AVCodecContext Struct Reference

#include <avcodec.h>

Collaboration diagram for AVCodecContext:


Data Fields
AVClass *	av_class
int	bit_rate
int	bit_rate_tolerance
int	flags
int	sub_id
int	me_method
void *	extradata
int	extradata_size
AVRational	time_base
int	width
int	height
int	gop_size
enum PixelFormat	pix_fmt
int	rate_emu
void(*	draw_horiz_band )(struct AVCodecContext s, const AVFrame src, int offset[4], int y, int type, int height)
int	sample_rate
	samples per sec
int	channels
enum SampleFormat	sample_fmt
	sample format, currenly unused
int	frame_size
int	frame_number
	audio or video frame number
int	real_pict_num
	returns the real picture number of previous encoded frame
int	delay
float	qcompress
	amount of qscale change between easy & hard scenes (0.0-1.0)
float	qblur
	amount of qscale smoothing over time (0.0-1.0)
int	qmin
int	qmax
int	max_qdiff
int	max_b_frames
float	b_quant_factor
int	rc_strategy
int	b_frame_strategy
int	hurry_up
struct AVCodec *	codec
void *	priv_data
int	rtp_mode
int	rtp_payload_size
void(*	rtp_callback )(struct AVCodecContext avctx, void data, int size, int mb_nb)
int	mv_bits
int	header_bits
int	i_tex_bits
int	p_tex_bits
int	i_count
int	p_count
int	skip_count
int	misc_bits
int	frame_bits
void *	opaque
char	codec_name [32]
enum CodecType	codec_type
enum CodecID	codec_id
unsigned int	codec_tag
int	workaround_bugs
int	luma_elim_threshold
int	chroma_elim_threshold
int	strict_std_compliance
float	b_quant_offset
int	error_resilience
int(*	get_buffer )(struct AVCodecContext c, AVFrame pic)
void(*	release_buffer )(struct AVCodecContext c, AVFrame pic)
int	has_b_frames
int	block_align
int	parse_only
int	mpeg_quant
char *	stats_out
char *	stats_in
float	rc_qsquish
float	rc_qmod_amp
int	rc_qmod_freq
RcOverride *	rc_override
int	rc_override_count
char *	rc_eq
int	rc_max_rate
int	rc_min_rate
int	rc_buffer_size
float	rc_buffer_aggressivity
float	i_quant_factor
float	i_quant_offset
float	rc_initial_cplx
int	dct_algo
float	lumi_masking
float	temporal_cplx_masking
float	spatial_cplx_masking
float	p_masking
float	dark_masking
int	unused
int	idct_algo
int	slice_count
int *	slice_offset
int	error_concealment
unsigned	dsp_mask
int	bits_per_sample
int	prediction_method
AVRational	sample_aspect_ratio
AVFrame *	coded_frame
int	debug
int	debug_mv
uint64_t	error [4]
int	mb_qmin
int	mb_qmax
int	me_cmp
int	me_sub_cmp
int	mb_cmp
int	ildct_cmp
int	dia_size
int	last_predictor_count
int	pre_me
int	me_pre_cmp
int	pre_dia_size
int	me_subpel_quality
enum PixelFormat(*	get_format )(struct AVCodecContext s, const enum PixelFormat fmt)
int	dtg_active_format
int	me_range
int	intra_quant_bias
int	inter_quant_bias
int	color_table_id
int	internal_buffer_count
void *	internal_buffer
int	global_quality
int	coder_type
int	context_model
int	slice_flags
int	xvmc_acceleration
int	mb_decision
uint16_t *	intra_matrix
uint16_t *	inter_matrix
unsigned int	stream_codec_tag
int	scenechange_threshold
int	lmin
int	lmax
struct AVPaletteControl *	palctrl
int	noise_reduction
int(*	reget_buffer )(struct AVCodecContext c, AVFrame pic)
int	rc_initial_buffer_occupancy
int	inter_threshold
int	flags2
int	error_rate
int	antialias_algo
int	quantizer_noise_shaping
int	thread_count
int(*	execute )(struct AVCodecContext c, int(func)(struct AVCodecContext c2, void arg), void *arg2, int ret, int count)
void *	thread_opaque
int	me_threshold
int	mb_threshold
int	intra_dc_precision
int	nsse_weight
int	skip_top
int	skip_bottom
int	profile
int	level
int	lowres
int	coded_width
int	coded_height
int	frame_skip_threshold
int	frame_skip_factor
int	frame_skip_exp
int	frame_skip_cmp
float	border_masking
int	mb_lmin
int	mb_lmax
int	me_penalty_compensation
enum AVDiscard	skip_loop_filter
enum AVDiscard	skip_idct
enum AVDiscard	skip_frame

Detailed Description

main external api structure.

Definition at line 562 of file avcodec.h.

Field Documentation

AVClass* AVCodecContext::av_class

Info on struct for av_log

set by avcodec_alloc_context

Definition at line 567 of file avcodec.h.

Referenced by avcodec_get_context_defaults().

int AVCodecContext::bit_rate

the average bitrate.

encoding: set by user. unused for constant quantizer encoding
decoding: set by lavc. 0 or some bitrate if this info is available in the stream

Definition at line 573 of file avcodec.h.

Referenced by a52_decode_frame(), ac3_decode_frame(), AC3_encode_init(), add_audio_stream(), add_av_stream(), add_codec(), add_video_stream(), adx_decode_header(), amr_nb_encode_init(), audio_encode_example(), av_encode(), avcodec_get_context_defaults(), avcodec_string(), decode_frame(), decode_frame_adu(), decode_frame_mp3on4(), decode_wave_header(), dts_decode_frame(), encode(), encode_init(), Faac_encode_init(), ff_xvid_encode_init(), find_stream_in_feed(), g726_init(), modify_current_stream(), MP3lame_encode_init(), mpa_decode_header(), MPA_encode_init(), mpeg_decode_postinit(), mpegvideo_extract_headers(), new_audio_stream(), new_video_stream(), oggvorbis_init_encoder(), FileAC3::open_file(), parse_ffconfig(), video_encode_example(), wma_decode_init(), and X264_init().

int AVCodecContext::bit_rate_tolerance

number of bits the bitstream is allowed to diverge from the reference. the reference can be CBR (for CBR pass1) or VBR (for pass2)

encoding: set by user. unused for constant quantizer encoding
decoding: unused

Definition at line 581 of file avcodec.h.

Referenced by add_codec(), avcodec_get_context_defaults(), encode(), ff_rate_estimate_qscale(), new_video_stream(), and parse_ffconfig().

int AVCodecContext::flags

CODEC_FLAG_*.

encoding: set by user.
decoding: set by user.

Definition at line 588 of file avcodec.h.

Referenced by add_video_stream(), av_encode(), av_parser_change(), avcodec_default_get_buffer(), avcodec_string(), common_init(), dct_get(), decode_frame(), do_video_stats(), dsputil_init_mmx(), encode(), encode_frame(), encode_init(), encode_q_branch(), Faac_encode_init(), ff_h263_decode_frame(), ff_xvid_encode_init(), get_flags(), h261_decode_frame(), idct_put(), indeo3_decode_frame(), iv_decode_frame(), mjpeg_decode_init(), mpeg_decode_frame(), mpeg_decode_init(), MPV_common_init(), new_audio_stream(), new_video_stream(), opt_input_file(), parse_ffconfig(), print_report(), render_fragments(), render_slice(), stream_component_open(), svq1_decode_init(), svq3_decode_frame(), vc9_decode_frame(), video_decode_example(), vp3_decode_frame(), and X264_init().

int AVCodecContext::sub_id

some codecs needs additionnal format info. It is stored here

encoding: set by user.
decoding: set by lavc. (FIXME is this ok?)

Definition at line 595 of file avcodec.h.

Referenced by avcodec_string(), decode_frame(), decode_frame_adu(), dvbsub_init_decoder(), mpa_decode_header(), mpeg1_decode_sequence(), mpeg_decode_postinit(), mpeg_decode_sequence_extension(), mpegvideo_extract_headers(), rv10_decode_init(), rv20_decode_picture_header(), and vcr2_init_sequence().

int AVCodecContext::me_method

motion estimation algorithm used for video coding.

encoding: MUST be set by user.
decoding: unused

Definition at line 602 of file avcodec.h.

Referenced by add_codec(), avcodec_get_context_defaults(), encode(), encode_frame(), ff_xvid_encode_init(), and new_video_stream().

void* AVCodecContext::extradata

some codecs need / can use extra-data like huffman tables. mjpeg: huffman tables rv10: additional flags mpeg4: global headers (they can be in the bitstream or here) the allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then extradata_size to avoid prolems if its read with the bitstream reader

encoding: set/allocated/freed by lavc.
decoding: set/allocated/freed by user.

Definition at line 614 of file avcodec.h.

Referenced by alac_set_info(), av_encode(), av_mpeg4_decode_header(), av_parser_change(), decode_ext_header(), decode_frame(), decode_init(), decode_init_mp3on4(), encode_end(), encode_init(), Faac_encode_init(), faac_init_mp4(), ff_h263_decode_frame(), ff_xvid_encode_close(), ff_xvid_encode_init(), flac_decode_init(), flic_decode_init(), idcin_decode_init(), mjpeg_decode_init(), oggvorbis_decode_init(), oggvorbis_encode_close(), oggvorbis_encode_init(), quicktime_new_ffmpeg(), ra288_decode_frame(), rv10_decode_init(), rv20_decode_picture_header(), sonic_decode_init(), svq3_decode_frame(), theora_decode_init(), Theora_decode_init(), vc9_decode_init(), vmdvideo_decode_init(), vorbis_decode_init(), vqa_decode_init(), wma_decode_init(), and xvid_strip_vol_header().

int AVCodecContext::extradata_size

AVRational AVCodecContext::time_base

time base in which the timestamps are specified.

encoding: MUST be set by user
decoding: set by lavc.

Definition at line 623 of file avcodec.h.

Referenced by add_av_stream(), add_codec(), add_video_stream(), av_encode(), avcodec_get_context_defaults(), avcodec_string(), decode_slice_header(), decode_vol_header(), decode_vop_header(), do_audio_out(), do_video_out(), do_video_stats(), encode(), ff_h261_encode_picture_header(), ff_rate_control_init(), ff_rate_estimate_qscale(), ff_vbv_update(), ff_xvid_encode_init(), h263_decode_picture_header(), init_pass2(), modify_qscale(), mpeg_decode_postinit(), mpegvideo_extract_headers(), mpegvideo_parse(), new_video_stream(), oggvorbis_decode_init(), opt_input_file(), opt_target(), output_packet(), parse_ffconfig(), prepare_grab(), Theora_decode_init(), video_encode_example(), write_audio_frame(), write_video_frame(), X264_init(), and xvid_correct_framerate().

int AVCodecContext::width

picture width / height.

encoding: MUST be set by user.
decoding: set by lavc. Note, for compatibility its possible to set this instead of coded_width/height before decoding

Definition at line 632 of file avcodec.h.

Referenced by aasc_decode_frame(), add_av_stream(), add_codec(), add_video_stream(), alloc_blocks(), av_encode(), avcodec_default_get_buffer(), avcodec_default_reget_buffer(), avcodec_encode_video(), avcodec_open(), avcodec_set_dimensions(), avcodec_string(), cinepak_decode(), cinepak_decode_init(), common_init(), cyuv_decode_init(), decode(), decode_frame(), decode_i_frame(), decode_init(), decode_p_frame(), decode_slice_header(), do_video_out(), do_video_stats(), dv_codec_profile(), dvvideo_decode_frame(), encode(), encode_frame(), encode_init(), ff_print_debug_info(), ff_xvid_encode_init(), find_stream_in_feed(), flic_decode_frame(), frame_start(), idcin_decode_vlcs(), indeo3_decode_init(), init_codec(), ipvideo_decode_init(), ipvideo_decode_opcodes(), ir2_decode_frame(), msrle_decode_pal4(), msvideo1_decode_16bit(), msvideo1_decode_8bit(), new_video_stream(), open_video(), opt_input_file(), pam_encode_frame(), parse_ffconfig(), pnm_decode_frame(), pnm_decode_header(), pnm_encode_frame(), pnm_parse(), pre_process_video_frame(), prepare_grab(), print_report(), quicktime_ffmpeg_decode(), quicktime_new_ffmpeg(), raw_decode(), raw_encode(), raw_init_decoder(), roqvideo_decode_frame(), rpza_decode_stream(), rv10_decode_init(), smc_decode_stream(), sp5x_decode_frame(), svq1_decode_init(), svq3_decode_frame(), theora_decode_header(), Theora_decode_init(), truemotion1_decode_16bit(), truemotion1_decode_24bit(), truemotion1_decode_header(), truemotion1_decode_init(), ulti_decode_init(), vc9_decode_frame(), vc9_decode_init(), video_decode_example(), video_encode_example(), vmd_decode(), vp3_decode_init(), write_video_frame(), X264_init(), xan_decode_init(), xan_wc3_copy_pixel_run(), xan_wc3_decode_frame(), and xan_wc3_output_pixel_run().

int AVCodecContext::height

Definition at line 632 of file avcodec.h.

Referenced by aasc_decode_frame(), add_av_stream(), add_codec(), add_video_stream(), alloc_blocks(), av_encode(), avcodec_default_get_buffer(), avcodec_default_reget_buffer(), avcodec_encode_video(), avcodec_open(), avcodec_set_dimensions(), avcodec_string(), cinepak_decode_init(), common_init(), cyuv_decode_init(), decode(), decode_frame(), decode_i_frame(), decode_init(), decode_p_frame(), decode_slice_header(), do_video_out(), do_video_stats(), dv_codec_profile(), dvvideo_decode_frame(), encode(), encode_frame(), encode_init(), ff_draw_horiz_band(), ff_print_debug_info(), ff_xvid_encode_init(), find_stream_in_feed(), flic_decode_frame(), flip(), frame_start(), idcin_decode_vlcs(), indeo3_decode_init(), init_codec(), ipvideo_decode_init(), ipvideo_decode_opcodes(), ir2_decode_frame(), mjpeg_decode_sof(), msrle_decode_pal4(), msrle_decode_pal8(), msvideo1_decode_16bit(), msvideo1_decode_8bit(), new_video_stream(), open_video(), opt_input_file(), pam_encode_frame(), parse_ffconfig(), pnm_decode_frame(), pnm_decode_header(), pnm_encode_frame(), pnm_parse(), pre_process_video_frame(), prepare_grab(), print_report(), qtrle_decode_16bpp(), qtrle_decode_24bpp(), qtrle_decode_32bpp(), qtrle_decode_4bpp(), qtrle_decode_8bpp(), quicktime_ffmpeg_decode(), quicktime_new_ffmpeg(), raw_decode(), raw_encode(), raw_init_decoder(), roqvideo_decode_frame(), rpza_decode_stream(), rv10_decode_init(), smc_decode_stream(), sp5x_decode_frame(), svq1_decode_init(), svq3_decode_frame(), theora_decode_header(), Theora_decode_init(), truemotion1_decode_16bit(), truemotion1_decode_24bit(), truemotion1_decode_frame(), truemotion1_decode_header(), ulti_decode_init(), vc9_decode_frame(), vc9_decode_init(), video_decode_example(), video_encode_example(), vmd_decode(), vp3_decode_init(), write_video_frame(), X264_init(), xan_decode_init(), and xan_wc3_decode_frame().

int AVCodecContext::gop_size

the number of pictures in a group of pitures, or 0 for intra_only.

encoding: set by user.
decoding: unused

Definition at line 641 of file avcodec.h.

Referenced by add_av_stream(), add_video_stream(), avcodec_get_context_defaults(), encode(), encode_frame(), ff_xvid_encode_init(), new_video_stream(), parse_ffconfig(), video_encode_example(), and X264_init().

enum PixelFormat AVCodecContext::pix_fmt

pixel format, see PIX_FMT_xxx.

encoding: set by user.
decoding: set by lavc.

Definition at line 648 of file avcodec.h.

Referenced by aasc_decode_init(), add_video_stream(), avcodec_align_dimensions(), avcodec_default_get_buffer(), avcodec_default_reget_buffer(), avcodec_get_context_defaults(), avcodec_string(), cinepak_decode_init(), cyuv_decode_init(), decode(), FFMPEG::decode(), decode_frame(), decode_init(), do_video_out(), dvvideo_decode_frame(), dvvideo_encode_frame(), dvvideo_init(), encode(), encode_frame(), encode_init(), ff_h263_decode_init(), ff_print_debug_info(), ff_xvid_encode_frame(), flic_decode_init(), get_chroma_factor(), h261_decode_init(), idcin_decode_init(), indeo3_decode_init(), ipvideo_decode_init(), ir2_decode_init(), mjpeg_decode_sof(), MPV_common_init(), msrle_decode_init(), msvideo1_decode_8bit(), msvideo1_decode_init(), new_video_stream(), open_video(), opt_input_file(), pam_encode_frame(), pnm_decode_frame(), pnm_decode_header(), pnm_encode_frame(), pnm_parse(), pre_process_video_frame(), qtrle_decode_init(), quicktime_ffmpeg_decode(), raw_decode(), raw_encode(), raw_init_decoder(), raw_init_encoder(), read_header(), roq_decode_init(), rpza_decode_init(), rv10_decode_init(), smc_decode_init(), sp5x_decode_frame(), svq1_decode_init(), Theora_decode_init(), truemotion1_decode_header(), ulti_decode_init(), vc9_decode_frame(), vc9_decode_init(), vcr2_init_sequence(), video_encode_example(), vmdvideo_decode_init(), vp3_decode_init(), vqa_decode_init(), write_video_frame(), xan_decode_frame(), xan_decode_init(), xan_wc3_build_palette(), xan_wc3_copy_pixel_run(), xan_wc3_decode_frame(), and xan_wc3_output_pixel_run().

int AVCodecContext::rate_emu

Frame rate emulation. If not zero lower layer (i.e. format handler) has to read frames at native frame rate.

encoding: set by user.
decoding: unused.

Definition at line 656 of file avcodec.h.

Referenced by opt_input_file().

void(* AVCodecContext::draw_horiz_band)(struct AVCodecContext *s, const AVFrame *src, int offset[4], int y, int type, int height)

if non NULL, 'draw_horiz_band' is called by the libavcodec decoder to draw an horizontal band. It improve cache usage. Not all codecs can do that. You must check the codec capabilities before

encoding: unused

decoding: set by user.

Parameters:

	height	the height of the slice
	y	the y position of the slice
	type	1->top field, 2->bottom field, 3->frame
	offset	offset into the AVFrame.data from which the slice should be read