diff options
Diffstat (limited to 'isoparser/src/main/java/com/googlecode/mp4parser/authoring/tracks/ChangeTimeScaleTrack.java')
| -rw-r--r-- | isoparser/src/main/java/com/googlecode/mp4parser/authoring/tracks/ChangeTimeScaleTrack.java | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/isoparser/src/main/java/com/googlecode/mp4parser/authoring/tracks/ChangeTimeScaleTrack.java b/isoparser/src/main/java/com/googlecode/mp4parser/authoring/tracks/ChangeTimeScaleTrack.java new file mode 100644 index 0000000..50f76c2 --- /dev/null +++ b/isoparser/src/main/java/com/googlecode/mp4parser/authoring/tracks/ChangeTimeScaleTrack.java @@ -0,0 +1,203 @@ +/* + * 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.tracks; + +import com.coremedia.iso.boxes.*; +import com.googlecode.mp4parser.authoring.Track; +import com.googlecode.mp4parser.authoring.TrackMetaData; + +import java.nio.ByteBuffer; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.LinkedList; +import java.util.List; +import java.util.Queue; +import java.util.logging.Logger; + +/** + * Changes the timescale of a track by wrapping the track. + */ +public class ChangeTimeScaleTrack implements Track { + private static final Logger LOG = Logger.getLogger(ChangeTimeScaleTrack.class.getName()); + + Track source; + List<CompositionTimeToSample.Entry> ctts; + List<TimeToSampleBox.Entry> tts; + long timeScale; + + /** + * Changes the time scale of the source track to the target time scale and makes sure + * that any rounding errors that may have summed are corrected exactly before the syncSamples. + * + * @param source the source track + * @param targetTimeScale the resulting time scale of this track. + * @param syncSamples at these sync points where rounding error are corrected. + */ + public ChangeTimeScaleTrack(Track source, long targetTimeScale, long[] syncSamples) { + this.source = source; + this.timeScale = targetTimeScale; + double timeScaleFactor = (double) targetTimeScale / source.getTrackMetaData().getTimescale(); + ctts = adjustCtts(source.getCompositionTimeEntries(), timeScaleFactor); + tts = adjustTts(source.getDecodingTimeEntries(), timeScaleFactor, syncSamples, getTimes(source, syncSamples, targetTimeScale)); + } + + 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; + + } + + public SampleDescriptionBox getSampleDescriptionBox() { + return source.getSampleDescriptionBox(); + } + + public List<TimeToSampleBox.Entry> getDecodingTimeEntries() { + return tts; + } + + public List<CompositionTimeToSample.Entry> getCompositionTimeEntries() { + return ctts; + } + + public long[] getSyncSamples() { + return source.getSyncSamples(); + } + + public List<SampleDependencyTypeBox.Entry> getSampleDependencies() { + return source.getSampleDependencies(); + } + + public TrackMetaData getTrackMetaData() { + TrackMetaData trackMetaData = (TrackMetaData) source.getTrackMetaData().clone(); + trackMetaData.setTimescale(timeScale); + return trackMetaData; + } + + public String getHandler() { + return source.getHandler(); + } + + public boolean isEnabled() { + return source.isEnabled(); + } + + public boolean isInMovie() { + return source.isInMovie(); + } + + public boolean isInPreview() { + return source.isInPreview(); + } + + public boolean isInPoster() { + return source.isInPoster(); + } + + public List<ByteBuffer> getSamples() { + return source.getSamples(); + } + + + /** + * Adjusting the composition times is easy. Just scale it by the factor - that's it. There is no rounding + * error summing up. + * + * @param source + * @param timeScaleFactor + * @return + */ + static List<CompositionTimeToSample.Entry> adjustCtts(List<CompositionTimeToSample.Entry> source, double timeScaleFactor) { + if (source != null) { + List<CompositionTimeToSample.Entry> entries2 = new ArrayList<CompositionTimeToSample.Entry>(source.size()); + for (CompositionTimeToSample.Entry entry : source) { + entries2.add(new CompositionTimeToSample.Entry(entry.getCount(), (int) Math.round(timeScaleFactor * entry.getOffset()))); + } + return entries2; + } else { + return null; + } + } + + static List<TimeToSampleBox.Entry> adjustTts(List<TimeToSampleBox.Entry> source, double timeScaleFactor, long[] syncSample, long[] syncSampleTimes) { + + long[] sourceArray = TimeToSampleBox.blowupTimeToSamples(source); + long summedDurations = 0; + + LinkedList<TimeToSampleBox.Entry> entries2 = new LinkedList<TimeToSampleBox.Entry>(); + for (int i = 1; i <= sourceArray.length; i++) { + long duration = sourceArray[i - 1]; + + long x = Math.round(timeScaleFactor * duration); + + + TimeToSampleBox.Entry last = entries2.peekLast(); + int ssIndex; + if ((ssIndex = Arrays.binarySearch(syncSample, i + 1)) >= 0) { + // we are at the sample before sync point + if (syncSampleTimes[ssIndex] != summedDurations) { + long correction = syncSampleTimes[ssIndex] - (summedDurations + x); + LOG.finest(String.format("Sample %d %d / %d - correct by %d", i, summedDurations, syncSampleTimes[ssIndex], correction)); + x += correction; + } + } + summedDurations += x; + if (last == null) { + entries2.add(new TimeToSampleBox.Entry(1, x)); + } else if (last.getDelta() != x) { + entries2.add(new TimeToSampleBox.Entry(1, x)); + } else { + last.setCount(last.getCount() + 1); + } + + } + return entries2; + } + + public Box getMediaHeaderBox() { + return source.getMediaHeaderBox(); + } + + public SubSampleInformationBox getSubsampleInformationBox() { + return source.getSubsampleInformationBox(); + } + + @Override + public String toString() { + return "ChangeTimeScaleTrack{" + + "source=" + source + + '}'; + } +}
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