Merge "AudioFlinger: prevent retrograde timestamps for direct mode" (3fac40b9) · Commits · e / os / android_frameworks_av

services/audioflinger/PlaybackTracks.h

+3 −2

Original line number	Diff line number	Diff line
		@@ -157,8 +157,9 @@ private:
		bool mFlushHwPending; // track requests for thread flush

		// for last call to getTimestamp
		bool mPreviousValid;
		uint32_t mPreviousFramesWritten;
		bool mPreviousTimestampValid;
		// This is either the first timestamp or one that has passed
		// the check to prevent retrograde motion.
		AudioTimestamp mPreviousTimestamp;
		}; // end of Track

services/audioflinger/Tracks.cpp

+48 −29

Original line number	Diff line number	Diff line
		@@ -405,9 +405,7 @@ AudioFlinger::PlaybackThread::Track::Track(
		mAudioTrackServerProxy(NULL),
		mResumeToStopping(false),
		mFlushHwPending(false),
		mPreviousValid(false),
		mPreviousFramesWritten(0)
		// mPreviousTimestamp
		mPreviousTimestampValid(false)
		{
		// client == 0 implies sharedBuffer == 0
		ALOG_ASSERT(!(client == 0 && sharedBuffer != 0));
		@@ -864,7 +862,7 @@ void AudioFlinger::PlaybackThread::Track::reset()
		if (mState == FLUSHED) {
		mState = IDLE;
		}
		mPreviousValid = false;
		mPreviousTimestampValid = false;
		}
		}

		@@ -886,19 +884,22 @@ status_t AudioFlinger::PlaybackThread::Track::getTimestamp(AudioTimestamp& times
		{
		// Client should implement this using SSQ; the unpresented frame count in latch is irrelevant
		if (isFastTrack()) {
		// FIXME no lock held to set mPreviousValid = false
		// FIXME no lock held to set mPreviousTimestampValid = false
		return INVALID_OPERATION;
		}
		sp<ThreadBase> thread = mThread.promote();
		if (thread == 0) {
		// FIXME no lock held to set mPreviousValid = false
		// FIXME no lock held to set mPreviousTimestampValid = false
		return INVALID_OPERATION;
		}

		Mutex::Autolock _l(thread->mLock);
		PlaybackThread playbackThread = (PlaybackThread )thread.get();

		status_t result = INVALID_OPERATION;
		if (!isOffloaded() && !isDirect()) {
		if (!playbackThread->mLatchQValid) {
		mPreviousValid = false;
		mPreviousTimestampValid = false;
		return INVALID_OPERATION;
		}
		uint32_t unpresentedFrames =
		@@ -914,36 +915,54 @@ status_t AudioFlinger::PlaybackThread::Track::getTimestamp(AudioTimestamp& times
		uint32_t framesWritten = i >= 0 ?
		playbackThread->mLatchQ.mFramesReleased[i] :
		mAudioTrackServerProxy->framesReleased();
		bool checkPreviousTimestamp = mPreviousValid && framesWritten >= mPreviousFramesWritten;
		if (framesWritten < unpresentedFrames) {
		mPreviousValid = false;
		return INVALID_OPERATION;
		mPreviousTimestampValid = false;
		// return invalid result
		} else {
		timestamp.mPosition = framesWritten - unpresentedFrames;
		timestamp.mTime = playbackThread->mLatchQ.mTimestamp.mTime;
		result = NO_ERROR;
		}
		mPreviousFramesWritten = framesWritten;
		uint32_t position = framesWritten - unpresentedFrames;
		struct timespec time = playbackThread->mLatchQ.mTimestamp.mTime;
		if (checkPreviousTimestamp) {
		if (time.tv_sec < mPreviousTimestamp.mTime.tv_sec \|\|
		(time.tv_sec == mPreviousTimestamp.mTime.tv_sec &&
		time.tv_nsec < mPreviousTimestamp.mTime.tv_nsec)) {
		ALOGW("Time is going backwards");
		} else { // offloaded or direct
		result = playbackThread->getTimestamp_l(timestamp);
		}

		// Prevent retrograde motion in timestamp.
		if (result == NO_ERROR) {
		if (mPreviousTimestampValid) {
		if (timestamp.mTime.tv_sec < mPreviousTimestamp.mTime.tv_sec \|\|
		(timestamp.mTime.tv_sec == mPreviousTimestamp.mTime.tv_sec &&
		timestamp.mTime.tv_nsec < mPreviousTimestamp.mTime.tv_nsec)) {
		ALOGW("WARNING - retrograde timestamp time");
		// FIXME Consider blocking this from propagating upwards.
		}

		// Looking at signed delta will work even when the timestamps
		// are wrapping around.
		int32_t deltaPosition = static_cast<int32_t>(timestamp.mPosition
		- mPreviousTimestamp.mPosition);
		// position can bobble slightly as an artifact; this hides the bobble
		static const uint32_t MINIMUM_POSITION_DELTA = 8u;
		if ((position <= mPreviousTimestamp.mPosition) \|\|
		(position - mPreviousTimestamp.mPosition) < MINIMUM_POSITION_DELTA) {
		position = mPreviousTimestamp.mPosition;
		time = mPreviousTimestamp.mTime;
		static const int32_t MINIMUM_POSITION_DELTA = 8;
		if (deltaPosition < 0) {
		#define TIME_TO_NANOS(time) ((uint64_t)time.tv_sec * 1000000000 + time.tv_nsec)
		ALOGW("WARNING - retrograde timestamp position corrected,"
		" %d = %u - %u, (at %llu, %llu nanos)",
		deltaPosition,
		timestamp.mPosition,
		mPreviousTimestamp.mPosition,
		TIME_TO_NANOS(timestamp.mTime),
		TIME_TO_NANOS(mPreviousTimestamp.mTime));
		#undef TIME_TO_NANOS
		}
		if (deltaPosition < MINIMUM_POSITION_DELTA) {
		// Current timestamp is bad. Use last valid timestamp.
		timestamp = mPreviousTimestamp;
		}
		}
		timestamp.mPosition = position;
		timestamp.mTime = time;
		mPreviousTimestamp = timestamp;
		mPreviousValid = true;
		return NO_ERROR;
		mPreviousTimestampValid = true;
		}

		return playbackThread->getTimestamp_l(timestamp);
		return result;
		}

		status_t AudioFlinger::PlaybackThread::Track::attachAuxEffect(int EffectId)