am 5893736d: am a67c7653: Merge "Increase kFastTrackMultiplier from 1 to 2" (5c474238) · Commits · e / os / android_frameworks_av

media/libmedia/AudioTrack.cpp

+7 −4

Original line number	Diff line number	Diff line
		@@ -866,7 +866,8 @@ status_t AudioTrack::createTrack_l(
		ALOGV("createTrack_l() output %d afLatency %d", output, afLatency);

		// The client's AudioTrack buffer is divided into n parts for purpose of wakeup by server, where
		// n = 1 fast track; nBuffering is ignored
		// n = 1 fast track with single buffering; nBuffering is ignored
		// n = 2 fast track with double buffering
		// n = 2 normal track, no sample rate conversion
		// n = 3 normal track, with sample rate conversion
		// (pessimistic; some non-1:1 conversion ratios don't actually need triple-buffering)
		@@ -1006,9 +1007,11 @@ status_t AudioTrack::createTrack_l(
		ALOGV("AUDIO_OUTPUT_FLAG_FAST successful; frameCount %u", frameCount);
		mAwaitBoost = true;
		if (sharedBuffer == 0) {
		// double-buffering is not required for fast tracks, due to tighter scheduling
		if (mNotificationFramesAct == 0 \|\| mNotificationFramesAct > frameCount) {
		mNotificationFramesAct = frameCount;
		// Theoretically double-buffering is not required for fast tracks,
		// due to tighter scheduling. But in practice, to accommodate kernels with
		// scheduling jitter, and apps with computation jitter, we use double-buffering.
		if (mNotificationFramesAct == 0 \|\| mNotificationFramesAct > frameCount/nBuffering) {
		mNotificationFramesAct = frameCount/nBuffering;
		}
		}
		} else {

services/audioflinger/Threads.cpp

+7 −7

Original line number	Diff line number	Diff line
		@@ -135,12 +135,12 @@ static const int kPriorityFastMixer = 3;

		// IAudioFlinger::createTrack() reports back to client the total size of shared memory area
		// for the track. The client then sub-divides this into smaller buffers for its use.
		// Currently the client uses double-buffering by default, but doesn't tell us about that.
		// So for now we just assume that client is double-buffered.
		// FIXME It would be better for client to tell AudioFlinger whether it wants double-buffering or
		// N-buffering, so AudioFlinger could allocate the right amount of memory.
		// Currently the client uses N-buffering by default, but doesn't tell us about the value of N.
		// So for now we just assume that client is double-buffered for fast tracks.
		// FIXME It would be better for client to tell AudioFlinger the value of N,
		// so AudioFlinger could allocate the right amount of memory.
		// See the client's minBufCount and mNotificationFramesAct calculations for details.
		static const int kFastTrackMultiplier = 1;
		static const int kFastTrackMultiplier = 2;

		// ----------------------------------------------------------------------------

		@@ -1210,7 +1210,7 @@ sp<AudioFlinger::PlaybackThread::Track> AudioFlinger::PlaybackThread::createTrac
		(
		(tid != -1) &&
		((frameCount == 0) \|\|
		(frameCount >= (mFrameCount * kFastTrackMultiplier)))
		(frameCount >= mFrameCount))
		)
		) &&
		// PCM data
		@@ -4687,7 +4687,7 @@ sp<AudioFlinger::RecordThread::RecordTrack> AudioFlinger::RecordThread::createR
		(
		(tid != -1) &&
		((frameCount == 0) \|\|
		(frameCount >= (mFrameCount * kFastTrackMultiplier)))
		(frameCount >= mFrameCount))
		) &&
		// FIXME when record supports non-PCM data, also check for audio_is_linear_pcm(format)
		// mono or stereo