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
17package com.coremedia.iso.boxes;
18
19import com.coremedia.iso.IsoTypeWriter;
20import com.coremedia.iso.boxes.sampleentry.SampleEntry;
21import com.googlecode.mp4parser.FullContainerBox;
22
23import java.nio.ByteBuffer;
24
25/**
26 * The sample description table gives detailed information about the coding type used, and any initialization
27 * information needed for that coding. <br>
28 * The information stored in the sample description box after the entry-count is both track-type specific as
29 * documented here, and can also have variants within a track type (e.g. different codings may use different
30 * specific information after some common fields, even within a video track).<br>
31 * For video tracks, a VisualSampleEntry is used; for audio tracks, an AudioSampleEntry. Hint tracks use an
32 * entry format specific to their protocol, with an appropriate name. Timed Text tracks use a TextSampleEntry
33 * For hint tracks, the sample description contains appropriate declarative data for the streaming protocol being
34 * used, and the format of the hint track. The definition of the sample description is specific to the protocol.
35 * Multiple descriptions may be used within a track.<br>
36 * The 'protocol' and 'codingname' fields are registered identifiers that uniquely identify the streaming protocol or
37 * compression format decoder to be used. A given protocol or codingname may have optional or required
38 * extensions to the sample description (e.g. codec initialization parameters). All such extensions shall be within
39 * boxes; these boxes occur after the required fields. Unrecognized boxes shall be ignored.
40 * <br>
41 * Defined in ISO/IEC 14496-12
42 *
43 * @see com.coremedia.iso.boxes.sampleentry.VisualSampleEntry
44 * @see com.coremedia.iso.boxes.sampleentry.TextSampleEntry
45 * @see com.coremedia.iso.boxes.sampleentry.AudioSampleEntry
46 */
47public class SampleDescriptionBox extends FullContainerBox {
48    public static final String TYPE = "stsd";
49
50    public SampleDescriptionBox() {
51        super(TYPE);
52    }
53
54    @Override
55    protected long getContentSize() {
56        return super.getContentSize() + 4;
57    }
58
59    @Override
60    public void _parseDetails(ByteBuffer content) {
61        parseVersionAndFlags(content);
62        content.get(new byte[4]);
63        parseChildBoxes(content);
64    }
65
66    @Override
67    protected void getContent(ByteBuffer byteBuffer) {
68        writeVersionAndFlags(byteBuffer);
69        IsoTypeWriter.writeUInt32(byteBuffer, boxes.size());
70        writeChildBoxes(byteBuffer);
71    }
72
73    public SampleEntry getSampleEntry() {
74        for (Box box : boxes) {
75            if (box instanceof SampleEntry) {
76                return (SampleEntry) box;
77            }
78        }
79        return null;
80    }
81}
82