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Commit 8c460498 authored by James Dong's avatar James Dong
Browse files

Speed up stsz box write in MPEG4Writer 

With this patch, the write time for 30+ minutes recording session is reduced from 10+ seconds down to around 2-3 seconds.

related-to-bug: 6435176

Change-Id: I83b705cea42d8de798e7032c770c5c7b033e267e
parent 5d3d12bf

include/media/stagefright/MPEG4Writer.h

+1 −1
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ public: 
    void writeCString(const char *s);

    void writeFourcc(const char *fourcc);

    void write(const void *data, size_t size);

    inline size_t write(const void *ptr, size_t size, size_t nmemb);

    void endBox();

    uint32_t interleaveDuration() const { return mInterleaveDurationUs; }

    status_t setInterleaveDuration(uint32_t duration);
@@ -168,7 +169,6 @@ private: 
    off64_t addSample_l(MediaBuffer *buffer);

    off64_t addLengthPrefixedSample_l(MediaBuffer *buffer);



    inline size_t write(const void *ptr, size_t size, size_t nmemb);

    bool exceedsFileSizeLimit();

    bool use32BitFileOffset() const;

    bool exceedsFileDurationLimit();

media/libstagefright/MPEG4Writer.cpp

+38 −10
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ public: 
private:

    enum {

        kMaxCttsOffsetTimeUs = 1000000LL,  // 1 second

        kSampleArraySize = 1000,

    };



    MPEG4Writer *mOwner;
@@ -96,11 +97,16 @@ private: 


    pthread_t mThread;



    // mNumSamples is used to track how many samples in mSampleSizes List.

    // This is to reduce the cost associated with mSampleSizes.size() call,

    // since it is O(n). Ideally, the fix should be in List class.

    size_t              mNumSamples;

    List<size_t>        mSampleSizes;

    /*

     * mNumSamples is used to track the total number of samples in

     * mSampleSizes List.

     *

     * A linked list of fixed sized array is used here to reduce the time

     * to write out stsz box.

     */

    uint32_t            mNumSamples;

    uint32_t*           mCurrentSampleSizeArr;

    List<uint32_t *>    mSampleSizes;

    bool                mSamplesHaveSameSize;



    List<MediaBuffer *> mChunkSamples;
@@ -1263,6 +1269,12 @@ MPEG4Writer::Track::~Track() { 
        free(mCodecSpecificData);

        mCodecSpecificData = NULL;

    }



    while (!mSampleSizes.empty()) {

        List<uint32_t *>::iterator it = mSampleSizes.begin();

        delete[] (*it);

        mSampleSizes.erase(it);

    }

}



void MPEG4Writer::Track::initTrackingProgressStatus(MetaData *params) {
@@ -2038,7 +2050,14 @@ status_t MPEG4Writer::Track::threadEntry() { 
                (lastTimestampUs * mTimeScale + 500000LL) / 1000000LL);

        CHECK_GE(currDurationTicks, 0ll);



        mSampleSizes.push_back(sampleSize);

        if ((mNumSamples % kSampleArraySize) == 0) {

            uint32_t *arr = new uint32_t[kSampleArraySize];

            CHECK(arr != NULL);

            mSampleSizes.push_back(arr);

            mCurrentSampleSizeArr = arr;

        }



        mCurrentSampleSizeArr[mNumSamples % kSampleArraySize] = htonl(sampleSize);

        ++mNumSamples;

        if (mNumSamples > 2) {
@@ -2788,22 +2807,31 @@ void MPEG4Writer::Track::writeStssBox() { 
}



void MPEG4Writer::Track::writeStszBox() {

    ALOGD("writeStszBox for %s track", isAudio()? "Audio": "Video");

    mOwner->beginBox("stsz");

    mOwner->writeInt32(0);  // version=0, flags=0

    if (mSamplesHaveSameSize) {

        List<size_t>::iterator it = mSampleSizes.begin();

        mOwner->writeInt32(*it);  // default sample size

        List<uint32_t *>::iterator it = mSampleSizes.begin();

        mOwner->writeInt32((*it)[0]);  // default sample size

    } else {

        mOwner->writeInt32(0);

    }

    mOwner->writeInt32(mNumSamples);

    uint32_t nSamples = mNumSamples;

    if (!mSamplesHaveSameSize) {

        for (List<size_t>::iterator it = mSampleSizes.begin();

        for (List<uint32_t *>::iterator it = mSampleSizes.begin();

            it != mSampleSizes.end(); ++it) {

            mOwner->writeInt32(*it);

            if (nSamples >= kSampleArraySize) {

                mOwner->write(*it, 4, kSampleArraySize);

                nSamples -= kSampleArraySize;

            } else {

                mOwner->write(*it, 4, nSamples);

                break;

            }

        }

    }

    mOwner->endBox();  // stsz

    ALOGD("writeStszBox: X");

}



void MPEG4Writer::Track::writeStscBox() {