Fix issue 2553359: Pandora does not work well with Passion deskdock / Cardock.
The problem is due to a too big difference between the buffer size used at the hardware interface and at the A2DP interface.
When no resampling occurs we don't notice problems but the timing is very tight. As soon as resampling is activated, the AudioTrack underruns.
This is because the AudioTrack buffers are not resized when moving the AudioTrack from hardware to A2DP output.
The AudioTrack buffers are calculated based on a hardware output buffer size of 3072 bytes. Which is much less than the A2DP output buffer size (10240).
The solution consists in creating new tracks with new buffers in AudioFlinger when the A2DP output is opened
instead of just transfering active tracks from hardware output mixer thread to the new A2DP output mixer thread.
To avoid synchronization issues between mixer threads and client processes, this is done by invalidating tracks
by setting a flag in their control block and having AudioTrack release the handle on this track (IAudioTrack)
and create a new IAudioTrack when this flag is detected next time obtainBuffer() or start() is executed.
AudioFlinger modifications:
- invalidate the tracks when setStreamOutput() is called
- make sure that notifications of output opening/closing and change of stream type to output mapping are sent synchronously to client process.
This is necessary so that AudioSystem has the new stream to output mapping when the AudioTrack detects the invalidate flag in the client process.
Previously their were sent when the corresponding thread loop was executed.
AudioTrack modifications:
- move frame count calculation and verification from set() to createTrack() so that is is updated every time a new IAudioTrack is created.
- detect track invalidate flag in obtainBuffer() and start() and create a new IAudioTrack.
AudioTrackShared modifications
- group all flags (out, flowControlFlag, forceReady...) into a single bit filed to save space.
Change-Id: I9ac26b6192230627d35084e1449640caaf7d56ee
diff --git a/libs/audioflinger/AudioPolicyManagerBase.cpp b/libs/audioflinger/AudioPolicyManagerBase.cpp
index c8b3f48..381a958 100644
--- a/libs/audioflinger/AudioPolicyManagerBase.cpp
+++ b/libs/audioflinger/AudioPolicyManagerBase.cpp
@@ -1249,6 +1249,17 @@
LOGV("setDeviceConnectionState() closing A2DP and duplicated output!");
if (mDuplicatedOutput != 0) {
+ AudioOutputDescriptor *dupOutputDesc = mOutputs.valueFor(mDuplicatedOutput);
+ AudioOutputDescriptor *hwOutputDesc = mOutputs.valueFor(mHardwareOutput);
+ // As all active tracks on duplicated output will be deleted,
+ // and as they were also referenced on hardware output, the reference
+ // count for their stream type must be adjusted accordingly on
+ // hardware output.
+ for (int i = 0; i < (int)AudioSystem::NUM_STREAM_TYPES; i++) {
+ int refCount = dupOutputDesc->mRefCount[i];
+ hwOutputDesc->changeRefCount((AudioSystem::stream_type)i,-refCount);
+ }
+
mpClientInterface->closeOutput(mDuplicatedOutput);
delete mOutputs.valueFor(mDuplicatedOutput);
mOutputs.removeItem(mDuplicatedOutput);
@@ -1288,11 +1299,6 @@
for (int i = 0; i < (int)AudioSystem::NUM_STREAM_TYPES; i++) {
if (getStrategy((AudioSystem::stream_type)i) == strategy) {
mpClientInterface->setStreamOutput((AudioSystem::stream_type)i, mHardwareOutput);
- int refCount = a2dpOutputDesc->mRefCount[i];
- // in the case of duplicated output, the ref count is first incremented
- // and then decremented on hardware output tus keeping its value
- hwOutputDesc->changeRefCount((AudioSystem::stream_type)i, refCount);
- a2dpOutputDesc->changeRefCount((AudioSystem::stream_type)i,-refCount);
}
}
// do not change newDevice if it was already set before this call by a previous call to
@@ -1318,11 +1324,6 @@
for (int i = 0; i < (int)AudioSystem::NUM_STREAM_TYPES; i++) {
if (getStrategy((AudioSystem::stream_type)i) == strategy) {
mpClientInterface->setStreamOutput((AudioSystem::stream_type)i, a2dpOutput);
- int refCount = hwOutputDesc->mRefCount[i];
- // in the case of duplicated output, the ref count is first incremented
- // and then decremented on hardware output tus keeping its value
- a2dpOutputDesc->changeRefCount((AudioSystem::stream_type)i, refCount);
- hwOutputDesc->changeRefCount((AudioSystem::stream_type)i,-refCount);
}
}
}