handle mpeg2ts PTS wraparound (799c9682) · Commits · e / os / android_frameworks_av

media/libstagefright/mpeg2ts/ATSParser.cpp

+21 −1

Original line number	Diff line number	Diff line
		@@ -92,8 +92,10 @@ private:
		KeyedVector<unsigned, sp<Stream> > mStreams;
		bool mFirstPTSValid;
		uint64_t mFirstPTS;
		int64_t mLastRecoveredPTS;

		status_t parseProgramMap(ABitReader *br);
		int64_t recoverPTS(uint64_t PTS_33bit);

		DISALLOW_EVIL_CONSTRUCTORS(Program);
		};
		@@ -182,7 +184,8 @@ ATSParser::Program::Program(
		mProgramNumber(programNumber),
		mProgramMapPID(programMapPID),
		mFirstPTSValid(false),
		mFirstPTS(0) {
		mFirstPTS(0),
		mLastRecoveredPTS(0) {
		ALOGV("new program number %u", programNumber);
		}

		@@ -425,6 +428,21 @@ status_t ATSParser::Program::parseProgramMap(ABitReader *br) {
		return OK;
		}

		int64_t ATSParser::Program::recoverPTS(uint64_t PTS_33bit) {
		// We only have the lower 33-bit of the PTS. It could overflow within a
		// reasonable amount of time. To handle the wrap-around, use fancy math
		// to get an extended PTS that is within [-0xffffffff, 0xffffffff]
		// of the latest recovered PTS.
		mLastRecoveredPTS = static_cast<int64_t>(
		((mLastRecoveredPTS - PTS_33bit + 0x100000000ll)
		& 0xfffffffe00000000ull) \| PTS_33bit);

		// We start from 0, but recovered PTS could be slightly below 0.
		// Clamp it to 0 as rest of the pipeline doesn't take negative pts.
		// (eg. video is read first and starts at 0, but audio starts at 0xfffffff0)
		return mLastRecoveredPTS < 0ll ? 0ll : mLastRecoveredPTS;
		}

		sp<MediaSource> ATSParser::Program::getSource(SourceType type) {
		size_t index = (type == AUDIO) ? 0 : 0;

		@@ -455,6 +473,8 @@ bool ATSParser::Program::hasSource(SourceType type) const {
		}

		int64_t ATSParser::Program::convertPTSToTimestamp(uint64_t PTS) {
		PTS = recoverPTS(PTS);

		if (!(mParser->mFlags & TS_TIMESTAMPS_ARE_ABSOLUTE)) {
		if (!mFirstPTSValid) {
		mFirstPTSValid = true;