Java Track类代码示例

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
private static int[] getClipSamples(Track track, double startTime, double endTime) {
    int currentSample = 0;
    double currentTime = 0;
    double lastTime = -1;
    int startSample = -1;
    int endSample = -1;

    for (int i = 0; i < track.getSampleDurations().length; i++) {
        long delta = track.getSampleDurations()[i];

        if (currentTime > lastTime && currentTime <= startTime) {
            // current sample is still before the new starttime
            startSample = currentSample;
        }
        if (currentTime > lastTime && currentTime <= endTime) {
            // current sample is after the new start time and still before the new endtime
            endSample = currentSample;
        }
        lastTime = currentTime;
        currentTime += (double) delta / (double) track.getTrackMetaData().getTimescale();
        currentSample++;
    }

    return new int[] {startSample, endSample};
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
private double correctTimeToNextSyncSample(Track track, double cutHere) {
    double[] timeOfSyncSamples = new double[track.getSyncSamples().length];
    long currentSample = 0;
    double currentTime = 0;
    for (int i = 0; i < track.getDecodingTimeEntries().size(); i++) {
        TimeToSampleBox.Entry entry = track.getDecodingTimeEntries().get(i);
        for (int j = 0; j < entry.getCount(); j++) {
            if (Arrays.binarySearch(track.getSyncSamples(), currentSample + 1) >= 0) {
                // samples always start with 1 but we start with zero therefore +1
                timeOfSyncSamples[Arrays.binarySearch(track.getSyncSamples(), currentSample + 1)] = currentTime;
            }
            currentTime += (double) entry.getDelta() / (double) track.getTrackMetaData().getTimescale();
            currentSample++;
        }
    }
    for (double timeOfSyncSample : timeOfSyncSamples) {
        if (timeOfSyncSample > cutHere) {
            return timeOfSyncSample;
        }
    }
    return timeOfSyncSamples[timeOfSyncSamples.length - 1];
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
/**
 * Calculates the length of each fragment in the given <code>track</code> (as part of <code>movie</code>).
 *
 * @param track target of calculation
 * @param movie the <code>track</code> must be part of this <code>movie</code>
 * @return the duration of each fragment in track timescale
 */
public long[] calculateFragmentDurations(Track track, Movie movie) {
    long[] startSamples = intersectionFinder.sampleNumbers(track, movie);
    long[] durations = new long[startSamples.length];
    int currentFragment = 0;
    int currentSample = 1; // sync samples start with 1 !

    for (TimeToSampleBox.Entry entry : track.getDecodingTimeEntries()) {
        for (int max = currentSample + l2i(entry.getCount()); currentSample < max; currentSample++) {
            // in this loop we go through the entry.getCount() samples starting from current sample.
            // the next entry.getCount() samples have the same decoding time.
            if (currentFragment != startSamples.length - 1 && currentSample == startSamples[currentFragment + 1]) {
                // we are not in the last fragment && the current sample is the start sample of the next fragment
                currentFragment++;
            }
            durations[currentFragment] += entry.getDelta();


        }
    }
    return durations;

}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
private AudioQuality getAacAudioQuality(Track track, AudioSampleEntry ase) {
    AudioQuality l = new AudioQuality();
    final ESDescriptorBox esDescriptorBox = ase.getBoxes(ESDescriptorBox.class).get(0);
    final AudioSpecificConfig audioSpecificConfig = esDescriptorBox.getEsDescriptor().getDecoderConfigDescriptor().getAudioSpecificInfo();
    if (audioSpecificConfig.getSbrPresentFlag() == 1) {
        l.fourCC = "AACH";
    } else if (audioSpecificConfig.getPsPresentFlag() == 1) {
        l.fourCC = "AACP"; //I'm not sure if that's what MS considers as AAC+ - because actually AAC+ and AAC-HE should be the same...
    } else {
        l.fourCC = "AACL";
    }
    l.bitrate = getBitrate(track);
    l.audioTag = 255;
    l.samplingRate = ase.getSampleRate();
    l.channels = ase.getChannelCount();
    l.bitPerSample = ase.getSampleSize();
    l.packetSize = 4;
    l.codecPrivateData = getAudioCodecPrivateData(audioSpecificConfig);
    //Index="0" Bitrate="103000" AudioTag="255" SamplingRate="44100" Channels="2" BitsPerSample="16" packetSize="4" CodecPrivateData=""
    return l;
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
private VideoQuality getVideoQuality(Track track, VisualSampleEntry vse) {
    VideoQuality l;
    if ("avc1".equals(getFormat(vse))) {
        AvcConfigurationBox avcConfigurationBox = vse.getBoxes(AvcConfigurationBox.class).get(0);
        l = new VideoQuality();
        l.bitrate = getBitrate(track);
        l.codecPrivateData = Hex.encodeHex(getAvcCodecPrivateData(avcConfigurationBox));
        l.fourCC = "AVC1";
        l.width = vse.getWidth();
        l.height = vse.getHeight();
        l.nalLength = avcConfigurationBox.getLengthSizeMinusOne() + 1;
    } else {
        throw new InternalError("I don't know how to handle video of type " + getFormat(vse));
    }
    return l;
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
public SilenceTrackImpl(Track ofType, long ms) {
    source = ofType;
    if ("mp4a".equals(ofType.getSampleDescriptionBox().getSampleEntry().getType())) {
        long numFrames = getTrackMetaData().getTimescale() * ms / 1000 / 1024;
        long standZeit = getTrackMetaData().getTimescale() * ms / numFrames / 1000;
        entry = new TimeToSampleBox.Entry(numFrames, standZeit);


        while (numFrames-- > 0) {
            samples.add((ByteBuffer) ByteBuffer.wrap(new byte[]{
                    0x21, 0x10, 0x04, 0x60, (byte) 0x8c, 0x1c,
            }).rewind());
        }

    } else {
        throw new RuntimeException("Tracks of type " + ofType.getClass().getSimpleName() + " are not supported");
    }
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
private static long[] getTimes(Track track, long[] syncSamples, long targetTimeScale) {
    long[] syncSampleTimes = new long[syncSamples.length];
    Queue<TimeToSampleBox.Entry> timeQueue = new LinkedList<TimeToSampleBox.Entry>(track.getDecodingTimeEntries());

    int currentSample = 1;  // first syncsample is 1
    long currentDuration = 0;
    long currentDelta = 0;
    int currentSyncSampleIndex = 0;
    long left = 0;


    while (currentSample <= syncSamples[syncSamples.length - 1]) {
        if (currentSample++ == syncSamples[currentSyncSampleIndex]) {
            syncSampleTimes[currentSyncSampleIndex++] = (currentDuration * targetTimeScale) / track.getTrackMetaData().getTimescale();
        }
        if (left-- == 0) {
            TimeToSampleBox.Entry entry = timeQueue.poll();
            left = entry.getCount() - 1;
            currentDelta = entry.getDelta();
        }
        currentDuration += currentDelta;
    }
    return syncSampleTimes;

}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
/**
 * Gets the chunk sizes for the given track.
 *
 * @param track
 * @param movie
 * @return
 */
int[] getChunkSizes(Track track, Movie movie) {

    long[] referenceChunkStarts = intersectionFinder.sampleNumbers(track, movie);
    int[] chunkSizes = new int[referenceChunkStarts.length];


    for (int i = 0; i < referenceChunkStarts.length; i++) {
        long start = referenceChunkStarts[i] - 1;
        long end;
        if (referenceChunkStarts.length == i + 1) {
            end = track.getSamples().size();
        } else {
            end = referenceChunkStarts[i + 1] - 1;
        }

        chunkSizes[i] = l2i(end - start);
        // The Stretch makes sure that there are as much audio and video chunks!
    }
    assert DefaultMp4Builder.this.track2Sample.get(track).size() == sum(chunkSizes) : "The number of samples and the sum of all chunk lengths must be equal";
    return chunkSizes;


}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
protected Box createTrex(Movie movie, Track track) {
    TrackExtendsBox trex = new TrackExtendsBox();
    trex.setTrackId(track.getTrackMetaData().getTrackId());
    trex.setDefaultSampleDescriptionIndex(1);
    trex.setDefaultSampleDuration(0);
    trex.setDefaultSampleSize(0);
    SampleFlags sf = new SampleFlags();
    if ("soun".equals(track.getHandler())) {
        // as far as I know there is no audio encoding
        // where the sample are not self contained.
        sf.setSampleDependsOn(2);
        sf.setSampleIsDependedOn(2);
    }
    trex.setDefaultSampleFlags(sf);
    return trex;
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
protected Box createMinf(Track track, Movie movie) {
    MediaInformationBox minf = new MediaInformationBox();
    minf.addBox(track.getMediaHeaderBox());
    minf.addBox(createDinf(movie, track));
    minf.addBox(createStbl(movie, track));
    return minf;
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
protected DataInformationBox createDinf(Movie movie, Track track) {
    DataInformationBox dinf = new DataInformationBox();
    DataReferenceBox dref = new DataReferenceBox();
    dinf.addBox(dref);
    DataEntryUrlBox url = new DataEntryUrlBox();
    url.setFlags(1);
    dref.addBox(url);
    return dinf;
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
public long getBitrate(Track track) {
    long bitrate = 0;
    for (ByteBuffer sample : track.getSamples()) {
        bitrate += sample.limit();
    }
    bitrate *= 8; // from bytes to bits
    bitrate /= ((double) getDuration(track)) / track.getTrackMetaData().getTimescale(); // per second
    return bitrate;
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
protected static long getDuration(Track track) {
    long duration = 0;
    for (TimeToSampleBox.Entry entry : track.getDecodingTimeEntries()) {
        duration += entry.getCount() * entry.getDelta();
    }
    return duration;
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
private Movie removeUnknownTracks(Movie source) {
    Movie nuMovie = new Movie();
    for (Track track : source.getTracks()) {
        if ("vide".equals(track.getHandler()) || "soun".equals(track.getHandler())) {
            nuMovie.addTrack(track);
        } else {
            LOG.fine("Removed track " + track);
        }
    }
    return nuMovie;
}
 

import com.googlecode.mp4parser.authoring.Track; //导入依赖的package包/类
/**
 * Returns a new <code>Movie</code> in that all tracks have the timescale 10000000. CTS & DTS are modified
 * in a way that even with more than one framerate the fragments exactly begin at the same time.
 *
 * @param movie
 * @return a movie with timescales suitable for smooth streaming manifests
 */
public Movie correctTimescale(Movie movie) {
    Movie nuMovie = new Movie();
    for (Track track : movie.getTracks()) {
        nuMovie.addTrack(new ChangeTimeScaleTrack(track, timeScale, ismvBuilder.getFragmentIntersectionFinder().sampleNumbers(track, movie)));
    }
    return nuMovie;

}