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kind of implement K05 ADPCM

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This commit is contained in:
tildearrow 2023-08-29 06:16:07 -05:00
parent 32ec87ca27
commit 61b0179da1
2 changed files with 73 additions and 5 deletions
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74
src/engine/sample.cpp
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@ -1196,6 +1196,10 @@ unsigned char c219ShiftToVal[16]={
5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 7, 7, 8, 8, 8, 8
};
signed char adpcmKTable[16]={
0, 1, 2, 4, 8, 16, 32, 64, -128, -64, -32, -16, -8, -4, -2, -1
};
void DivSample::render(unsigned int formatMask) {
// step 1: convert to 16-bit if needed
if (depth!=DIV_SAMPLE_DEPTH_16BIT) {
@ -1228,11 +1232,20 @@ void DivSample::render(unsigned int formatMask) {
case DIV_SAMPLE_DEPTH_ADPCM_B: // ADPCM-B
ymb_decode(dataB,data16,samples);
break;
case DIV_SAMPLE_DEPTH_ADPCM_K: // K05 ADPCM
case DIV_SAMPLE_DEPTH_ADPCM_K: { // K05 ADPCM
signed char s=0;
for (unsigned int i=0; i<samples; i++) {
// TODO: ADPCM-K
unsigned char nibble=dataK[i>>1];
if (i&1) { // TODO: is this right?
nibble>>=4;
} else {
nibble&=15;
}
s+=adpcmKTable[nibble];
data16[i]=s<<8;
}
break;
}
case DIV_SAMPLE_DEPTH_8BIT: // 8-bit PCM
for (unsigned int i=0; i<samples; i++) {
data16[i]=data8[i]<<8;
@ -1308,7 +1321,62 @@ void DivSample::render(unsigned int formatMask) {
}
if (NOT_IN_FORMAT(DIV_SAMPLE_DEPTH_ADPCM_K)) { // K05 ADPCM
if (!initInternal(DIV_SAMPLE_DEPTH_ADPCM_K,samples)) return;
// TODO: ADPCM-K
signed char accum=0;
unsigned char out=0;
for (unsigned int i=0; i<samples; i++) {
signed char target=data16[i]>>8;
short delta=target-accum;
unsigned char next=0;
if (delta!=0) {
int b=bsr((delta>=0)?delta:-delta);
if (delta>=0) {
if (b>7) b=7;
next=b&15;
// test previous
if (next>1) {
const signed char t1=accum+adpcmKTable[next];
const signed char t2=accum+adpcmKTable[next-1];
const signed char d1=((t1-target)<0)?(target-t1):(t1-target);
const signed char d2=((t2-target)<0)?(target-t2):(t2-target);
if (d2<d1) next--;
}
} else {
if (b>8) b=8;
next=(16-b)&15;
// test next
if (next<15) {
const signed char t1=accum+adpcmKTable[next];
const signed char t2=accum+adpcmKTable[next+1];
const signed char d1=((t1-target)<0)?(target-t1):(t1-target);
const signed char d2=((t2-target)<0)?(target-t2):(t2-target);
if (d2<d1) next++;
}
}
/*if (accum+adpcmKTable[next]>=128 || accum+adpcmKTable[next]<-128) {
if (delta>=0) {
next--;
} else {
next++;
if (next>15) next=15;
}
}*/
}
out<<=4;
out|=next;
accum+=adpcmKTable[next];
if (i&1) {
dataK[i>>1]=out;
out=0;
}
}
}
if (NOT_IN_FORMAT(DIV_SAMPLE_DEPTH_8BIT)) { // 8-bit PCM
if (!initInternal(DIV_SAMPLE_DEPTH_8BIT,samples)) return;