libavcodec/mpeg4videodec.c File Reference

#include "mpegvideo.h"
#include "mpeg4video.h"
#include "h263.h"
#include "thread.h"

Go to the source code of this file.

Defines

#define SPRITE_TRAJ_VLC_BITS   6

#define DC_VLC_BITS   9

#define MB_TYPE_B_VLC_BITS   4

Functions

void mpeg4_pred_ac (MpegEncContext *s, DCTELEM *block, int n, int dir)

predicts the ac.

static int mpeg4_is_resync (MpegEncContext *s)

check if the next stuff is a resync marker or the end.

static void mpeg4_decode_sprite_trajectory (MpegEncContext *s, GetBitContext *gb)

int mpeg4_decode_video_packet_header (MpegEncContext *s)

decodes the next video packet.

static int get_amv (MpegEncContext *s, int n)

gets the average motion vector for a GMC MB.

static int mpeg4_decode_dc (MpegEncContext *s, int n, int *dir_ptr)

decodes the dc value.

static int mpeg4_decode_partition_a (MpegEncContext *s)

decodes first partition.

static int mpeg4_decode_partition_b (MpegEncContext *s, int mb_count)

decode second partition.

int ff_mpeg4_decode_partitions (MpegEncContext *s)

decodes the first & second partition

static int mpeg4_decode_block (MpegEncContext *s, DCTELEM *block, int n, int coded, int intra, int rvlc)

decodes a block.

static int mpeg4_decode_partitioned_mb (MpegEncContext *s, DCTELEM block[6][64])

decode partition C of one MB.

static int mpeg4_decode_mb (MpegEncContext *s, DCTELEM block[6][64])

static int mpeg4_decode_gop_header (MpegEncContext *s, GetBitContext *gb)

static int decode_vol_header (MpegEncContext *s, GetBitContext *gb)

static int decode_user_data (MpegEncContext *s, GetBitContext *gb)

decodes the user data stuff in the header.

static int decode_vop_header (MpegEncContext *s, GetBitContext *gb)

int ff_mpeg4_decode_picture_header (MpegEncContext *s, GetBitContext *gb)

decode mpeg4 headers

static av_cold int decode_init (AVCodecContext *avctx)

Variables

static VLC dc_lum

static VLC dc_chrom

static VLC sprite_trajectory

static VLC mb_type_b_vlc

static const int mb_type_b_map [4]

AVCodec ff_mpeg4_decoder

Define Documentation

#define DC_VLC_BITS 9

Definition at line 33 of file mpeg4videodec.c.

#define MB_TYPE_B_VLC_BITS 4

Definition at line 34 of file mpeg4videodec.c.

Referenced by decode_init(), and mpeg4_decode_mb().

#define SPRITE_TRAJ_VLC_BITS 6

Definition at line 32 of file mpeg4videodec.c.

Referenced by decode_init(), and mpeg4_decode_sprite_trajectory().

Function Documentation

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

Definition at line 2197 of file mpeg4videodec.c.

static int decode_user_data	(	MpegEncContext *	s,
		GetBitContext *	gb
	)			`[static]`

decodes the user data stuff in the header.

Also initializes divx/xvid/lavc_version/build.

Definition at line 1840 of file mpeg4videodec.c.

Referenced by ff_mpeg4_decode_picture_header().

static int decode_vol_header	(	MpegEncContext *	s,
		GetBitContext *	gb
	)			`[static]`

Definition at line 1530 of file mpeg4videodec.c.

Referenced by ff_mpeg4_decode_picture_header().

static int decode_vop_header	(	MpegEncContext *	s,
		GetBitContext *	gb
	)			`[static]`

Definition at line 1894 of file mpeg4videodec.c.

Referenced by ff_mpeg4_decode_picture_header().

int ff_mpeg4_decode_partitions ( MpegEncContext * s )

decodes the first & second partition

Returns:: <0 if error (and sets error type in the error_status_table)

Definition at line 790 of file mpeg4videodec.c.

Referenced by decode_slice().

int ff_mpeg4_decode_picture_header	(	MpegEncContext *	s,
		GetBitContext *	gb
	)

decode mpeg4 headers

Returns:: <0 if no VOP found (or a damaged one) FRAME_SKIPPED if a not coded VOP is found 0 if a VOP is found

Definition at line 2111 of file mpeg4videodec.c.

Referenced by av_mpeg4_decode_header(), and ff_h263_decode_frame().

static int get_amv	(	MpegEncContext *	s,
		int	n
	)			`[inline, static]`

gets the average motion vector for a GMC MB.

Parameters:

n

either 0 for the x component or 1 for y

Returns:: the average MV for a GMC MB

Definition at line 446 of file mpeg4videodec.c.

Referenced by mpeg4_decode_mb(), and mpeg4_decode_partition_a().

static int mpeg4_decode_block	(	MpegEncContext *	s,
		DCTELEM *	block,
		int	n,
		int	coded,
		int	intra,
		int	rvlc
	)			`[inline, static]`

decodes a block.

Returns:: <0 if an error occurred

Definition at line 843 of file mpeg4videodec.c.

Referenced by mpeg4_decode_mb(), and mpeg4_decode_partitioned_mb().

static int mpeg4_decode_dc	(	MpegEncContext *	s,
		int	n,
		int *	dir_ptr
	)			`[inline, static]`

decodes the dc value.

Parameters:

	n	block index (0-3 are luma, 4-5 are chroma)
	dir_ptr	the prediction direction will be stored here

Returns:: the quantized dc

Definition at line 493 of file mpeg4videodec.c.

Referenced by mpeg4_decode_block(), mpeg4_decode_partition_a(), and mpeg4_decode_partition_b().

static int mpeg4_decode_gop_header	(	MpegEncContext *	s,
		GetBitContext *	gb
	)			`[static]`

Definition at line 1509 of file mpeg4videodec.c.

Referenced by ff_mpeg4_decode_picture_header().

static int mpeg4_decode_mb	(	MpegEncContext *	s,
		DCTELEM	block[6][64]
	)			`[static]`

Definition at line 1171 of file mpeg4videodec.c.

Referenced by decode_init(), and decode_vop_header().

static int mpeg4_decode_partition_a ( MpegEncContext * s ) [static]

decodes first partition.

Returns:: number of MBs decoded or <0 if an error occurred

Definition at line 538 of file mpeg4videodec.c.

Referenced by ff_mpeg4_decode_partitions().

static int mpeg4_decode_partition_b	(	MpegEncContext *	s,
		int	mb_count
	)			`[static]`

decode second partition.

Returns:: <0 if an error occurred

Definition at line 703 of file mpeg4videodec.c.

Referenced by ff_mpeg4_decode_partitions().

static int mpeg4_decode_partitioned_mb	(	MpegEncContext *	s,
		DCTELEM	block[6][64]
	)			`[static]`

decode partition C of one MB.

Returns:: <0 if an error occurred

Definition at line 1089 of file mpeg4videodec.c.

Referenced by decode_vop_header().

static void mpeg4_decode_sprite_trajectory	(	MpegEncContext *	s,
		GetBitContext *	gb
	)			`[static]`

Definition at line 155 of file mpeg4videodec.c.

Referenced by decode_vop_header(), and mpeg4_decode_video_packet_header().

int mpeg4_decode_video_packet_header ( MpegEncContext * s )

decodes the next video packet.

Returns:: <0 if something went wrong

Definition at line 349 of file mpeg4videodec.c.

Referenced by ff_h263_resync().

static int mpeg4_is_resync ( MpegEncContext * s ) [inline, static]

check if the next stuff is a resync marker or the end.

Returns:: 0 if not

Definition at line 112 of file mpeg4videodec.c.

Referenced by mpeg4_decode_mb(), and mpeg4_decode_partitioned_mb().

void mpeg4_pred_ac	(	MpegEncContext *	s,
		DCTELEM *	block,
		int	n,
		int	dir
	)

predicts the ac.

Parameters:

	n	block index (0-3 are luma, 4-5 are chroma)
	dir	the ac prediction direction

Definition at line 53 of file mpeg4videodec.c.

Referenced by ff_msmpeg4_decode_block(), and mpeg4_decode_block().

Variable Documentation

VLC dc_chrom [static]

Definition at line 37 of file mpeg4videodec.c.

VLC dc_lum [static]

Definition at line 37 of file mpeg4videodec.c.

AVCodec ff_mpeg4_decoder

Initial value:

 {
    "mpeg4",
    AVMEDIA_TYPE_VIDEO,
    CODEC_ID_MPEG4,
    sizeof(MpegEncContext),
    decode_init,
    NULL,
    ff_h263_decode_end,
    ff_h263_decode_frame,
    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_FRAME_THREADS,
    .flush= ff_mpeg_flush,
    .max_lowres= 3,
    .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
    .pix_fmts= ff_hwaccel_pixfmt_list_420,
    .update_thread_context= ONLY_IF_THREADS_ENABLED(ff_mpeg_update_thread_context)
}

Definition at line 2243 of file mpeg4videodec.c.

const int mb_type_b_map[4] [static]

Initial value:

 {
    MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
    MB_TYPE_L0L1 | MB_TYPE_16x16,
    MB_TYPE_L1 | MB_TYPE_16x16,
    MB_TYPE_L0 | MB_TYPE_16x16,
}

Definition at line 41 of file mpeg4videodec.c.

Referenced by mpeg4_decode_mb().

VLC mb_type_b_vlc [static]

Definition at line 39 of file mpeg4videodec.c.

VLC sprite_trajectory [static]

Definition at line 38 of file mpeg4videodec.c.


Defines
#define	SPRITE_TRAJ_VLC_BITS 6
#define	DC_VLC_BITS 9
#define	MB_TYPE_B_VLC_BITS 4
Functions
void	mpeg4_pred_ac (MpegEncContext s, DCTELEM block, int n, int dir)
	predicts the ac.
static int	mpeg4_is_resync (MpegEncContext *s)
	check if the next stuff is a resync marker or the end.
static void	mpeg4_decode_sprite_trajectory (MpegEncContext s, GetBitContext gb)
int	mpeg4_decode_video_packet_header (MpegEncContext *s)
	decodes the next video packet.
static int	get_amv (MpegEncContext *s, int n)
	gets the average motion vector for a GMC MB.
static int	mpeg4_decode_dc (MpegEncContext s, int n, int dir_ptr)
	decodes the dc value.
static int	mpeg4_decode_partition_a (MpegEncContext *s)
	decodes first partition.
static int	mpeg4_decode_partition_b (MpegEncContext *s, int mb_count)
	decode second partition.
int	ff_mpeg4_decode_partitions (MpegEncContext *s)
	decodes the first & second partition
static int	mpeg4_decode_block (MpegEncContext s, DCTELEM block, int n, int coded, int intra, int rvlc)
	decodes a block.
static int	mpeg4_decode_partitioned_mb (MpegEncContext *s, DCTELEM block[6][64])
	decode partition C of one MB.
static int	mpeg4_decode_mb (MpegEncContext *s, DCTELEM block[6][64])
static int	mpeg4_decode_gop_header (MpegEncContext s, GetBitContext gb)
static int	decode_vol_header (MpegEncContext s, GetBitContext gb)
static int	decode_user_data (MpegEncContext s, GetBitContext gb)
	decodes the user data stuff in the header.
static int	decode_vop_header (MpegEncContext s, GetBitContext gb)
int	ff_mpeg4_decode_picture_header (MpegEncContext s, GetBitContext gb)
	decode mpeg4 headers
static av_cold int	decode_init (AVCodecContext *avctx)
Variables
static VLC	dc_lum
static VLC	dc_chrom
static VLC	sprite_trajectory
static VLC	mb_type_b_vlc
static const int	mb_type_b_map [4]
AVCodec	ff_mpeg4_decoder