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Fix bug causing stack overflow in SasAudio, #9190. Move the mixbuffer off the stack for easier-to-diagnose error (this trashed the info I needed to debug pretty badly...)

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This commit is contained in:
Henrik Rydgård 2016-12-27 18:31:43 +01:00
parent c89ad2294c
commit ad04f97acb
2 changed files with 16 additions and 17 deletions
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32
Core/HW/SasAudio.cpp
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@ -493,32 +493,30 @@ void SasInstance::MixVoice(SasVoice &voice) {
++delay;
}
// Resample to the correct pitch, writing exactly "grainSize" samples.
// Resample to the correct pitch, writing exactly "grainSize" samples. We need a buffer that can
// fit 4x that, as the max pitch is 0x4000.
// TODO: Special case no-resample case (and 2x and 0.5x) for speed, it's not uncommon
int16_t temp[PSP_SAS_MAX_GRAIN + 2];
// Sanity check sampleFrac. Should be at most 2 samples ahead, if more then something has gone wrong (pitch
// cannot legally be more than 2x, though games might do more so we leave a margin...).
// In the future we should figure out all these cases.
u32 sampleFrac = voice.sampleFrac;
if (sampleFrac > PSP_SAS_PITCH_BASE * 4)
sampleFrac = 0;
// Two passes: First read, then resample.
temp[0] = voice.resampleHist[0];
temp[1] = voice.resampleHist[1];
mixTemp_[0] = voice.resampleHist[0];
mixTemp_[1] = voice.resampleHist[1];
int samplesToRead = (sampleFrac + voice.pitch * (grainSize - delay)) >> PSP_SAS_PITCH_BASE_SHIFT;
voice.ReadSamples(&temp[2], samplesToRead);
int voicePitch = voice.pitch;
u32 sampleFrac = voice.sampleFrac;
int samplesToRead = (sampleFrac + voicePitch * (grainSize - delay)) >> PSP_SAS_PITCH_BASE_SHIFT;
if (samplesToRead > ARRAY_SIZE(mixTemp_) - 2) {
PanicAlert("Too many samples to read! This shouldn't happen.");
}
voice.ReadSamples(&mixTemp_[2], samplesToRead);
int tempPos = 2 + samplesToRead;
for (int i = delay; i < grainSize; i++) {
const int16_t *s = temp + (sampleFrac >> PSP_SAS_PITCH_BASE_SHIFT);
const int16_t *s = mixTemp_ + (sampleFrac >> PSP_SAS_PITCH_BASE_SHIFT);
// Linear interpolation. Good enough. Need to make resampleHist bigger if we want more.
int f = sampleFrac & PSP_SAS_PITCH_MASK;
int sample = (s[0] * (PSP_SAS_PITCH_MASK - f) + s[1] * f) >> PSP_SAS_PITCH_BASE_SHIFT;
sampleFrac += voice.pitch;
sampleFrac += voicePitch;
// The maximum envelope height (PSP_SAS_ENVELOPE_HEIGHT_MAX) is (1 << 30) - 1.
// Reduce it to 14 bits, by shifting off 15. Round up by adding (1 << 14) first.
@ -539,8 +537,8 @@ void SasInstance::MixVoice(SasVoice &voice) {
sendBuffer[i * 2 + 1] += sample * voice.effectRight >> 12;
}
voice.resampleHist[0] = temp[tempPos - 2];
voice.resampleHist[1] = temp[tempPos - 1];
voice.resampleHist[0] = mixTemp_[tempPos - 2];
voice.resampleHist[1] = mixTemp_[tempPos - 1];
voice.sampleFrac = sampleFrac - (tempPos - 2) * PSP_SAS_PITCH_BASE;;

1
Core/HW/SasAudio.h
View File

@ -311,4 +311,5 @@ public:
private:
SasReverb reverb_;
int grainSize;
int16_t mixTemp_[PSP_SAS_MAX_GRAIN * 4 + 2 + 8]; // some extra margin for very high pitches.
};