libavcodec/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

Defines

#define DECORRELATE(left, right)

Functions

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.

void ff_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 *data_size, 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

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 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().

Function Documentation

static void allocate_buffers ( FLACContext * s ) [static]

Definition at line 133 of file flacdec.c.

static int decode_frame ( FLACContext * s ) [static]

Definition at line 470 of file flacdec.c.

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

Definition at line 245 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 402 of file flacdec.c.

Referenced by decode_frame().

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

Definition at line 285 of file flacdec.c.

Referenced by decode_subframe().

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

Definition at line 335 of file flacdec.c.

Referenced by decode_subframe(), and shorten_decode_frame().

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

Definition at line 124 of file flacdec.c.

Referenced by decode_frame(), and 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 68 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_block_header	(	const uint8_t *	block_header,
		int *	last,
		int *	type,
		int *	size
	)

Parse the metadata block parameters from the header.

Parameters:

`[in]`	block_header	header data, at least 4 bytes
`[out]`	last	indicator for last metadata block
`[out]`	type	metadata block type
`[out]`	size	metadata block size

Definition at line 179 of file flacdec.c.

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

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 145 of file flacdec.c.

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

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

Definition at line 655 of file flacdec.c.

static int flac_decode_frame	(	AVCodecContext *	avctx,
		void *	data,
		int *	data_size,
		AVPacket *	avpkt
	)			`[static]`

Definition at line 556 of file flacdec.c.

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

Definition at line 95 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:

	buf	input buffer, starting with the "fLaC" marker
	buf_size	buffer size

Returns:: number of bytes in the header, or 0 if more data is needed

Definition at line 224 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:

	s	the flac decoding context
	buf	input buffer, starting with the "fLaC" marker
	buf_size	buffer size

Returns:: non-zero if metadata is invalid

Definition at line 198 of file flacdec.c.

Referenced by flac_decode_frame().

Variable Documentation

AVCodec ff_flac_decoder

Initial value:

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

Definition at line 667 of file flacdec.c.


Data Structures
struct	FLACContext
Defines
#define	DECORRELATE(left, right)
Functions
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.
void	ff_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 data_size, AVPacket avpkt)
static av_cold int	flac_decode_close (AVCodecContext *avctx)
Variables
AVCodec	ff_flac_decoder