mp4parser
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Published
20 hours ago •
sannies
sannies
Trim Video
Does anyone know how to trim a video with the library. I find some solution in stackoverflow, but it always return the video from 0 second to 15 second, not matter what startMs and endMs. Does anyone know how to fix it? Thanks!
String src = "/storage/emulated/0/Video/my.mp4";
String des = FileUtil.getVideoDirectory();
File file = new File(src);
long startMs = 15000;
long endMs = 25000;
try {
VideoUtil.startTrim(file, des, startMs, endMs);
} catch (IOException e) {
e.printStackTrace();
Log.e(TAG,"startTrim error " + e.getMessage());
}
@SuppressWarnings("ResultOfMethodCallIgnored")
public static void startTrim(@NonNull File src, @NonNull String dst, long startMs, long endMs) throws IOException {
final String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.US).format(new Date());
final String fileName = "MP4_" + timeStamp + ".mp4";
final String filePath = dst + fileName;
File file = new File(filePath);
file.getParentFile().mkdirs();
Log.e(TAG, "Generated file path " + filePath);
genVideoUsingMp4Parser(src, file, startMs, endMs);
}
@SuppressWarnings("ResultOfMethodCallIgnored")
private static void genVideoUsingMp4Parser(@NonNull File src, @NonNull File dst, long startMs, long endMs) throws IOException {
// NOTE: Switched to using FileDataSourceViaHeapImpl since it does not use memory mapping (VM).
// Otherwise we get OOM with large movie files.
Movie movie = MovieCreator.build(new FileDataSourceViaHeapImpl(src.getAbsolutePath()));
List<Track> tracks = movie.getTracks();
movie.setTracks(new LinkedList<Track>());
// remove all tracks we will create new tracks from the old
double startTime1 = startMs / 1000;
double endTime1 = endMs / 1000;
Log.e(TAG,"startTime1 " + startTime1 + ", endTime1 " + endTime1 );
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) {
// This exception here could be a false positive in case we have multiple tracks
// with sync samples at exactly the same positions. E.g. a single movie containing
// multiple qualities of the same video (Microsoft Smooth Streaming file)
throw new RuntimeException("The startTime has already been corrected by another track with SyncSample. Not Supported.");
}
startTime1 = correctTimeToSyncSample(track, startTime1, false);
endTime1 = correctTimeToSyncSample(track, endTime1, true);
timeCorrected = true;
}
}
Log.e(TAG,"after correctTimeToSyncSample startTime1 " + startTime1 + ", endTime1 " + endTime1 );
for (Track track : tracks) {
long currentSample = 0;
double currentTime = 0;
double lastTime = -1;
long startSample1 = -1;
long endSample1 = -1;
for (int i = 0; i < track.getSampleDurations().length; i++) {
long delta = track.getSampleDurations()[i];
if (currentTime > lastTime && currentTime <= startTime1) {
// current sample is still before the new starttime
startSample1 = currentSample;
}
if (currentTime > lastTime && currentTime <= endTime1) {
// current sample is after the new start time and still before the new endtime
endSample1 = currentSample;
}
lastTime = currentTime;
currentTime += (double) delta / (double) track.getTrackMetaData().getTimescale();
currentSample++;
}
Log.e(TAG,"startSample1 " + startSample1 + ", endSample1 " + endSample1 );
movie.addTrack(new AppendTrack(new CroppedTrack(track, startSample1, endSample1)));
}
dst.getParentFile().mkdirs();
if (!dst.exists()) {
dst.createNewFile();
}
Container out = new DefaultMp4Builder().build(movie);
FileOutputStream fos = new FileOutputStream(dst);
FileChannel fc = fos.getChannel();
out.writeContainer(fc);
fc.close();
fos.close();
Log.e(TAG,"startTrim success " );
}
private static double correctTimeToSyncSample(@NonNull Track track, double cutHere, boolean next) {
double[] timeOfSyncSamples = new double[track.getSyncSamples().length];
long currentSample = 0;
double currentTime = 0;
for (int i = 0; i < track.getSampleDurations().length; i++) {
long delta = track.getSampleDurations()[i];
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) delta / (double) track.getTrackMetaData().getTimescale();
currentSample++;
}
double previous = 0;
for (double timeOfSyncSample : timeOfSyncSamples) {
if (timeOfSyncSample > cutHere) {
if (next) {
return timeOfSyncSample;
} else {
return previous;
}
}
previous = timeOfSyncSample;
}
return timeOfSyncSamples[timeOfSyncSamples.length - 1];
}
@Allansk2 Ever figure this out? Also the video that is created, is it H264 codec or MPEG4?
@avanibhatnagar
try {
Movie orig_movie = MovieCreator.build(videoInput);
File audioFile = new File(audioPath);
AACTrackImpl aacTrack = new AACTrackImpl(new FileDataSourceImpl(audioFile));
//get duration of video
IsoFile isoFile = new IsoFile(videoPath);
double lengthInSeconds = (double)
isoFile.getMovieBox().getMovieHeaderBox().getDuration() /
isoFile.getMovieBox().getMovieHeaderBox().getTimescale();
Track track = (Track) orig_movie.getTracks().get(0);
Track audioTrack = (Track) aacTrack;
double startTime1 = 0;
double endTime1 = lengthInSeconds;
boolean timeCorrected = false;
if (audioTrack.getSyncSamples() != null && audioTrack.getSyncSamples().length > 0) {
if (timeCorrected) {
throw new RuntimeException("The startTime has already been corrected by another track with SyncSample. Not Supported.");
}
startTime1 = correctTimeToSyncSample(audioTrack, startTime1, false);
endTime1 = correctTimeToSyncSample(audioTrack, endTime1, true);
timeCorrected = true;
}
long currentSample = 0;
double currentTime = 0;
double lastTime = -1;
long startSample1 = -1;
long endSample1 = -1;
for (int i = 0; i < audioTrack.getSampleDurations().length; i++) {
long delta = audioTrack.getSampleDurations()[i];
if (currentTime > lastTime && currentTime <= startTime1) {
// current sample is still before the new starttime
startSample1 = currentSample;
}
if (currentTime > lastTime && currentTime <= endTime1) {
// current sample is after the new start time and still before the new endtime
endSample1 = currentSample;
}
lastTime = currentTime;
currentTime += (double) delta / (double) audioTrack.getTrackMetaData().getTimescale();
currentSample++;
}
CroppedTrack cropperAacTrack = new CroppedTrack(aacTrack, startSample1, endSample1);
Movie movie = new Movie();
movie.addTrack(track);
movie.addTrack(cropperAacTrack);
Container mp4file = new DefaultMp4Builder().build(movie);
FileChannel fc = new FileOutputStream(new File(output)).getChannel();
mp4file.writeContainer(fc);
fc.close();
} catch (Exception e) {
e.printStackTrace();
}
}
private static double correctTimeToSyncSample(Track track, double cutHere, boolean next) {
double[] timeOfSyncSamples = new double[track.getSyncSamples().length];
long currentSample = 0;
double currentTime = 0;
for (int i = 0; i < track.getSampleDurations().length; i++) {
long delta = track.getSampleDurations()[i];
if (Arrays.binarySearch(track.getSyncSamples(), currentSample + 1) >= 0) {
timeOfSyncSamples[Arrays.binarySearch(track.getSyncSamples(), currentSample + 1)] = currentTime;
}
currentTime += (double) delta / (double) track.getTrackMetaData().getTimescale();
currentSample++;
}
double previous = 0;
for (double timeOfSyncSample : timeOfSyncSamples) {
if (timeOfSyncSample > cutHere) {
if (next) {
return timeOfSyncSample;
} else {
return previous;
}
}
previous = timeOfSyncSample;
}
return timeOfSyncSamples[timeOfSyncSamples.length - 1];
}
When I have to trim the 6-sec video like startTime on 1sec and endTime 5sec then getSyncSamples give the timeOfSyncSample always 0.0
Hey @vijendrapatidar. It is a bit late but were you able to solve your problem here?
