// Mix samples from the various audio channels into a single sample queue.
// This single sample queue is where __AudioMix should read from. If the sample queue is full, we should
// just sleep the main emulator thread a little.
void __AudioUpdate()
{
// Audio throttle doesn't really work on the PSP since the mixing intervals are so closely tied
// to the CPU. Much better to throttle the frame rate on frame display and just throw away audio
// if the buffer somehow gets full.
s32 mixBuffer[hwBlockSize * 2];
memset(mixBuffer, 0, sizeof(mixBuffer));
for (u32 i = 0; i < PSP_AUDIO_CHANNEL_MAX + 1; i++)
{
if (!chans[i].reserved)
continue;
__AudioWakeThreads(chans[i], 0, hwBlockSize);
if (!chans[i].sampleQueue.size()) {
// ERROR_LOG(HLE, "No queued samples, skipping channel %i", i);
continue;
}
for (int s = 0; s < hwBlockSize; s++)
{
if (chans[i].sampleQueue.size() >= 2)
{
s16 sampleL = chans[i].sampleQueue.pop_front();
s16 sampleR = chans[i].sampleQueue.pop_front();
mixBuffer[s * 2 + 0] += sampleL;
mixBuffer[s * 2 + 1] += sampleR;
}
else
{
ERROR_LOG(HLE, "Channel %i buffer underrun at %i of %i", i, s, hwBlockSize);
break;
}
}
}
if (g_Config.bEnableSound) {
lock_guard guard(section);
if (outAudioQueue.room() >= hwBlockSize * 2) {
// Push the mixed samples onto the output audio queue.
for (int i = 0; i < hwBlockSize; i++) {
s16 sampleL = clamp_s16(mixBuffer[i * 2 + 0]);
s16 sampleR = clamp_s16(mixBuffer[i * 2 + 1]);
outAudioQueue.push((s16)sampleL);
outAudioQueue.push((s16)sampleR);
}
} else {
// This happens quite a lot. There's still something slightly off
// about the amount of audio we produce.
DEBUG_LOG(HLE, "Audio outbuffer overrun! room = %i / %i", outAudioQueue.room(), (u32)outAudioQueue.capacity());
}
}
}
if (g_Config.bEnableSound) {
section.lock();
if (outAudioQueue.room() >= hwBlockSize * 2) {
// Push the mixed samples onto the output audio queue.
for (int i = 0; i < hwBlockSize; i++) {
s32 sampleL = mixBuffer[i * 2 + 0] >> 2; // TODO - what factor?
s32 sampleR = mixBuffer[i * 2 + 1] >> 2;
outAudioQueue.push((s16)sampleL);
outAudioQueue.push((s16)sampleR);
}
} else {
// This happens quite a lot. There's still something slightly off
// about the amount of audio we produce.
DEBUG_LOG(HLE, "Audio outbuffer overrun! room = %i / %i", outAudioQueue.room(), (u32)outAudioQueue.capacity());
}
section.unlock();
}
}
void __AudioSetOutputFrequency(int freq)
{
WARN_LOG(HLE, "Switching audio frequency to %i", freq);
mixFrequency = freq;
}
// numFrames is number of stereo frames.
int __AudioMix(short *outstereo, int numFrames)
{