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sceSas: Resample audio according to pitch

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Henrik Rydgard committed 2012-12-16 21:20:16 +01:00
1 parent 15b7c1c96c
commit 369afa5b93
3 files changed
+66 -16
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Core/HW/SasAudio.cpp
+48 -8
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@@ -148,28 +148,54 @@ void SasInstance::Mix(u32 outAddr)
if (!voice.playing)
continue;
// TODO: Special case no-resample case for speed
if (voice.vagAddr != 0) {
for (int i = 0; i < grainSize; i++) {
// Load resample history (so we can use a wide filter)
resampleBuffer[0] = voice.resampleHist[0];
resampleBuffer[1] = voice.resampleHist[1];
// Figure out number of samples to read.
int curSample = voice.samplePos / PSP_SAS_PITCH_BASE;
int lastSample = (voice.samplePos + grainSize * voice.pitch) / PSP_SAS_PITCH_BASE;
int numSamples = lastSample - curSample;
// Read N samples into the resample buffer. Could do either PCM or VAG here.
for (int i = 0; i < numSamples; i++) {
int sample = voice.vag.GetSample();
voice.samplePos++;
if (voice.samplePos >= voice.vagSize || voice.vag.End()) {
if (voice.loop) {
voice.vag.Loop();
voice.Loop();
} else {
voice.playing = false;
// TODO: clear rest of buffer
memset(resampleBuffer, 0, (numSamples - i) * sizeof(resampleBuffer[0]));
}
break;
}
int l = sample * voice.volumeLeft >> 15;
int r = sample * voice.volumeRight >> 15;
resampleBuffer[i + 2] = sample;
}
// Save resample history
voice.resampleHist[0] = resampleBuffer[numSamples - 2];
voice.resampleHist[1] = resampleBuffer[numSamples - 1];
// Resample to the correct pitch, writing exactly "grainSize" samples.
int bufferPos = (voice.samplePos & (PSP_SAS_PITCH_BASE - 1)) + 2 * PSP_SAS_PITCH_BASE;
for (int i = 0; i < grainSize; i++) {
// For now: nearest neighbour, not even using the resample history at all.
int sample = resampleBuffer[bufferPos / PSP_SAS_PITCH_BASE];
bufferPos += voice.pitch;
// We mix into this 32-bit temp buffer and clip in a second loop
mixBuffer[i * 2] += l;
mixBuffer[i * 2 + 1] += r;
mixBuffer[i * 2] += sample * voice.volumeLeft >> 15;
mixBuffer[i * 2 + 1] += sample * voice.volumeRight >> 15;
}
}
else if (voice.pcmAddr != 0) {
// PCM mixing should be easy, can probably share code with VAG if we predecode those
// PCM mixing should be easy, can share code with VAG
}
else if (voice.noiseFreq != 0) {
// Generate noise?
@@ -185,4 +211,18 @@ void SasInstance::Mix(u32 outAddr)
else if (sample < -32768) out[i] = -32768;
else out[i] = sample;
}
}
void SasVoice::Reset()
{
resampleHist[0] = 0;
resampleHist[1] = 0;
}
void SasVoice::Loop()
{
if (vagAddr) {
vag.Start(Memory::GetPointer(vagAddr));
samplePos = 0;
}
}