aaudio: fix getXRunCount
Mixer was not advancing FIFO when underflowed so the client could not
detect the xrun.
Also underruns could cause the stream to drift in time relative to other
streams.
Bug: 64033855
Test: trigger underruns by sleeping in a callback
Change-Id: Ia038f5048ffbff3b82e9d86e6807483dfe6879d0
diff --git a/services/oboeservice/AAudioMixer.cpp b/services/oboeservice/AAudioMixer.cpp
index 8222734..952aa82 100644
--- a/services/oboeservice/AAudioMixer.cpp
+++ b/services/oboeservice/AAudioMixer.cpp
@@ -88,11 +88,11 @@
}
partIndex++;
}
- fifo->getFifoControllerBase()->advanceReadIndex(mFramesPerBurst - framesLeft);
- if (framesLeft > 0) {
- //ALOGW("AAudioMixer::mix() UNDERFLOW by %d / %d frames ----- UNDERFLOW !!!!!!!!!!",
- // framesLeft, mFramesPerBurst);
- }
+ // Always advance by one burst even if we do not have the data.
+ // Otherwise the stream timing will drift whenever there is an underflow.
+ // This actual underflow can then be detected by the client for XRun counting.
+ fifo->getFifoControllerBase()->advanceReadIndex(mFramesPerBurst);
+
#if AAUDIO_MIXER_ATRACE_ENABLED
ATRACE_END();
#endif /* AAUDIO_MIXER_ATRACE_ENABLED */