FFmpeg/libavformat/id3v2.h
David Goldwich 7a019dffe5 id3v2: add support for non-text and GEOB type tag frames
This extends the ID3v2 parser to allow for reading of non-text (i.e.
other than T***) meta tag frames providing a ff_id3v2_read_all()
function. An additional data structure 'ID3v2ExtraMeta' is introduced
for these tags since AVDictionary is string oriented and unsuitable
for binary data.

A parser for tag frames of type GEOB is implemented, which is needed
to extract keyring information from encrypted OMA files. GEOB data
is parsed into 'ID3v2ExtraMetaGEOB' data structures.

The routine to decode characters from different encodings to UTF-8,
formerly part of the read_ttag() function, is moved to its own
function. Because some tag frames contain subparts of unknown length,
the function is now also able to read until a null character is found.
In addition, the function now takes care of allocating a buffer long
enough to hold the decoded characters.

Signed-off-by: David Goldwich <david.goldwich@gmail.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
2011-09-21 08:28:21 +02:00

126 lines
3.5 KiB
C

/*
* ID3v2 header parser
* Copyright (c) 2003 Fabrice Bellard
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVFORMAT_ID3V2_H
#define AVFORMAT_ID3V2_H
#include <stdint.h>
#include "avformat.h"
#include "metadata.h"
#define ID3v2_HEADER_SIZE 10
/**
* Default magic bytes for ID3v2 header: "ID3"
*/
#define ID3v2_DEFAULT_MAGIC "ID3"
#define ID3v2_FLAG_DATALEN 0x0001
#define ID3v2_FLAG_UNSYNCH 0x0002
#define ID3v2_FLAG_ENCRYPTION 0x0004
#define ID3v2_FLAG_COMPRESSION 0x0008
enum ID3v2Encoding {
ID3v2_ENCODING_ISO8859 = 0,
ID3v2_ENCODING_UTF16BOM = 1,
ID3v2_ENCODING_UTF16BE = 2,
ID3v2_ENCODING_UTF8 = 3,
};
typedef struct ID3v2ExtraMeta {
const char *tag;
void *data;
struct ID3v2ExtraMeta *next;
} ID3v2ExtraMeta;
typedef struct ID3v2ExtraMetaGEOB {
uint32_t datasize;
uint8_t *mime_type;
uint8_t *file_name;
uint8_t *description;
uint8_t *data;
} ID3v2ExtraMetaGEOB;
typedef struct ID3v2EMFunc {
const char *tag3;
const char *tag4;
void (*read)(AVFormatContext*, AVIOContext*, int, char*, ID3v2ExtraMeta **);
void (*free)();
} ID3v2EMFunc;
/**
* Detect ID3v2 Header.
* @param buf must be ID3v2_HEADER_SIZE byte long
* @param magic magic bytes to identify the header, machine byte order.
* If in doubt, use ID3v2_DEFAULT_MAGIC.
*/
int ff_id3v2_match(const uint8_t *buf, const char *magic);
/**
* Get the length of an ID3v2 tag.
* @param buf must be ID3v2_HEADER_SIZE bytes long and point to the start of an
* already detected ID3v2 tag
*/
int ff_id3v2_tag_len(const uint8_t *buf);
/**
* Read an ID3v2 tag (text tags only)
*/
void ff_id3v2_read(AVFormatContext *s, const char *magic);
/**
* Read an ID3v2 tag, including supported extra metadata (currently only GEOB)
* @param extra_meta If not NULL, extra metadata is parsed into a list of
* ID3v2ExtraMeta structs and *extra_meta points to the head of the list
*/
void ff_id3v2_read_all(AVFormatContext *s, const char *magic, ID3v2ExtraMeta **extra_meta);
/**
* Free memory allocated parsing special (non-text) metadata.
* @param extra_meta Pointer to a pointer to the head of a ID3v2ExtraMeta list, *extra_meta is set to NULL.
*/
void ff_id3v2_free_extra_meta(ID3v2ExtraMeta **extra_meta);
extern const ID3v2EMFunc ff_id3v2_extra_meta_funcs[];
extern const AVMetadataConv ff_id3v2_34_metadata_conv[];
extern const AVMetadataConv ff_id3v2_4_metadata_conv[];
extern const AVMetadataConv ff_id3v2_2_metadata_conv[];
/**
* A list of text information frames allowed in both ID3 v2.3 and v2.4
* http://www.id3.org/id3v2.4.0-frames
* http://www.id3.org/id3v2.4.0-changes
*/
extern const char ff_id3v2_tags[][4];
/**
* ID3v2.4-only text information frames.
*/
extern const char ff_id3v2_4_tags[][4];
/**
* ID3v2.3-only text information frames.
*/
extern const char ff_id3v2_3_tags[][4];
#endif /* AVFORMAT_ID3V2_H */