Merge "File writer size estimation improvement" into gingerbread (fa7a87fb) · Commits · e / os / android_frameworks_base

include/media/stagefright/MPEG4Writer.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -152,6 +152,7 @@ private:
		bool exceedsFileSizeLimit();
		bool use32BitFileOffset() const;
		bool exceedsFileDurationLimit();
		bool isFileStreamable() const;
		void trackProgressStatus(const Track* track, int64_t timeUs, status_t err = OK);

		MPEG4Writer(const MPEG4Writer &);

media/libstagefright/MPEG4Writer.cpp

+38 −18

Original line number	Diff line number	Diff line
		@@ -309,11 +309,10 @@ int64_t MPEG4Writer::estimateMoovBoxSize(int32_t bitRate) {
		//
		// Statistical analysis shows that metadata usually accounts
		// for a small portion of the total file size, usually < 0.6%.
		// Currently, lets set to 0.4% for now.

		// The default MIN_MOOV_BOX_SIZE is set to 0.4% x 1MB,
		// The default MIN_MOOV_BOX_SIZE is set to 0.6% x 1MB / 2,
		// where 1MB is the common file size limit for MMS application.
		// The default MAX _MOOV_BOX_SIZE value is based on about 4
		// The default MAX _MOOV_BOX_SIZE value is based on about 3
		// minute video recording with a bit rate about 3 Mbps, because
		// statistics also show that most of the video captured are going
		// to be less than 3 minutes.
		@@ -321,20 +320,33 @@ int64_t MPEG4Writer::estimateMoovBoxSize(int32_t bitRate) {
		// If the estimation is wrong, we will pay the price of wasting
		// some reserved space. This should not happen so often statistically.
		static const int32_t factor = mUse32BitOffset? 1: 2;
		static const int64_t MIN_MOOV_BOX_SIZE = 4 * 1024; // 4 KB
		static const int64_t MIN_MOOV_BOX_SIZE = 3 * 1024; // 3 KB
		static const int64_t MAX_MOOV_BOX_SIZE = (180 * 3000000 * 6LL / 8000);
		int64_t size = MIN_MOOV_BOX_SIZE;

		// Max file size limit is set
		if (mMaxFileSizeLimitBytes != 0 && mIsFileSizeLimitExplicitlyRequested) {
		size = mMaxFileSizeLimitBytes * 4 / 1000;
		} else if (mMaxFileDurationLimitUs != 0) {
		if (bitRate <= 0) {
		// We could not estimate the file size since bitRate is not set.
		size = MIN_MOOV_BOX_SIZE;
		size = mMaxFileSizeLimitBytes * 6 / 1000;
		}

		// Max file duration limit is set
		if (mMaxFileDurationLimitUs != 0) {
		if (bitRate > 0) {
		int64_t size2 =
		((mMaxFileDurationLimitUs * bitRate * 6) / 1000 / 8000000);
		if (mMaxFileSizeLimitBytes != 0 && mIsFileSizeLimitExplicitlyRequested) {
		// When both file size and duration limits are set,
		// we use the smaller limit of the two.
		if (size > size2) {
		size = size2;
		}
		} else {
		size = ((mMaxFileDurationLimitUs * bitRate * 4) / 1000 / 8000000);
		// Only max file duration limit is set
		size = size2;
		}
		}
		}

		if (size < MIN_MOOV_BOX_SIZE) {
		size = MIN_MOOV_BOX_SIZE;
		}
		@@ -787,6 +799,10 @@ void MPEG4Writer::write(const void *data, size_t size) {
		write(data, 1, size, mFile);
		}

		bool MPEG4Writer::isFileStreamable() const {
		return mStreamableFile;
		}

		bool MPEG4Writer::exceedsFileSizeLimit() {
		// No limit
		if (mMaxFileSizeLimitBytes == 0) {
		@@ -799,7 +815,7 @@ bool MPEG4Writer::exceedsFileSizeLimit() {
		nTotalBytesEstimate += (*it)->getEstimatedTrackSizeBytes();
		}

		return (nTotalBytesEstimate + 1024 >= mMaxFileSizeLimitBytes);
		return (nTotalBytesEstimate >= mMaxFileSizeLimitBytes);
		}

		bool MPEG4Writer::exceedsFileDurationLimit() {
		@@ -887,13 +903,17 @@ void MPEG4Writer::Track::updateTrackSizeEstimate() {

		int64_t stszBoxSizeBytes = mSamplesHaveSameSize? 4: (mNumSamples * 4);

		mEstimatedTrackSizeBytes = mMdatSizeBytes + // media data size
		mNumStscTableEntries * 12 + // stsc box size
		mEstimatedTrackSizeBytes = mMdatSizeBytes; // media data size
		if (!mOwner->isFileStreamable()) {
		// Reserved free space is not large enough to hold
		// all meta data and thus wasted.
		mEstimatedTrackSizeBytes += mNumStscTableEntries * 12 + // stsc box size
		mNumStssTableEntries * 4 + // stss box size
		mNumSttsTableEntries * 8 + // stts box size
		stcoBoxSizeBytes + // stco box size
		stszBoxSizeBytes; // stsz box size
		}
		}

		void MPEG4Writer::Track::addOneStscTableEntry(
		size_t chunkId, size_t sampleId) {