libavcodec/flacdec.c File Reference

FLAC (Free Lossless Audio Codec) decoder. More...

#include <limits.h>
#include "libavutil/crc.h"
#include "avcodec.h"
#include "bitstream.h"
#include "golomb.h"
#include "flac.h"
#include <assert.h>

Go to the source code of this file.

Data Structures

struct  FLACContext

Defines

#define ALT_BITSTREAM_READER
#define MAX_CHANNELS   8
#define MAX_BLOCKSIZE   65535
#define DECORRELATE(left, right)

Enumerations

enum  decorrelation_type { INDEPENDENT, LEFT_SIDE, RIGHT_SIDE, MID_SIDE }

Functions

static int64_t get_utf8 (GetBitContext *gb)
static void allocate_buffers (FLACContext *s)
int ff_flac_is_extradata_valid (AVCodecContext *avctx, enum FLACExtradataFormat *format, uint8_t **streaminfo_start)
 Validate the FLAC extradata.
static av_cold int flac_decode_init (AVCodecContext *avctx)
static void dump_headers (AVCodecContext *avctx, FLACStreaminfo *s)
void ff_flac_parse_streaminfo (AVCodecContext *avctx, struct FLACStreaminfo *s, const uint8_t *buffer)
 Parse the Streaminfo metadata block.
static int metadata_parse (FLACContext *s)
 Parse a list of metadata blocks.
static int decode_residuals (FLACContext *s, int channel, int pred_order)
static int decode_subframe_fixed (FLACContext *s, int channel, int pred_order)
static int decode_subframe_lpc (FLACContext *s, int channel, int pred_order)
static int decode_subframe (FLACContext *s, int channel)
static int decode_frame (FLACContext *s, int alloc_data_size)
static int flac_decode_frame (AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
static av_cold int flac_decode_close (AVCodecContext *avctx)
static void flac_flush (AVCodecContext *avctx)

Variables

static const int sample_rate_table []
static const int sample_size_table []
static const int blocksize_table []
AVCodec flac_decoder

Detailed Description

FLAC (Free Lossless Audio Codec) decoder.

Author:
Alex Beregszaszi
For more information on the FLAC format, visit: http://flac.sourceforge.net/

This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed through, starting from the initial 'fLaC' signature; or by passing the 34-byte streaminfo structure through avctx->extradata[_size] followed by data starting with the 0xFFF8 marker.

Definition in file flacdec.c.

Define Documentation

#define ALT_BITSTREAM_READER

Definition at line 38 of file flacdec.c.

#define DECORRELATE ( left,
right   ) 

Value:

assert(s->channels == 2);\
            for (i = 0; i < s->blocksize; i++) {\
                int a= s->decoded[0][i];\
                int b= s->decoded[1][i];\
                if (s->is32) {\
                    *samples_32++ = (left)  << s->sample_shift;\
                    *samples_32++ = (right) << s->sample_shift;\
                } else {\
                    *samples_16++ = (left)  << s->sample_shift;\
                    *samples_16++ = (right) << s->sample_shift;\
                }\
            }\
            break;

Referenced by flac_decode_frame().

#define MAX_BLOCKSIZE   65535

Definition at line 49 of file flacdec.c.

Referenced by filter_channel(), read_decoding_params(), and read_major_sync().

#define MAX_CHANNELS   8

Definition at line 48 of file flacdec.c.

Enumeration Type Documentation

enum decorrelation_type

Enumerator:
INDEPENDENT 
LEFT_SIDE 
RIGHT_SIDE 
MID_SIDE 

Definition at line 51 of file flacdec.c.

Function Documentation

static void allocate_buffers ( FLACContext *  s  )  [static]

Definition at line 161 of file flacdec.c.

static int decode_frame ( FLACContext *  s,
int  alloc_data_size 
) [static]

Definition at line 475 of file flacdec.c.

static int decode_residuals ( FLACContext *  s,
int  channel,
int  pred_order 
) [static]

Definition at line 263 of file flacdec.c.

Referenced by decode_subframe_fixed(), and decode_subframe_lpc().

static int decode_subframe ( FLACContext *  s,
int  channel 
) [inline, static]

Definition at line 420 of file flacdec.c.

Referenced by decode_frame().

static int decode_subframe_fixed ( FLACContext *  s,
int  channel,
int  pred_order 
) [static]

Definition at line 303 of file flacdec.c.

Referenced by decode_subframe().

static int decode_subframe_lpc ( FLACContext *  s,
int  channel,
int  pred_order 
) [static]

Definition at line 353 of file flacdec.c.

Referenced by decode_subframe(), and shorten_decode_frame().

static void dump_headers ( AVCodecContext *  avctx,
FLACStreaminfo *  s 
) [static]

Definition at line 151 of file flacdec.c.

Referenced by ff_flac_parse_streaminfo().

int ff_flac_is_extradata_valid ( AVCodecContext *  avctx,
enum FLACExtradataFormat *  format,
uint8_t **  streaminfo_start 
)

Validate the FLAC extradata.

Parameters:
[in] avctx codec context containing the extradata.
[out] format extradata format.
[out] streaminfo_start pointer to start of 34-byte STREAMINFO data.
Returns:
1 if valid, 0 if not valid.

Definition at line 100 of file flacdec.c.

Referenced by ff_flac_write_header(), flac_decode_init(), flac_write_trailer(), and ogg_build_flac_headers().

void ff_flac_parse_streaminfo ( AVCodecContext *  avctx,
struct FLACStreaminfo *  s,
const uint8_t *  buffer 
)

Parse the Streaminfo metadata block.

Parameters:
[out] avctx codec context to set basic stream parameters
[out] s where parsed information is stored
[in] buffer pointer to start of 34-byte streaminfo data

Definition at line 183 of file flacdec.c.

Referenced by flac_decode_init(), flac_header(), and metadata_parse().

static av_cold int flac_decode_close ( AVCodecContext *  avctx  )  [static]

Definition at line 706 of file flacdec.c.

static int flac_decode_frame ( AVCodecContext *  avctx,
void *  data,
int *  data_size,
const uint8_t *  buf,
int  buf_size 
) [static]

Definition at line 589 of file flacdec.c.

static av_cold int flac_decode_init ( AVCodecContext *  avctx  )  [static]

Definition at line 127 of file flacdec.c.

static void flac_flush ( AVCodecContext *  avctx  )  [static]

Definition at line 719 of file flacdec.c.

static int64_t get_utf8 ( GetBitContext *  gb  )  [static]

Definition at line 91 of file flacdec.c.

Referenced by decode_frame().

static int metadata_parse ( FLACContext *  s  )  [static]

Parse a list of metadata blocks.

This list of blocks must begin with the fLaC marker.

Parameters:
s the flac decoding context containing the gb bit reader used to parse metadata
Returns:
1 if some metadata was read, 0 if no fLaC marker was found

Definition at line 224 of file flacdec.c.

Referenced by flac_decode_frame().

Variable Documentation

const int blocksize_table[] [static]

Initial value:

 {
     0,    192, 576<<0, 576<<1, 576<<2, 576<<3,      0,      0,
256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7
}

Definition at line 86 of file flacdec.c.

Referenced by decode_frame().

AVCodec flac_decoder

Initial value:

 {
    "flac",
    CODEC_TYPE_AUDIO,
    CODEC_ID_FLAC,
    sizeof(FLACContext),
    flac_decode_init,
    NULL,
    flac_decode_close,
    flac_decode_frame,
    CODEC_CAP_DELAY,
    .flush= flac_flush,
    .long_name= NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
}

Definition at line 727 of file flacdec.c.

const int sample_rate_table[] [static]

Initial value:

{ 0,
  88200, 176400, 192000,
  8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
  0, 0, 0, 0 }

Definition at line 77 of file flacdec.c.

Referenced by decode_frame().

const int sample_size_table[] [static]

Initial value:

{ 0, 8, 12, 0, 16, 20, 24, 0 }

Definition at line 83 of file flacdec.c.

Referenced by decode_frame().

Generated on Fri Oct 26 02:35:43 2012 for FFmpeg by  doxygen 1.5.8