Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5d6fb5e4 authored by Lajos Molnar's avatar Lajos Molnar
Browse files

mediaplayer: handle bad input in VideoFrameScheduler 

Bug: 17626098
Change-Id: I2ae22ed43b35ff532a47818b118dd328ce2abf63
parent cae1c0fa

media/libmediaplayerservice/VideoFrameScheduler.cpp

+15 −3
Original line number Diff line number Diff line
@@ -152,7 +152,7 @@ void VideoFrameScheduler::PLL::test() { 


#endif



void VideoFrameScheduler::PLL::fit(

bool VideoFrameScheduler::PLL::fit(

        nsecs_t phase, nsecs_t period, size_t numSamplesToUse,

        int64_t *a, int64_t *b, int64_t *err) {

    if (numSamplesToUse > mNumSamples) {
@@ -187,6 +187,10 @@ void VideoFrameScheduler::PLL::fit( 
    }



    int64_t div   = numSamplesToUse * sumXX - sumX * sumX;

    if (div == 0) {

        return false;

    }



    int64_t a_nom = numSamplesToUse * sumXY - sumX * sumY;

    int64_t b_nom = sumXX * sumY            - sumX * sumXY;

    *a = divRound(a_nom, div);
@@ -198,6 +202,7 @@ void VideoFrameScheduler::PLL::fit( 
            (long long)*a,   (*a / (float)(1 << kPrecision)),

            (long long)*b,   (*b / (float)(1 << kPrecision)),

            (long long)*err, (*err / (float)(1 << (kPrecision * 2))));

    return true;

}



void VideoFrameScheduler::PLL::prime(size_t numSamplesToUse) {
@@ -226,7 +231,7 @@ void VideoFrameScheduler::PLL::prime(size_t numSamplesToUse) { 
    deltas.sort(compare<nsecs_t>);

    size_t numDeltas = deltas.size();

    if (numDeltas > 1) {

        nsecs_t deltaMinLimit = min(deltas[0] / kMultiplesThresholdDiv, kMinPeriod);

        nsecs_t deltaMinLimit = max(deltas[0] / kMultiplesThresholdDiv, kMinPeriod);

        nsecs_t deltaMaxLimit = deltas[numDeltas / 2] * kMultiplesThresholdDiv;

        for (size_t i = numDeltas / 2 + 1; i < numDeltas; ++i) {

            if (deltas[i] > deltaMaxLimit) {
@@ -314,8 +319,15 @@ nsecs_t VideoFrameScheduler::PLL::addSample(nsecs_t time) { 


        if (doFit) {

            int64_t a, b, err;

            if (!fit(mPhase, mPeriod, kMaxSamplesToEstimatePeriod, &a, &b, &err)) {

                // samples are not suitable for fitting.  this means they are

                // also not suitable for priming.

                ALOGV("could not fit - keeping old period:%lld", (long long)mPeriod);

                return mPeriod;

            }



            mRefitAt = time + kRefitRefreshPeriod;

            fit(mPhase, mPeriod, kMaxSamplesToEstimatePeriod, &a, &b, &err);



            mPhase += (mPeriod * b) >> kPrecision;

            mPeriod = (mPeriod * a) >> kPrecision;

            ALOGV("new phase:%lld period:%lld", (long long)mPhase, (long long)mPeriod);

media/libmediaplayerservice/VideoFrameScheduler.h

+2 −1
Original line number Diff line number Diff line
@@ -71,7 +71,8 @@ private: 
        nsecs_t mTimes[kHistorySize];



        void test();

        void fit(nsecs_t phase, nsecs_t period, size_t numSamples,

        // returns whether fit was successful

        bool fit(nsecs_t phase, nsecs_t period, size_t numSamples,

                int64_t *a, int64_t *b, int64_t *err);

        void prime(size_t numSamples);

    };