back(us);
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index af5c60bf2..ada89d4d2 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -1283,7 +1283,6 @@ void FurnaceGUI::play(int row) {
     chanOscChan[i].pitch=0.0f;
   }
   memset(chanOscBright,0,DIV_MAX_CHANS*sizeof(float));
-  e->walkSong(loopOrder,loopRow,loopEnd);
   memset(lastIns,-1,sizeof(int)*DIV_MAX_CHANS);
   if (wasFollowing) {
     followPattern=true;
@@ -1302,6 +1301,7 @@ void FurnaceGUI::play(int row) {
   }
   curNibble=false;
   orderNibble=false;
+  chordInputOffset=0;
   activeNotes.clear();
 }
 
@@ -1314,10 +1314,10 @@ void FurnaceGUI::setOrder(unsigned char order, bool forced) {
 
 void FurnaceGUI::stop() {
   bool wasPlaying=e->isPlaying();
-  e->walkSong(loopOrder,loopRow,loopEnd);
   e->stop();
   curNibble=false;
   orderNibble=false;
+  chordInputOffset=0;
   if (followPattern && wasPlaying) {
     nextScroll=-1.0f;
     nextAddScroll=0.0f;
@@ -1360,13 +1360,24 @@ void FurnaceGUI::stopPreviewNote(SDL_Scancode scancode, bool autoNote) {
   }
 }
 
-void FurnaceGUI::noteInput(int num, int key, int vol) {
+void FurnaceGUI::noteInput(int num, int key, int vol, int chanOff) {
   int ch=cursor.xCoarse;
   int ord=curOrder;
   int y=cursor.y;
   int tick=0;
   int speed=0;
 
+  if (chanOff>0 && noteInputChord) {
+    ch=e->getViableChannel(ch,chanOff,curIns);
+    if ((!e->isPlaying() || !followPattern)) {
+      y-=editStep;
+      while (y<0) {
+        if (--ord<0) ord=0;
+        y+=e->curSubSong->patLen;
+      }
+    }
+  }
+
   if (e->isPlaying() && !e->isStepping() && followPattern) {
     e->getPlayPosTick(ord,y,tick,speed);
     if (tick<=(speed/2)) { // round
@@ -1380,12 +1391,12 @@ void FurnaceGUI::noteInput(int num, int key, int vol) {
     }
   }
 
-  logV("chan %d, %d:%d %d/%d",ch,ord,y,tick,speed);
+  logV("noteInput: chan %d, offset %d, %d:%d %d/%d",ch,chanOff,ord,y,tick,speed);
 
   DivPattern* pat=e->curPat[ch].getPattern(e->curOrders->ord[ch][ord],true);
   bool removeIns=false;
 
-  prepareUndo(GUI_UNDO_PATTERN_EDIT);
+  prepareUndo(GUI_UNDO_PATTERN_EDIT,UndoRegion(ord,ch,y,ord,ch,y));
 
   if (key==GUI_NOTE_OFF) { // note off
     pat->newData[y][DIV_PAT_NOTE]=DIV_NOTE_OFF;
@@ -1423,8 +1434,10 @@ void FurnaceGUI::noteInput(int num, int key, int vol) {
       pat->newData[y][DIV_PAT_VOL]=-1;
     }
   }
-  editAdvance();
-  makeUndo(GUI_UNDO_PATTERN_EDIT);
+  if ((!e->isPlaying() || !followPattern) && (chanOff<1 || !noteInputChord)) {
+    editAdvance();
+  }
+  makeUndo(GUI_UNDO_PATTERN_EDIT,UndoRegion(ord,ch,y,ord,ch,y));
   curNibble=false;
 }
 
@@ -1433,6 +1446,8 @@ void FurnaceGUI::valueInput(int num, bool direct, int target) {
   int ord=curOrder;
   int y=cursor.y;
 
+  logV("valueInput: chan %d, %d:%d",ch,ord,y);
+
   if (e->isPlaying() && !e->isStepping() && followPattern) {
     e->getPlayPos(ord,y);
   }
@@ -1543,7 +1558,6 @@ void FurnaceGUI::orderInput(int num) {
         }
       }
     }
-    e->walkSong(loopOrder,loopRow,loopEnd);
     makeUndo(GUI_UNDO_CHANGE_ORDER);
   }
 }
@@ -1742,8 +1756,9 @@ void FurnaceGUI::keyDown(SDL_Event& ev) {
               if (num>119) num=119; // B-9
 
               if (edit) {
-                noteInput(num,key);
+                noteInput(num,key,-1,chordInputOffset);
               }
+              chordInputOffset++;
             }
           } else if (edit) { // value
             auto it=valueKeys.find(ev.key.keysym.sym);
@@ -1839,7 +1854,10 @@ void FurnaceGUI::keyDown(SDL_Event& ev) {
 }
 
 void FurnaceGUI::keyUp(SDL_Event& ev) {
-  // nothing for now
+  // this is very, very lazy...
+  if (--chordInputOffset<0) {
+    chordInputOffset=0;
+  }
 }
 
 bool dirExists(String s) {
@@ -2316,6 +2334,17 @@ void FurnaceGUI::openFileDialog(FurnaceGUIFileDialogs type) {
         dpiScale
       );
       break;
+    case GUI_FILE_MUSIC_OPEN:
+      if (!dirExists(workingDirMusic)) workingDirMusic=getHomeDir();
+      hasOpened=fileDialog->openLoad(
+        _("Open Audio File"),
+        audioLoadFormats,
+        workingDirMusic,
+        dpiScale,
+        NULL,
+        false
+      );
+      break;
     case GUI_FILE_TEST_OPEN:
       if (!dirExists(workingDirTest)) workingDirTest=getHomeDir();
       hasOpened=fileDialog->openLoad(
@@ -2553,7 +2582,7 @@ int FurnaceGUI::load(String path) {
   }
   pushRecentFile(path);
   // walk song
-  e->walkSong(loopOrder,loopRow,loopEnd);
+  e->calcSongTimestamps();
   // do not auto-play a backup
   if (path.find(backupPath)!=0) {
     if (settings.playOnLoad==2 || (settings.playOnLoad==1 && wasPlaying)) {
@@ -2711,20 +2740,11 @@ int FurnaceGUI::loadStream(String path) {
 
 
 void FurnaceGUI::exportAudio(String path, DivAudioExportModes mode) {
-  songOrdersLengths.clear();
+  e->calcSongTimestamps();
+  DivSongTimestamps& ts=e->curSubSong->ts;
 
-  int loopOrder=0;
-  int loopRow=0;
-  int loopEnd=0;
-  e->walkSong(loopOrder,loopRow,loopEnd);
-
-  e->findSongLength(loopOrder,loopRow,audioExportOptions.fadeOut,songFadeoutSectionLength,songHasSongEndCommand,songOrdersLengths,songLength); // for progress estimation
-
-  songLoopedSectionLength=songLength;
-  for (int i=0; i<loopOrder && i<(int)songOrdersLengths.size(); i++) {
-    songLoopedSectionLength-=songOrdersLengths[i];
-  }
-  songLoopedSectionLength-=loopRow;
+  songLength=ts.totalTime.toDouble();
+  double loopLength=songLength-(ts.loopStartTime.seconds+(double)ts.loopStartTime.micros/1000000.0);
 
   e->saveAudio(path.c_str(),audioExportOptions);
 
@@ -2732,19 +2752,15 @@ void FurnaceGUI::exportAudio(String path, DivAudioExportModes mode) {
   e->getTotalAudioFiles(totalFiles);
   int totalLoops=0;
 
-  lengthOfOneFile=songLength;
-
-  if (!songHasSongEndCommand) {
+  if (ts.isLoopable) {
     e->getTotalLoops(totalLoops);
-
-    lengthOfOneFile+=songLoopedSectionLength*totalLoops;
-    lengthOfOneFile+=songFadeoutSectionLength; // account for fadeout
+    songLength+=loopLength*totalLoops;
+    songLength+=audioExportOptions.fadeOut;
   }
 
-  totalLength=lengthOfOneFile*totalFiles;
+  totalLength=songLength*totalFiles;
 
   curProgress=0.0f;
-
   displayExporting=true;
 }
 
@@ -3848,6 +3864,7 @@ bool FurnaceGUI::loop() {
   DECLARE_METRIC(log)
   DECLARE_METRIC(effectList)
   DECLARE_METRIC(userPresets)
+  DECLARE_METRIC(refPlayer)
   DECLARE_METRIC(popup)
 
 #ifdef IS_MOBILE
@@ -3869,6 +3886,7 @@ bool FurnaceGUI::loop() {
 
   while (!quit) {
     SDL_Event ev;
+    SelectionPoint prevCursor=cursor;
     if (e->isPlaying()) {
       WAKE_UP;
     }
@@ -4003,6 +4021,9 @@ bool FurnaceGUI::loop() {
           break;
         case SDL_KEYUP:
           // for now
+          if (!ImGui::GetIO().WantCaptureKeyboard || (newFilePicker->isOpened() && !ImGui::GetIO().WantTextInput)) {
+            keyUp(ev);
+          }
           insEditMayBeDirty=true;
           if (introPos<11.0 && introSkip<0.5 && !shortIntro) {
             introSkipDo=false;
@@ -4186,14 +4207,19 @@ bool FurnaceGUI::loop() {
         if (action!=0) {
           doAction(action);
         } else switch (msg.type&0xf0) {
+          case TA_MIDI_NOTE_OFF:
+            if (--chordInputOffset<0) chordInputOffset=0;
+            break;
           case TA_MIDI_NOTE_ON:
             if (midiMap.valueInputStyle==0 || midiMap.valueInputStyle>3 || cursor.xFine==0) {
               if (midiMap.noteInput && edit && msg.data[1]!=0) {
                 noteInput(
                   msg.data[0]-12,
                   0,
-                  midiMap.volInput?msg.data[1]:-1
+                  midiMap.volInput?msg.data[1]:-1,
+                  chordInputOffset
                 );
+                chordInputOffset++;
               }
             } else {
               if (edit && msg.data[1]!=0) {
@@ -4462,6 +4488,7 @@ bool FurnaceGUI::loop() {
         IMPORT_CLOSE(memoryOpen);
         IMPORT_CLOSE(csPlayerOpen);
         IMPORT_CLOSE(userPresetsOpen);
+        IMPORT_CLOSE(refPlayerOpen);
       } else if (pendingLayoutImportStep==1) {
         // let the UI settle
       } else if (pendingLayoutImportStep==2) {
@@ -4648,6 +4675,7 @@ bool FurnaceGUI::loop() {
                 showError(fmt::sprintf(_("cannot add chip! (%s)"),e->getLastError()));
               } else {
                 MARK_MODIFIED;
+                recalcTimestamps=true;
               }
               ImGui::CloseCurrentPopup();
               if (e->song.autoSystem) {
@@ -4677,6 +4705,7 @@ bool FurnaceGUI::loop() {
                 if (picked!=DIV_SYSTEM_NULL) {
                   if (e->changeSystem(i,picked,preserveChanPos)) {
                     MARK_MODIFIED;
+                    recalcTimestamps=true;
                     if (e->song.autoSystem) {
                       autoDetectSystem();
                     }
@@ -4701,6 +4730,7 @@ bool FurnaceGUI::loop() {
                   showError(fmt::sprintf(_("cannot remove chip! (%s)"),e->getLastError()));
                 } else {
                   MARK_MODIFIED;
+                  recalcTimestamps=true;
                 }
                 if (e->song.autoSystem) {
                   autoDetectSystem();
@@ -4832,6 +4862,7 @@ bool FurnaceGUI::loop() {
         if (ImGui::MenuItem(_("effect list"),BIND_FOR(GUI_ACTION_WINDOW_EFFECT_LIST),effectListOpen)) effectListOpen=!effectListOpen;
         if (ImGui::MenuItem(_("play/edit controls"),BIND_FOR(GUI_ACTION_WINDOW_EDIT_CONTROLS),editControlsOpen)) editControlsOpen=!editControlsOpen;
         if (ImGui::MenuItem(_("piano/input pad"),BIND_FOR(GUI_ACTION_WINDOW_PIANO),pianoOpen)) pianoOpen=!pianoOpen;
+        if (ImGui::MenuItem(_("reference music player"),BIND_FOR(GUI_ACTION_WINDOW_REF_PLAYER),refPlayerOpen)) refPlayerOpen=!refPlayerOpen;
         if (spoilerOpen) if (ImGui::MenuItem(_("spoiler"),NULL,spoilerOpen)) spoilerOpen=!spoilerOpen;
 
         ImGui::EndMenu();
@@ -4850,8 +4881,7 @@ bool FurnaceGUI::loop() {
       }
       ImGui::PushStyleColor(ImGuiCol_Text,uiColors[GUI_COLOR_PLAYBACK_STAT]);
       if (e->isPlaying() && settings.playbackTime) {
-        int totalTicks=e->getTotalTicks();
-        int totalSeconds=e->getTotalSeconds();
+        TimeMicros totalTime=e->getCurTime();
 
         String info;
 
@@ -4880,32 +4910,10 @@ bool FurnaceGUI::loop() {
 
         info+=_("| ");
 
-        if (totalSeconds==0x7fffffff) {
+        if (totalTime.seconds==0x7fffffff) {
           info+=_("Don't you have anything better to do?");
         } else {
-          if (totalSeconds>=86400) {
-            int totalDays=totalSeconds/86400;
-            int totalYears=totalDays/365;
-            totalDays%=365;
-            int totalMonths=totalDays/30;
-            totalDays%=30;
-
-#ifdef HAVE_LOCALE
-            info+=fmt::sprintf(ngettext("%d year ","%d years ",totalYears),totalYears);
-            info+=fmt::sprintf(ngettext("%d month ","%d months ",totalMonths),totalMonths);
-            info+=fmt::sprintf(ngettext("%d day ","%d days ",totalDays),totalDays);
-#else
-            info+=fmt::sprintf(_GN("%d year ","%d years ",totalYears),totalYears);
-            info+=fmt::sprintf(_GN("%d month ","%d months ",totalMonths),totalMonths);
-            info+=fmt::sprintf(_GN("%d day ","%d days ",totalDays),totalDays);
-#endif
-          }
-
-          if (totalSeconds>=3600) {
-            info+=fmt::sprintf("%.2d:",(totalSeconds/3600)%24);
-          }
-
-          info+=fmt::sprintf("%.2d:%.2d.%.2d",(totalSeconds/60)%60,totalSeconds%60,totalTicks/10000);
+          info+=totalTime.toString(2,TA_TIME_FORMAT_AUTO_MS_ZERO);
         }
 
         ImGui::TextUnformatted(info.c_str());
@@ -5054,6 +5062,7 @@ bool FurnaceGUI::loop() {
       MEASURE(memory,drawMemory());
       MEASURE(effectList,drawEffectList());
       MEASURE(userPresets,drawUserPresets());
+      MEASURE(refPlayer,drawRefPlayer());
       MEASURE(patManager,drawPatManager());
 
     } else {
@@ -5101,6 +5110,7 @@ bool FurnaceGUI::loop() {
       MEASURE(log,drawLog());
       MEASURE(effectList,drawEffectList());
       MEASURE(userPresets,drawUserPresets());
+      MEASURE(refPlayer,drawRefPlayer());
 
     }
 
@@ -5252,6 +5262,9 @@ bool FurnaceGUI::loop() {
         case GUI_FILE_CMDSTREAM_OPEN:
           workingDirROM=fileDialog->getPath()+DIR_SEPARATOR_STR;
           break;
+        case GUI_FILE_MUSIC_OPEN:
+          workingDirMusic=fileDialog->getPath()+DIR_SEPARATOR_STR;
+          break;
         case GUI_FILE_TEST_OPEN:
         case GUI_FILE_TEST_OPEN_MULTI:
         case GUI_FILE_TEST_SAVE:
@@ -5890,6 +5903,17 @@ bool FurnaceGUI::loop() {
                 showError(fmt::sprintf(_("Error while loading file! (%s)"),lastError));
               }
               break;
+            case GUI_FILE_MUSIC_OPEN:
+              e->synchronizedSoft([this,copyOfName]() {
+                bool wasPlaying=e->getFilePlayer()->isPlaying();
+                if (!e->getFilePlayer()->loadFile(copyOfName.c_str())) {
+                  showError(fmt::sprintf(_("Error while loading file!")));
+                } else if (wasPlaying && filePlayerSync && refPlayerOpen && e->isPlaying()) {
+                  e->syncFilePlayer();
+                  e->getFilePlayer()->play();
+                }
+              });
+              break;
             case GUI_FILE_TEST_OPEN:
               showWarning(fmt::sprintf(_("You opened: %s"),copyOfName),GUI_WARN_GENERIC);
               break;
@@ -6025,46 +6049,21 @@ bool FurnaceGUI::loop() {
       if (audioExportOptions.mode!=DIV_EXPORT_MODE_MANY_CHAN) {
         ImGui::Text(_("Please wait..."));
       }
-      float* progressLambda=&curProgress;
-      int curPosInRows=0;
-      int* curPosInRowsLambda=&curPosInRows;
-      int loopsLeft=0;
-      int* loopsLeftLambda=&loopsLeft;
-      int totalLoops=0;
-      int* totalLoopsLambda=&totalLoops;
       int curFile=0;
       int* curFileLambda=&curFile;
       if (e->isExporting()) {
         e->lockEngine(
-          [this, progressLambda, curPosInRowsLambda, curFileLambda, loopsLeftLambda, totalLoopsLambda] () {
-            int curRow=0; int curOrder=0;
-            e->getCurSongPos(curRow, curOrder);
+          [this, curFileLambda] () {
             *curFileLambda=0;
             e->getCurFileIndex(*curFileLambda);
-            *curPosInRowsLambda=curRow;
-            for (int i=0; i<MIN(curOrder,(int)songOrdersLengths.size()); i++) *curPosInRowsLambda+=songOrdersLengths[i];
-            if (!songHasSongEndCommand) {
-              e->getLoopsLeft(*loopsLeftLambda);
-              e->getTotalLoops(*totalLoopsLambda);
-              if ((*totalLoopsLambda)!=(*loopsLeftLambda)) { // we are going 2nd, 3rd, etc. time through the song
-                *curPosInRowsLambda-=(songLength-songLoopedSectionLength); // a hack so progress bar does not jump?
-              }
-              if (e->getIsFadingOut()) { // we are in fadeout??? why it works like that bruh
-                // LIVE WITH IT damn it
-                *curPosInRowsLambda-=(songLength-songLoopedSectionLength); // a hack so progress bar does not jump?
-              }
-            }
-            if (totalLength<0.1) {
-              // DON'T
-              *progressLambda=0;
-            } else {
-              *progressLambda=(float)((*curPosInRowsLambda)+((*totalLoopsLambda)-(*loopsLeftLambda))*songLength+lengthOfOneFile*(*curFileLambda))/(float)totalLength;
-            }
+            curProgress=(e->getCurTime().toDouble()+(songLength*(*curFileLambda)))/totalLength;
           }
         );
       }
 
-      ImGui::Text(_("Row %d of %d"),curPosInRows+((totalLoops)-(loopsLeft))*songLength,lengthOfOneFile);
+      if (curProgress<0.0f) curProgress=0.0f;
+      if (curProgress>1.0f) curProgress=1.0f;
+
       if (audioExportOptions.mode==DIV_EXPORT_MODE_MANY_CHAN) ImGui::Text(_("Channel %d of %d"),curFile+1,totalFiles);
 
       ImGui::ProgressBar(curProgress,ImVec2(320.0f*dpiScale,0),fmt::sprintf("%.2f%%",curProgress*100.0f).c_str());
@@ -6515,6 +6514,7 @@ bool FurnaceGUI::loop() {
               selStart.order=0;
               selEnd.order=0;
               MARK_MODIFIED;
+              recalcTimestamps=true;
               ImGui::CloseCurrentPopup();
             }
             if (ImGui::Button(_("Current subsong"))) {
@@ -6528,6 +6528,7 @@ bool FurnaceGUI::loop() {
               selStart.order=0;
               selEnd.order=0;
               MARK_MODIFIED;
+              recalcTimestamps=true;
               ImGui::CloseCurrentPopup();
             }
             if (ImGui::Button(_("Orders"))) {
@@ -6542,6 +6543,7 @@ bool FurnaceGUI::loop() {
               selStart.order=0;
               selEnd.order=0;
               MARK_MODIFIED;
+              recalcTimestamps=true;
               ImGui::CloseCurrentPopup();
             }
             if (ImGui::Button(_("Pattern"))) {
@@ -6553,6 +6555,7 @@ bool FurnaceGUI::loop() {
                 }
               });
               MARK_MODIFIED;
+              recalcTimestamps=true;
               ImGui::CloseCurrentPopup();
             }
             if (ImGui::Button(_("Instruments"))) {
@@ -6596,6 +6599,7 @@ bool FurnaceGUI::loop() {
                 e->curSubSong->rearrangePatterns();
               });
               MARK_MODIFIED;
+              recalcTimestamps=true;
               ImGui::CloseCurrentPopup();
             }
             if (ImGui::Button(_("Remove unused patterns"))) {
@@ -6604,6 +6608,7 @@ bool FurnaceGUI::loop() {
                 e->curSubSong->removeUnusedPatterns();
               });
               MARK_MODIFIED;
+              recalcTimestamps=true;
               ImGui::CloseCurrentPopup();
             }
             if (ImGui::Button(_("Remove unused instruments"))) {
@@ -6657,6 +6662,7 @@ bool FurnaceGUI::loop() {
               selStart=cursor;
               selEnd=cursor;
               curOrder=0;
+              recalcTimestamps=true;
               MARK_MODIFIED;
             }
             ImGui::CloseCurrentPopup();
@@ -6675,6 +6681,7 @@ bool FurnaceGUI::loop() {
               MARK_MODIFIED;
             }
             updateROMExportAvail();
+            recalcTimestamps=true;
             ImGui::CloseCurrentPopup();
           }
           ImGui::SameLine();
@@ -7387,6 +7394,26 @@ bool FurnaceGUI::loop() {
       }
     }
 
+    if (recalcTimestamps) {
+      logV("need to recalc timestamps...");
+      e->calcSongTimestamps();
+      recalcTimestamps=false;
+    }
+
+    if (!e->isPlaying() && e->getFilePlayerSync()) {
+      if (cursor.y!=prevCursor.y || cursor.order!=prevCursor.order) {
+        DivFilePlayer* fp=e->getFilePlayer();
+        logV("cursor moved to %d:%d",cursor.order,cursor.y);
+        if (!fp->isPlaying()) {
+          TimeMicros rowTS=e->curSubSong->ts.getTimes(cursor.order,cursor.y);
+          if (rowTS.seconds!=-1) {
+            TimeMicros cueTime=e->getFilePlayerCue();
+            fp->setPosSeconds(cueTime+rowTS);
+          }
+        }
+      }
+    }
+
     sampleMapWaitingInput=(curWindow==GUI_WINDOW_INS_EDIT && sampleMapFocused);
     
     curWindowThreadSafe=curWindow;
@@ -7436,6 +7463,9 @@ bool FurnaceGUI::loop() {
             break;
         }
       }
+
+      // reset chord count just in case
+      chordInputOffset=0;
     }
 
     if (!settings.renderClearPos || renderBackend==GUI_BACKEND_METAL) {
@@ -8183,11 +8213,13 @@ void FurnaceGUI::syncState() {
   workingDirAudioExport=e->getConfString("lastDirAudioExport",workingDir);
   workingDirVGMExport=e->getConfString("lastDirVGMExport",workingDir);
   workingDirROMExport=e->getConfString("lastDirROMExport",workingDir);
+  workingDirROM=e->getConfString("lastDirROM",workingDir);
   workingDirFont=e->getConfString("lastDirFont",workingDir);
   workingDirColors=e->getConfString("lastDirColors",workingDir);
   workingDirKeybinds=e->getConfString("lastDirKeybinds",workingDir);
   workingDirLayout=e->getConfString("lastDirLayout",workingDir);
   workingDirConfig=e->getConfString("lastDirConfig",workingDir);
+  workingDirMusic=e->getConfString("lastDirMusic",workingDir);
   workingDirTest=e->getConfString("lastDirTest",workingDir);
 
   editControlsOpen=e->getConfBool("editControlsOpen",true);
@@ -8231,6 +8263,7 @@ void FurnaceGUI::syncState() {
   findOpen=e->getConfBool("findOpen",false);
   spoilerOpen=e->getConfBool("spoilerOpen",false);
   userPresetsOpen=e->getConfBool("userPresetsOpen",false);
+  refPlayerOpen=e->getConfBool("refPlayerOpen",false);
 
   insListDir=e->getConfBool("insListDir",false);
   waveListDir=e->getConfBool("waveListDir",false);
@@ -8266,6 +8299,8 @@ void FurnaceGUI::syncState() {
   followOrders=e->getConfBool("followOrders",true);
   followPattern=e->getConfBool("followPattern",true);
   noteInputPoly=e->getConfBool("noteInputPoly",true);
+  noteInputChord=e->getConfBool("noteInputChord",false);
+  filePlayerSync=e->getConfBool("filePlayerSync",true);
   audioExportOptions.loops=e->getConfInt("exportLoops",0);
   if (audioExportOptions.loops<0) audioExportOptions.loops=0;
   audioExportOptions.fadeOut=e->getConfDouble("exportFadeOut",0.0);
@@ -8354,11 +8389,13 @@ void FurnaceGUI::commitState(DivConfig& conf) {
   conf.set("lastDirAudioExport",workingDirAudioExport);
   conf.set("lastDirVGMExport",workingDirVGMExport);
   conf.set("lastDirROMExport",workingDirROMExport);
+  conf.set("lastDirROM",workingDirROM);
   conf.set("lastDirFont",workingDirFont);
   conf.set("lastDirColors",workingDirColors);
   conf.set("lastDirKeybinds",workingDirKeybinds);
   conf.set("lastDirLayout",workingDirLayout);
   conf.set("lastDirConfig",workingDirConfig);
+  conf.set("lastDirMusic",workingDirMusic);
   conf.set("lastDirTest",workingDirTest);
 
   // commit last open windows
@@ -8399,6 +8436,7 @@ void FurnaceGUI::commitState(DivConfig& conf) {
   conf.set("findOpen",findOpen);
   conf.set("spoilerOpen",spoilerOpen);
   conf.set("userPresetsOpen",userPresetsOpen);
+  conf.set("refPlayerOpen",refPlayerOpen);
 
   // commit dir state
   conf.set("insListDir",insListDir);
@@ -8430,6 +8468,8 @@ void FurnaceGUI::commitState(DivConfig& conf) {
   conf.set("followPattern",followPattern);
   conf.set("orderEditMode",orderEditMode);
   conf.set("noteInputPoly",noteInputPoly);
+  conf.set("noteInputChord",noteInputChord);
+  conf.set("filePlayerSync",filePlayerSync);
   if (settings.persistFadeOut) {
     conf.set("exportLoops",audioExportOptions.loops);
     conf.set("exportFadeOut",audioExportOptions.fadeOut);
@@ -8630,8 +8670,10 @@ FurnaceGUI::FurnaceGUI():
   sysDupCloneChannels(true),
   sysDupEnd(false),
   noteInputPoly(true),
+  noteInputChord(false),
   notifyWaveChange(false),
   notifySampleChange(false),
+  recalcTimestamps(true),
   wantScrollListIns(false),
   wantScrollListWave(false),
   wantScrollListSample(false),
@@ -8653,15 +8695,18 @@ FurnaceGUI::FurnaceGUI():
   safeMode(false),
   midiWakeUp(true),
   makeDrumkitMode(false),
+  filePlayerSync(true),
   audioEngineChanged(false),
   settingsChanged(false),
   debugFFT(false),
+  debugRowTimestamps(false),
   vgmExportVersion(0x171),
   vgmExportTrailingTicks(-1),
   vgmExportCorrectedRate(44100),
   drawHalt(10),
   macroPointSize(16),
   waveEditStyle(0),
+  chordInputOffset(0),
   displayInsTypeListMakeInsSample(-1),
   makeDrumkitOctave(3),
   mobileEditPage(0),
@@ -8726,12 +8771,8 @@ FurnaceGUI::FurnaceGUI():
   patFont(NULL),
   bigFont(NULL),
   headFont(NULL),
-  songLength(0),
-  songLoopedSectionLength(0),
-  songFadeoutSectionLength(0),
-  songHasSongEndCommand(false),
-  lengthOfOneFile(0),
-  totalLength(0),
+  songLength(0.0),
+  totalLength(0.0),
   curProgress(0.0f),
   totalFiles(0),
   localeRequiresJapanese(false),
@@ -8757,9 +8798,6 @@ FurnaceGUI::FurnaceGUI():
   soloChan(-1),
   orderEditMode(0),
   orderCursor(-1),
-  loopOrder(-1),
-  loopRow(-1),
-  loopEnd(-1),
   isClipping(0),
   newSongCategory(0),
   latchTarget(0),
@@ -8830,6 +8868,7 @@ FurnaceGUI::FurnaceGUI():
   csPlayerOpen(false),
   cvOpen(false),
   userPresetsOpen(false),
+  refPlayerOpen(false),
   cvNotSerious(false),
   shortIntro(false),
   insListDir(false),
@@ -9031,6 +9070,7 @@ FurnaceGUI::FurnaceGUI():
   resampleTarget(32000),
   resampleStrat(5),
   amplifyVol(100.0),
+  amplifyOff(0.0),
   sampleSelStart(-1),
   sampleSelEnd(-1),
   sampleInfo(true),
@@ -9115,6 +9155,9 @@ FurnaceGUI::FurnaceGUI():
   xyOscIntensity(2.0f),
   xyOscThickness(2.0f),
   tunerPlan(NULL),
+  fpCueInput(""),
+  fpCueInputFailed(false),
+  fpCueInputFailReason(""),
   followLog(true),
 #ifdef IS_MOBILE
   pianoOctaves(7),
@@ -9294,8 +9337,6 @@ FurnaceGUI::FurnaceGUI():
 
   memset(romExportAvail,0,sizeof(bool)*DIV_ROM_MAX);
 
-  songOrdersLengths.clear();
-
   strncpy(noteOffLabel,"OFF",32);
   strncpy(noteRelLabel,"===",32);
   strncpy(macroRelLabel,"REL",32);
diff --git a/src/gui/gui.h b/src/gui/gui.h
index 2b3839574..b2d85e7f1 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -573,6 +573,7 @@ enum FurnaceGUIWindows {
   GUI_WINDOW_MEMORY,
   GUI_WINDOW_CS_PLAYER,
   GUI_WINDOW_USER_PRESETS,
+  GUI_WINDOW_REF_PLAYER,
   GUI_WINDOW_SPOILER
 };
 
@@ -653,6 +654,7 @@ enum FurnaceGUIFileDialogs {
   GUI_FILE_TG100_ROM_OPEN,
   GUI_FILE_MU5_ROM_OPEN,
   GUI_FILE_CMDSTREAM_OPEN,
+  GUI_FILE_MUSIC_OPEN,
 
   GUI_FILE_TEST_OPEN,
   GUI_FILE_TEST_OPEN_MULTI,
@@ -779,6 +781,7 @@ enum FurnaceGUIActions {
   GUI_ACTION_WINDOW_MEMORY,
   GUI_ACTION_WINDOW_CS_PLAYER,
   GUI_ACTION_WINDOW_USER_PRESETS,
+  GUI_ACTION_WINDOW_REF_PLAYER,
 
   GUI_ACTION_COLLAPSE_WINDOW,
   GUI_ACTION_CLOSE_WINDOW,
@@ -1696,7 +1699,7 @@ class FurnaceGUI {
   String workingDirSong, workingDirIns, workingDirWave, workingDirSample, workingDirAudioExport;
   String workingDirVGMExport, workingDirROMExport;
   String workingDirFont, workingDirColors, workingDirKeybinds;
-  String workingDirLayout, workingDirROM, workingDirTest;
+  String workingDirLayout, workingDirROM, workingDirMusic, workingDirTest;
   String workingDirConfig;
   String mmlString[32];
   String mmlStringW, grooveString, grooveListString, mmlStringModTable;
@@ -1718,7 +1721,9 @@ class FurnaceGUI {
   bool vgmExportDirectStream, displayInsTypeList, displayWaveSizeList;
   bool portrait, injectBackUp, mobileMenuOpen, warnColorPushed;
   bool wantCaptureKeyboard, oldWantCaptureKeyboard, displayMacroMenu;
-  bool displayNew, displayExport, displayPalette, fullScreen, preserveChanPos, sysDupCloneChannels, sysDupEnd, noteInputPoly, notifyWaveChange, notifySampleChange;
+  bool displayNew, displayExport, displayPalette, fullScreen, preserveChanPos, sysDupCloneChannels, sysDupEnd, noteInputPoly, noteInputChord;
+  bool notifyWaveChange, notifySampleChange;
+  bool recalcTimestamps;
   bool wantScrollListIns, wantScrollListWave, wantScrollListSample;
   bool displayPendingIns, pendingInsSingle, displayPendingRawSample, snesFilterHex, modTableHex, displayEditString;
   bool displayPendingSamples, replacePendingSample;
@@ -1731,7 +1736,8 @@ class FurnaceGUI {
   bool safeMode;
   bool midiWakeUp;
   bool makeDrumkitMode;
-  bool audioEngineChanged, settingsChanged, debugFFT;
+  bool filePlayerSync;
+  bool audioEngineChanged, settingsChanged, debugFFT, debugRowTimestamps;
   bool willExport[DIV_MAX_CHIPS];
   int vgmExportVersion;
   int vgmExportTrailingTicks;
@@ -1740,6 +1746,7 @@ class FurnaceGUI {
   int drawHalt;
   int macroPointSize;
   int waveEditStyle;
+  int chordInputOffset;
   int displayInsTypeListMakeInsSample;
   int makeDrumkitOctave;
   int mobileEditPage;
@@ -1826,13 +1833,8 @@ class FurnaceGUI {
   char emptyLabel[32];
   char emptyLabel2[32];
 
-  std::vector<int> songOrdersLengths; // lengths of all orders (for drawing song export progress)
-  int songLength; // length of all the song in rows
-  int songLoopedSectionLength; // length of looped part of the song
-  int songFadeoutSectionLength; // length of fading part of the song
-  bool songHasSongEndCommand; // song has "Song end" command (FFxx)
-  int lengthOfOneFile; // length of one rendering pass. song length times num of loops + fadeout
-  int totalLength; // total length of render (lengthOfOneFile times num of files for per-channel export)
+  double songLength; // length of the song in seconds
+  double totalLength; // total length of render (songLength times num of files for per-channel export)
   float curProgress;
   int totalFiles;
 
@@ -2385,7 +2387,7 @@ class FurnaceGUI {
   FixedQueue<bool*,64> pendingLayoutImportReopen;
 
   int curIns, curWave, curSample, curOctave, curOrder, playOrder, prevIns, oldRow, editStep, editStepCoarse, soloChan, orderEditMode, orderCursor;
-  int loopOrder, loopRow, loopEnd, isClipping, newSongCategory, latchTarget, undoOrder;
+  int isClipping, newSongCategory, latchTarget, undoOrder;
   int wheelX, wheelY, dragSourceX, dragSourceXFine, dragSourceY, dragSourceOrder, dragDestinationX, dragDestinationXFine, dragDestinationY, dragDestinationOrder, oldBeat, oldBar;
   int curGroove, exitDisabledTimer;
   int curPaletteChoice, curPaletteType;
@@ -2402,7 +2404,7 @@ class FurnaceGUI {
   bool mixerOpen, debugOpen, inspectorOpen, oscOpen, volMeterOpen, statsOpen, compatFlagsOpen;
   bool pianoOpen, notesOpen, tunerOpen, spectrumOpen, channelsOpen, regViewOpen, logOpen, effectListOpen, chanOscOpen;
   bool subSongsOpen, findOpen, spoilerOpen, patManagerOpen, sysManagerOpen, clockOpen, speedOpen;
-  bool groovesOpen, xyOscOpen, memoryOpen, csPlayerOpen, cvOpen, userPresetsOpen;
+  bool groovesOpen, xyOscOpen, memoryOpen, csPlayerOpen, cvOpen, userPresetsOpen, refPlayerOpen;
 
   bool cvNotSerious;
 
@@ -2631,7 +2633,7 @@ class FurnaceGUI {
   int resizeSize, silenceSize;
   double resampleTarget;
   int resampleStrat;
-  float amplifyVol;
+  float amplifyVol, amplifyOff;
   int sampleSelStart, sampleSelEnd;
   bool sampleInfo, sampleCompatRate;
   bool sampleDragActive, sampleDragMode, sampleDrag16, sampleZoomAuto;
@@ -2776,6 +2778,11 @@ class FurnaceGUI {
   float keyHit1[DIV_MAX_CHANS];
   int lastIns[DIV_MAX_CHANS];
 
+  // file player temp variables
+  String fpCueInput;
+  bool fpCueInputFailed;
+  String fpCueInputFailReason;
+
   // log window
   bool followLog;
 
@@ -3036,6 +3043,7 @@ class FurnaceGUI {
   void drawTutorial();
   void drawXYOsc();
   void drawUserPresets();
+  void drawRefPlayer();
 
   float drawSystemChannelInfo(const DivSysDef* whichDef, int keyHitOffset=-1, float width=-1.0f);
   void drawSystemChannelInfoText(const DivSysDef* whichDef);
@@ -3118,7 +3126,7 @@ class FurnaceGUI {
   void doDrag(bool copy=false);
   void editOptions(bool topMenu);
   DivSystem systemPicker(bool fullWidth);
-  void noteInput(int num, int key, int vol=-1);
+  void noteInput(int num, int key, int vol=-1, int chanOff=0);
   void valueInput(int num, bool direct=false, int target=-1);
   void orderInput(int num);
 
diff --git a/src/gui/guiConst.cpp b/src/gui/guiConst.cpp
index 8de7769a0..4ab37c8af 100644
--- a/src/gui/guiConst.cpp
+++ b/src/gui/guiConst.cpp
@@ -674,6 +674,7 @@ const FurnaceGUIActionDef guiActions[GUI_ACTION_MAX]={
   D("WINDOW_MEMORY", _N("Memory Composition"), 0),
   D("WINDOW_CS_PLAYER", _N("Command Stream Player"), 0),
   D("WINDOW_USER_PRESETS", _N("User Presets"), 0),
+  D("WINDOW_REF_PLAYER", _N("Reference Music Player"), 0),
 
   D("COLLAPSE_WINDOW", _N("Collapse/expand current window"), 0),
   D("CLOSE_WINDOW", _N("Close current window"), FURKMOD_SHIFT|SDLK_ESCAPE),
diff --git a/src/gui/mixer.cpp b/src/gui/mixer.cpp
index 3bb33a567..ba029cbd7 100644
--- a/src/gui/mixer.cpp
+++ b/src/gui/mixer.cpp
@@ -362,8 +362,21 @@ void FurnaceGUI::drawMixer() {
             }
           }
 
-          // metronome/sample preview
+          // file player/metronome/sample preview
           if (displayInternalPorts) {
+            if (portSet(_("Music Player"),0xffc,0,16,0,16,selectedSubPort,portPos)) {
+              selectedPortSet=0xffc;
+              if (selectedSubPort>=0) {
+                portDragActive=true;
+                ImGui::InhibitInertialScroll();
+                auto subPortI=portPos.find((selectedPortSet<<4)|selectedSubPort);
+                if (subPortI!=portPos.cend()) {
+                  subPortPos=subPortI->second;
+                } else {
+                  portDragActive=false;
+                }
+              }
+            }
             if (portSet(_("Sample Preview"),0xffd,0,1,0,1,selectedSubPort,portPos)) {
               selectedPortSet=0xffd;
               if (selectedSubPort>=0) {
diff --git a/src/gui/newSong.cpp b/src/gui/newSong.cpp
index bb92c81d1..b7c582c0c 100644
--- a/src/gui/newSong.cpp
+++ b/src/gui/newSong.cpp
@@ -290,6 +290,7 @@ void FurnaceGUI::drawNewSong() {
     samplePos=0;
     updateSampleTex=true;
     notifySampleChange=true;
+    e->calcSongTimestamps();
     selStart=SelectionPoint();
     selEnd=SelectionPoint();
     cursor=SelectionPoint();
diff --git a/src/gui/orders.cpp b/src/gui/orders.cpp
index ed4a823d9..2f85a69b0 100644
--- a/src/gui/orders.cpp
+++ b/src/gui/orders.cpp
@@ -90,30 +90,11 @@ void FurnaceGUI::drawMobileOrderSel() {
 
     // time
     if (e->isPlaying() && settings.playbackTime) {
-      int totalTicks=e->getTotalTicks();
-      int totalSeconds=e->getTotalSeconds();
-      String info="";
+      TimeMicros totalTime=e->getCurTime();
+      String info=totalTime.toString(2,TA_TIME_FORMAT_AUTO_MS_ZERO);
 
-      if (totalSeconds==0x7fffffff) {
+      if (totalTime.seconds==0x7fffffff) {
         info="∞";
-      } else {
-        if (totalSeconds>=86400) {
-          int totalDays=totalSeconds/86400;
-          int totalYears=totalDays/365;
-          totalDays%=365;
-          int totalMonths=totalDays/30;
-          totalDays%=30;
-
-          info+=fmt::sprintf("%dy",totalYears);
-          info+=fmt::sprintf("%dm",totalMonths);
-          info+=fmt::sprintf("%dd",totalDays);
-        }
-
-        if (totalSeconds>=3600) {
-          info+=fmt::sprintf("%.2d:",(totalSeconds/3600)%24);
-        }
-
-        info+=fmt::sprintf("%.2d:%.2d.%.2d",(totalSeconds/60)%60,totalSeconds%60,totalTicks/10000);
       }
 
       ImVec2 textSize=ImGui::CalcTextSize(info.c_str());
@@ -344,7 +325,7 @@ void FurnaceGUI::drawOrders() {
             ImGui::PopClipRect();
           }
           ImGui::PushStyleColor(ImGuiCol_Text,uiColors[GUI_COLOR_ORDER_ROW_INDEX]);
-          bool highlightLoop=(i>=loopOrder && i<=loopEnd);
+          bool highlightLoop=(i>=e->curSubSong->ts.loopStart.order && i<=e->curSubSong->ts.loopEnd.order && e->curSubSong->ts.isLoopDefined);
           if (highlightLoop) ImGui::TableSetBgColor(ImGuiTableBgTarget_CellBg,ImGui::GetColorU32(uiColors[GUI_COLOR_SONG_LOOP]));
           if (settings.orderRowsBase==1) {
             snprintf(selID,4096,"%.2X##O_S%.2x",i,i);
@@ -392,7 +373,6 @@ void FurnaceGUI::drawOrders() {
                       if (e->curOrders->ord[j][i]<(unsigned char)(DIV_MAX_PATTERNS-1)) e->curOrders->ord[j][i]++;
                     }
                   });
-                  e->walkSong(loopOrder,loopRow,loopEnd);
                   makeUndo(GUI_UNDO_CHANGE_ORDER);
                 } else {
                   orderCursor=j;
@@ -400,7 +380,6 @@ void FurnaceGUI::drawOrders() {
                 }
               } else {
                 setOrder(i);
-                e->walkSong(loopOrder,loopRow,loopEnd);
                 if (orderEditMode!=0) {
                   orderCursor=j;
                   curNibble=false;
@@ -441,7 +420,6 @@ void FurnaceGUI::drawOrders() {
                       if (e->curOrders->ord[j][i]>0) e->curOrders->ord[j][i]--;
                     }
                   });
-                  e->walkSong(loopOrder,loopRow,loopEnd);
                   makeUndo(GUI_UNDO_CHANGE_ORDER);
                 } else {
                   orderCursor=j;
@@ -449,7 +427,6 @@ void FurnaceGUI::drawOrders() {
                 }
               } else {
                 setOrder(i);
-                e->walkSong(loopOrder,loopRow,loopEnd);
                 if (orderEditMode!=0) {
                   orderCursor=j;
                   curNibble=false;
diff --git a/src/gui/pattern.cpp b/src/gui/pattern.cpp
index 94564817d..46f799c27 100644
--- a/src/gui/pattern.cpp
+++ b/src/gui/pattern.cpp
@@ -406,6 +406,16 @@ inline void FurnaceGUI::patternRow(int i, bool isPlaying, float lineHeight, int
   for (int k=mustSetXOf; k<=chans; k++)  {
     patChanX[k]=ImGui::GetCursorScreenPos().x;
   }
+
+  if (debugRowTimestamps) {
+    TimeMicros rowTS=e->curSubSong->ts.getTimes(ord,i);
+    if (rowTS.seconds==-1) {
+      ImGui::Text("---");
+    } else {
+      String timeFormatted=rowTS.toString(2,TA_TIME_FORMAT_AUTO_MS_ZERO);
+      ImGui::TextUnformatted(timeFormatted.c_str());
+    }
+  }
 }
 
 void FurnaceGUI::drawPattern() {
diff --git a/src/gui/refPlayer.cpp b/src/gui/refPlayer.cpp
new file mode 100644
index 000000000..f7f46cd2c
--- /dev/null
+++ b/src/gui/refPlayer.cpp
@@ -0,0 +1,243 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2025 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "gui.h"
+#include <fmt/printf.h>
+#include "imgui.h"
+#include "IconsFontAwesome4.h"
+#include "misc/cpp/imgui_stdlib.h"
+
+void FurnaceGUI::drawRefPlayer() {
+  DivFilePlayer* fp=e->getFilePlayer();
+  if (nextWindow==GUI_WINDOW_REF_PLAYER) {
+    refPlayerOpen=true;
+    ImGui::SetNextWindowFocus();
+    nextWindow=GUI_WINDOW_NOTHING;
+  }
+  fp->setActive(refPlayerOpen);
+  if (!refPlayerOpen) return;
+
+  if (ImGui::Begin("Music Player",&refPlayerOpen,globalWinFlags,_("Music Player"))) {
+    bool playPosNegative=false;
+    ssize_t playPos=fp->getPos();
+    if (playPos<0) {
+      playPos=-playPos;
+      playPosNegative=true;
+    }
+    size_t minPos=0;
+    size_t maxPos=fp->getFileInfo().frames;
+    int fileRate=fp->getFileInfo().samplerate;
+    if (fileRate<1) fileRate=1;
+    int posHours=(playPos/fileRate)/3600;
+    int posMinutes=((playPos/fileRate)/60)%60;
+    int posSeconds=(playPos/fileRate)%60;
+    int posMillis=(1000*(playPos%fileRate))/fileRate;
+    if (fp->isLoaded()) {
+      if (playPosNegative) {
+        ImGui::Text("-%d:%02d:%02d.%03d",posHours,posMinutes,posSeconds,posMillis);
+      } else {
+        ImGui::Text("%d:%02d:%02d.%03d",posHours,posMinutes,posSeconds,posMillis);
+      }
+    } else {
+      ImGui::TextUnformatted(_("no file loaded"));
+    }
+
+    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+    if (ImGui::SliderScalar("##Position",ImGuiDataType_U64,&playPos,&minPos,&maxPos,"")) {
+      fp->setPos(playPos);
+    }
+
+    if (ImGui::Button(ICON_FA_FOLDER_OPEN "##Open")) {
+      openFileDialog(GUI_FILE_MUSIC_OPEN);
+    }
+    if (ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
+      e->synchronizedSoft([this,fp]() {
+        if (!fp->closeFile()) {
+          showError(_("you haven't loaded a file!"));
+        }
+      });
+    }
+    ImGui::SetItemTooltip(_("open file\n(right click to unload current file)"));
+    ImGui::SameLine();
+    if (ImGui::Button(ICON_FA_STEP_BACKWARD)) {
+      // handled outside
+    }
+    if (fp->isPlaying()) {
+      if (ImGui::IsItemClicked(ImGuiMouseButton_Left)) {
+        fp->stop();
+        fp->setPosSeconds(e->getFilePlayerCue());
+      }
+      if (ImGui::IsItemClicked(ImGuiMouseButton_Middle)) {
+        fp->stop();
+        fp->setPos(0);
+      }
+      if (ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
+        fp->setPosSeconds(e->getFilePlayerCue());
+      }
+      ImGui::SetItemTooltip(
+        _("left click: go to cue position\n"
+        "middle click: go to beginning\n"
+        "right click: go to cue position (but don't stop)")
+      );
+    } else {
+      if (ImGui::IsItemClicked(ImGuiMouseButton_Left)) {
+        // try setting cue pos
+        TimeMicros curPos=fp->getPosSeconds();
+        TimeMicros rowTS=e->curSubSong->ts.getTimes(curOrder,0);
+        if (rowTS.seconds==-1) {
+          showError(_("the first row of this order isn't going to play."));
+        } else {
+          e->setFilePlayerCue(curPos-rowTS);
+        }
+      }
+      if (ImGui::IsItemClicked(ImGuiMouseButton_Middle)) {
+        fp->setPos(0);
+      }
+      if (ImGui::BeginPopupContextItem("Edit Cue Position",ImGuiPopupFlags_MouseButtonRight)) {
+        ImGui::TextUnformatted(_("Set cue position at first order:"));
+        TimeMicros cueTime=e->getFilePlayerCue();
+        bool altered=false;
+        fpCueInput=cueTime.toString(-1,TA_TIME_FORMAT_AUTO);
+        pushWarningColor(false,fpCueInputFailed);
+        if (ImGui::InputText("##CuePos",&fpCueInput)) {
+          try {
+            cueTime=TimeMicros::fromString(fpCueInput);
+            altered=true;
+            fpCueInputFailed=false;
+          } catch (std::invalid_argument& e) {
+            fpCueInputFailed=true;
+            fpCueInputFailReason=e.what();
+          }
+        }
+        if (!ImGui::IsItemActive()) {
+          fpCueInputFailed=false;
+        }
+        if (ImGui::IsItemHovered() && fpCueInputFailed) {
+          ImGui::SetTooltip("%s",fpCueInputFailReason.c_str());
+        }
+        popWarningColor();
+        if (altered) {
+          e->setFilePlayerCue(cueTime);
+        }
+        if (ImGui::Button(_("OK"))) {
+          ImGui::CloseCurrentPopup();
+        }
+        ImGui::EndPopup();
+      }
+      ImGui::SetItemTooltip(
+        _("left click: set cue position here\n"
+        " - current playback time becomes position at first row of current order\n"
+        "middle click: go to beginning\n"
+        "right click: fine edit cue position")
+      );
+    }
+    ImGui::SameLine();
+    if (fp->isPlaying()) {
+      pushToggleColors(true);
+      if (ImGui::Button(ICON_FA_PAUSE "##Pause")) {
+        fp->stop();
+      }
+      if (ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
+        // try setting cue pos
+        TimeMicros curPos=fp->getPosSeconds();
+        TimeMicros rowTS=e->curSubSong->ts.getTimes(curOrder,0);
+        if (rowTS.seconds==-1) {
+          showError(_("the first row of this order isn't going to play."));
+        } else {
+          e->setFilePlayerCue(curPos-rowTS);
+          fp->stop();
+        }
+      }
+      ImGui::SetItemTooltip(_("pause\n(right click to set cue position and pause)"));
+      popToggleColors();
+    } else {
+      if (ImGui::Button(ICON_FA_PLAY "##Play")) {
+        fp->play();
+      }
+      ImGui::SetItemTooltip(_("play"));
+    }
+    ImGui::SameLine();
+
+    if (ImGui::Button(ICON_FA_STEP_FORWARD "##PlayPos")) {
+      // handled outside
+    }
+    if (ImGui::IsItemClicked(ImGuiMouseButton_Left) || ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
+      TimeMicros rowTS;
+      if (ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
+        rowTS=e->curSubSong->ts.getTimes(cursor.order,cursor.y);
+      } else {
+        rowTS=e->curSubSong->ts.getTimes(curOrder,0);
+      }
+      TimeMicros cueTime=e->getFilePlayerCue();
+      if (rowTS.seconds==-1) {
+        if (ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
+          showError(_("the row that the pattern cursor is at isn't going to play. try moving the cursor."));
+        } else {
+          showError(_("the first row of this order isn't going to play. try another order."));
+        }
+      } else {
+        fp->setPosSeconds(rowTS+cueTime);
+        fp->play();
+      }
+    }
+    if (ImGui::IsItemHovered() && (ImGui::IsMouseReleased(ImGuiMouseButton_Left) || ImGui::IsMouseReleased(ImGuiMouseButton_Right))) {
+      fp->stop();
+    }
+    ImGui::SetItemTooltip(_(
+      "hold left click to play from current order\n"
+      "hold right click to play from pattern cursor position\n"
+      "release mouse button to stop"
+    ));
+    ImGui::SameLine();
+
+    pushToggleColors(filePlayerSync);
+    if (ImGui::Button(_("Sync"))) {
+      filePlayerSync=!filePlayerSync;
+    }
+    ImGui::SetItemTooltip(_("synchronize playback with tracker playback"));
+    popToggleColors();
+    e->setFilePlayerSync(filePlayerSync);
+
+    ImGui::SameLine();
+    ImGui::Text(_("Mix:"));
+    
+    float vol=fp->getVolume();
+    ImGui::SameLine();
+    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+    if (ImGui::SliderFloat("##Volume",&vol,-1.0f,1.0f,_("<-- Tracker / Reference -->"))) {
+      if (vol<-1.0f) vol=-1.0f;
+      if (vol>1.0f) vol=1.0f;
+      fp->setVolume(vol);
+    }
+    if (ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
+      fp->setVolume(0.0f);
+    }
+    ImGui::SetItemTooltip(_("right click to reset"));
+
+    //ImGui::Text("Memory usage: %" PRIu64 "K",fp->getMemUsage()>>10);
+  }
+  if (ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows)) curWindow=GUI_WINDOW_REF_PLAYER;
+  ImGui::End();
+
+
+  if (!refPlayerOpen) {
+    fp->stop();
+    e->setFilePlayerSync(false);
+  }
+}
diff --git a/src/gui/sampleEdit.cpp b/src/gui/sampleEdit.cpp
index 441c0294a..bf2152aa2 100644
--- a/src/gui/sampleEdit.cpp
+++ b/src/gui/sampleEdit.cpp
@@ -1212,7 +1212,7 @@ void FurnaceGUI::drawSampleEdit() {
       sameLineMaybe();
       ImGui::Button(ICON_FA_VOLUME_UP "##SAmplify");
       if (ImGui::IsItemHovered()) {
-        ImGui::SetTooltip(_("Amplify"));
+        ImGui::SetTooltip(_("Amplify/Offset"));
       }
       if (openSampleAmplifyOpt) {
         openSampleAmplifyOpt=false;
@@ -1226,6 +1226,11 @@ void FurnaceGUI::drawSampleEdit() {
         }
         ImGui::SameLine();
         ImGui::Text("(%.1fdB)",20.0*log10(amplifyVol/100.0f));
+        ImGui::Text(_("DC offset"));
+        if (ImGui::InputFloat("##Offset",&amplifyOff,-100.0,100.0,"%g%%")) {
+          if (amplifyOff<-100) amplifyOff=-100;
+          if (amplifyOff>100) amplifyOff=100;
+        }
         if (ImGui::Button(_("Apply"))) {
           sample->prepareUndo(true);
           e->lockEngine([this,sample]() {
@@ -1233,15 +1238,17 @@ void FurnaceGUI::drawSampleEdit() {
             float vol=amplifyVol/100.0f;
 
             if (sample->depth==DIV_SAMPLE_DEPTH_16BIT) {
+              float off=32767.0f*(amplifyOff/100.0f);
               for (unsigned int i=start; i<end; i++) {
-                float val=sample->data16[i]*vol;
+                float val=off+sample->data16[i]*vol;
                 if (val<-32768) val=-32768;
                 if (val>32767) val=32767;
                 sample->data16[i]=val;
               }
             } else if (sample->depth==DIV_SAMPLE_DEPTH_8BIT) {
+              float off=127.0f*(amplifyOff/100.0f);
               for (unsigned int i=start; i<end; i++) {
-                float val=sample->data8[i]*vol;
+                float val=off+sample->data8[i]*vol;
                 if (val<-128) val=-128;
                 if (val>127) val=127;
                 sample->data8[i]=val;
diff --git a/src/gui/speed.cpp b/src/gui/speed.cpp
index 02e04481a..c680b506f 100644
--- a/src/gui/speed.cpp
+++ b/src/gui/speed.cpp
@@ -58,6 +58,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
         if (setHz<1) setHz=1;
         if (setHz>999) setHz=999;
         e->setSongRate(setHz);
+        recalcTimestamps=true;
       }
       if (tempoView) {
         ImGui::SameLine();
@@ -82,6 +83,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
             e->curSubSong->speeds.len=1;
           });
           if (e->isPlaying()) play();
+          recalcTimestamps=true;
         }
         if (ImGui::IsItemHovered()) {
           ImGui::SetTooltip(_("click for one speed"));
@@ -94,6 +96,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
             e->curSubSong->speeds.val[3]=e->curSubSong->speeds.val[1];
           });
           if (e->isPlaying()) play();
+          recalcTimestamps=true;
         }
         if (ImGui::IsItemHovered()) {
           ImGui::SetTooltip(_("click for groove pattern"));
@@ -105,6 +108,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
             e->curSubSong->speeds.val[1]=e->curSubSong->speeds.val[0];
           });
           if (e->isPlaying()) play();
+          recalcTimestamps=true;
         }
         if (ImGui::IsItemHovered()) {
           ImGui::SetTooltip(_("click for two (alternating) speeds"));
@@ -138,6 +142,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
               e->curSubSong->speeds.val[i]=intVersion[i];
             }
           });
+          recalcTimestamps=true;
           if (e->isPlaying()) play();
           MARK_MODIFIED;
         }
@@ -151,6 +156,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
         if (ImGui::InputScalar("##Speed1",ImGuiDataType_U8,&e->curSubSong->speeds.val[0],&_ONE,&_THREE)) { MARK_MODIFIED
           if (e->curSubSong->speeds.val[0]<1) e->curSubSong->speeds.val[0]=1;
           if (e->isPlaying()) play();
+          recalcTimestamps=true;
         }
         if (e->curSubSong->speeds.len>1) {
           ImGui::SameLine();
@@ -158,6 +164,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
           if (ImGui::InputScalar("##Speed2",ImGuiDataType_U8,&e->curSubSong->speeds.val[1],&_ONE,&_THREE)) { MARK_MODIFIED
             if (e->curSubSong->speeds.val[1]<1) e->curSubSong->speeds.val[1]=1;
             if (e->isPlaying()) play();
+            recalcTimestamps=true;
           }
         }
       }
@@ -172,6 +179,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
         if (e->curSubSong->virtualTempoN<1) e->curSubSong->virtualTempoN=1;
         if (e->curSubSong->virtualTempoN>255) e->curSubSong->virtualTempoN=255;
         e->virtualTempoChanged();
+        recalcTimestamps=true;
       }
       if (ImGui::IsItemHovered()) {
         ImGui::SetTooltip(_("Numerator"));
@@ -182,6 +190,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
         if (e->curSubSong->virtualTempoD<1) e->curSubSong->virtualTempoD=1;
         if (e->curSubSong->virtualTempoD>255) e->curSubSong->virtualTempoD=255;
         e->virtualTempoChanged();
+        recalcTimestamps=true;
       }
       if (ImGui::IsItemHovered()) {
         ImGui::SetTooltip(_("Denominator (set to base tempo)"));
@@ -198,6 +207,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
         if (realTB<1) realTB=1;
         if (realTB>16) realTB=16;
         e->curSubSong->timeBase=realTB-1;
+        recalcTimestamps=true;
       }
       ImGui::SameLine();
       ImGui::Text("%.2f BPM",calcBPM(e->curSubSong->speeds,e->curSubSong->hz,e->curSubSong->virtualTempoN,e->curSubSong->virtualTempoD));
@@ -237,6 +247,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
         if (patLen<1) patLen=1;
         if (patLen>DIV_MAX_PATTERNS) patLen=DIV_MAX_PATTERNS;
         e->curSubSong->patLen=patLen;
+        recalcTimestamps=true;
       }
 
       ImGui::TableNextRow();
@@ -253,6 +264,7 @@ void FurnaceGUI::drawSpeed(bool asChild) {
         if (curOrder>=ordLen) {
           setOrder(ordLen-1);
         }
+        recalcTimestamps=true;
       }
 
       ImGui::EndTable();
diff --git a/src/gui/subSongs.cpp b/src/gui/subSongs.cpp
index 97732c027..b21861251 100644
--- a/src/gui/subSongs.cpp
+++ b/src/gui/subSongs.cpp
@@ -38,6 +38,7 @@ void FurnaceGUI::drawSubSongs(bool asChild) {
           if (ImGui::Selectable(id,i==e->getCurrentSubSong())) {
             makeCursorUndo();
             e->changeSongP(i);
+            recalcTimestamps=true;
             updateScroll(0);
             oldRow=0;
             cursor.xCoarse=0;
@@ -76,6 +77,7 @@ void FurnaceGUI::drawSubSongs(bool asChild) {
       } else {
         makeCursorUndo();
         e->changeSongP(e->song.subsong.size()-1);
+        recalcTimestamps=true;
         updateScroll(0);
         oldRow=0;
         cursor.xCoarse=0;
@@ -98,6 +100,7 @@ void FurnaceGUI::drawSubSongs(bool asChild) {
       } else {
         makeCursorUndo();
         e->changeSongP(e->song.subsong.size()-1);
+        recalcTimestamps=true;
         updateScroll(0);
         oldRow=0;
         cursor.xCoarse=0;
diff --git a/src/gui/sysManager.cpp b/src/gui/sysManager.cpp
index 9f9de0318..4ebb1f888 100644
--- a/src/gui/sysManager.cpp
+++ b/src/gui/sysManager.cpp
@@ -110,6 +110,7 @@ void FurnaceGUI::drawSysManager() {
           if (picked!=DIV_SYSTEM_NULL) {
             if (e->changeSystem(i,picked,preserveChanPos)) {
               MARK_MODIFIED;
+              recalcTimestamps=true;
               if (e->song.autoSystem) {
                 autoDetectSystem();
               }
@@ -179,6 +180,7 @@ void FurnaceGUI::drawSysManager() {
             showError(fmt::sprintf(_("cannot add chip! (%s)"),e->getLastError()));
           } else {
             MARK_MODIFIED;
+            recalcTimestamps=true;
           }
           if (e->song.autoSystem) {
             autoDetectSystem();
diff --git a/src/gui/tutorial.cpp b/src/gui/tutorial.cpp
index 2b6d0eb2c..50812fbd2 100644
--- a/src/gui/tutorial.cpp
+++ b/src/gui/tutorial.cpp
@@ -1082,7 +1082,7 @@ void FurnaceGUI::drawTutorial() {
         oneQuarter=(oneQuarter*e->curSubSong->virtualTempoN)/e->curSubSong->virtualTempoD;
         oneQuarter/=e->curSubSong->hz;
         oneQuarter/=4;
-        if (cv->playSongs && e->getTotalSeconds()>=oneQuarter) {
+        if (cv->playSongs && e->getCurTime().seconds>=oneQuarter) {
           if (loadRandomDemoSong()) {
             cv->loadInstruments();
             e->changeSongP(0);
diff --git a/src/log.cpp b/src/log.cpp
index 617a567b6..215b4ddfc 100644
--- a/src/log.cpp
+++ b/src/log.cpp
@@ -253,8 +253,8 @@ bool finishLogFile() {
 
   // flush
   logFileLockI.lock();
-  logFileNotify.notify_one();
   while (!iAmReallyDead) {
+    logFileNotify.notify_one();
     std::this_thread::yield();
     std::this_thread::sleep_for(std::chrono::milliseconds(10));
   }
diff --git a/src/timeutils.cpp b/src/timeutils.cpp
new file mode 100644
index 000000000..8a0e27649
--- /dev/null
+++ b/src/timeutils.cpp
@@ -0,0 +1,404 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2025 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "timeutils.h"
+#include <fmt/printf.h>
+#include <stdexcept>
+
+String TimeMicros::toString(signed char prec, TATimeFormats hms) {
+  String ret;
+  int actualSeconds=seconds;
+  int actualMicros=micros;
+  bool negative=(seconds<0);
+  if (seconds<0 && micros!=0) {
+    actualSeconds++;
+    actualMicros=1000000-micros;
+  }
+  if (negative) actualSeconds=-actualSeconds;
+
+  // handle auto formats
+  switch (hms) {
+    case TA_TIME_FORMAT_AUTO:
+      hms=TA_TIME_FORMAT_SECONDS;
+      if (actualSeconds>60) hms=TA_TIME_FORMAT_MS;
+      if (actualSeconds>3600) hms=TA_TIME_FORMAT_HMS;
+      if (actualSeconds>86400) hms=TA_TIME_FORMAT_DAYS_HMS;
+      break;
+    case TA_TIME_FORMAT_AUTO_ZERO:
+      hms=TA_TIME_FORMAT_SECONDS;
+      if (actualSeconds>60) hms=TA_TIME_FORMAT_MS_ZERO;
+      if (actualSeconds>3600) hms=TA_TIME_FORMAT_HMS_ZERO;
+      if (actualSeconds>86400) hms=TA_TIME_FORMAT_DAYS_HMS_ZERO;
+      break;
+    case TA_TIME_FORMAT_AUTO_MS:
+      hms=TA_TIME_FORMAT_MS;
+      if (actualSeconds>3600) hms=TA_TIME_FORMAT_HMS;
+      if (actualSeconds>86400) hms=TA_TIME_FORMAT_DAYS_HMS;
+      break;
+    case TA_TIME_FORMAT_AUTO_MS_ZERO:
+      hms=TA_TIME_FORMAT_MS_ZERO;
+      if (actualSeconds>3600) hms=TA_TIME_FORMAT_HMS_ZERO;
+      if (actualSeconds>86400) hms=TA_TIME_FORMAT_DAYS_HMS_ZERO;
+      break;
+    default:
+      break;
+  }
+
+  switch (hms) {
+    case TA_TIME_FORMAT_SECONDS: { // seconds
+      if (negative) {
+        ret=fmt::sprintf("-%d",actualSeconds);
+      } else {
+        ret=fmt::sprintf("%d",actualSeconds);
+      }
+      break;
+    }
+    case TA_TIME_FORMAT_MS: { // m:ss
+      int m=actualSeconds/60;
+      int s=actualSeconds%60;
+      
+      if (negative) {
+        ret=fmt::sprintf("-%d:%02d",m,s);
+      } else {
+        ret=fmt::sprintf("%d:%02d",m,s);
+      }
+      break;
+    }
+    case TA_TIME_FORMAT_HMS: { // h:mm:ss
+      int h=actualSeconds/3600;
+      int m=(actualSeconds/60)%60;
+      int s=actualSeconds%60;
+
+      if (negative) {
+        ret=fmt::sprintf("-%d:%02d:%02d",h,m,s);
+      } else {
+        ret=fmt::sprintf("%d:%02d:%02d",h,m,s);
+      }
+      break;
+    }
+    case TA_TIME_FORMAT_MS_ZERO: { // mm:ss
+      int m=actualSeconds/60;
+      int s=actualSeconds%60;
+      
+      if (negative) {
+        ret=fmt::sprintf("-%02d:%02d",m,s);
+      } else {
+        ret=fmt::sprintf("%02d:%02d",m,s);
+      }
+      break;
+    }
+    case TA_TIME_FORMAT_HMS_ZERO: { // hh:mm:ss
+      int h=actualSeconds/3600;
+      int m=(actualSeconds/60)%60;
+      int s=actualSeconds%60;
+
+      if (negative) {
+        ret=fmt::sprintf("-%02d:%02d:%02d",h,m,s);
+      } else {
+        ret=fmt::sprintf("%02d:%02d:%02d",h,m,s);
+      }
+      break;
+    }
+    case TA_TIME_FORMAT_DAYS_HMS: { // ?y?m?d h:mm:ss
+      int days=actualSeconds/86400;
+      int years=days/365;
+      days%=365;
+      int months=days/30;
+      days%=30;
+      int h=(actualSeconds/3600)%24;
+      int m=(actualSeconds/60)%60;
+      int s=actualSeconds%60;
+
+      if (negative) {
+        ret=fmt::sprintf("-%dy%dm%dd %d:%02d:%02d",years,months,days,h,m,s);
+      } else {
+        ret=fmt::sprintf("%dy%dm%dd %d:%02d:%02d",years,months,days,h,m,s);
+      }
+      break;
+    }
+    case TA_TIME_FORMAT_DAYS_HMS_ZERO: { // ?y?m?d hh:mm:ss
+      int days=actualSeconds/86400;
+      int years=days/365;
+      days%=365;
+      int months=days/30;
+      days%=30;
+      int h=(actualSeconds/3600)%24;
+      int m=(actualSeconds/60)%60;
+      int s=actualSeconds%60;
+
+      if (negative) {
+        ret=fmt::sprintf("-%dy%dm%dd %02d:%02d:%02d",years,months,days,h,m,s);
+      } else {
+        ret=fmt::sprintf("%dy%dm%dd %02d:%02d:%02d",years,months,days,h,m,s);
+      }
+      break;
+    }
+    default:
+      return "ERROR!";
+  }
+
+  if (prec<0) {
+    // automatic precision
+    prec=6;
+    int precMicros=actualMicros;
+    while ((precMicros%10)==0 && prec>1) {
+      prec--;
+      precMicros/=10;
+    }
+  }
+
+  if (prec>0) {
+    if (prec>6) prec=6;
+    switch (prec) {
+      case 1:
+        ret+=fmt::sprintf(".%01d",actualMicros/100000);
+        break;
+      case 2:
+        ret+=fmt::sprintf(".%02d",actualMicros/10000);
+        break;
+      case 3:
+        ret+=fmt::sprintf(".%03d",actualMicros/1000);
+        break;
+      case 4:
+        ret+=fmt::sprintf(".%04d",actualMicros/100);
+        break;
+      case 5:
+        ret+=fmt::sprintf(".%05d",actualMicros/10);
+        break;
+      case 6:
+        ret+=fmt::sprintf(".%06d",actualMicros);
+        break;
+    }
+  }
+
+  return ret;
+}
+
+TimeMicros TimeMicros::fromString(const String& s) {
+  bool seenYears=false;
+  bool seenMonths=false;
+  bool seenDays=false;
+  bool seenDecimal=false;
+  bool needSomething=true;
+  bool canNegative=true;
+  bool isNegative=false;
+  unsigned int element[4];
+  unsigned int elementDigits[4];
+  int elementCount=0;
+  int curElement=0;
+  int curElementDigits=0;
+
+  int years=0;
+  int months=0;
+  int days=0;
+
+  element[0]=0;
+  element[1]=0;
+  element[2]=0;
+  element[3]=0;
+  elementDigits[0]=0;
+  elementDigits[1]=0;
+  elementDigits[2]=0;
+  elementDigits[3]=0;
+
+  for (char i: s) {
+    switch (i) {
+      // numbers
+      case '0': case '1': case '2': case '3': case '4':
+      case '5': case '6': case '7': case '8': case '9':
+        if (curElementDigits<9) {
+          curElement*=10;
+          curElement+=(i-'0');
+          curElementDigits++;
+          needSomething=false;
+        } else {
+          throw std::invalid_argument("value out of range");
+        }
+        break;
+
+      // negative indicator
+      case '-':
+        if (!canNegative) {
+          throw std::invalid_argument("negative symbol shall be at the beginning");
+        }
+        isNegative=true;
+        break;
+
+      // element separator
+      case ':':
+        if (needSomething) {
+          throw std::invalid_argument("missing value");
+        }
+        if (seenDecimal) {
+          throw std::invalid_argument("after decimal");
+        }
+        if (elementCount>=3) {
+          throw std::invalid_argument("too many elements");
+        }
+        element[elementCount]=curElement;
+        elementDigits[elementCount++]=curElementDigits;
+        curElement=0;
+        curElementDigits=0;
+        break;
+
+      // decimal separator
+      case '.': case ',':
+        if (needSomething && elementCount!=0) {
+          throw std::invalid_argument("wrong decimal separator");
+        }
+        if (elementCount>=3) {
+          throw std::invalid_argument("too many elements");
+        }
+        element[elementCount]=curElement;
+        elementDigits[elementCount++]=curElementDigits;
+        curElement=0;
+        curElementDigits=0;
+        needSomething=true;
+        seenDecimal=true;
+        break;
+
+      // year/month/day marker
+      case 'Y': case 'y':
+        if (seenYears) {
+          throw std::invalid_argument("already have years");
+        }
+        if (elementCount!=0) {
+          throw std::invalid_argument("years must be before time");
+        }
+        years=curElement;
+        curElement=0;
+        curElementDigits=0;
+        needSomething=true;
+        seenYears=true;
+        break;
+      case 'M': case 'm':
+        if (seenMonths) {
+          throw std::invalid_argument("already have months");
+        }
+        if (elementCount!=0) {
+          throw std::invalid_argument("months must be before time");
+        }
+        months=curElement;
+        curElement=0;
+        curElementDigits=0;
+        needSomething=true;
+        seenMonths=true;
+        break;
+      case 'D': case 'd':
+        if (seenDays) {
+          throw std::invalid_argument("already have days");
+        }
+        if (elementCount!=0) {
+          throw std::invalid_argument("days must be before time");
+        }
+        days=curElement;
+        curElement=0;
+        curElementDigits=0;
+        needSomething=true;
+        seenDays=true;
+        break;
+
+      // ignore spaces
+      case ' ':
+        break;
+      
+      // fail if any other character is seen
+      default:
+        throw std::invalid_argument("invalid character");
+        break;
+    }
+    canNegative=false;
+  }
+
+  // fail if you didn't provide an element
+  if (needSomething) {
+    throw std::invalid_argument("missing value at the end");
+  }
+
+  element[elementCount]=curElement;
+  elementDigits[elementCount]=curElementDigits;
+
+  // safety checks (yeah I know these are a bit off but whatever)
+  if (years>68 || months>828 || (years*365+months*30+days)>24855) {
+    throw std::invalid_argument("years/months/days out of range");
+  }
+  
+  // now combine elements
+  TimeMicros ret;
+  ret.seconds=86400*(years*365+months*30+days);
+  if (seenDecimal || elementCount==3) {
+    if (elementDigits[elementCount]<6) {
+      for (int i=elementDigits[elementCount]; i<6; i++) {
+        element[elementCount]*=10;
+      }
+    } else if (elementDigits[elementCount]>6) {
+      for (int i=elementDigits[elementCount]; i>6; i--) {
+        element[elementCount]/=10;
+      }
+    }
+    ret.micros=element[elementCount];
+    
+    elementCount--;
+  }
+  switch (elementCount) {
+    case 0: // seconds only
+      ret.seconds+=element[0];
+      break;
+    case 1: // minutes and seconds
+      if (element[0]>=35791394) {
+        throw std::invalid_argument("minutes out of range");
+      }
+      if (element[1]>=60) {
+        throw std::invalid_argument("seconds out of range");
+      }
+      ret.seconds+=(element[0]*60)+element[1];
+      break;
+    case 2: // hours, minutes and seconds
+      if (seenYears || seenMonths || seenDays) {
+        if (element[0]>=24) {
+          throw std::invalid_argument("hours out of range");
+        }
+      } else {
+        if (element[0]>=596523) {
+          throw std::invalid_argument("hours out of range");
+        }
+      }
+      if (element[1]>=60) {
+        throw std::invalid_argument("minutes out of range");
+      }
+      if (element[2]>=60) {
+        throw std::invalid_argument("seconds out of range");
+      }
+      ret.seconds+=(element[0]*3600)+(element[1]*60)+element[2];
+      break;
+    default:
+      throw std::invalid_argument("shouldn't happen");
+      break;
+  }
+
+  if (isNegative) {
+    ret.seconds=-ret.seconds;
+    if (ret.micros!=0) {
+      ret.micros=1000000-ret.micros;
+      ret.seconds--;
+    }
+  }
+
+  return ret;
+}
diff --git a/src/timeutils.h b/src/timeutils.h
new file mode 100644
index 000000000..48b1d3cbe
--- /dev/null
+++ b/src/timeutils.h
@@ -0,0 +1,127 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2025 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _TIMEUTILS_H
+#define _TIMEUTILS_H
+
+#ifdef __unix__
+#include <time.h>
+#include <sys/time.h>
+#endif
+
+#include "ta-utils.h"
+
+enum TATimeFormats: unsigned char {
+  TA_TIME_FORMAT_SECONDS=0, // seconds only
+  TA_TIME_FORMAT_MS, // m:ss
+  TA_TIME_FORMAT_HMS, // h:mm:ss
+
+  TA_TIME_FORMAT_MS_ZERO, // mm:ss
+  TA_TIME_FORMAT_HMS_ZERO, // hh:mm:ss
+
+  TA_TIME_FORMAT_DAYS_HMS, // years, months, days, h:mm:ss
+  TA_TIME_FORMAT_DAYS_HMS_ZERO, // years, months, days, hh:mm:ss
+
+  TA_TIME_FORMAT_AUTO, // automatic
+  TA_TIME_FORMAT_AUTO_ZERO, // automatic (zero)
+  TA_TIME_FORMAT_AUTO_MS, // automatic (from minutes)
+  TA_TIME_FORMAT_AUTO_MS_ZERO, // automatic (from minutes; zero)
+};
+
+struct TimeMicros {
+  int seconds, micros;
+
+  inline float toFloat() {
+    return seconds+(float)micros/1000000.0f;
+  }
+  inline double toDouble() {
+    return seconds+(double)micros/1000000.0;
+  }
+
+  // operators
+  inline TimeMicros& operator+(TimeMicros& other) {
+    seconds+=other.seconds;
+    micros+=other.micros;
+    while (micros>=1000000) {
+      micros-=1000000;
+      seconds++;
+    }
+    return *this;
+  }
+  inline TimeMicros& operator+(int other) {
+    seconds+=other;
+    return *this;
+  }
+  inline TimeMicros& operator-(TimeMicros& other) {
+    seconds-=other.seconds;
+    micros-=other.micros;
+    while (micros<0) {
+      micros+=1000000;
+      seconds--;
+    }
+    return *this;
+  }
+  inline TimeMicros& operator-(int other) {
+    seconds-=other;
+    return *this;
+  }
+
+  // comparison operators
+  inline bool operator==(TimeMicros& other) {
+    return (seconds==other.seconds && micros==other.micros);
+  }
+  inline bool operator>(TimeMicros& other) {
+    return (seconds>other.seconds || (seconds==other.seconds && micros>other.micros));
+  }
+  inline bool operator>=(TimeMicros& other) {
+    return (seconds>other.seconds || (seconds==other.seconds && micros>=other.micros));
+  }
+
+  inline bool operator!=(TimeMicros& other) {
+    return !(*this==other);
+  }
+  inline bool operator<(TimeMicros& other) {
+    return !(*this>=other);
+  }
+  inline bool operator<=(TimeMicros& other) {
+    return !(*this>other);
+  }
+
+  /**
+   * convert this TimeMicros to a String.
+   * @param prec maximum digit precision (0-6). use -1 for automatic precision.
+   * @param hms how many denominations to include (0: seconds, 1: minutes, 2: hours).
+   * @return formatted TimeMicros.
+   */
+  String toString(signed char prec=6, TATimeFormats hms=TA_TIME_FORMAT_SECONDS);
+  static TimeMicros fromString(const String& s);
+
+  TimeMicros(int s, int u):
+    seconds(s), micros(u) {}
+#ifdef __unix__
+  TimeMicros(struct timeval tv):
+    seconds(tv.tv_sec), micros(tv.tv_usec) {}
+  TimeMicros(struct timespec ts):
+    seconds(ts.tv_sec), micros(ts.tv_nsec/1000) {}
+#endif
+  TimeMicros():
+    seconds(0), micros(0) {}
+};
+
+#endif