AudioTrack: Add hasStarted method (65ffdfc7) · Commits · e / os / android_frameworks_av

include/media/AudioTrack.h

+25 −0

Original line number	Diff line number	Diff line
		@@ -758,6 +758,9 @@ public:
		* The timestamp parameter is undefined on return, if status is not NO_ERROR.
		*/
		status_t getTimestamp(AudioTimestamp& timestamp);
		private:
		status_t getTimestamp_l(AudioTimestamp& timestamp);
		public:

		/* Return the extended timestamp, with additional timebase info and improved drain behavior.
		*
		@@ -840,6 +843,24 @@ public:
		status_t pendingDuration(int32_t *msec,
		ExtendedTimestamp::Location location = ExtendedTimestamp::LOCATION_SERVER);

		/* hasStarted() is used to determine if audio is now audible at the device after
		* a start() command. The underlying implementation checks a nonzero timestamp position
		* or increment for the audible assumption.
		*
		* hasStarted() returns true if the track has been started() and audio is audible
		* and no subsequent pause() or flush() has been called. Immediately after pause() or
		* flush() hasStarted() will return false.
		*
		* If stop() has been called, hasStarted() will return true if audio is still being
		* delivered or has finished delivery (even if no audio was written) for both offloaded
		* and normal tracks. This property removes a race condition in checking hasStarted()
		* for very short clips, where stop() must be called to finish drain.
		*
		* In all cases, hasStarted() may turn false briefly after a subsequent start() is called
		* until audio becomes audible again.
		*/
		bool hasStarted(); // not const

		protected:
		/* copying audio tracks is not allowed */
		AudioTrack(const AudioTrack& other);
		@@ -1041,6 +1062,10 @@ protected:
		// and could be easily widened to uint64_t
		int64_t mStartUs; // the start time after flush or stop.
		// only used for offloaded and direct tracks.
		ExtendedTimestamp mStartEts; // Extended timestamp at start for normal
		// AudioTracks.
		AudioTimestamp mStartTs; // Timestamp at start for offloaded or direct
		// AudioTracks.

		bool mPreviousTimestampValid;// true if mPreviousTimestamp is valid
		bool mTimestampStartupGlitchReported; // reduce log spam

media/libmedia/AudioTrack.cpp

+90 −7

Original line number	Diff line number	Diff line
		@@ -543,6 +543,7 @@ status_t AudioTrack::set(
		mTimestampStartupGlitchReported = false;
		mRetrogradeMotionReported = false;
		mPreviousLocation = ExtendedTimestamp::LOCATION_INVALID;
		mStartTs.mPosition = 0;
		mUnderrunCountOffset = 0;
		mFramesWritten = 0;
		mFramesWrittenServerOffset = 0;
		@@ -570,6 +571,17 @@ status_t AudioTrack::start()
		mState = STATE_ACTIVE;
		}
		(void) updateAndGetPosition_l();

		// save start timestamp
		if (isOffloadedOrDirect_l()) {
		if (getTimestamp_l(mStartTs) != OK) {
		mStartTs.mPosition = 0;
		}
		} else {
		if (getTimestamp_l(&mStartEts) != OK) {
		mStartEts.clear();
		}
		}
		if (previousState == STATE_STOPPED \|\| previousState == STATE_FLUSHED) {
		// reset current position as seen by client to 0
		mPosition = 0;
		@@ -578,19 +590,17 @@ status_t AudioTrack::start()
		mRetrogradeMotionReported = false;
		mPreviousLocation = ExtendedTimestamp::LOCATION_INVALID;

		// read last server side position change via timestamp.
		ExtendedTimestamp ets;
		if (mProxy->getTimestamp(&ets) == OK &&
		ets.mTimeNs[ExtendedTimestamp::LOCATION_SERVER] > 0) {
		if (!isOffloadedOrDirect_l()
		&& mStartEts.mTimeNs[ExtendedTimestamp::LOCATION_SERVER] > 0) {
		// Server side has consumed something, but is it finished consuming?
		// It is possible since flush and stop are asynchronous that the server
		// is still active at this point.
		ALOGV("start: server read:%lld cumulative flushed:%lld client written:%lld",
		(long long)(mFramesWrittenServerOffset
		+ ets.mPosition[ExtendedTimestamp::LOCATION_SERVER]),
		(long long)ets.mFlushed,
		+ mStartEts.mPosition[ExtendedTimestamp::LOCATION_SERVER]),
		(long long)mStartEts.mFlushed,
		(long long)mFramesWritten);
		mFramesWrittenServerOffset = -ets.mPosition[ExtendedTimestamp::LOCATION_SERVER];
		mFramesWrittenServerOffset = -mStartEts.mPosition[ExtendedTimestamp::LOCATION_SERVER];
		}
		mFramesWritten = 0;
		mProxy->clearTimestamp(); // need new server push for valid timestamp
		@@ -2328,7 +2338,11 @@ status_t AudioTrack::getTimestamp_l(ExtendedTimestamp *timestamp)
		status_t AudioTrack::getTimestamp(AudioTimestamp& timestamp)
		{
		AutoMutex lock(mLock);
		return getTimestamp_l(timestamp);
		}

		status_t AudioTrack::getTimestamp_l(AudioTimestamp& timestamp)
		{
		bool previousTimestampValid = mPreviousTimestampValid;
		// Set false here to cover all the error return cases.
		mPreviousTimestampValid = false;
		@@ -2750,6 +2764,75 @@ status_t AudioTrack::pendingDuration(int32_t *msec, ExtendedTimestamp::Location
		return NO_ERROR;
		}

		bool AudioTrack::hasStarted()
		{
		AutoMutex lock(mLock);
		switch (mState) {
		case STATE_STOPPED:
		if (isOffloadedOrDirect_l()) {
		// check if we have started in the past to return true.
		return mStartUs > 0;
		}
		// A normal audio track may still be draining, so
		// check if stream has ended. This covers fasttrack position
		// instability and start/stop without any data written.
		if (mProxy->getStreamEndDone()) {
		return true;
		}
		// fall through
		case STATE_ACTIVE:
		case STATE_STOPPING:
		break;
		case STATE_PAUSED:
		case STATE_PAUSED_STOPPING:
		case STATE_FLUSHED:
		return false; // we're not active
		default:
		LOG_ALWAYS_FATAL("Invalid mState in hasStarted(): %d", mState);
		break;
		}

		// wait indicates whether we need to wait for a timestamp.
		// This is conservatively figured - if we encounter an unexpected error
		// then we will not wait.
		bool wait = false;
		if (isOffloadedOrDirect_l()) {
		AudioTimestamp ts;
		status_t status = getTimestamp_l(ts);
		if (status == WOULD_BLOCK) {
		wait = true;
		} else if (status == OK) {
		wait = (ts.mPosition == 0 \|\| ts.mPosition == mStartTs.mPosition);
		}
		ALOGV("hasStarted wait:%d ts:%u start position:%lld",
		(int)wait,
		ts.mPosition,
		(long long)mStartTs.mPosition);
		} else {
		int location = ExtendedTimestamp::LOCATION_SERVER; // for ALOG
		ExtendedTimestamp ets;
		status_t status = getTimestamp_l(&ets);
		if (status == WOULD_BLOCK) { // no SERVER or KERNEL frame info in ets
		wait = true;
		} else if (status == OK) {
		for (location = ExtendedTimestamp::LOCATION_KERNEL;
		location >= ExtendedTimestamp::LOCATION_SERVER; --location) {
		if (ets.mTimeNs[location] < 0 \|\| mStartEts.mTimeNs[location] < 0) {
		continue;
		}
		wait = ets.mPosition[location] == 0
		\|\| ets.mPosition[location] == mStartEts.mPosition[location];
		break;
		}
		}
		ALOGV("hasStarted wait:%d ets:%lld start position:%lld",
		(int)wait,
		(long long)ets.mPosition[location],
		(long long)mStartEts.mPosition[location]);
		}
		return !wait;
		}

		// =========================================================================

		void AudioTrack::DeathNotifier::binderDied(const wp<IBinder>& who __unused)