1 | package org.farng.mp3.id3; |
2 | |
3 | import org.farng.mp3.InvalidTagException; |
4 | import org.farng.mp3.object.ObjectNumberHashMap; |
5 | import org.farng.mp3.object.ObjectNumberVariableLength; |
6 | |
7 | import java.io.IOException; |
8 | import java.io.RandomAccessFile; |
9 | |
10 | /** |
11 | * <h3>4.21. Position synchronisation frame</h3> |
12 | * <p/> |
13 | * <p> This frame delivers information to the listener of how far into the<br> audio stream he |
14 | * picked up; in effect, it states the time offset from<br> the first frame in the stream. The frame layout |
15 | * is:</p> |
16 | * <p/> |
17 | * <p> <Head for 'Position synchronisation', ID: "POSS"><br> |
18 | * <p/> |
19 | * Time stamp format $xx<br> |
20 | * Position |
21 | * $xx (xx ...)</p> |
22 | * <p/> |
23 | * <p> Where time stamp format is:</p> |
24 | * <p/> |
25 | * <p> $01 Absolute time, 32 bit sized, using MPEG frames as unit<br> |
26 | * $02 Absolute time, 32 bit sized, using milliseconds as unit</p> |
27 | * <p/> |
28 | * <p> and position is where in the audio the listener starts to receive,<br> i.e. the |
29 | * beginning of the next frame. If this frame is used in the<br> |
30 | * <p/> |
31 | * beginning of a file the value is always 0. There may only be one<br> "POSS" frame |
32 | * in each tag.<br> </p> |
33 | * |
34 | * @author Eric Farng |
35 | * @version $Revision: 1.4 $ |
36 | */ |
37 | public class FrameBodyPOSS extends AbstractID3v2FrameBody { |
38 | |
39 | /** |
40 | * Creates a new FrameBodyPOSS object. |
41 | */ |
42 | public FrameBodyPOSS() { |
43 | super(); |
44 | } |
45 | |
46 | /** |
47 | * Creates a new FrameBodyPOSS object. |
48 | */ |
49 | public FrameBodyPOSS(final FrameBodyPOSS body) { |
50 | super(body); |
51 | } |
52 | |
53 | /** |
54 | * Creates a new FrameBodyPOSS object. |
55 | */ |
56 | public FrameBodyPOSS(final byte timeStampFormat, final long position) { |
57 | setObject(ObjectNumberHashMap.TIME_STAMP_FORMAT, new Byte(timeStampFormat)); |
58 | setObject("Position", new Long(position)); |
59 | } |
60 | |
61 | /** |
62 | * Creates a new FrameBodyPOSS object. |
63 | */ |
64 | public FrameBodyPOSS(final RandomAccessFile file) throws IOException, InvalidTagException { |
65 | this.read(file); |
66 | } |
67 | |
68 | public String getIdentifier() { |
69 | return "POSS"; |
70 | } |
71 | |
72 | protected void setupObjectList() { |
73 | appendToObjectList(new ObjectNumberHashMap(ObjectNumberHashMap.TIME_STAMP_FORMAT, 1)); |
74 | appendToObjectList(new ObjectNumberVariableLength("Position", 1)); |
75 | } |
76 | } |