android - 给定视频 URL，如何将视频剪辑保存到 Android 手机上？

Question

给定一个视频网址(例如:www.example.com/video.mp4)，我如何以编程方式保存视频的短片(例如:5 秒，00:00:10 - 00:00:15)在手机上的 Android 应用程序中？

目前，这是我所拥有的 - 但这会将整个视频从 url 保存到设备。看来我需要使用 MediaExtractor 和 MediaMuxer。

URL url = new URL(http_url_path);
URLConnection ucon = url.openConnection();

// Define InputStreams to read from the URLConnection.
// uses 5KB download buffer
InputStream is = ucon.getInputStream();
BufferedInputStream in = new BufferedInputStream(is, BUFFER_SIZE);
FileOutputStream out = new FileOutputStream(file);
byte[] buff = new byte[BUFFER_SIZE];

int len = 0;
while ((len = in.read(buff)) != -1) {
    out.write(buff, 0, len);
}

Answer 1

依赖isoviewer-1.0-RC-27。

public static double[] startTrim(File src, File dst, int startMs, int endMs) throws IOException {
    Movie movie = MovieCreator.build(src.getAbsolutePath());
    List<Track> tracks = movie.getTracks();
    movie.setTracks(new LinkedList<Track>());
    double startTime = startMs/1000;
    double endTime = endMs/1000;
    boolean timeCorrected = false;
    // Here we try to find a track that has sync samples. Since we can only start decoding
    // at such a sample we SHOULD make sure that the start of the new fragment is exactly
    // such a frame
    for (Track track : tracks) {
        if (track.getSyncSamples() != null && track.getSyncSamples().length > 0) {
            if (timeCorrected) {          
                throw new RuntimeException("The startTime has already been corrected by another track with SyncSample. Not Supported.");
            }
            //false,Short interception;true,Long interception
            startTime = correctTimeToSyncSample(track, startTime, true);
            endTime = correctTimeToSyncSample(track, endTime, false);
            timeCorrected = true;
        }
    }
    int x = 0;
    for (Track track : tracks) {
        long currentSample = 0;
        double currentTime = 0;
        long startSample = -1;
        long endSample = -1;
        x++;
        for (int i = 0; i < track.getDecodingTimeEntries().size(); i++) {
            TimeToSampleBox.Entry entry = track.getDecodingTimeEntries().get(i);
            for (int j = 0; j < entry.getCount(); j++) {
                // entry.getDelta() is the amount of time the current sample covers.
                if (currentTime <= startTime) {
                    // current sample is still before the new starttime
                    startSample = currentSample;
                }
                if (currentTime <= endTime) {
                    // current sample is after the new start time and still before the new endtime
                    endSample = currentSample;
                } else {
                    // current sample is after the end of the cropped video
                    break;
                }
                currentTime += (double) entry.getDelta() / (double) track.getTrackMetaData().getTimescale();
                currentSample++;
            }
        }
        movie.addTrack(new CroppedTrack(track, startSample, endSample));
        break;
    }
    Container container = new DefaultMp4Builder().build(movie);  
    if (!dst.exists()) {
        dst.createNewFile();
    }

    FileOutputStream fos = new FileOutputStream(dst);
    FileChannel fc = fos.getChannel();
    container.writeContainer(fc);      
    fc.close();
    fos.close();
    double[] doubleArray = new double[2] ;
    doubleArray[0] = startTime;
    doubleArray[1] = endTime;
    return doubleArray;

}