AudioFlinger: PatchPanel: prioritize quality vs latency for FM Bridge
When a SwBridge is created, the default behavior is to start playback as
soon as possible, prioritizing the lowest strategy vs quality (potential
glitches).
This CL prevents this behavior for FM Tuner input devices if no fast mixer
and fast capture are used.
Signed-off-by: Francois Gaffie <francois.gaffie@renault.com>
Change-Id: I24cfb97d09518be4ab15775d8575957a220c25dc
diff --git a/services/audioflinger/PatchPanel.cpp b/services/audioflinger/PatchPanel.cpp
index a381c7d..b82601a 100644
--- a/services/audioflinger/PatchPanel.cpp
+++ b/services/audioflinger/PatchPanel.cpp
@@ -573,6 +573,12 @@
// create a special playback track to render to playback thread.
// this track is given the same buffer as the PatchRecord buffer
+
+ // Default behaviour is to start as soon as possible to have the lowest possible latency even if
+ // it might glitch.
+ // Disable this behavior for FM Tuner source if no fast capture/mixer available.
+ const bool isFmBridge = mAudioPatch.sources[0].ext.device.type == AUDIO_DEVICE_IN_FM_TUNER;
+ const size_t frameCountToBeReady = isFmBridge && !usePassthruPatchRecord ? frameCount / 4 : 1;
sp<PlaybackThread::PatchTrack> tempPatchTrack = new PlaybackThread::PatchTrack(
mPlayback.thread().get(),
streamType,
@@ -582,7 +588,9 @@
frameCount,
tempRecordTrack->buffer(),
tempRecordTrack->bufferSize(),
- outputFlags);
+ outputFlags,
+ {} /*timeout*/,
+ frameCountToBeReady);
status = mPlayback.checkTrack(tempPatchTrack.get());
if (status != NO_ERROR) {
return status;