prepare BRR encoding/decoding

CMakeLists.txt

@@ -444,6 +444,7 @@ src/engine/platform/ym2608Interface.cpp
 src/engine/platform/ym2610Interface.cpp
 
 src/engine/blip_buf.c
+src/engine/brrUtils.c
 src/engine/safeReader.cpp
 src/engine/safeWriter.cpp
 src/engine/config.cpp

src/engine/brrUtils.c

@@ -0,0 +1,82 @@
+/* brrUtils - BRR audio codec utilities
+ * Copyright (C) 2022 tildearrow 
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "brrUtils.h"
+
+void brrEncode(short* buf, unsigned char* out, long len) {
+  if (len==0) return;
+  // TODO
+}
+
+#define DO_ONE_SAMPLE \
+  if (next&8) next|=0xfff8; \
+\
+  next<<=(buf[0]>>4); /* range */ \
+\
+  switch (control&0xc) { /* filter */ \
+    case 0: \
+      break; \
+    case 4: \
+      next+=(last1*15)/16; \
+      break; \
+    case 8: \
+      next+=(last1*61)/32-(last2*15)/16; \
+      break; \
+    case 12: \
+      next+=(last1*115)/64-(last2*13)/16; \
+      break; \
+  } \
+\
+  if (next>32767) next=32767; \
+  if (next<-32768) next=-32768; \
+\
+  last2=last1; \
+  last1=next; \
+  *out=next; \
+  out++;
+
+void brrDecode(unsigned char* buf, short* out, long len) {
+  if (len==0) return;
+
+  int last1=0;
+  int last2=0;
+  int next=0;
+
+  // don't read out of bounds
+  len-=8;
+
+  for (long i=0; i<len; i+=9) {
+    unsigned char control=buf[0];
+
+    for (unsigned char j=1; j<9; j++) {
+      next=buf[j]&15;
+      DO_ONE_SAMPLE;
+
+      next=buf[j]>>4;
+      DO_ONE_SAMPLE;
+    }
+
+    // end bit
+    if (control&1) break;
+    buf+=9;
+  }
+}

src/engine/brrUtils.h

@@ -0,0 +1,50 @@
+/* brrUtils - BRR audio codec utilities
+ * Copyright (C) 2022 tildearrow 
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef _BRR_UTILS_H
+#define _BRR_UTILS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * read len samples from buf, encode in BRR and output to out.
+ * @param buf input data.
+ * @param out output buffer. shall be at least 9*(len/16) shorts in size.
+ * @param len input length (should be a multiple of 16. if it isn't, the output will be padded).
+ */
+void brrEncode(short* buf, unsigned char* out, long len);
+
+/**
+ * read len bytes from buf, decode BRR and output to out.
+ * @param buf input data.
+ * @param out output buffer. shall be at least 16*(len/9) shorts in size.
+ * @param len input length (shall be a multiple of 9).
+ */
+void brrDecode(unsigned char* buf, short* out, long len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/engine/platform/snes.cpp

@@ -24,7 +24,7 @@
 
 #define CHIP_FREQBASE 131072
 
-#define rWrite(a,v) {dsp.write(a,v); regPool[(a)&0x7f]=v; }
+#define rWrite(a,v) if (!skipRegisterWrites) {writes.emplace(a,v); if (dumpWrites) {addWrite(a,v);} }
 #define chWrite(c,a,v) {rWrite((a)+(c)*16,v)}
 #define sampleTableAddr(c) (sampleTableBase+(c)*4)
 #define waveTableAddr(c) (sampleTableBase+8*4+(c)*9*16)
@@ -69,6 +69,14 @@ void DivPlatformSNES::acquire(short* bufL, short* bufR, size_t start, size_t len
   short out[2];
   short chOut[16];
   for (size_t h=start; h<start+len; h++) {
+    // TODO: delay
+    if (!writes.empty()) {
+      QueuedWrite w=writes.front();
+      dsp.write(w.addr,w.val);
+      regPool[w.addr&0x7f]=w.val;
+      writes.pop();
+    }
+
     dsp.set_output(out,1);
     dsp.run(32);
     dsp.get_voice_outputs(chOut);
@@ -407,7 +415,9 @@ void DivPlatformSNES::reset() {
   dsp.set_output(NULL,0);
   memset(regPool,0,128);
   // TODO more initial values
-  sampleTableBase=0x100; // hack: this can't be 0 or channel 1 won't play??
+  // this can't be 0 or channel 1 won't play
+  // this can't be 0x100 either as that's used by SPC700 page 1 and the stack
+  sampleTableBase=0x200;
   rWrite(0x5d,sampleTableBase>>8);
   rWrite(0x0c,127); // global volume left
   rWrite(0x1c,127); // global volume right

src/engine/platform/snes.h

@@ -73,6 +73,13 @@ class DivPlatformSNES: public DivDispatch {
   signed char gblVolL, gblVolR;
   size_t sampleTableBase;
 
+  struct QueuedWrite {
+    unsigned char addr;
+    unsigned char val;
+    QueuedWrite(unsigned char a, unsigned char v): addr(a), val(v) {}
+  };
+  std::queue<QueuedWrite> writes;
+
   signed char sampleMem[65536];
   size_t sampleMemLen;
   unsigned char regPool[0x80];

src/engine/sample.cpp

@@ -33,6 +33,7 @@ extern "C" {
 #include "../../extern/adpcm/ymb_codec.h"
 #include "../../extern/adpcm/ymz_codec.h"
 }
+#include "brrUtils.h"
 
 DivSampleHistory::~DivSampleHistory() {
   if (data!=NULL) delete[] data;
@@ -851,7 +852,7 @@ void DivSample::render() {
         }
         break;
       case DIV_SAMPLE_DEPTH_BRR: // BRR
-        // TODO!
+        brrDecode(dataBRR,data16,samples);
         break;
       case DIV_SAMPLE_DEPTH_VOX: // VOX
         oki_decode(dataVOX,data16,samples);
@@ -908,7 +909,10 @@ void DivSample::render() {
       data8[i]=data16[i]>>8;
     }
   }
-  // TODO: BRR!
+  if (depth!=DIV_SAMPLE_DEPTH_VOX) { // BRR
+    if (!initInternal(DIV_SAMPLE_DEPTH_BRR,samples)) return;
+    brrEncode(data16,dataBRR,samples);
+  }
   if (depth!=DIV_SAMPLE_DEPTH_VOX) { // VOX
     if (!initInternal(DIV_SAMPLE_DEPTH_VOX,samples)) return;
     oki_encode(data16,dataVOX,samples);