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Use ring buffer for samples and detect buffer underruns

This commit is contained in:
Flyinghead 2018-04-29 17:56:01 +02:00
parent 39e0f378cb
commit a953a0baa7
1 changed files with 19 additions and 18 deletions
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37
core/oslib/audiobackend_coreaudio.cpp
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@ -12,6 +12,7 @@
It does work on my macmini though
*/
#include <atomic>
#include "oslib/audiobackend_coreaudio.h"
#if HOST_OS == OS_DARWIN
@ -21,29 +22,31 @@
AudioUnit audioUnit;
u8 samples_temp[1024 * 4];
#define BUFSIZE 8192
u8 samples_temp[BUFSIZE];
volatile int samples_ptr = 0;
std::atomic<int> samples_wptr;
int samples_rptr;
cResetEvent bufferEmpty(false, true);
OSStatus coreaudio_callback(void* ctx, AudioUnitRenderActionFlags* flags, const AudioTimeStamp* ts,
UInt32 bus, UInt32 frames, AudioBufferList* abl)
{
verify(frames <= 1024);
u8* src = samples_temp;
for (int i = 0; i < abl->mNumberBuffers; i++) {
memcpy(abl->mBuffers[i].mData, src, abl->mBuffers[i].mDataByteSize);
src += abl->mBuffers[i].mDataByteSize;
if ((samples_rptr + abl->mBuffers[i].mDataByteSize) % BUFSIZE > samples_wptr) {
//printf("Core Audio: buffer underrun");
memset(abl->mBuffers[i].mData, '\0', abl->mBuffers[i].mDataByteSize);
}
else
{
memcpy(abl->mBuffers[i].mData, samples_temp + samples_rptr, abl->mBuffers[i].mDataByteSize);
samples_rptr = (samples_rptr + abl->mBuffers[i].mDataByteSize) % BUFSIZE;
}
}
samples_ptr -= frames * 2 * 2;
if (samples_ptr < 0)
samples_ptr = 0;
if (samples_ptr == 0)
bufferEmpty.Set();
bufferEmpty.Set();
return noErr;
}
@ -114,11 +117,9 @@ static u32 coreaudio_push(void* frame, u32 samples, bool wait)
{
if (wait)
bufferEmpty.Wait();
if (samples_ptr == 0) {
memcpy(&samples_temp[samples_ptr], frame, samples * 4);
samples_ptr += samples * 4;
}
memcpy(&samples_temp[samples_wptr], frame, samples * 4);
samples_wptr = (samples_wptr + samples * 4) % BUFSIZE;
return 1;
}