Merge "Add Timestamp Validation in MPEG4Writer" into main (06a2373a) · Commits · e / os / android_frameworks_av

media/libstagefright/MPEG4Writer.cpp

+37 −0

Original line number	Diff line number	Diff line
		@@ -172,6 +172,7 @@ public:
		const char *getTrackType() const;
		void resetInternal();
		int64_t trackMetaDataSize();
		bool isTimestampValid(int64_t timeUs);

		private:
		// A helper class to handle faster write box with table entries
		@@ -2430,6 +2431,42 @@ status_t MPEG4Writer::setNextFd(int fd) {
		return OK;
		}

		bool MPEG4Writer::isSampleMetadataValid(size_t trackIndex, int64_t timeUs) {
		// Track Index starts from zero, so it should be at least 1 less than size.
		if (trackIndex >= mTracks.size()) {
		ALOGE("Incorrect trackIndex %zu, mTracks->size() %zu", trackIndex, mTracks.size());
		return false;
		}

		List<Track *>::iterator it = mTracks.begin();

		// (*it) is already pointing to trackIndex 0.
		for (int i = 1; i <= trackIndex; i++) {
		it++;
		}

		return (*it)->isTimestampValid(timeUs);
		}

		bool MPEG4Writer::Track::isTimestampValid(int64_t timeUs) {
		// No timescale if HEIF
		if (mIsHeif) {
		return true;
		}

		// Ensure that the timeUs value does not have extremely low or high values
		// that would cause an underflow or overflow, like in the calculation -
		// mdhdDuration = (trakDurationUs * mTimeScale + 5E5) / 1E6
		if (abs(timeUs) >= (INT64_MAX - 5E5) / mTimeScale) {
		return false;
		}
		// Limit check for calculations in ctts box
		if (abs(timeUs) + kMaxCttsOffsetTimeUs >= INT64_MAX / mTimeScale) {
		return false;
		}
		return true;
		}

		bool MPEG4Writer::Track::isExifData(
		MediaBufferBase buffer, uint32_t tiffHdrOffset) const {
		if (!mIsHeif) {

+3 −0

Original line number	Diff line number	Diff line
		@@ -77,6 +77,9 @@ public:
		virtual void setStartTimeOffsetMs(int ms) { mStartTimeOffsetMs = ms; }
		virtual int32_t getStartTimeOffsetMs() const { return mStartTimeOffsetMs; }
		virtual status_t setNextFd(int fd);
		// Returns true if the timestamp is valid which is compatible with the Mpeg4.
		// Note that this overloads that method in the base class.
		bool isSampleMetadataValid(size_t trackIndex, int64_t timeUs) override;

		protected:
		virtual ~MPEG4Writer();