flacdec.c File Reference

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

#include <limits.h>
#include "libavutil/crc.h"
#include "avcodec.h"
#include "internal.h"
#include "get_bits.h"
#include "bytestream.h"
#include "golomb.h"
#include "flac.h"
#include "flacdata.h"
#include <assert.h>

Go to the source code of this file.

Data Structures

struct  FLACContext

Macros

#define DECORRELATE(left, right)

Typedefs

typedef struct FLACContext FLACContext

Functions

static void allocate_buffers (FLACContext *s)
int avpriv_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 avpriv_flac_parse_streaminfo (AVCodecContext *avctx, struct FLACStreaminfo *s, const uint8_t *buffer)
 Parse the Streaminfo metadata block.
void avpriv_flac_parse_block_header (const uint8_t *block_header, int *last, int *type, int *size)
 Parse the metadata block parameters from the header.
static int parse_streaminfo (FLACContext *s, const uint8_t *buf, int buf_size)
 Parse the STREAMINFO from an inline header.
static int get_metadata_size (const uint8_t *buf, int buf_size)
 Determine the size of an inline header.
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)
static int flac_decode_frame (AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
static av_cold int flac_decode_close (AVCodecContext *avctx)

Variables

AVCodec ff_flac_decoder

Detailed Description

FLAC (Free Lossless Audio Codec) decoder.

Author
Alex Beregszaszi
See Also
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.

Macro Definition Documentation

#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().

Typedef Documentation

typedef struct FLACContext FLACContext

Function Documentation

static void allocate_buffers ( FLACContext s)
static

Definition at line 135 of file flacdec.c.

Referenced by decode_frame(), flac_decode_init(), and parse_streaminfo().

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

Validate the FLAC extradata.

Parameters
[in]avctxcodec context containing the extradata.
[out]formatextradata format.
[out]streaminfo_startpointer to start of 34-byte STREAMINFO data.
Returns
1 if valid, 0 if not valid.

Definition at line 67 of file flacdec.c.

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

void avpriv_flac_parse_block_header ( const uint8_t *  block_header,
int *  last,
int *  type,
int *  size 
)

Parse the metadata block parameters from the header.

Parameters
[in]block_headerheader data, at least 4 bytes
[out]lastindicator for last metadata block
[out]typemetadata block type
[out]sizemetadata block size

Definition at line 181 of file flacdec.c.

Referenced by flac_read_header(), get_metadata_size(), and parse_streaminfo().

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

Parse the Streaminfo metadata block.

Parameters
[out]avctxcodec context to set basic stream parameters
[out]swhere parsed information is stored
[in]bufferpointer to start of 34-byte streaminfo data

Definition at line 147 of file flacdec.c.

Referenced by flac_decode_init(), flac_header(), flac_read_header(), and parse_streaminfo().

static int decode_frame ( FLACContext s)
static

Definition at line 472 of file flacdec.c.

Referenced by flac_decode_frame().

static int decode_residuals ( FLACContext s,
int  channel,
int  pred_order 
)
static

Definition at line 247 of file flacdec.c.

Referenced by decode_subframe_fixed(), and decode_subframe_lpc().

static int decode_subframe ( FLACContext s,
int  channel 
)
inlinestatic

Definition at line 404 of file flacdec.c.

Referenced by decode_frame().

static int decode_subframe_fixed ( FLACContext s,
int  channel,
int  pred_order 
)
static

Definition at line 287 of file flacdec.c.

Referenced by decode_subframe().

static int decode_subframe_lpc ( FLACContext s,
int  channel,
int  pred_order 
)
static

Definition at line 337 of file flacdec.c.

Referenced by decode_subframe().

static void dump_headers ( AVCodecContext avctx,
FLACStreaminfo s 
)
static

Definition at line 126 of file flacdec.c.

Referenced by avpriv_flac_parse_streaminfo(), and decode_frame().

static av_cold int flac_decode_close ( AVCodecContext avctx)
static

Definition at line 658 of file flacdec.c.

static int flac_decode_frame ( AVCodecContext avctx,
void data,
int *  got_frame_ptr,
AVPacket avpkt 
)
static

Definition at line 558 of file flacdec.c.

static av_cold int flac_decode_init ( AVCodecContext avctx)
static

Definition at line 94 of file flacdec.c.

static int get_metadata_size ( const uint8_t *  buf,
int  buf_size 
)
static

Determine the size of an inline header.

Parameters
bufinput buffer, starting with the "fLaC" marker
buf_sizebuffer size
Returns
number of bytes in the header, or 0 if more data is needed

Definition at line 226 of file flacdec.c.

Referenced by flac_decode_frame().

static int parse_streaminfo ( FLACContext s,
const uint8_t *  buf,
int  buf_size 
)
static

Parse the STREAMINFO from an inline header.

Parameters
sthe flac decoding context
bufinput buffer, starting with the "fLaC" marker
buf_sizebuffer size
Returns
non-zero if metadata is invalid

Definition at line 200 of file flacdec.c.

Referenced by flac_decode_frame().

Variable Documentation

AVCodec ff_flac_decoder
Initial value:
{
.name = "flac",
.priv_data_size = sizeof(FLACContext),
.capabilities = CODEC_CAP_DR1,
.long_name= NULL_IF_CONFIG_SMALL("FLAC (Free Lossless Audio Codec)"),
}

Definition at line 670 of file flacdec.c.