| 1 | package org.farng.mp3.id3; |
| 2 | |
| 3 | import org.farng.mp3.InvalidTagException; |
| 4 | import org.farng.mp3.object.ObjectByteArraySizeTerminated; |
| 5 | import org.farng.mp3.object.ObjectNumberFixedLength; |
| 6 | import org.farng.mp3.object.ObjectStringNullTerminated; |
| 7 | |
| 8 | import java.io.IOException; |
| 9 | import java.io.RandomAccessFile; |
| 10 | |
| 11 | /** |
| 12 | * <h3>4.19. Audio encryption</h3> |
| 13 | * <p/> |
| 14 | * <p> This frame indicates if the actual audio stream is encrypted, and by<br> |
| 15 | * <p/> |
| 16 | * whom. Since standardisation of such encryption scheme is beyond this<br> document, all |
| 17 | * "AENC" frames begin with a terminated string with a<br> URL containing an email address, or a |
| 18 | * link to a location where an<br> email address can be found, that belongs to the organisation<br> |
| 19 | * <p/> |
| 20 | * responsible for this specific encrypted audio file. Questions<br> regarding the encrypted |
| 21 | * audio should be sent to the email address<br> specified. If a $00 is found directly after the 'Frame |
| 22 | * size' and the<br> audio file indeed is encrypted, the whole file may be considered<br> |
| 23 | * useless.</p> |
| 24 | * <p/> |
| 25 | * <p> After the 'Owner identifier', a pointer to an unencrypted part of the<br> audio can be |
| 26 | * specified. The 'Preview start' and 'Preview length' is<br> described in frames. If no part is |
| 27 | * unencrypted, these fields should<br> be left zeroed. After the 'preview length' field follows optionally |
| 28 | * a<br> data block required for decryption of the audio. There may be more<br> |
| 29 | * <p/> |
| 30 | * than one "AENC" frames in a tag, but only one with the same 'Owner<br> |
| 31 | * identifier'.</p> |
| 32 | * <p/> |
| 33 | * <p> <Header for 'Audio encryption', ID: "AENC"><br> |
| 34 | * Owner identifier <text string> $00<br> |
| 35 | * <p/> |
| 36 | * Preview start $xx xx<br> Preview |
| 37 | * length $xx xx<br> Encryption info <binary |
| 38 | * data><br> |
| 39 | * <p/> |
| 40 | * </p> |
| 41 | * |
| 42 | * @author Eric Farng |
| 43 | * @version $Revision: 1.4 $ |
| 44 | */ |
| 45 | public class FrameBodyAENC extends AbstractID3v2FrameBody { |
| 46 | |
| 47 | /** |
| 48 | * Creates a new FrameBodyAENC object. |
| 49 | */ |
| 50 | public FrameBodyAENC() { |
| 51 | super(); |
| 52 | } |
| 53 | |
| 54 | /** |
| 55 | * Creates a new FrameBodyAENC object. |
| 56 | */ |
| 57 | public FrameBodyAENC(final FrameBodyAENC body) { |
| 58 | super(body); |
| 59 | } |
| 60 | |
| 61 | /** |
| 62 | * Creates a new FrameBodyAENC object. |
| 63 | */ |
| 64 | public FrameBodyAENC(final String owner, final short previewStart, final short previewLength, final byte[] data) { |
| 65 | super(); |
| 66 | setObject("Owner", owner); |
| 67 | setObject("Preview Start", new Short(previewStart)); |
| 68 | setObject("Preview Length", new Short(previewLength)); |
| 69 | setObject("Encryption Info", data); |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * Creates a new FrameBodyAENC object. |
| 74 | */ |
| 75 | public FrameBodyAENC(final RandomAccessFile file) throws IOException, InvalidTagException { |
| 76 | super(); |
| 77 | read(file); |
| 78 | } |
| 79 | |
| 80 | public String getIdentifier() { |
| 81 | return "AENC" + (char) 0 + getOwner(); |
| 82 | } |
| 83 | |
| 84 | public String getOwner() { |
| 85 | return (String) getObject("Owner"); |
| 86 | } |
| 87 | |
| 88 | public void getOwner(final String description) { |
| 89 | setObject("Owner", description); |
| 90 | } |
| 91 | |
| 92 | protected void setupObjectList() { |
| 93 | appendToObjectList(new ObjectStringNullTerminated("Owner")); |
| 94 | appendToObjectList(new ObjectNumberFixedLength("Preview Start", 2)); |
| 95 | appendToObjectList(new ObjectNumberFixedLength("Preview Length", 2)); |
| 96 | appendToObjectList(new ObjectByteArraySizeTerminated("Encryption Info")); |
| 97 | } |
| 98 | } |