aaudio: write if there is room
Go ahead and write the data to the buffer if there is room,
even if it exceeds the setBufferSizeInFrames().
There is no point of holding it in the application buffer.
By making the data available to the DSP we can reduce glitches
or reduce latency.
Because this offers better glitch protection, we can allow
setBufferSizeInFrames() to accept a buffer size of zero.
This will provide the lowest possible latency.
Test: OboeTester glitch test
Change-Id: Ie706867c5dd57c29b4393c806cd51ae09198873e
diff --git a/media/libaaudio/src/client/AudioStreamInternalPlay.cpp b/media/libaaudio/src/client/AudioStreamInternalPlay.cpp
index b8ef247..dc9f48c 100644
--- a/media/libaaudio/src/client/AudioStreamInternalPlay.cpp
+++ b/media/libaaudio/src/client/AudioStreamInternalPlay.cpp
@@ -167,8 +167,10 @@
ATRACE_INT("aaWrote", framesWritten);
}
+ // Sleep if there is too much data in the buffer.
// Calculate an ideal time to wake up.
- if (wakeTimePtr != nullptr && framesWritten >= 0) {
+ if (wakeTimePtr != nullptr
+ && (mAudioEndpoint.getFullFramesAvailable() >= getBufferSize())) {
// By default wake up a few milliseconds from now. // TODO review
int64_t wakeTime = currentNanoTime + (1 * AAUDIO_NANOS_PER_MILLISECOND);
aaudio_stream_state_t state = getState();
@@ -184,14 +186,10 @@
break;
case AAUDIO_STREAM_STATE_STARTED:
{
- // When do we expect the next read burst to occur?
-
- // Calculate frame position based off of the writeCounter because
- // the readCounter might have just advanced in the background,
- // causing us to sleep until a later burst.
- int64_t nextPosition = mAudioEndpoint.getDataWriteCounter() + mFramesPerBurst
- - mAudioEndpoint.getBufferSizeInFrames();
- wakeTime = mClockModel.convertPositionToTime(nextPosition);
+ // Sleep until the readCounter catches up and we only have
+ // the getBufferSize() frames of data sitting in the buffer.
+ int64_t nextReadPosition = mAudioEndpoint.getDataWriteCounter() - getBufferSize();
+ wakeTime = mClockModel.convertPositionToTime(nextReadPosition);
}
break;
default: