Merge "HLS: reduce number of guessed wrong seq numbers" (7184bab9) · Commits · e / os / android_frameworks_av

include/media/stagefright/Utils.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -71,7 +71,7 @@ struct HLSTime {
		sp<AMessage> mMeta;

		HLSTime(const sp<AMessage> &meta = NULL);
		int64_t getSegmentTimeUs(bool midpoint = false) const;
		int64_t getSegmentTimeUs() const;
		};

		bool operator <(const HLSTime &t0, const HLSTime &t1);

media/libstagefright/Utils.cpp

+21 −3

Original line number	Diff line number	Diff line
		@@ -852,14 +852,32 @@ HLSTime::HLSTime(const sp<AMessage>& meta) :
		}
		}

		int64_t HLSTime::getSegmentTimeUs(bool midpoint) const {
		int64_t HLSTime::getSegmentTimeUs() const {
		int64_t segmentStartTimeUs = -1ll;
		if (mMeta != NULL) {
		CHECK(mMeta->findInt64("segmentStartTimeUs", &segmentStartTimeUs));
		if (midpoint) {

		int64_t segmentFirstTimeUs;
		if (mMeta->findInt64("segmentFirstTimeUs", &segmentFirstTimeUs)) {
		segmentStartTimeUs += mTimeUs - segmentFirstTimeUs;
		}

		// adjust segment time by playlist age (for live streaming)
		int64_t playlistTimeUs;
		if (mMeta->findInt64("playlistTimeUs", &playlistTimeUs)) {
		int64_t playlistAgeUs = ALooper::GetNowUs() - playlistTimeUs;

		int64_t durationUs;
		CHECK(mMeta->findInt64("segmentDurationUs", &durationUs));
		segmentStartTimeUs += durationUs / 2;

		// round to nearest whole segment
		playlistAgeUs = (playlistAgeUs + durationUs / 2)
		/ durationUs * durationUs;

		segmentStartTimeUs -= playlistAgeUs;
		if (segmentStartTimeUs < 0) {
		segmentStartTimeUs = 0;
		}
		}
		}
		return segmentStartTimeUs;

media/libstagefright/httplive/LiveSession.cpp

+50 −8

Original line number	Diff line number	Diff line
		@@ -67,7 +67,7 @@ struct LiveSession::BandwidthEstimator : public RefBase {
		BandwidthEstimator();

		void addBandwidthMeasurement(size_t numBytes, int64_t delayUs);
		bool estimateBandwidth(int32_t *bandwidth);
		bool estimateBandwidth(int32_t bandwidth, bool isStable = NULL);

		private:
		// Bandwidth estimation parameters
		@@ -81,6 +81,9 @@ private:

		Mutex mLock;
		List<BandwidthEntry> mBandwidthHistory;
		List<int32_t> mPrevEstimates;
		bool mHasNewSample;
		bool mIsStable;
		int64_t mTotalTransferTimeUs;
		size_t mTotalTransferBytes;

		@@ -88,6 +91,8 @@ private:
		};

		LiveSession::BandwidthEstimator::BandwidthEstimator() :
		mHasNewSample(false),
		mIsStable(true),
		mTotalTransferTimeUs(0),
		mTotalTransferBytes(0) {
		}
		@@ -102,6 +107,7 @@ void LiveSession::BandwidthEstimator::addBandwidthMeasurement(
		mTotalTransferTimeUs += delayUs;
		mTotalTransferBytes += numBytes;
		mBandwidthHistory.push_back(entry);
		mHasNewSample = true;

		// trim old samples, keeping at least kMaxBandwidthHistoryItems samples,
		// and total transfer time at least kMaxBandwidthHistoryWindowUs.
		@@ -116,14 +122,43 @@ void LiveSession::BandwidthEstimator::addBandwidthMeasurement(
		}
		}

		bool LiveSession::BandwidthEstimator::estimateBandwidth(int32_t *bandwidthBps) {
		bool LiveSession::BandwidthEstimator::estimateBandwidth(int32_t bandwidthBps, bool isStable) {
		AutoMutex autoLock(mLock);

		if (mBandwidthHistory.size() < 2) {
		return false;
		}

		if (!mHasNewSample) {
		bandwidthBps = (--mPrevEstimates.end());
		if (isStable) {
		*isStable = mIsStable;
		}
		return true;
		}

		bandwidthBps = ((double)mTotalTransferBytes 8E6 / mTotalTransferTimeUs);
		mPrevEstimates.push_back(*bandwidthBps);
		while (mPrevEstimates.size() > 3) {
		mPrevEstimates.erase(mPrevEstimates.begin());
		}
		mHasNewSample = false;

		int32_t minEstimate = -1, maxEstimate = -1;
		List<int32_t>::iterator it;
		for (it = mPrevEstimates.begin(); it != mPrevEstimates.end(); it++) {
		int32_t estimate = *it;
		if (minEstimate < 0 \|\| minEstimate > estimate) {
		minEstimate = estimate;
		}
		if (maxEstimate < 0 \|\| maxEstimate < estimate) {
		maxEstimate = estimate;
		}
		}
		mIsStable = (maxEstimate <= minEstimate * 4 / 3);
		if (isStable) {
		*isStable = mIsStable;
		}
		return true;
		}

		@@ -1930,7 +1965,7 @@ void LiveSession::onChangeConfiguration3(const sp<AMessage> &msg) {
		fetcher->getFetcherID(),
		(long long)startTime.mTimeUs,
		(long long)mLastSeekTimeUs,
		(long long)startTime.getSegmentTimeUs(true /* midpoint */),
		(long long)startTime.getSegmentTimeUs(),
		seekMode);

		// Set the target segment start time to the middle point of the
		@@ -1945,7 +1980,7 @@ void LiveSession::onChangeConfiguration3(const sp<AMessage> &msg) {
		sources[kSubtitleIndex],
		getMetadataSource(sources, mNewStreamMask, switching),
		startTime.mTimeUs < 0 ? mLastSeekTimeUs : startTime.mTimeUs,
		startTime.getSegmentTimeUs(true /* midpoint */),
		startTime.getSegmentTimeUs(),
		startTime.mSeq,
		seekMode);
		}
		@@ -2296,7 +2331,8 @@ bool LiveSession::switchBandwidthIfNeeded(bool bufferHigh, bool bufferLow) {
		}

		int32_t bandwidthBps;
		if (mBandwidthEstimator->estimateBandwidth(&bandwidthBps)) {
		bool isStable;
		if (mBandwidthEstimator->estimateBandwidth(&bandwidthBps, &isStable)) {
		ALOGV("bandwidth estimated at %.2f kbps", bandwidthBps / 1024.0f);
		mLastBandwidthBps = bandwidthBps;
		} else {
		@@ -2308,12 +2344,18 @@ bool LiveSession::switchBandwidthIfNeeded(bool bufferHigh, bool bufferLow) {
		// canSwithDown and canSwitchUp can't both be true.
		// we only want to switch up when measured bw is 120% higher than current variant,
		// and we only want to switch down when measured bw is below current variant.
		bool canSwithDown = bufferLow
		bool canSwitchDown = bufferLow
		&& (bandwidthBps < (int32_t)curBandwidth);
		bool canSwitchUp = bufferHigh
		&& (bandwidthBps > (int32_t)curBandwidth * 12 / 10);

		if (canSwithDown \|\| canSwitchUp) {
		if (canSwitchDown \|\| canSwitchUp) {
		// bandwidth estimating has some delay, if we have to downswitch when
		// it hasn't stabilized, be very conservative on bandwidth.
		if (!isStable && canSwitchDown) {
		bandwidthBps /= 2;
		}

		ssize_t bandwidthIndex = getBandwidthIndex(bandwidthBps);

		// it's possible that we're checking for canSwitchUp case, but the returned
		@@ -2321,7 +2363,7 @@ bool LiveSession::switchBandwidthIfNeeded(bool bufferHigh, bool bufferLow) {
		// of measured bw. In that case we don't want to do anything, since we have
		// both enough buffer and enough bw.
		if ((canSwitchUp && bandwidthIndex > mCurBandwidthIndex)
		\|\| (canSwithDown && bandwidthIndex < mCurBandwidthIndex)) {
		\|\| (canSwitchDown && bandwidthIndex < mCurBandwidthIndex)) {
		// if not yet prepared, just restart again with new bw index.
		// this is faster and playback experience is cleaner.
		changeConfiguration(

media/libstagefright/httplive/M3UParser.cpp

+32 −5

Original line number	Diff line number	Diff line
		@@ -250,6 +250,9 @@ M3UParser::M3UParser(
		mIsVariantPlaylist(false),
		mIsComplete(false),
		mIsEvent(false),
		mFirstSeqNumber(-1),
		mLastSeqNumber(-1),
		mTargetDurationUs(-1ll),
		mDiscontinuitySeq(0),
		mDiscontinuityCount(0),
		mSelectedIndex(-1) {
		@@ -283,6 +286,19 @@ size_t M3UParser::getDiscontinuitySeq() const {
		return mDiscontinuitySeq;
		}

		int64_t M3UParser::getTargetDuration() const {
		return mTargetDurationUs;
		}

		int32_t M3UParser::getFirstSeqNumber() const {
		return mFirstSeqNumber;
		}

		void M3UParser::getSeqNumberRange(int32_t firstSeq, int32_t lastSeq) const {
		*firstSeq = mFirstSeqNumber;
		*lastSeq = mLastSeqNumber;
		}

		sp<AMessage> M3UParser::meta() {
		return mMeta;
		}
		@@ -664,12 +680,23 @@ status_t M3UParser::parse(const void *_data, size_t size) {
		}

		// error checking of all fields that's required to appear once
		// (currently only checking "target-duration")
		// (currently only checking "target-duration"), and
		// initialization of playlist properties (eg. mTargetDurationUs)
		if (!mIsVariantPlaylist) {
		int32_t targetDurationSecs;
		if (!mIsVariantPlaylist && (mMeta == NULL \|\| !mMeta->findInt32(
		"target-duration", &targetDurationSecs))) {
		if (mMeta == NULL \|\| !mMeta->findInt32(
		"target-duration", &targetDurationSecs)) {
		ALOGE("Media playlist missing #EXT-X-TARGETDURATION");
		return ERROR_MALFORMED;
		}
		mTargetDurationUs = targetDurationSecs * 1000000ll;

		mFirstSeqNumber = 0;
		if (mMeta != NULL) {
		mMeta->findInt32("media-sequence", &mFirstSeqNumber);
		}
		mLastSeqNumber = mFirstSeqNumber + mItems.size() - 1;
		}

		return OK;
		}

media/libstagefright/httplive/M3UParser.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,9 @@ struct M3UParser : public RefBase {
		bool isComplete() const;
		bool isEvent() const;
		size_t getDiscontinuitySeq() const;
		int64_t getTargetDuration() const;
		int32_t getFirstSeqNumber() const;
		void getSeqNumberRange(int32_t firstSeq, int32_t lastSeq) const;

		sp<AMessage> meta();

		@@ -70,6 +73,9 @@ private:
		bool mIsVariantPlaylist;
		bool mIsComplete;
		bool mIsEvent;
		int32_t mFirstSeqNumber;
		int32_t mLastSeqNumber;
		int64_t mTargetDurationUs;
		size_t mDiscontinuitySeq;
		int32_t mDiscontinuityCount;