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A generic parser and writer for all ISO 14496 based files (MP4, Quicktime, DCF, PDCF, ...)
/*
* Copyright 2012 Sebastian Annies, Hamburg
*
* Licensed under the Apache License, Version 2.0 (the License);
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.googlecode.mp4parser.authoring.builder;
import com.coremedia.iso.boxes.OriginalFormatBox;
import com.coremedia.iso.boxes.sampleentry.AudioSampleEntry;
import com.coremedia.iso.boxes.sampleentry.SampleEntry;
import com.googlecode.mp4parser.authoring.Movie;
import com.googlecode.mp4parser.authoring.Track;
import com.googlecode.mp4parser.util.Path;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.logging.Logger;
import static com.googlecode.mp4parser.util.Math.lcm;
/**
* This FragmentIntersectionFinder cuts the input movie video tracks in
* fragments of the same length exactly before the sync samples. Audio tracks are cut
* into pieces of similar length.
*/
public class SyncSampleIntersectFinderImpl implements FragmentIntersectionFinder {
private static Logger LOG = Logger.getLogger(SyncSampleIntersectFinderImpl.class.getName());
private final int minFragmentDurationSeconds;
private Movie movie;
private Track referenceTrack;
/**
* Creates a SyncSampleIntersectFinderImpl that will not create any fragment
* smaller than the given minFragmentDurationSeconds
*
* @param movie this movie is the reference
* @param referenceTrack used for audio tracks to find similar boundaries of segments.
* @param minFragmentDurationSeconds the smallest allowable duration of a fragment.
*/
public SyncSampleIntersectFinderImpl(Movie movie, Track referenceTrack, int minFragmentDurationSeconds) {
this.movie = movie;
this.referenceTrack = referenceTrack;
this.minFragmentDurationSeconds = minFragmentDurationSeconds;
}
static String getFormat(Track track) {
SampleEntry se = track.getSampleDescriptionBox().getSampleEntry();
String type = se.getType();
if (type.equals("encv") || type.equals("enca") || type.equals("encv")) {
OriginalFormatBox frma = Path.getPath(se, "sinf/frma");
type = frma.getDataFormat();
}
return type;
}
/**
* Gets an array of sample numbers that are meant to be the first sample of each
* chunk or fragment.
*
* @param track concerned track
* @return an array containing the ordinal of each fragment's first sample
*/
public long[] sampleNumbers(Track track) {
if ("vide".equals(track.getHandler())) {
if (track.getSyncSamples() != null && track.getSyncSamples().length > 0) {
List times = getSyncSamplesTimestamps(movie, track);
return getCommonIndices(track.getSyncSamples(), getTimes(track, movie), track.getTrackMetaData().getTimescale(), times.toArray(new long[times.size()][]));
} else {
throw new RuntimeException("Video Tracks need sync samples. Only tracks other than video may have no sync samples.");
}
} else if ("soun".equals(track.getHandler())) {
if (referenceTrack == null) {
for (Track candidate : movie.getTracks()) {
if (candidate.getSyncSamples() != null && "vide".equals(candidate.getHandler()) && candidate.getSyncSamples().length > 0) {
referenceTrack = candidate;
}
}
}
if (referenceTrack != null) {
// Gets the reference track's fra
long[] refSyncSamples = sampleNumbers(referenceTrack);
int refSampleCount = referenceTrack.getSamples().size();
long[] syncSamples = new long[refSyncSamples.length];
long minSampleRate = 192000;
for (Track testTrack : movie.getTracks()) {
if (getFormat(track).equals(getFormat(testTrack))) {
AudioSampleEntry ase = (AudioSampleEntry) testTrack.getSampleDescriptionBox().getSampleEntry();
if (ase.getSampleRate() < minSampleRate) {
minSampleRate = ase.getSampleRate();
long sc = testTrack.getSamples().size();
double stretch = (double) sc / refSampleCount;
long samplesPerFrame = testTrack.getSampleDurations()[0]; // Assuming all audio tracks have the same number of samples per frame, which they do for all known types
for (int i = 0; i < syncSamples.length; i++) {
long start = (long) Math.ceil(stretch * (refSyncSamples[i] - 1) * samplesPerFrame);
syncSamples[i] = start;
// The Stretch makes sure that there are as much audio and video chunks!
}
break;
}
}
}
AudioSampleEntry ase = (AudioSampleEntry) track.getSampleDescriptionBox().getSampleEntry();
long samplesPerFrame = track.getSampleDurations()[0]; // Assuming all audio tracks have the same number of samples per frame, which they do for all known types
double factor = (double) ase.getSampleRate() / (double) minSampleRate;
if (factor != Math.rint(factor)) { // Not an integer
throw new RuntimeException("Sample rates must be a multiple of the lowest sample rate to create a correct file!");
}
for (int i = 0; i < syncSamples.length; i++) {
syncSamples[i] = (long) (1 + syncSamples[i] * factor / (double) samplesPerFrame);
}
return syncSamples;
}
throw new RuntimeException("There was absolutely no Track with sync samples. I can't work with that!");
} else {
// Ok, my track has no sync samples - let's find one with sync samples.
for (Track candidate : movie.getTracks()) {
if (candidate.getSyncSamples() != null && candidate.getSyncSamples().length > 0) {
long[] refSyncSamples = sampleNumbers(candidate);
int refSampleCount = candidate.getSamples().size();
long[] syncSamples = new long[refSyncSamples.length];
long sc = track.getSamples().size();
double stretch = (double) sc / refSampleCount;
for (int i = 0; i < syncSamples.length; i++) {
long start = (long) Math.ceil(stretch * (refSyncSamples[i] - 1)) + 1;
syncSamples[i] = start;
// The Stretch makes sure that there are as much audio and video chunks!
}
return syncSamples;
}
}
throw new RuntimeException("There was absolutely no Track with sync samples. I can't work with that!");
}
}
/**
* Calculates the timestamp of all tracks' sync samples.
*
* @param movie track is located in this movie
* @param track get this track's samples timestamps
* @return a list of timestamps
*/
public static List getSyncSamplesTimestamps(Movie movie, Track track) {
List times = new LinkedList();
for (Track currentTrack : movie.getTracks()) {
if (currentTrack.getHandler().equals(track.getHandler())) {
long[] currentTrackSyncSamples = currentTrack.getSyncSamples();
if (currentTrackSyncSamples != null && currentTrackSyncSamples.length > 0) {
final long[] currentTrackTimes = getTimes(currentTrack, movie);
times.add(currentTrackTimes);
}
}
}
return times;
}
public long[] getCommonIndices(long[] syncSamples, long[] syncSampleTimes, long timeScale, long[]... otherTracksTimes) {
List nuSyncSamples = new LinkedList();
List nuSyncSampleTimes = new LinkedList();
for (int i = 0; i < syncSampleTimes.length; i++) {
boolean foundInEveryRef = true;
for (long[] times : otherTracksTimes) {
foundInEveryRef &= (Arrays.binarySearch(times, syncSampleTimes[i]) >= 0);
}
if (foundInEveryRef) {
// use sample only if found in every other track.
nuSyncSamples.add(syncSamples[i]);
nuSyncSampleTimes.add(syncSampleTimes[i]);
}
}
// We have two arrays now:
// nuSyncSamples: Contains all common sync samples
// nuSyncSampleTimes: Contains the times of all sync samples
// Start: Warn user if samples are not matching!
if (nuSyncSamples.size() < (syncSamples.length * 0.25)) {
String log = "";
log += String.format("%5d - Common: [", nuSyncSamples.size());
for (long l : nuSyncSamples) {
log += (String.format("%10d,", l));
}
log += ("]");
LOG.warning(log);
log = "";
log += String.format("%5d - In : [", syncSamples.length);
for (long l : syncSamples) {
log += (String.format("%10d,", l));
}
log += ("]");
LOG.warning(log);
LOG.warning("There are less than 25% of common sync samples in the given track.");
throw new RuntimeException("There are less than 25% of common sync samples in the given track.");
} else if (nuSyncSamples.size() < (syncSamples.length * 0.5)) {
LOG.fine("There are less than 50% of common sync samples in the given track. This is implausible but I'm ok to continue.");
} else if (nuSyncSamples.size() < syncSamples.length) {
LOG.finest("Common SyncSample positions vs. this tracks SyncSample positions: " + nuSyncSamples.size() + " vs. " + syncSamples.length);
}
// End: Warn user if samples are not matching!
List finalSampleList = new LinkedList();
if (minFragmentDurationSeconds > 0) {
// if minFragmentDurationSeconds is greater 0
// we need to throw away certain samples.
long lastSyncSampleTime = -1;
Iterator nuSyncSamplesIterator = nuSyncSamples.iterator();
Iterator nuSyncSampleTimesIterator = nuSyncSampleTimes.iterator();
while (nuSyncSamplesIterator.hasNext() && nuSyncSampleTimesIterator.hasNext()) {
long curSyncSample = nuSyncSamplesIterator.next();
long curSyncSampleTime = nuSyncSampleTimesIterator.next();
if (lastSyncSampleTime == -1 || (curSyncSampleTime - lastSyncSampleTime) / timeScale >= minFragmentDurationSeconds) {
finalSampleList.add(curSyncSample);
lastSyncSampleTime = curSyncSampleTime;
}
}
} else {
// the list of all samples is the final list of samples
// since minFragmentDurationSeconds ist not used.
finalSampleList = nuSyncSamples;
}
// transform the list to an array
long[] finalSampleArray = new long[finalSampleList.size()];
for (int i = 0; i < finalSampleArray.length; i++) {
finalSampleArray[i] = finalSampleList.get(i);
}
return finalSampleArray;
}
private static long[] getTimes(Track track, Movie m) {
long[] syncSamples = track.getSyncSamples();
long[] syncSampleTimes = new long[syncSamples.length];
int currentSample = 1; // first syncsample is 1
long currentDuration = 0;
int currentSyncSampleIndex = 0;
final long scalingFactor = calculateTracktimesScalingFactor(m, track);
while (currentSample <= syncSamples[syncSamples.length - 1]) {
if (currentSample == syncSamples[currentSyncSampleIndex]) {
syncSampleTimes[currentSyncSampleIndex++] = currentDuration * scalingFactor;
}
currentDuration += track.getSampleDurations()[-1 + currentSample++];
}
return syncSampleTimes;
}
private static long calculateTracktimesScalingFactor(Movie m, Track track) {
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());
}
}
}
return timeScale;
}
}
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