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1 /*
2  * Copyright 2008 CoreMedia AG, Hamburg
3  *
4  * Licensed under the Apache License, Version 2.0 (the License);
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an AS IS BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.coremedia.iso.boxes;
18 
19 
20 import com.coremedia.iso.IsoTypeReader;
21 import com.coremedia.iso.IsoTypeWriter;
22 import com.googlecode.mp4parser.AbstractFullBox;
23 
24 import java.io.IOException;
25 import java.nio.ByteBuffer;
26 import java.util.LinkedList;
27 import java.util.List;
28 
29 import static com.googlecode.mp4parser.util.CastUtils.l2i;
30 
31 /**
32  * <code>
33  * Box Type  : 'elst'<br>
34  * Container: {@link EditBox}('edts')<br>
35  * Mandatory: No<br>
36  * Quantity  : Zero or one</code><br><br>
37  * This box contains an explicit timeline map. Each entry defines part of the track time-line: by mapping part of
38  * the media time-line, or by indicating 'empty' time, or by defining a 'dwell', where a single time-point in the
39  * media is held for a period.<br>
40  * Note that edits are not restricted to fall on sample times. This means that when entering an edit, it can be
41  * necessary to (a) back up to a sync point, and pre-roll from there and then (b) be careful about the duration of
42  * the first sample - it might have been truncated if the edit enters it during its normal duration. If this is audio,
43  * that frame might need to be decoded, and then the final slicing done. Likewise, the duration of the last sample
44  * in an edit might need slicing. <br>
45  * Starting offsets for tracks (streams) are represented by an initial empty edit. For example, to play a track from
46  * its start for 30 seconds, but at 10 seconds into the presentation, we have the following edit list:<br>
47  * <p/>
48  * <li>Entry-count = 2</li>
49  * <li>Segment-duration = 10 seconds</li>
50  * <li>Media-Time = -1</li>
51  * <li>Media-Rate = 1</li>
52  * <li>Segment-duration = 30 seconds (could be the length of the whole track)</li>
53  * <li>Media-Time = 0 seconds</li>
54  * <li>Media-Rate = 1</li>
55  */
56 public class EditListBox extends AbstractFullBox {
57     private List<Entry> entries = new LinkedList<Entry>();
58     public static final String TYPE = "elst";
59 
EditListBox()60     public EditListBox() {
61         super(TYPE);
62     }
63 
64 
getEntries()65     public List<Entry> getEntries() {
66         return entries;
67     }
68 
setEntries(List<Entry> entries)69     public void setEntries(List<Entry> entries) {
70         this.entries = entries;
71     }
72 
getContentSize()73     protected long getContentSize() {
74         long contentSize = 8;
75         if (getVersion() == 1) {
76             contentSize += entries.size() * 20;
77         } else {
78             contentSize += entries.size() * 12;
79         }
80 
81         return contentSize;
82     }
83 
84     @Override
_parseDetails(ByteBuffer content)85     public void _parseDetails(ByteBuffer content) {
86         parseVersionAndFlags(content);
87         int entryCount = l2i(IsoTypeReader.readUInt32(content));
88         entries = new LinkedList<Entry>();
89         for (int i = 0; i < entryCount; i++) {
90             entries.add(new Entry(this, content));
91 
92         }
93     }
94 
95     @Override
getContent(ByteBuffer byteBuffer)96     protected void getContent(ByteBuffer byteBuffer) {
97         writeVersionAndFlags(byteBuffer);
98         IsoTypeWriter.writeUInt32(byteBuffer, entries.size());
99         for (Entry entry : entries) {
100             entry.getContent(byteBuffer);
101         }
102     }
103 
104     @Override
toString()105     public String toString() {
106         return "EditListBox{" +
107                 "entries=" + entries +
108                 '}';
109     }
110 
111     public static class Entry {
112         private long segmentDuration;
113         private long mediaTime;
114         private double mediaRate;
115         EditListBox editListBox;
116 
117         /**
118          * Creates a new <code>Entry</code> with all values set.
119          *
120          * @param segmentDuration duration in movie timescale
121          * @param mediaTime       starting time
122          * @param mediaRate       relative play rate
123          */
Entry(EditListBox editListBox, long segmentDuration, long mediaTime, double mediaRate)124         public Entry(EditListBox editListBox, long segmentDuration, long mediaTime, double mediaRate) {
125             this.segmentDuration = segmentDuration;
126             this.mediaTime = mediaTime;
127             this.mediaRate = mediaRate;
128             this.editListBox = editListBox;
129         }
130 
Entry(EditListBox editListBox, ByteBuffer bb)131         public Entry(EditListBox editListBox, ByteBuffer bb) {
132             if (editListBox.getVersion() == 1) {
133                 segmentDuration = IsoTypeReader.readUInt64(bb);
134                 mediaTime = IsoTypeReader.readUInt64(bb);
135                 mediaRate = IsoTypeReader.readFixedPoint1616(bb);
136             } else {
137                 segmentDuration = IsoTypeReader.readUInt32(bb);
138                 mediaTime = IsoTypeReader.readUInt32(bb);
139                 mediaRate = IsoTypeReader.readFixedPoint1616(bb);
140             }
141             this.editListBox = editListBox;
142         }
143 
144         /**
145          * The segment duration is an integer that specifies the duration
146          * of this edit segment in units of the timescale in the Movie
147          * Header Box
148          *
149          * @return segment duration in movie timescale
150          */
getSegmentDuration()151         public long getSegmentDuration() {
152             return segmentDuration;
153         }
154 
155         /**
156          * The segment duration is an integer that specifies the duration
157          * of this edit segment in units of the timescale in the Movie
158          * Header Box
159          *
160          * @param segmentDuration new segment duration in movie timescale
161          */
setSegmentDuration(long segmentDuration)162         public void setSegmentDuration(long segmentDuration) {
163             this.segmentDuration = segmentDuration;
164         }
165 
166         /**
167          * The media time is an integer containing the starting time
168          * within the media of a specific edit segment(in media time
169          * scale units, in composition time)
170          *
171          * @return starting time
172          */
getMediaTime()173         public long getMediaTime() {
174             return mediaTime;
175         }
176 
177         /**
178          * The media time is an integer containing the starting time
179          * within the media of a specific edit segment(in media time
180          * scale units, in composition time)
181          *
182          * @param mediaTime starting time
183          */
setMediaTime(long mediaTime)184         public void setMediaTime(long mediaTime) {
185             this.mediaTime = mediaTime;
186         }
187 
188         /**
189          * The media rate specifies the relative rate at which to play the
190          * media corresponding to a specific edit segment.
191          *
192          * @return relative play rate
193          */
getMediaRate()194         public double getMediaRate() {
195             return mediaRate;
196         }
197 
198         /**
199          * The media rate specifies the relative rate at which to play the
200          * media corresponding to a specific edit segment.
201          *
202          * @param mediaRate new relative play rate
203          */
setMediaRate(double mediaRate)204         public void setMediaRate(double mediaRate) {
205             this.mediaRate = mediaRate;
206         }
207 
208         @Override
equals(Object o)209         public boolean equals(Object o) {
210             if (this == o) return true;
211             if (o == null || getClass() != o.getClass()) return false;
212 
213             Entry entry = (Entry) o;
214 
215             if (mediaTime != entry.mediaTime) return false;
216             if (segmentDuration != entry.segmentDuration) return false;
217 
218             return true;
219         }
220 
221         @Override
hashCode()222         public int hashCode() {
223             int result = (int) (segmentDuration ^ (segmentDuration >>> 32));
224             result = 31 * result + (int) (mediaTime ^ (mediaTime >>> 32));
225             return result;
226         }
227 
getContent(ByteBuffer bb)228         public void getContent(ByteBuffer bb)  {
229             if (editListBox.getVersion() == 1) {
230                 IsoTypeWriter.writeUInt64(bb, segmentDuration);
231                 IsoTypeWriter.writeUInt64(bb, mediaTime);
232             } else {
233                 IsoTypeWriter.writeUInt32(bb, l2i(segmentDuration));
234                 bb.putInt(l2i(mediaTime));
235             }
236             IsoTypeWriter.writeFixedPont1616(bb, mediaRate);
237         }
238 
239         @Override
toString()240         public String toString() {
241             return "Entry{" +
242                     "segmentDuration=" + segmentDuration +
243                     ", mediaTime=" + mediaTime +
244                     ", mediaRate=" + mediaRate +
245                     '}';
246         }
247     }
248 }
249