h261dec.c File Reference

#include "libavutil/avassert.h"
#include "libavutil/thread.h"
#include "avcodec.h"
#include "mpeg_er.h"
#include "mpegutils.h"
#include "mpegvideo.h"
#include "h263.h"
#include "h261.h"
#include "internal.h"

Go to the source code of this file.

Macros
#define	H261_MBA_VLC_BITS   8
#define	H261_MTYPE_VLC_BITS   6
#define	H261_MV_VLC_BITS   7
#define	H261_CBP_VLC_BITS   9
#define	TCOEFF_VLC_BITS   9
#define	MBA_STUFFING   33
#define	MBA_STARTCODE   34

Functions
static av_cold void	h261_decode_init_static (void)
static av_cold int	h261_decode_init (AVCodecContext *avctx)
static int	h261_decode_gob_header (H261Context *h)
	Decode the group of blocks header or slice header. More...
static int	h261_resync (H261Context *h)
	Decode the group of blocks / video packet header. More...
static int	h261_decode_mb_skipped (H261Context *h, int mba1, int mba2)
	Decode skipped macroblocks. More...
static int	decode_mv_component (GetBitContext *gb, int v)
static int	h261_decode_block (H261Context *h, int16_t *block, int n, int coded)
	Decode a macroblock. More...
static int	h261_decode_mb (H261Context *h)
static int	h261_decode_picture_header (H261Context *h)
	Decode the H.261 picture header. More...
static int	h261_decode_gob (H261Context *h)
static int	get_consumed_bytes (MpegEncContext *s, int buf_size)
	returns the number of bytes consumed for building the current frame More...
static int	h261_decode_frame (AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
static av_cold int	h261_decode_end (AVCodecContext *avctx)

Variables
static VLC	h261_mba_vlc
static VLC	h261_mtype_vlc
static VLC	h261_mv_vlc
static VLC	h261_cbp_vlc
static const int	mvmap [17]
const AVCodec	ff_h261_decoder

Detailed Description

H.261 decoder.

Definition in file h261dec.c.

Macro Definition Documentation

H261_MBA_VLC_BITS

#define H261_MBA_VLC_BITS   8

Definition at line 38 of file h261dec.c.

H261_MTYPE_VLC_BITS

#define H261_MTYPE_VLC_BITS   6

Definition at line 39 of file h261dec.c.

H261_MV_VLC_BITS

#define H261_MV_VLC_BITS   7

Definition at line 40 of file h261dec.c.

H261_CBP_VLC_BITS

#define H261_CBP_VLC_BITS   9

Definition at line 41 of file h261dec.c.

TCOEFF_VLC_BITS

#define TCOEFF_VLC_BITS   9

Definition at line 42 of file h261dec.c.

MBA_STUFFING

#define MBA_STUFFING   33

Definition at line 43 of file h261dec.c.

MBA_STARTCODE

#define MBA_STARTCODE   34

Definition at line 44 of file h261dec.c.

Function Documentation

h261_decode_init_static()

static av_cold void h261_decode_init_static ( void  )

static

Definition at line 51 of file h261dec.c.

Referenced by h261_decode_init().

h261_decode_init()

static av_cold int h261_decode_init ( AVCodecContext *  avctx )

static

Definition at line 68 of file h261dec.c.

h261_decode_gob_header()

static int h261_decode_gob_header ( H261Context *  h )

static

Decode the group of blocks header or slice header.

Returns

<0 if an error occurred

Definition at line 93 of file h261dec.c.

Referenced by h261_resync().

h261_resync()

static int h261_resync ( H261Context *  h )

static

Decode the group of blocks / video packet header.

Returns

<0 if no resync found

Definition at line 147 of file h261dec.c.

Referenced by h261_decode_frame().

h261_decode_mb_skipped()

static int h261_decode_mb_skipped ( H261Context *  h, int  mba1, int  mba2  )

static

Decode skipped macroblocks.

Returns

0

Definition at line 188 of file h261dec.c.

Referenced by h261_decode_gob().

decode_mv_component()

static int decode_mv_component ( GetBitContext *  gb, int  v  )

static

Definition at line 232 of file h261dec.c.

Referenced by h261_decode_mb().

h261_decode_block()

static int h261_decode_block ( H261Context *  h, int16_t *  block, int  n, int  coded  )

static

Decode a macroblock.

Returns

<0 if an error occurred

Definition at line 258 of file h261dec.c.

Referenced by h261_decode_mb().

h261_decode_mb()

static int h261_decode_mb ( H261Context *  h )

static

Definition at line 350 of file h261dec.c.

Referenced by h261_decode_gob().

h261_decode_picture_header()

static int h261_decode_picture_header ( H261Context *  h )

static

Decode the H.261 picture header.

Returns

<0 if no startcode found

Definition at line 474 of file h261dec.c.

Referenced by h261_decode_frame().

h261_decode_gob()

static int h261_decode_gob ( H261Context *  h )

static

Definition at line 538 of file h261dec.c.

Referenced by h261_decode_frame().

get_consumed_bytes()

static int get_consumed_bytes ( MpegEncContext *  s, int  buf_size  )

static

returns the number of bytes consumed for building the current frame

Definition at line 570 of file h261dec.c.

Referenced by h261_decode_frame().

h261_decode_frame()

static int h261_decode_frame ( AVCodecContext *  avctx, void *  data, int *  got_frame, AVPacket *  avpkt  )

static

Definition at line 581 of file h261dec.c.

h261_decode_end()

static av_cold int h261_decode_end ( AVCodecContext *  avctx )

static

Definition at line 659 of file h261dec.c.

Variable Documentation

h261_mba_vlc

VLC h261_mba_vlc

static

Definition at line 46 of file h261dec.c.

Referenced by h261_decode_init_static(), and h261_decode_mb().

h261_mtype_vlc

VLC h261_mtype_vlc

static

Definition at line 47 of file h261dec.c.

Referenced by h261_decode_init_static(), and h261_decode_mb().

h261_mv_vlc

VLC h261_mv_vlc

static

Definition at line 48 of file h261dec.c.

Referenced by decode_mv_component(), and h261_decode_init_static().

h261_cbp_vlc

VLC h261_cbp_vlc

static

Definition at line 49 of file h261dec.c.

Referenced by h261_decode_init_static(), and h261_decode_mb().

mvmap

const int mvmap[17]

static

Initial value:

= {
    0, -1, -2, -3, -4, -5, -6, -7, -8, -9, -10, -11, -12, -13, -14, -15, -16
}

Definition at line 228 of file h261dec.c.

Referenced by decode_mv_component().

ff_h261_decoder

const AVCodec ff_h261_decoder

Initial value:

= {
    .name           = "h261",
    .long_name      = NULL_IF_CONFIG_SMALL("H.261"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_H261,
    .priv_data_size = sizeof(H261Context),
    .init           = h261_decode_init,
    .close          = h261_decode_end,
    .decode         = h261_decode_frame,
    .capabilities   = AV_CODEC_CAP_DR1,
    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
    .max_lowres     = 3,
}

Definition at line 668 of file h261dec.c.