GUI: sample resampling

CMakeLists.txt

@@ -282,6 +282,7 @@ src/engine/config.cpp
 src/engine/dispatchContainer.cpp
 src/engine/engine.cpp
 src/engine/fileOps.cpp
+src/engine/filter.cpp
 src/engine/instrument.cpp
 src/engine/macroInt.cpp
 src/engine/pattern.cpp

src/engine/filter.cpp

@@ -0,0 +1,88 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2022 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 <stddef.h>
+#define _USE_MATH_DEFINES
+#include <math.h>
+#include "filter.h"
+#include "../ta-log.h"
+
+float* DivFilterTables::cubicTable=NULL;
+float* DivFilterTables::sincTable=NULL;
+float* DivFilterTables::sincIntegralTable=NULL;
+
+// portions from Schism Tracker (scripts/lutgen.c)
+// licensed under same license as this program.
+float* DivFilterTables::getCubicTable() {
+  if (cubicTable==NULL) {
+    logD("initializing cubic spline table.\n");
+    cubicTable=new float[4096];
+
+    for (int i=0; i<1024; i++) {
+      float x=(float)i/1024.0;
+      cubicTable[(i<<2)]=-0.5*pow(x,3)+1.0*pow(x,2)-0.5*x;
+      cubicTable[1+(i<<2)]=1.5*pow(x,3)-2.5*pow(x,2)+1.0;
+      cubicTable[2+(i<<2)]=-1.5*pow(x,3)+2.0*pow(x,2)+0.5*x;
+      cubicTable[3+(i<<2)]=0.5*pow(x,3)-0.5*pow(x,2);
+    }
+  }
+  return cubicTable;
+}
+
+float* DivFilterTables:: getSincTable() {
+  if (sincTable==NULL) {
+    logD("initializing sinc table.\n");
+    sincTable=new float[65536];
+
+    sincTable[0]=1.0f;
+    for (int i=1; i<65536; i++) {
+      int mapped=((i&8191)<<3)|(i>>13);
+      double x=(double)i*M_PI/8192.0;
+      sincTable[mapped]=sin(x)/x;
+    }
+
+    for (int i=0; i<65536; i++) {
+      int mapped=((i&8191)<<3)|(i>>13);
+      sincTable[mapped]*=pow(cos(M_PI*(double)i/131072.0),2.0);
+    }
+  }
+  return sincTable;
+}
+
+float* DivFilterTables::getSincIntegralTable() {
+  if (sincIntegralTable==NULL) {
+    logD("initializing sinc integral table.\n");
+    sincIntegralTable=new float[65536];
+
+    sincIntegralTable[0]=-0.5f;
+    for (int i=1; i<65536; i++) {
+      int mapped=((i&8191)<<3)|(i>>13);
+      int mappedPrev=(((i-1)&8191)<<3)|((i-1)>>13);
+      double x=(double)i*M_PI/8192.0;
+      double sinc=sin(x)/x;
+      sincIntegralTable[mapped]=sincIntegralTable[mappedPrev]+(sinc/8192.0);
+    }
+
+    for (int i=0; i<65536; i++) {
+      int mapped=((i&8191)<<3)|(i>>13);
+      sincIntegralTable[mapped]*=pow(cos(M_PI*(double)i/131072.0),2.0);
+    }
+  }
+  return sincIntegralTable;
+}

src/engine/filter.h

@@ -0,0 +1,43 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2022 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.
+ */
+
+class DivFilterTables {
+  public:
+    static float* cubicTable;
+    static float* sincTable;
+    static float* sincIntegralTable;
+
+    /**
+     * get a 1024x4 cubic spline table.
+     * @return the table.
+     */
+    static float* getCubicTable();
+
+    /**
+     * get a 8192x8 one-side sine-windowed sinc table.
+     * @return the table.
+     */
+    static float* getSincTable();
+
+    /**
+     * get a 8192x8 one-side sine-windowed sinc integral table.
+     * @return the table.
+     */
+    static float* getSincIntegralTable();
+};

src/engine/sample.cpp

@@ -19,9 +19,10 @@
 
 #include "sample.h"
 #include "../ta-log.h"
+#include <math.h>
 #include <string.h>
 #include <sndfile.h>
-#include <math.h>
+#include "filter.h"
 
 extern "C" {
 #include "../../extern/adpcm/bs_codec.h"
@@ -178,6 +179,348 @@ bool DivSample::resize(unsigned int count) {
   return false;
 }
 
+#define RESAMPLE_BEGIN \
+  if (samples<1) return true; \
+  int finalCount=(double)samples*(r/(double)rate); \
+  signed char* oldData8=data8; \
+  short* oldData16=data16; \
+  if (depth==16) { \
+    if (data16!=NULL) { \
+      data16=NULL; \
+      initInternal(16,finalCount); \
+    } \
+  } else if (depth==8) {  \
+    if (data8!=NULL) { \
+      data8=NULL; \
+      initInternal(8,finalCount); \
+    } \
+  } else { \
+    return false; \
+  }
+
+#define RESAMPLE_END \
+  samples=finalCount; \
+  if (depth==16) { \
+    delete[] oldData16; \
+  } else if (depth==8) { \
+    delete[] oldData8; \
+  }
+
+bool DivSample::resampleNone(double r) {
+  RESAMPLE_BEGIN;
+
+  if (depth==16) {
+    for (int i=0; i<finalCount; i++) {
+      unsigned int pos=(unsigned int)((double)i*((double)rate/r));
+      if (pos>=samples) {
+        data16[i]=0;
+      } else {
+        data16[i]=oldData16[pos];
+      }
+    }
+  } else if (depth==8) {
+    for (int i=0; i<finalCount; i++) {
+      unsigned int pos=(unsigned int)((double)i*((double)rate/r));
+      if (pos>=samples) {
+        data8[i]=0;
+      } else {
+        data8[i]=oldData8[pos];
+      }
+    }
+  }
+
+  rate=r;
+
+  RESAMPLE_END;
+  return true;
+}
+
+bool DivSample::resampleLinear(double r) {
+  RESAMPLE_BEGIN;
+
+  double posFrac=0;
+  unsigned int posInt=0;
+  double factor=(double)rate/r;
+
+  if (depth==16) {
+    for (int i=0; i<finalCount; i++) {
+      short s1=(posInt>=samples)?0:oldData16[posInt];
+      short s2=(posInt+1>=samples)?((loopStart>=0 && loopStart<(int)samples)?oldData16[loopStart]:0):oldData16[posInt+1];
+
+      data16[i]=s1+(float)(s2-s1)*posFrac;
+
+      posFrac+=factor;
+      while (posFrac>=1.0) {
+        posFrac-=1.0;
+        posInt++;
+      }
+    }
+  } else if (depth==8) {
+    for (int i=0; i<finalCount; i++) {
+      short s1=(posInt>=samples)?0:oldData8[posInt];
+      short s2=(posInt+1>=samples)?((loopStart>=0 && loopStart<(int)samples)?oldData8[loopStart]:0):oldData8[posInt+1];
+
+      data8[i]=s1+(float)(s2-s1)*posFrac;
+
+      posFrac+=factor;
+      while (posFrac>=1.0) {
+        posFrac-=1.0;
+        posInt++;
+      }
+    }
+  }
+
+  rate=r;
+
+  RESAMPLE_END;
+  return true;
+}
+
+bool DivSample::resampleCubic(double r) {
+  RESAMPLE_BEGIN;
+
+  double posFrac=0;
+  unsigned int posInt=0;
+  double factor=(double)rate/r;
+  float* cubicTable=DivFilterTables::getCubicTable();
+
+  if (depth==16) {
+    for (int i=0; i<finalCount; i++) {
+      unsigned int n=((unsigned int)(posFrac*1024.0))&1023;
+      float* t=&cubicTable[n<<2];
+      float s0=(posInt<1)?0:oldData16[posInt-1];
+      float s1=(posInt>=samples)?0:oldData16[posInt];
+      float s2=(posInt+1>=samples)?((loopStart>=0 && loopStart<(int)samples)?oldData16[loopStart]:0):oldData16[posInt+1];
+      float s3=(posInt+2>=samples)?((loopStart>=0 && loopStart<(int)samples)?oldData16[loopStart]:0):oldData16[posInt+2];
+
+      float result=s0*t[0]+s1*t[1]+s2*t[2]+s3*t[3];
+      if (result<-32768) result=-32768;
+      if (result>32767) result=32767;
+      data16[i]=result;
+
+      posFrac+=factor;
+      while (posFrac>=1.0) {
+        posFrac-=1.0;
+        posInt++;
+      }
+    }
+  } else if (depth==8) {
+    for (int i=0; i<finalCount; i++) {
+      unsigned int n=((unsigned int)(posFrac*1024.0))&1023;
+      float* t=&cubicTable[n<<2];
+      float s0=(posInt<1)?0:oldData8[posInt-1];
+      float s1=(posInt>=samples)?0:oldData8[posInt];
+      float s2=(posInt+1>=samples)?((loopStart>=0 && loopStart<(int)samples)?oldData8[loopStart]:0):oldData8[posInt+1];
+      float s3=(posInt+2>=samples)?((loopStart>=0 && loopStart<(int)samples)?oldData8[loopStart]:0):oldData8[posInt+2];
+
+      float result=s0*t[0]+s1*t[1]+s2*t[2]+s3*t[3];
+      if (result<-128) result=-128;
+      if (result>127) result=127;
+      data8[i]=result;
+
+      posFrac+=factor;
+      while (posFrac>=1.0) {
+        posFrac-=1.0;
+        posInt++;
+      }
+    }
+  }
+
+  rate=r;
+
+  RESAMPLE_END;
+  return true;
+}
+
+bool DivSample::resampleBlep(double r) {
+  RESAMPLE_BEGIN;
+
+  double posFrac=0;
+  unsigned int posInt=0;
+  double factor=r/(double)rate;
+  float* sincITable=DivFilterTables::getSincIntegralTable();
+  float s[16];
+
+  memset(s,0,16*sizeof(float));
+
+  if (depth==16) {
+    memset(data16,0,finalCount*sizeof(short));
+    for (int i=0; i<finalCount; i++) {
+      if (posInt<samples) {
+        int result=data16[i]+oldData16[posInt];
+        if (result<-32768) result=-32768;
+        if (result>32767) result=32767;
+        data16[i]=result;
+      }
+      
+      posFrac+=1.0;
+      while (posFrac>=1.0) {
+        unsigned int n=((unsigned int)(posFrac*8192.0))&8191;
+        posFrac-=factor;
+        posInt++;
+
+        float* t1=&sincITable[(8191-n)<<3];
+        float* t2=&sincITable[n<<3];
+        float delta=oldData16[posInt]-oldData16[posInt-1];
+
+        for (int j=0; j<8; j++) {
+          if (i-j>0) {
+            float result=data16[i-j]+t1[j]*-delta;
+            if (result<-32768) result=-32768;
+            if (result>32767) result=32767;
+            data16[i-j]=result;
+          }
+          if (i+j+1<finalCount) {
+            float result=data16[i+j+1]+t2[j]*delta;
+            if (result<-32768) result=-32768;
+            if (result>32767) result=32767;
+            data16[i+j+1]=result;
+          }
+        }
+      }
+    }
+  } else if (depth==8) {
+    memset(data8,0,finalCount*sizeof(short));
+    for (int i=0; i<finalCount; i++) {
+      if (posInt<samples) {
+        int result=data8[i]+oldData8[posInt];
+        if (result<-128) result=-128;
+        if (result>127) result=127;
+        data8[i]=result;
+      }
+      
+      posFrac+=1.0;
+      while (posFrac>=1.0) {
+        unsigned int n=((unsigned int)(posFrac*8192.0))&8191;
+        posFrac-=factor;
+        posInt++;
+
+        float* t1=&sincITable[(8191-n)<<3];
+        float* t2=&sincITable[n<<3];
+        float delta=oldData8[posInt]-oldData8[posInt-1];
+
+        for (int j=0; j<8; j++) {
+          if (i-j>0) {
+            float result=data8[i-j]+t1[j]*-delta;
+            if (result<-128) result=-128;
+            if (result>127) result=127;
+            data8[i-j]=result;
+          }
+          if (i+j+1<finalCount) {
+            float result=data8[i+j+1]+t2[j]*delta;
+            if (result<-128) result=-128;
+            if (result>127) result=127;
+            data8[i+j+1]=result;
+          }
+        }
+      }
+    }
+  }
+
+  rate=r;
+
+  RESAMPLE_END;
+  return true;
+}
+
+bool DivSample::resampleSinc(double r) {
+  RESAMPLE_BEGIN;
+
+  double posFrac=0;
+  unsigned int posInt=0;
+  double factor=(double)rate/r;
+  float* sincTable=DivFilterTables::getSincTable();
+  float s[16];
+
+  memset(s,0,16*sizeof(float));
+
+  if (depth==16) {
+    for (int i=0; i<finalCount+8; i++) {
+      unsigned int n=((unsigned int)(posFrac*8192.0))&8191;
+      float result=0;
+      float* t1=&sincTable[(8191-n)<<3];
+      float* t2=&sincTable[n<<3];
+      for (int j=0; j<8; j++) {
+        result+=s[j]*t2[7-j];
+        result+=s[8+j]*t1[j];
+      }
+      if (result<-32768) result=-32768;
+      if (result>32767) result=32767;
+      if (i>=8) {
+        data16[i-8]=result;
+      }
+      
+      posFrac+=factor;
+      while (posFrac>=1.0) {
+        posFrac-=1.0;
+        posInt++;
+
+        for (int j=0; j<15; j++) s[j]=s[j+1];
+        s[15]=(posInt>=samples)?0:oldData16[posInt];
+      }
+    }
+  } else if (depth==8) {
+    for (int i=0; i<finalCount+8; i++) {
+      unsigned int n=((unsigned int)(posFrac*8192.0))&8191;
+      float result=0;
+      float* t1=&sincTable[(8191-n)<<3];
+      float* t2=&sincTable[n<<3];
+      for (int j=0; j<8; j++) {
+        result+=s[j]*t2[7-j];
+        result+=s[8+j]*t1[j];
+      }
+      if (result<-32768) result=-32768;
+      if (result>32767) result=32767;
+      if (i>=8) {
+        data8[i-8]=result;
+      }
+      
+      posFrac+=factor;
+      while (posFrac>=1.0) {
+        posFrac-=1.0;
+        posInt++;
+
+        for (int j=0; j<15; j++) s[j]=s[j+1];
+        s[15]=(posInt>=samples)?0:oldData8[posInt];
+      }
+    }
+  }
+
+  rate=r;
+
+  RESAMPLE_END;
+  return true;
+}
+
+bool DivSample::resample(double r, int filter) {
+  if (depth!=8 && depth!=16) return false;
+  switch (filter) {
+    case DIV_RESAMPLE_NONE:
+      return resampleNone(r);
+      break;
+    case DIV_RESAMPLE_LINEAR:
+      return resampleLinear(r);
+      break;
+    case DIV_RESAMPLE_CUBIC:
+      return resampleCubic(r);
+      break;
+    case DIV_RESAMPLE_BLEP:
+      return resampleBlep(r);
+      break;
+    case DIV_RESAMPLE_SINC:
+      return resampleSinc(r);
+      break;
+    case DIV_RESAMPLE_BEST:
+      if (r>rate) {
+        return resampleSinc(r);
+      } else {
+        return resampleBlep(r);
+      }
+      break;
+  }
+  return false;
+}
+
 void DivSample::render() {
   // step 1: convert to 16-bit if needed
   if (depth!=16) {

src/engine/sample.h

@@ -19,6 +19,15 @@
 
 #include "../ta-utils.h"
 
+enum DivResampleFilters {
+  DIV_RESAMPLE_NONE=0,
+  DIV_RESAMPLE_LINEAR,
+  DIV_RESAMPLE_CUBIC,
+  DIV_RESAMPLE_BLEP,
+  DIV_RESAMPLE_SINC,
+  DIV_RESAMPLE_BEST
+};
+
 struct DivSample {
   String name;
   int rate, centerRate, loopStart, loopOffP;
@@ -53,6 +62,15 @@ struct DivSample {
 
   unsigned int samples;
 
+  /**
+   * @warning DO NOT USE - internal functions
+   */
+  bool resampleNone(double rate);
+  bool resampleLinear(double rate);
+  bool resampleCubic(double rate);
+  bool resampleBlep(double rate);
+  bool resampleSinc(double rate);
+
   /**
    * save this sample to a file.
    * @param path a path.
@@ -84,6 +102,15 @@ struct DivSample {
    */
   bool resize(unsigned int count);
 
+  /**
+   * change the sample rate.
+   * @warning do not attempt to resample outside of a synchronized block!
+   * @param rate number of samples.
+   * @param filter the interpolation filter.
+   * @return whether it was successful.
+   */
+  bool resample(double rate, int filter);
+
   /**
    * initialize the rest of sample formats for this sample.
    */

src/gui/sampleEdit.cpp

@@ -159,7 +159,9 @@ void FurnaceGUI::drawSampleEdit() {
         }
         if (ImGui::Button("Resize")) {
           e->synchronized([this,sample]() {
-            sample->resize(resizeSize);
+            if (!sample->resize(resizeSize)) {
+              showError("couldn't resize! make sure your sample is 8 or 16-bit.");
+            }
             e->renderSamples();
           });
           updateSampleTex=true;
@@ -202,7 +204,16 @@ void FurnaceGUI::drawSampleEdit() {
           if (resampleTarget>96000) resampleTarget=96000;
         }
         ImGui::Combo("Filter",&resampleStrat,resampleStrats,6);
-        ImGui::Button("Resample");
+        if (ImGui::Button("Resample")) {
+          e->synchronized([this,sample]() {
+            if (!sample->resample(resampleTarget,resampleStrat)) {
+              showError("couldn't resample! make sure your sample is 8 or 16-bit.");
+            }
+            e->renderSamples();
+          });
+          updateSampleTex=true;
+          ImGui::CloseCurrentPopup();
+        }
         ImGui::EndPopup();
       } else {
         resampleTarget=sample->rate;
@@ -332,7 +343,7 @@ void FurnaceGUI::drawSampleEdit() {
 
         ImGui::ImageButton(sampleTex,avail,ImVec2(0,0),ImVec2(1,1),0);
         if (ImGui::IsItemClicked()) {
-          printf("drawing\n");
+          logD("drawing\n");
         }
 
         ImGui::Text("A workaround! Pretty cool huh?");