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A generic parser and writer for all ISO 14496 based files (MP4, Quicktime, DCF, PDCF, ...)

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/*  
 * Copyright 2008 CoreMedia AG, 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.coremedia.iso.boxes;


import com.coremedia.iso.IsoTypeReader;
import com.coremedia.iso.IsoTypeWriter;
import com.googlecode.mp4parser.AbstractFullBox;

import java.lang.ref.SoftReference;
import java.nio.ByteBuffer;
import java.util.*;

import static com.googlecode.mp4parser.util.CastUtils.l2i;

/**
 * 

4cc = "{@value #TYPE}"

* This box contains a compact version of a table that allows indexing from decoding time to sample number. * Other tables give sample sizes and pointers, from the sample number. Each entry in the table gives the * number of consecutive samples with the same time delta, and the delta of those samples. By adding the * deltas a complete time-to-sample map may be built.
* The Decoding Time to Sample Box contains decode time delta's: DT(n+1) = DT(n) + STTS(n) where STTS(n) * is the (uncompressed) table entry for sample n.
* The sample entries are ordered by decoding time stamps; therefore the deltas are all non-negative.
* The DT axis has a zero origin; DT(i) = SUM(for j=0 to i-1 of delta(j)), and the sum of all * deltas gives the length of the media in the track (not mapped to the overall timescale, and not considering * any edit list).
* The Edit List Box provides the initial CT value if it is non-empty (non-zero). */ public class TimeToSampleBox extends AbstractFullBox { public static final String TYPE = "stts"; List entries = Collections.emptyList(); public TimeToSampleBox() { super(TYPE); } protected long getContentSize() { return 8 + entries.size() * 8; } @Override public void _parseDetails(ByteBuffer content) { parseVersionAndFlags(content); int entryCount = l2i(IsoTypeReader.readUInt32(content)); entries = new ArrayList(entryCount); for (int i = 0; i < entryCount; i++) { entries.add(new Entry(IsoTypeReader.readUInt32(content), IsoTypeReader.readUInt32(content))); } } @Override protected void getContent(ByteBuffer byteBuffer) { writeVersionAndFlags(byteBuffer); IsoTypeWriter.writeUInt32(byteBuffer, entries.size()); for (Entry entry : entries) { IsoTypeWriter.writeUInt32(byteBuffer, entry.getCount()); IsoTypeWriter.writeUInt32(byteBuffer, entry.getDelta()); } } public List getEntries() { return entries; } public void setEntries(List entries) { this.entries = entries; } public String toString() { return "TimeToSampleBox[entryCount=" + entries.size() + "]"; } public static class Entry { long count; long delta; public Entry(long count, long delta) { this.count = count; this.delta = delta; } public long getCount() { return count; } public long getDelta() { return delta; } public void setCount(long count) { this.count = count; } public void setDelta(long delta) { this.delta = delta; } @Override public String toString() { return "Entry{" + "count=" + count + ", delta=" + delta + '}'; } } static Map, SoftReference> cache = new WeakHashMap, SoftReference>(); /** * Decompresses the list of entries and returns the list of decoding times. * * @param entries compressed entries * @return decoding time per sample */ public static synchronized long[] blowupTimeToSamples(List entries) { SoftReference cacheEntry; if ((cacheEntry = cache.get(entries)) != null) { long[] cacheVal; if ((cacheVal = cacheEntry.get()) != null) { return cacheVal; } } long numOfSamples = 0; for (TimeToSampleBox.Entry entry : entries) { numOfSamples += entry.getCount(); } assert numOfSamples <= Integer.MAX_VALUE; long[] decodingTime = new long[(int) numOfSamples]; int current = 0; for (TimeToSampleBox.Entry entry : entries) { for (int i = 0; i < entry.getCount(); i++) { decodingTime[current++] = entry.getDelta(); } } cache.put(entries, new SoftReference(decodingTime)); return decodingTime; } }




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