/**
* Creates an audio stream for playback. The audio device used will depend on playbackDeviceId_.
*/
void PlayAudioEngine::createPlaybackStream(){
AAudioStreamBuilder* builder = createStreamBuilder();
if (builder != nullptr){
setupPlaybackStreamParameters(builder);
aaudio_result_t result = AAudioStreamBuilder_openStream(builder, &playStream_);
if (result == AAUDIO_OK && playStream_ != nullptr){
// check that we got PCM_FLOAT format
if (sampleFormat_ != AAudioStream_getFormat(playStream_)) {
LOGW("Sample format is not PCM_FLOAT");
}
sampleRate_ = AAudioStream_getSampleRate(playStream_);
framesPerBurst_ = AAudioStream_getFramesPerBurst(playStream_);
// Set the buffer size to the burst size - this will give us the minimum possible latency
AAudioStream_setBufferSizeInFrames(playStream_, framesPerBurst_);
bufSizeInFrames_ = framesPerBurst_;
PrintAudioStreamInfo(playStream_);
prepareOscillators();
// Start the stream - the dataCallback function will start being called
result = AAudioStream_requestStart(playStream_);
if (result != AAUDIO_OK) {
LOGE("Error starting stream. %s", AAudio_convertResultToText(result));
}
// Store the underrun count so we can tune the latency in the dataCallback
playStreamUnderrunCount_ = AAudioStream_getXRunCount(playStream_);
} else {
LOGE("Failed to create stream. Error: %s", AAudio_convertResultToText(result));
}
AAudioStreamBuilder_delete(builder);
} else {
LOGE("Unable to obtain an AAudioStreamBuilder object");
}
}
static void testOpenOptions(aaudio_direction_t direction,
int32_t channelCount,
int32_t sampleRate,
aaudio_format_t format) {
aaudio_result_t result = AAUDIO_OK;
int32_t bufferCapacity;
int32_t framesPerBurst = 0;
int32_t actualChannelCount = 0;
int32_t actualSampleRate = 0;
aaudio_format_t actualDataFormat = AAUDIO_FORMAT_UNSPECIFIED;
aaudio_sharing_mode_t actualSharingMode = AAUDIO_SHARING_MODE_SHARED;
aaudio_direction_t actualDirection;
AAudioStreamBuilder *aaudioBuilder = nullptr;
AAudioStream *aaudioStream = nullptr;
printf("TestOpen: dir = %d, chans = %3d, rate = %6d format = %d\n",
direction, channelCount, sampleRate, format);
// Use an AAudioStreamBuilder to contain requested parameters.
ASSERT_EQ(AAUDIO_OK, AAudio_createStreamBuilder(&aaudioBuilder));
// Request stream properties.
AAudioStreamBuilder_setDirection(aaudioBuilder, direction);
AAudioStreamBuilder_setSampleRate(aaudioBuilder, sampleRate);
AAudioStreamBuilder_setChannelCount(aaudioBuilder, channelCount);
AAudioStreamBuilder_setFormat(aaudioBuilder, format);
AAudioStreamBuilder_setDataCallback(aaudioBuilder, MyDataCallbackProc, nullptr);
//AAudioStreamBuilder_setPerformanceMode(aaudioBuilder, AAUDIO_PERFORMANCE_MODE_NONE);
AAudioStreamBuilder_setPerformanceMode(aaudioBuilder, AAUDIO_PERFORMANCE_MODE_LOW_LATENCY);
//AAudioStreamBuilder_setPerformanceMode(aaudioBuilder, AAUDIO_PERFORMANCE_MODE_POWER_SAVING);
// Create an AAudioStream using the Builder.
result = AAudioStreamBuilder_openStream(aaudioBuilder, &aaudioStream);
if (result != AAUDIO_OK) {
printf("Stream not opened! That may be OK.\n");
goto finish;
}
// Check to see what kind of stream we actually got.
actualSampleRate = AAudioStream_getSampleRate(aaudioStream);
actualChannelCount = AAudioStream_getChannelCount(aaudioStream);
actualDataFormat = AAudioStream_getFormat(aaudioStream);
actualDirection = AAudioStream_getDirection(aaudioStream);
printf(" dir = %d, chans = %3d, rate = %6d format = %d\n",
direction, actualChannelCount, actualSampleRate, actualDataFormat);
// If we ask for something specific then we should get that.
if (channelCount != AAUDIO_UNSPECIFIED) {
EXPECT_EQ(channelCount, actualChannelCount);
}
if (sampleRate != AAUDIO_UNSPECIFIED) {
EXPECT_EQ(sampleRate, actualSampleRate);
}
if (format != AAUDIO_FORMAT_UNSPECIFIED) {
EXPECT_EQ(format, actualDataFormat);
}
EXPECT_EQ(direction, actualDirection);
// This is the number of frames that are read in one chunk by a DMA controller
// or a DSP or a mixer.
framesPerBurst = AAudioStream_getFramesPerBurst(aaudioStream);
bufferCapacity = AAudioStream_getBufferCapacityInFrames(aaudioStream);
printf(" bufferCapacity = %d, remainder = %d\n",
bufferCapacity, bufferCapacity % framesPerBurst);
finish:
AAudioStream_close(aaudioStream);
AAudioStreamBuilder_delete(aaudioBuilder);
printf(" result = %d = %s\n", result, AAudio_convertResultToText(result));
}