/**
* we try to get the nearest synchronized sample to our desired start time. Afterwards, we are
* ready to crop each track of the video.
*/
private double correctTimeToNextSyncSample(Track track, double cropVidPlace, boolean nextPlace) {
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++;
}
}
double previous = 0;
for (double timeOfSyncSample : timeOfSyncSamples) {
if (timeOfSyncSample > cropVidPlace) {
if (nextPlace) {
return timeOfSyncSample;
} else {
return previous;
}
}
previous = timeOfSyncSample;
}
return timeOfSyncSamples[timeOfSyncSamples.length - 1];
}
protected static long getDuration(Track track) {
long duration = 0;
for (TimeToSampleBox.Entry entry : track.getDecodingTimeEntries()) {
duration += entry.getCount() * entry.getDelta();
}
return duration;
}
private static long[] getTimes(Movie m, Track track) {
long[] syncSamples = track.getSyncSamples();
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;
long timeScale = 1;
for (Track track1 : m.getTracks()) {
if (track1.getHandler().equals(track.getHandler())) {
if (track1.getTrackMetaData().getTimescale() != track.getTrackMetaData().getTimescale()) {
timeScale = lcm(timeScale, track1.getTrackMetaData().getTimescale());
}
}
}
while (currentSample <= syncSamples[syncSamples.length - 1]) {
if (currentSample++ == syncSamples[currentSyncSampleIndex]) {
syncSampleTimes[currentSyncSampleIndex++] = currentDuration * timeScale;
}
if (left-- == 0) {
TimeToSampleBox.Entry entry = timeQueue.poll();
left = entry.getCount() - 1;
currentDelta = entry.getDelta();
}
currentDuration += currentDelta;
}
return syncSampleTimes;
}
private TrackBox createTrackBox(Track track, Movie movie) {
LOG.info("Creating Mp4TrackImpl " + track);
TrackBox trackBox = new TrackBox();
TrackHeaderBox tkhd = new TrackHeaderBox();
tkhd.setVersion(1);
int flags = 0;
if (track.isEnabled()) {
flags += 1;
}
if (track.isInMovie()) {
flags += 2;
}
if (track.isInPreview()) {
flags += 4;
}
if (track.isInPoster()) {
flags += 8;
}
tkhd.setFlags(flags);
tkhd.setAlternateGroup(track.getTrackMetaData().getGroup());
tkhd.setCreationTime(DateHelper.convert(track.getTrackMetaData().getCreationTime()));
// We need to take edit list box into account in trackheader duration
// but as long as I don't support edit list boxes it is sufficient to
// just translate media duration to movie timescale
tkhd.setDuration(
getDuration(track) * getTimescale(movie) / track.getTrackMetaData().getTimescale());
tkhd.setHeight(track.getTrackMetaData().getHeight());
tkhd.setWidth(track.getTrackMetaData().getWidth());
tkhd.setLayer(track.getTrackMetaData().getLayer());
tkhd.setModificationTime(DateHelper.convert(new Date()));
tkhd.setTrackId(track.getTrackMetaData().getTrackId());
tkhd.setVolume(track.getTrackMetaData().getVolume());
trackBox.addBox(tkhd);
/*
EditBox edit = new EditBox();
EditListBox editListBox = new EditListBox();
editListBox.setEntries(Collections.singletonList(
new EditListBox.Entry(editListBox, (long) (track.getTrackMetaData().getStartTime() * getTimescale(movie)), -1, 1)));
edit.addBox(editListBox);
trackBox.addBox(edit);
*/
MediaBox mdia = new MediaBox();
trackBox.addBox(mdia);
MediaHeaderBox mdhd = new MediaHeaderBox();
mdhd.setCreationTime(DateHelper.convert(track.getTrackMetaData().getCreationTime()));
mdhd.setDuration(getDuration(track));
mdhd.setTimescale(track.getTrackMetaData().getTimescale());
mdhd.setLanguage(track.getTrackMetaData().getLanguage());
mdia.addBox(mdhd);
HandlerBox hdlr = new HandlerBox();
mdia.addBox(hdlr);
hdlr.setHandlerType(track.getHandler());
MediaInformationBox minf = new MediaInformationBox();
minf.addBox(track.getMediaHeaderBox());
// dinf: all these three boxes tell us is that the actual
// data is in the current file and not somewhere external
DataInformationBox dinf = new DataInformationBox();
DataReferenceBox dref = new DataReferenceBox();
dinf.addBox(dref);
DataEntryUrlBox url = new DataEntryUrlBox();
url.setFlags(1);
dref.addBox(url);
minf.addBox(dinf);
//
SampleTableBox stbl = new SampleTableBox();
stbl.addBox(track.getSampleDescriptionBox());
List<TimeToSampleBox.Entry> decodingTimeToSampleEntries = track.getDecodingTimeEntries();
if (decodingTimeToSampleEntries != null && !track.getDecodingTimeEntries().isEmpty()) {
TimeToSampleBox stts = new TimeToSampleBox();
stts.setEntries(track.getDecodingTimeEntries());
stbl.addBox(stts);
}
List<CompositionTimeToSample.Entry> compositionTimeToSampleEntries =
track.getCompositionTimeEntries();
if (compositionTimeToSampleEntries != null && !compositionTimeToSampleEntries.isEmpty()) {
CompositionTimeToSample ctts = new CompositionTimeToSample();
ctts.setEntries(compositionTimeToSampleEntries);
stbl.addBox(ctts);
}
long[] syncSamples = track.getSyncSamples();
if (syncSamples != null && syncSamples.length > 0) {
SyncSampleBox stss = new SyncSampleBox();
stss.setSampleNumber(syncSamples);
stbl.addBox(stss);
}
if (track.getSampleDependencies() != null && !track.getSampleDependencies().isEmpty()) {
SampleDependencyTypeBox sdtp = new SampleDependencyTypeBox();
sdtp.setEntries(track.getSampleDependencies());
stbl.addBox(sdtp);
}
HashMap<Track, int[]> track2ChunkSizes = new HashMap<Track, int[]>();
for (Track current : movie.getTracks()) {
track2ChunkSizes.put(current, getChunkSizes(current, movie));
}
int[] tracksChunkSizes = track2ChunkSizes.get(track);
SampleToChunkBox stsc = new SampleToChunkBox();
stsc.setEntries(new LinkedList<SampleToChunkBox.Entry>());
long lastChunkSize = Integer.MIN_VALUE; // to be sure the first chunks hasn't got the same size
for (int i = 0; i < tracksChunkSizes.length; i++) {
// The sample description index references the sample description box
// that describes the samples of this chunk. My Tracks cannot have more
// than one sample description box. Therefore 1 is always right
// the first chunk has the number '1'
if (lastChunkSize != tracksChunkSizes[i]) {
stsc.getEntries().add(new SampleToChunkBox.Entry(i + 1, tracksChunkSizes[i], 1));
lastChunkSize = tracksChunkSizes[i];
}
}
stbl.addBox(stsc);
SampleSizeBox stsz = new SampleSizeBox();
stsz.setSampleSizes(track2SampleSizes.get(track));
stbl.addBox(stsz);
// The ChunkOffsetBox we create here is just a stub
// since we haven't created the whole structure we can't tell where the
// first chunk starts (mdat box). So I just let the chunk offset
// start at zero and I will add the mdat offset later.
StaticChunkOffsetBox stco = new StaticChunkOffsetBox();
this.chunkOffsetBoxes.add(stco);
long offset = 0;
long[] chunkOffset = new long[tracksChunkSizes.length];
// all tracks have the same number of chunks
if (LOG.isLoggable(Level.FINE)) {
LOG.fine("Calculating chunk offsets for track_" + track.getTrackMetaData().getTrackId());
}
for (int i = 0; i < tracksChunkSizes.length; i++) {
// The filelayout will be:
// chunk_1_track_1,... ,chunk_1_track_n, chunk_2_track_1,... ,chunk_2_track_n, ... ,
// chunk_m_track_1,... ,chunk_m_track_n
// calculating the offsets
if (LOG.isLoggable(Level.FINER)) {
LOG.finer(
"Calculating chunk offsets for track_"
+ track.getTrackMetaData().getTrackId()
+ " chunk "
+ i);
}
for (Track current : movie.getTracks()) {
if (LOG.isLoggable(Level.FINEST)) {
LOG.finest("Adding offsets of track_" + current.getTrackMetaData().getTrackId());
}
int[] chunkSizes = track2ChunkSizes.get(current);
long firstSampleOfChunk = 0;
for (int j = 0; j < i; j++) {
firstSampleOfChunk += chunkSizes[j];
}
if (current == track) {
chunkOffset[i] = offset;
}
for (int j = l2i(firstSampleOfChunk); j < firstSampleOfChunk + chunkSizes[i]; j++) {
offset += track2SampleSizes.get(current)[j];
}
}
}
stco.setChunkOffsets(chunkOffset);
stbl.addBox(stco);
minf.addBox(stbl);
mdia.addBox(minf);
return trackBox;
}
/**
* all the trimming happens in this method.
*
* <p>STEP A ==>> For each track in the video, we first get the start time for all the tracks.
*
* <p>STEP B ==>> For each track in the video, we crop the tracks with a 'start time' and 'end
* time' and add it to the Movie object.
*
* <p>STEP C ==>> Finally write the newly created movie to the disk.
*/
private String cropSelectedVideo() {
FileInputStream fileInputStream = null;
FileChannel fileChannel = null;
try {
File videoFile = new File(mFullPathToVideoFile);
fileInputStream = new FileInputStream(videoFile);
fileChannel = fileInputStream.getChannel();
Movie movie = MovieCreator.build(fileChannel);
if (movie == null) {
return null;
} else {
List<Track> tracks = movie.getTracks();
movie.setTracks(new LinkedList<Track>());
boolean timeCorrected = false;
if ((tracks == null) && (tracks.size() <= 0)) {
return null;
} else {
/**
* 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 fragment is exactly the such a
* frame.
*/
for (Track track : tracks) {
if (track.getSyncSamples() != null && track.getSyncSamples().length > 0) {
if (timeCorrected) {
/**
* This exception here can be false position in case we have multiple tracks with
* sync sample at exactly the same position. E.g. a single movie containing multiple
* qualities of the same video.
*/
} else {
mStartTime = correctTimeToNextSyncSample(track, mStartTime, false);
mEndTime = correctTimeToNextSyncSample(track, mEndTime, true);
timeCorrected = true;
}
}
}
for (Track track : tracks) {
long currentVidSample = 0;
double currentTime = 0;
long startVidSample = -1;
long endVidSample = -1;
for (int i = 0; i < track.getDecodingTimeEntries().size(); i++) {
TimeToSampleBox.Entry myEntry = track.getDecodingTimeEntries().get(i);
for (int j = 0; j < myEntry.getCount(); j++) {
// I am trying to find the start time and end time when the trimmimg occurs
if (currentTime <= mStartTime) {
// our current video sample is before the starting time for the crop
// if the startVidSample is equal to the length of the video,
// an error happened, and we should throw an exception
startVidSample =
currentVidSample; // the new begining of the video will be set to this place
// of the video
} else if (currentTime <= mEndTime) {
// our current video sample is after the starting time for the crop
// but before the end time of the crop
endVidSample =
currentVidSample; // the new end of the video will be set to this place of the
// video
} else {
// our current video sample is after the end time of the cropping
// we just stop this this loop
break;
}
// getDelta() : the amount of time the current video sample covers
currentTime +=
(double) myEntry.getDelta() / (double) track.getTrackMetaData().getTimescale();
currentVidSample++;
}
}
movie.addTrack(new CroppedTrack(track, startVidSample, endVidSample));
}
}
}
IsoFile isoFile = new DefaultMp4Builder().build(movie);
/** STEP C ==>> After we created the Movie, we have to place it into a nonvolatile memory. */
return Util.placeFileInNonVolatileDrive(isoFile, mVideFolderPath, "trim_output");
} catch (Exception e) {
Log.e(TAG, "IO ERROR: " + e);
} finally {
if (fileInputStream != null) {
try {
fileInputStream.close();
} catch (IOException e) {
Log.e(TAG, "IO ERROR: " + e);
}
}
if (fileChannel != null) {
try {
fileChannel.close();
} catch (IOException e) {
Log.e(TAG, "IO ERROR: " + e);
}
}
}
return null;
}
