mp3dec.c File Reference

#include <string.h>
#include "libavutil/opt.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/dict.h"
#include "libavutil/mathematics.h"
#include "avformat.h"
#include "internal.h"
#include "avio_internal.h"
#include "demux.h"
#include "id3v2.h"
#include "id3v1.h"
#include "replaygain.h"
#include "libavcodec/codec_id.h"
#include "libavcodec/mpegaudio.h"
#include "libavcodec/mpegaudiodecheader.h"

Go to the source code of this file.

Data Structures
struct	MP3DecContext

Macros
#define	XING_FLAG_FRAMES   0x01
#define	XING_FLAG_SIZE   0x02
#define	XING_FLAG_TOC   0x04
#define	XING_FLAC_QSCALE   0x08
#define	XING_TOC_COUNT   100
#define	LAST_BITS(k, n)
#define	MIDDLE_BITS(k, m, n)
#define	MP3_PACKET_SIZE   1024
#define	SEEK_WINDOW   4096
#define	MIN_VALID   3

Enumerations
enum	CheckRet { CHECK_WRONG_HEADER = -1 , CHECK_SEEK_FAILED = -2 }

Functions
static int	check (AVIOContext *pb, int64_t pos, uint32_t *header)
static int	mp3_read_probe (const AVProbeData *p)
static void	read_xing_toc (AVFormatContext *s, int64_t filesize, int64_t duration)
static void	mp3_parse_info_tag (AVFormatContext *s, AVStream *st, MPADecodeHeader *c, uint32_t spf)
static void	mp3_parse_vbri_tag (AVFormatContext *s, AVStream *st, int64_t base)
static const AVDictionaryEntry *	find_itunes_smpb (const AVDictionary *metadata)
	Look the iTunSMPB tag up under every key it can land on.
static void	mp3_parse_itunes_smpb (AVFormatContext *s, AVStream *st, const MPADecodeHeader *c, uint32_t spf)
	Parse the gapless playback information Apple encoders store in an iTunSMPB comment instead of in the LAME extension of the Xing tag.
static int	mp3_parse_vbr_tags (AVFormatContext *s, AVStream *st, int64_t base)
	Try to find Xing/Info/VBRI tags and compute duration from info therein.
static int	mp3_read_header (AVFormatContext *s)
static int	mp3_read_packet (AVFormatContext *s, AVPacket *pkt)
static int64_t	mp3_sync (AVFormatContext *s, int64_t target_pos, int flags)
static int	mp3_seek (AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

Variables
static const AVOption	options []
static const AVClass	demuxer_class
const FFInputFormat	ff_mp3_demuxer

Macro Definition Documentation

XING_FLAG_FRAMES

#define XING_FLAG_FRAMES   0x01

Definition at line 40 of file mp3dec.c.

Referenced by mp3_parse_info_tag().

XING_FLAG_SIZE

#define XING_FLAG_SIZE   0x02

Definition at line 41 of file mp3dec.c.

Referenced by mp3_parse_info_tag().

XING_FLAG_TOC

#define XING_FLAG_TOC   0x04

Definition at line 42 of file mp3dec.c.

Referenced by mp3_parse_info_tag().

XING_FLAC_QSCALE

#define XING_FLAC_QSCALE   0x08

Definition at line 43 of file mp3dec.c.

Referenced by mp3_parse_info_tag().

XING_TOC_COUNT

#define XING_TOC_COUNT   100

Definition at line 45 of file mp3dec.c.

Referenced by read_xing_toc().

LAST_BITS

#define LAST_BITS	(		k,
			n )

Value:

((k) & ((1 << (n)) - 1))

MIDDLE_BITS

#define MIDDLE_BITS	(		k,
			m,
			n )

Value:

LAST_BITS((k) >> (m), ((n) - (m) + 1))

Referenced by mp3_parse_info_tag().

MP3_PACKET_SIZE

#define MP3_PACKET_SIZE   1024

Definition at line 519 of file mp3dec.c.

Referenced by mp3_read_packet().

SEEK_WINDOW

#define SEEK_WINDOW   4096

Definition at line 545 of file mp3dec.c.

Referenced by mp3_sync().

MIN_VALID

#define MIN_VALID   3

Referenced by mp3_sync().

Enumeration Type Documentation

CheckRet

enum CheckRet

Enumerator
CHECK_WRONG_HEADER
CHECK_SEEK_FAILED

Definition at line 61 of file mp3dec.c.

Function Documentation

check()

static int check ( AVIOContext * pb, int64_t pos, uint32_t * header )

static

Definition at line 547 of file mp3dec.c.

mp3_read_probe()

static int mp3_read_probe ( const AVProbeData * p )

static

Definition at line 70 of file mp3dec.c.

read_xing_toc()

static void read_xing_toc ( AVFormatContext * s, int64_t filesize, int64_t duration )

static

Definition at line 135 of file mp3dec.c.

Referenced by mp3_parse_info_tag().

mp3_parse_info_tag()

static void mp3_parse_info_tag ( AVFormatContext * s, AVStream * st, MPADecodeHeader * c, uint32_t spf )

static

Definition at line 161 of file mp3dec.c.

Referenced by mp3_parse_vbr_tags().

mp3_parse_vbri_tag()

static void mp3_parse_vbri_tag ( AVFormatContext * s, AVStream * st, int64_t base )

static

Definition at line 297 of file mp3dec.c.

Referenced by mp3_parse_vbr_tags().

find_itunes_smpb()

static const AVDictionaryEntry * find_itunes_smpb ( const AVDictionary * metadata )

static

Look the iTunSMPB tag up under every key it can land on.

A COMM frame keeps its language in the key, and while Apple writes eng, anything that retags the file is free to write its own, valid or not.

The bare key is for files remuxed by versions that exposed a COMM descriptor as a metadata key of its own: those wrote the tag back out as a TXXX frame, which carries no language and is keyed by its description alone.

Definition at line 325 of file mp3dec.c.

Referenced by mp3_parse_itunes_smpb().

mp3_parse_itunes_smpb()

static void mp3_parse_itunes_smpb ( AVFormatContext * s, AVStream * st, const MPADecodeHeader * c, uint32_t spf )

static

Parse the gapless playback information Apple encoders store in an iTunSMPB comment instead of in the LAME extension of the Xing tag.

Definition at line 345 of file mp3dec.c.

Referenced by mp3_parse_vbr_tags().

mp3_parse_vbr_tags()

static int mp3_parse_vbr_tags ( AVFormatContext * s, AVStream * st, int64_t base )

static

Try to find Xing/Info/VBRI tags and compute duration from info therein.

Definition at line 383 of file mp3dec.c.

Referenced by mp3_read_header().

mp3_read_header()

static int mp3_read_header ( AVFormatContext * s )

static

Definition at line 442 of file mp3dec.c.

mp3_read_packet()

static int mp3_read_packet ( AVFormatContext * s, AVPacket * pkt )

static

Definition at line 521 of file mp3dec.c.

mp3_sync()

static int64_t mp3_sync ( AVFormatContext * s, int64_t target_pos, int flags )

static

Definition at line 572 of file mp3dec.c.

Referenced by mp3_seek().

mp3_seek()

static int mp3_seek ( AVFormatContext * s, int stream_index, int64_t timestamp, int flags )

static

Definition at line 622 of file mp3dec.c.

Variable Documentation

options

const AVOption options[]

static

Initial value:

= {
    { "usetoc", "use table of contents",  0x42 , AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM},
    { NULL },
}

Definition at line 675 of file mp3dec.c.

demuxer_class

const AVClass demuxer_class

static

Initial value:

= {
    .class_name = "mp3",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
    .category   = AV_CLASS_CATEGORY_DEMUXER,
}

Definition at line 680 of file mp3dec.c.

ff_mp3_demuxer

const FFInputFormat ff_mp3_demuxer

Initial value:

= {
    .p.name         = "mp3",
    .p.long_name    = NULL_IF_CONFIG_SMALL("MP2/3 (MPEG audio layer 2/3)"),
    .p.flags        = AVFMT_GENERIC_INDEX,
    .p.extensions   = "mp2,mp3,m2a,mpa", 
    .p.priv_class   = &demuxer_class,
    .p.mime_type    = "audio/mpeg",
    .flags_internal = FF_INFMT_FLAG_ID3V2_AUTO,
    .read_probe     = mp3_read_probe,
    .read_header    = mp3_read_header,
    .read_packet    = mp3_read_packet,
    .read_seek      = mp3_seek,
    .priv_data_size = sizeof(MP3DecContext),
}

Definition at line 688 of file mp3dec.c.