Format I/O context. More...

#include <avformat.h>

Data Fields
const AVClass *	av_class
	A class for logging and AVOptions. More...

const struct AVInputFormat *	iformat
	The input container format. More...

const struct AVOutputFormat *	oformat
	The output container format. More...

void *	priv_data
	Format private data. More...

AVIOContext *	pb
	I/O context. More...

int	ctx_flags
	Flags signalling stream properties. More...

unsigned int	nb_streams
	Number of elements in AVFormatContext.streams. More...

AVStream **	streams
	A list of all streams in the file. More...

unsigned int	nb_stream_groups
	Number of elements in AVFormatContext.stream_groups. More...

AVStreamGroup **	stream_groups
	A list of all stream groups in the file. More...

unsigned int	nb_chapters
	Number of chapters in AVChapter array. More...

AVChapter **	chapters

char *	url
	input or output URL. More...

int64_t	start_time
	Position of the first frame of the component, in AV_TIME_BASE fractional seconds. More...

int64_t	duration
	Duration of the stream, in AV_TIME_BASE fractional seconds. More...

int64_t	bit_rate
	Total stream bitrate in bit/s, 0 if not available. More...

unsigned int	packet_size

int	max_delay

int	flags
	Flags modifying the (de)muxer behaviour. More...

int64_t	probesize
	Maximum number of bytes read from input in order to determine stream properties. More...

int64_t	max_analyze_duration
	Maximum duration (in AV_TIME_BASE units) of the data read from input in avformat_find_stream_info(). More...

const uint8_t *	key

int	keylen

unsigned int	nb_programs

AVProgram **	programs

enum AVCodecID	video_codec_id
	Forced video codec_id. More...

enum AVCodecID	audio_codec_id
	Forced audio codec_id. More...

enum AVCodecID	subtitle_codec_id
	Forced subtitle codec_id. More...

enum AVCodecID	data_codec_id
	Forced Data codec_id. More...

AVDictionary *	metadata
	Metadata that applies to the whole file. More...

int64_t	start_time_realtime
	Start time of the stream in real world time, in microseconds since the Unix epoch (00:00 1st January 1970). More...

int	fps_probe_size
	The number of frames used for determining the framerate in avformat_find_stream_info(). More...

int	error_recognition
	Error recognition; higher values will detect more errors but may misdetect some more or less valid parts as errors. More...

AVIOInterruptCB	interrupt_callback
	Custom interrupt callbacks for the I/O layer. More...

int	debug
	Flags to enable debugging. More...

int	max_streams
	The maximum number of streams. More...

unsigned int	max_index_size
	Maximum amount of memory in bytes to use for the index of each stream. More...

unsigned int	max_picture_buffer
	Maximum amount of memory in bytes to use for buffering frames obtained from realtime capture devices. More...

int64_t	max_interleave_delta
	Maximum buffering duration for interleaving. More...

int	max_ts_probe
	Maximum number of packets to read while waiting for the first timestamp. More...

int	max_chunk_duration
	Max chunk time in microseconds. More...

int	max_chunk_size
	Max chunk size in bytes Note, not all formats support this and unpredictable things may happen if it is used when not supported. More...

int	max_probe_packets
	Maximum number of packets that can be probed. More...

int	strict_std_compliance
	Allow non-standard and experimental extension. More...

int	event_flags
	Flags indicating events happening on the file, a combination of AVFMT_EVENT_FLAG_*. More...

int	avoid_negative_ts
	Avoid negative timestamps during muxing. More...

int	audio_preload
	Audio preload in microseconds. More...

int	use_wallclock_as_timestamps
	forces the use of wallclock timestamps as pts/dts of packets This has undefined results in the presence of B frames. More...

int	skip_estimate_duration_from_pts
	Skip duration calcuation in estimate_timings_from_pts. More...

int	avio_flags
	avio flags, used to force AVIO_FLAG_DIRECT. More...

enum AVDurationEstimationMethod	duration_estimation_method
	The duration field can be estimated through various ways, and this field can be used to know how the duration was estimated. More...

int64_t	skip_initial_bytes
	Skip initial bytes when opening stream. More...

unsigned int	correct_ts_overflow
	Correct single timestamp overflows. More...

int	seek2any
	Force seeking to any (also non key) frames. More...

int	flush_packets
	Flush the I/O context after each packet. More...

int	probe_score
	format probing score. More...

int	format_probesize
	Maximum number of bytes read from input in order to identify the input format. More...

char *	codec_whitelist
	',' separated list of allowed decoders. More...

char *	format_whitelist
	',' separated list of allowed demuxers. More...

char *	protocol_whitelist
	',' separated list of allowed protocols. More...

char *	protocol_blacklist
	',' separated list of disallowed protocols. More...

int	io_repositioned
	IO repositioned flag. More...

const struct AVCodec *	video_codec
	Forced video codec. More...

const struct AVCodec *	audio_codec
	Forced audio codec. More...

const struct AVCodec *	subtitle_codec
	Forced subtitle codec. More...

const struct AVCodec *	data_codec
	Forced data codec. More...

int	metadata_header_padding
	Number of bytes to be written as padding in a metadata header. More...

void *	opaque
	User data. More...

av_format_control_message	control_message_cb
	Callback used by devices to communicate with application. More...

int64_t	output_ts_offset
	Output timestamp offset, in microseconds. More...

uint8_t *	dump_separator
	dump format separator. More...

int(*	io_open )(struct AVFormatContext s, AVIOContext pb, const char url, int flags, AVDictionary **options)
	A callback for opening new IO streams. More...

int(*	io_close2 )(struct AVFormatContext s, AVIOContext pb)
	A callback for closing the streams opened with AVFormatContext.io_open(). More...

Detailed Description

Format I/O context.

New fields can be added to the end with minor version bumps. Removal, reordering and changes to existing fields require a major version bump. sizeof(AVFormatContext) must not be used outside libav*, use avformat_alloc_context() to create an AVFormatContext.

Fields can be accessed through AVOptions (av_opt*), the name string used matches the associated command line parameter name and can be found in libavformat/options_table.h. The AVOption/command line parameter names differ in some cases from the C structure field names for historic reasons or brevity.

Examples: avio_read_callback.c, decode_filter_audio.c, decode_filter_video.c, demux_decode.c, extract_mvs.c, hw_decode.c, mux.c, qsv_decode.c, qsv_transcode.c, remux.c, show_metadata.c, transcode.c, transcode_aac.c, and vaapi_transcode.c.

Definition at line 1255 of file avformat.h.

Field Documentation

◆ av_class

const AVClass* AVFormatContext::av_class

A class for logging and AVOptions.

Set by avformat_alloc_context(). Exports (de)muxer private options if they exist.

Definition at line 1260 of file avformat.h.

Referenced by av_bsf_alloc(), av_hwdevice_ctx_alloc(), and av_hwframe_ctx_alloc().

◆ iformat

const struct AVInputFormat* AVFormatContext::iformat

The input container format.

Demuxing only, set by avformat_open_input().

Definition at line 1267 of file avformat.h.

Referenced by assert_file_overwrite(), av_dump_format(), avformat_find_stream_info(), dump_stream_format(), dump_stream_group(), estimate_timings(), hls_read_packet(), ifile_open(), rawvideo_read_header(), read_thread(), show_format(), show_stream(), show_stream_group(), and ts_discontinuity_detect().

◆ oformat

const struct AVOutputFormat* AVFormatContext::oformat

The output container format.

Muxing only, must be set by the caller before avformat_write_header().

Examples: mux.c, remux.c, and transcode.c.

Definition at line 1274 of file avformat.h.

Referenced by add_stream(), av_dump_format(), create_streams(), dash_check_bitstream(), dash_init(), dump_stream_format(), dump_stream_group(), ff_rtp_chain_mux_open(), ff_rtp_get_payload_type(), hds_write_header(), hls_mux_init(), hls_start(), hls_write_packet(), init_fps(), ism_write_header(), log_slave(), main(), map_auto_audio(), map_auto_data(), map_auto_subtitle(), map_auto_video(), mpeg_mux_init(), mpegts_init(), mux_fixup_ts(), new_stream_video(), of_open(), open_output_file(), ost_add(), rtp_mpegts_write_header(), seg_check_bitstream(), seg_write_packet(), segment_mux_init(), segment_start(), and streamcopy_init().

◆ priv_data

void* AVFormatContext::priv_data

Format private data.

This is an AVOptions-enabled struct if and only if iformat/oformat.priv_class is not NULL.

muxing: set by avformat_write_header()
demuxing: set by avformat_open_input()

Definition at line 1283 of file avformat.h.

◆ pb

AVIOContext* AVFormatContext::pb

I/O context.

demuxing: either set by the user before avformat_open_input() (then the user must close it manually) or set by avformat_open_input().
muxing: set by the user before avformat_write_header(). The caller must take care of closing / freeing the IO context.

Do NOT set this field if AVFMT_NOFILE flag is set in iformat/oformat.flags. In such a case, the (de)muxer will handle I/O in some other way and this field will be NULL.

Examples: avio_read_callback.c, mux.c, qsv_transcode.c, remux.c, transcode.c, and vaapi_transcode.c.

Definition at line 1297 of file avformat.h.

Referenced by apng_write_header(), apng_write_trailer(), asfrtp_parse_packet(), avformat_find_stream_info(), avi_read_close(), chunk_end(), chunk_start(), cine_read_header(), cine_read_packet(), cine_read_seek(), close_demux_for_component(), close_slave(), concat_parse_script(), dash_flush(), dash_free(), dash_init(), dash_write_packet(), dnxhd_encode_block(), dnxhd_encode_dc(), dnxhd_encode_thread(), efi_read(), estimate_timings(), estimate_timings_from_bit_rate(), estimate_timings_from_pts(), event_loop(), ff_mov_add_hinted_packet(), ff_mov_close_hinting(), ff_mov_generate_squashed_ttml_packet(), ff_rtp_chain_mux_open(), ff_rtsp_tcp_write_packet(), ff_rtsp_undo_setup(), ff_sauce_read(), ff_wms_parse_sdp_a_line(), fifo_thread_write_trailer(), film_write_packet(), finish(), flush_dynbuf(), flush_packet(), free_playlist_list(), free_representation(), frm_read_header(), frm_read_packet(), gdv_read_header(), gdv_read_packet(), hds_flush(), hds_free(), hds_write_header(), hls_mux_init(), hls_read_header(), hls_start(), hls_write_packet(), hls_write_trailer(), init_fps(), ism_flush(), ism_free(), ism_write_header(), laf_read_header(), laf_read_packet(), LLVMFuzzerTestOneInput(), main(), microdvd_write_packet(), mpegts_write_packet_internal(), msnwc_tcp_read_header(), msnwc_tcp_read_packet(), mv_read_header(), mv_read_packet(), mv_read_seek(), mxf_parse_handle_essence(), mxf_read_local_tags(), mxf_seek_to_previous_partition(), of_open(), open_output_file(), parse_audio_var(), parse_global_var(), parse_playlist(), parse_video_var(), put_vcd_padding_sector(), rcwt_flush_cluster(), rcwt_write_header(), rdt_parse_packet(), read_gab2_sub(), read_header(), read_packet(), read_seek(), read_table(), read_thread(), reopen_demux_for_component(), rtp_mpegts_write_close(), rtp_mpegts_write_header(), rtp_mpegts_write_packet(), rv10_write_header(), sap_read_header(), sap_write_close(), sbg_read_header(), scc_write_header(), scc_write_packet(), sds_read_header(), sds_read_packet(), seg_free(), seg_init(), seg_write_header(), seg_write_packet(), seg_write_trailer(), segment_end(), segment_start(), show_format(), smush_read_header(), smush_read_packet(), srt_write_packet(), tedcaptions_read_header(), ttml_write_header(), ttml_write_packet(), ttml_write_trailer(), update_stream_timings(), var_read_metadata(), webm_chunk_deinit(), webm_chunk_init(), webm_chunk_write_header(), webm_chunk_write_packet(), webm_chunk_write_trailer(), webvtt_write_header(), webvtt_write_packet(), write_header(), write_muxed_file(), write_packet_header(), wsaud_write_header(), wsaud_write_init(), wsaud_write_packet(), wsaud_write_trailer(), wv_write_packet(), and wv_write_trailer().

◆ ctx_flags

int AVFormatContext::ctx_flags

Flags signalling stream properties.

A combination of AVFMTCTX_*. Set by libavformat.

Definition at line 1304 of file avformat.h.

Referenced by avformat_find_stream_info(), handle_packet(), hls_read_header(), hls_read_packet(), sap_read_header(), and tb_unreliable().

◆ nb_streams

unsigned int AVFormatContext::nb_streams

Number of elements in AVFormatContext.streams.

Set by avformat_new_stream(), must not be modified by any other code.

Examples: mux.c, qsv_decode.c, remux.c, and transcode.c.

Definition at line 1311 of file avformat.h.

Referenced by add_stream(), asfrtp_parse_sdp_line(), at_write_header(), av_dump_format(), av_find_best_stream(), av_program_add_stream_index(), avformat_find_stream_info(), close_slave(), concat_parse_script(), concat_read_header(), copy_metadata(), create_streams(), create_subcc_streams(), estimate_timings(), estimate_timings_from_bit_rate(), estimate_timings_from_pts(), ff_decklink_write_header(), ff_metadata_conv_ctx(), ff_nut_reset_ts(), ff_rdt_parse_open(), ff_rfps_calculate(), fifo_mux_init(), fifo_thread_write_header(), fill_all_stream_timings(), film_init(), find_stream(), get_system_header_size(), handle_file(), handle_id3(), has_duration(), hds_write_header(), hls_read_header(), hls_read_packet(), id3_has_changed_values(), ifile_open(), init_filters(), laf_read_header(), laf_read_packet(), log_slave(), main(), match_streams(), match_streams_exact_id(), match_streams_one_to_one(), movie_common_init(), mpeg_mux_deinit(), mpeg_mux_end(), mpeg_mux_init(), mv_read_packet(), mv_read_seek(), mxf_compute_index_tables(), mxf_parse_structural_metadata(), of_add_metadata(), of_parse_group_token(), open_demux_for_component(), open_input_file(), open_output_file(), open_slave(), open_track_resource_context(), output_packet(), probe_file(), put_system_header(), read_gab2_sub(), read_interval_packets(), read_packet(), read_thread(), real_seek(), remove_decoded_packets(), reopen_demux_for_component(), rv10_write_header(), sap_fetch_packet(), sap_read_header(), seg_init(), set_disposition_bits(), set_dispositions(), setup_sync_queues(), show_format(), stream_component_close(), stream_component_open(), tee_write_header(), update_stream_timings(), update_streams_from_subdemuxer(), write_headers(), write_index(), and write_mainheader().

◆ streams

AVStream** AVFormatContext::streams

A list of all streams in the file.

New streams are created with avformat_new_stream().

demuxing: streams are created by libavformat in avformat_open_input(). If AVFMTCTX_NOHEADER is set in ctx_flags, then new streams may also appear in av_read_frame().
muxing: streams are created by the user before avformat_write_header().

Freed by libavformat in avformat_free_context().

Examples: decode_filter_audio.c, decode_filter_video.c, demux_decode.c, extract_mvs.c, hw_decode.c, mux.c, qsv_decode.c, qsv_transcode.c, remux.c, transcode.c, and vaapi_transcode.c.

Definition at line 1323 of file avformat.h.

Referenced by apng_write_header(), asfrtp_parse_packet(), asfrtp_parse_sdp_line(), at_write_header(), av_find_best_stream(), avformat_find_stream_info(), cine_read_packet(), copy_metadata(), create_subcc_streams(), dash_check_bitstream(), dash_read_packet(), decklink_write_audio_packet(), decklink_write_video_packet(), dump_stream_format(), dv_parse_sdp_line(), encode_write(), encode_write_frame(), estimate_timings(), estimate_timings_from_bit_rate(), estimate_timings_from_pts(), ff_alsa_open(), ff_decklink_write_header(), ff_decklink_write_packet(), ff_load_image(), ff_metadata_conv_ctx(), ff_mov_init_hinting(), ff_rdt_parse_open(), ff_rfps_calculate(), ff_rtp_chain_mux_open(), ff_sauce_read(), ff_write_chained(), fifo_mux_init(), fifo_thread_attempt_recovery(), fifo_thread_write_header(), fifo_thread_write_packet(), fill_all_stream_timings(), fill_timing_for_id3_timestamped_stream(), film_init(), film_write_header(), film_write_packet(), find_stream(), flush_packet(), frm_read_packet(), get_private_data(), get_system_header_size(), get_timebase(), handle_file(), has_duration(), hds_write_header(), hevc_parse_sdp_line(), hls_read_header(), hls_read_packet(), hls_write_header(), id3_has_changed_values(), ifile_open(), imf_read_packet(), init_convert_timestamp(), init_filters(), laf_read_packet(), lavfi_read_header(), lavfi_read_packet(), log_packet(), log_slave(), main(), match_streams_exact_id(), match_streams_one_to_one(), mov_read_chapters(), mov_write_ttml_document_from_queue(), mov_write_udta_sdp(), movie_common_init(), mpeg_mux_deinit(), mpeg_mux_end(), mpeg_mux_init(), mpeg_mux_write_packet(), mpegts_push_data(), mpegts_write_packet_internal(), mv_read_packet(), mv_read_seek(), mxf_compute_index_tables(), mxf_parse_structural_metadata(), mxf_set_audio_pts(), next_duration(), of_add_metadata(), of_parse_group_token(), open_codec_context(), open_demux_for_component(), open_input_file(), open_output_file(), open_slave(), open_track_resource_context(), opt_map(), opt_target(), opus_header(), opus_packet(), output_packet(), output_segment_list(), pmt_cb(), probe_file(), put_system_header(), rcwt_write_header(), read_gab2_sub(), read_packet(), read_seek(), read_thread(), real_seek(), remove_decoded_packets(), reopen_demux_for_component(), rtp_mpegts_write_header(), rtp_mpegts_write_packet(), sap_fetch_packet(), sap_read_header(), sap_write_header(), sbg_read_packet(), sbg_read_seek2(), scc_write_header(), seek_test(), seg_check_bitstream(), seg_init(), set_disposition_bits(), srt_write_header(), stream_component_close(), stream_component_open(), tee_write_packet(), ttml_write_header(), update_stream_extradata(), update_stream_timings(), update_streams_from_subdemuxer(), v4l2_set_parameters(), video_decode(), video_decode_example(), webm_chunk_write_header(), webvtt_write_header(), write_headers(), write_hls_media_playlist(), and wsaud_write_header().

◆ nb_stream_groups

unsigned int AVFormatContext::nb_stream_groups

Number of elements in AVFormatContext.stream_groups.

Set by avformat_stream_group_create(), must not be modified by any other code.

Definition at line 1330 of file avformat.h.

Referenced by av_dump_format(), dump_stream_group(), of_parse_group_token(), of_parse_iamf_submixes(), show_format(), and show_stream_groups().

◆ stream_groups

AVStreamGroup** AVFormatContext::stream_groups

A list of all stream groups in the file.

New groups are created with avformat_stream_group_create(), and filled with avformat_stream_group_add_stream().

demuxing: groups may be created by libavformat in avformat_open_input(). If AVFMTCTX_NOHEADER is set in ctx_flags, then new groups may also appear in av_read_frame().
muxing: groups may be created by the user before avformat_write_header().

Freed by libavformat in avformat_free_context().

Definition at line 1342 of file avformat.h.

Referenced by dump_stream_group(), of_parse_group_token(), of_parse_iamf_submixes(), and show_stream_groups().

◆ nb_chapters

unsigned int AVFormatContext::nb_chapters

Number of chapters in AVChapter array.

When muxing, chapters are normally written in the file header, so nb_chapters should normally be initialized before write_header is called. Some muxers (e.g. mov and mkv) can also write chapters in the trailer. To write chapters in the trailer, nb_chapters must be zero when write_header is called and non-zero when write_trailer is called.

muxing: set by user
demuxing: set by libavformat

Definition at line 1355 of file avformat.h.

Referenced by av_dump_format(), copy_chapters(), copy_meta(), event_loop(), ff_metadata_conv_ctx(), of_add_metadata(), ogm_chapter(), parse_forced_key_frames(), show_chapters(), and write_headers().

◆ chapters

AVChapter** AVFormatContext::chapters

Definition at line 1356 of file avformat.h.

Referenced by av_dump_format(), copy_chapters(), ff_metadata_conv_ctx(), of_add_metadata(), ogm_chapter(), parse_forced_key_frames(), show_chapters(), and write_chapter().

◆ url

char* AVFormatContext::url

input or output URL.

Unlike the old filename field, this field has no length restriction.

demuxing: set by avformat_open_input(), initialized to an empty string if url parameter was NULL in avformat_open_input().
muxing: may be set by the caller before calling avformat_write_header() (or avformat_init_output() if that is called first) to a string which is freeable by av_free(). Set to an empty string if it was NULL in avformat_init_output().

Freed by libavformat in avformat_free_context().

Definition at line 1371 of file avformat.h.

Referenced by add_file(), append_single_file(), assert_file_overwrite(), at_write_header(), create_streams(), dash_init(), decklink_setup_video(), destroy_context(), fbdev_read_header(), ff_alsa_open(), ff_decklink_list_formats(), ff_decklink_read_header(), ff_decklink_write_header(), ff_rtsp_setup_output_streams(), fifo_init(), fifo_thread_write_header(), hls_append_segment(), hls_delete_old_segments(), hls_mux_init(), hls_rename_temp_file(), hls_start(), hls_write_packet(), hls_write_trailer(), lavfi_read_header(), log_slave(), map_auto_audio(), map_auto_data(), map_auto_video(), of_open(), open_input_file(), parse_device_name(), read_header(), seg_init(), seg_write_header(), seg_write_packet(), segment_end(), segment_start(), set_segment_filename(), show_format(), sls_flag_file_rename(), sls_flag_use_localtime_filename(), sls_flags_filename_process(), tee_write_header(), v4l2_read_header(), and webm_chunk_init().

◆ start_time

int64_t AVFormatContext::start_time

Position of the first frame of the component, in AV_TIME_BASE fractional seconds.

NEVER set this value directly: It is deduced from the AVStream values.

Demuxing only, set by libavformat.

Definition at line 1380 of file avformat.h.

Referenced by av_dump_format(), estimate_timings(), event_loop(), fill_all_stream_timings(), ifile_open(), movie_common_init(), read_packets(), read_thread(), rewind_file(), show_format(), and update_stream_timings().

◆ duration

int64_t AVFormatContext::duration

Duration of the stream, in AV_TIME_BASE fractional seconds.

Only set this value if you know none of the individual stream durations and also do not set any of them. This is deduced from the AVStream values if not set.

Demuxing only, set by libavformat.

Definition at line 1390 of file avformat.h.

Referenced by av_dump_format(), concat_read_header(), estimate_timings(), estimate_timings_from_bit_rate(), event_loop(), fill_all_stream_timings(), get_best_effort_duration(), has_duration(), ifile_open(), libjxl_receive_frame(), of_open(), opus_find_frame_end(), process_command(), request_frame(), show_format(), update_stream_timings(), and xfade_opencl_config_output().

◆ bit_rate

int64_t AVFormatContext::bit_rate

Total stream bitrate in bit/s, 0 if not available.

Never set it directly if the file_size and the duration are known as FFmpeg can compute it automatically.

Definition at line 1397 of file avformat.h.

Referenced by av_dump_format(), estimate_timings(), estimate_timings_from_bit_rate(), event_loop(), get_bit_rate(), LLVMFuzzerTestOneInput(), psy_3gpp_init(), reconfig_encoder(), show_format(), and update_stream_timings().

◆ packet_size

unsigned int AVFormatContext::packet_size

Definition at line 1399 of file avformat.h.

Referenced by dss_723_1_read_packet(), dss_read_seek(), mpeg_mux_init(), and rawvideo_read_header().

◆ max_delay

int AVFormatContext::max_delay

Definition at line 1400 of file avformat.h.

Referenced by ff_rtp_chain_mux_open(), fifo_mux_init(), hls_mux_init(), mpeg_mux_init(), of_open(), output_packet(), rtp_mpegts_write_header(), sap_read_header(), segment_mux_init(), and webm_chunk_init().

◆ flags

int AVFormatContext::flags

Flags modifying the (de)muxer behaviour.

A combination of AVFMT_FLAG_*. Set by the user before avformat_open_input() / avformat_write_header().

Definition at line 1406 of file avformat.h.

Referenced by aic_decode_frame(), android_camera_read_packet(), aribcaption_decode(), avfilter_init_dict(), avformat_find_stream_info(), check_output_yuv2gbrp(), check_yuv2yuv1(), check_yuv2yuvX(), dash_init(), decode_frame(), decode_frame_header(), decode_slice_thread(), deint_vaapi_build_filter_params(), device_open(), dnxhd_decode_macroblock(), fbdev_read_header(), fbdev_read_packet(), ff_alsa_open(), ff_rtp_chain_mux_open(), ff_vaapi_encode_init(), ff_vk_decode_flush(), fic_decode_frame(), fifo_mux_init(), find_slice_quant(), hds_write_header(), hls_read_header(), hqx_decode_frame(), ifile_open(), imm5_init(), init_fps(), libjxl_receive_frame(), main(), mlp_encode_init(), mov_write_isml_manifest(), mss1_decode_frame(), nvenc_check_capabilities(), nvenc_map_preset(), nvenc_setup_device(), nvenc_setup_encoder(), nvenc_setup_h264_config(), nvenc_setup_rate_control(), of_open(), open_file(), open_slave(), open_track_resource_context(), psy_3gpp_init(), read_packet(), read_thread(), reopen_demux_for_component(), segment_mux_init(), set_enable_expr(), setup_frame(), tdsc_init(), vaapi_decode_find_best_format(), vaapi_encode_init_gop_structure(), vaapi_encode_init_rate_control(), vaapi_encode_init_slice_structure(), vaapi_encode_set_output_property(), vaapi_frames_init(), vble_decode_frame(), vpx_init(), webm_chunk_init(), write_major_sync(), and X264_frame().

◆ probesize

int64_t AVFormatContext::probesize

Maximum number of bytes read from input in order to determine stream properties.

Used when reading the global header and in avformat_find_stream_info().

Demuxing only, set by the caller before avformat_open_input().

Note: this is not used for determining the input format

See also: format_probesize

Definition at line 1442 of file avformat.h.

Referenced by avformat_find_stream_info(), hls_read_header(), lavfi_read_header(), and reopen_demux_for_component().

◆ max_analyze_duration

int64_t AVFormatContext::max_analyze_duration

Maximum duration (in AV_TIME_BASE units) of the data read from input in avformat_find_stream_info().

Demuxing only, set by the caller before avformat_find_stream_info(). Can be set to 0 to let avformat choose using a heuristic.

Definition at line 1450 of file avformat.h.

Referenced by avformat_find_stream_info(), hls_read_header(), and reopen_demux_for_component().

◆ key

const uint8_t* AVFormatContext::key

Definition at line 1452 of file avformat.h.

Referenced by av_tea_init(), av_xtea_init(), av_xtea_le_init(), tea_crypt_ecb(), xtea_crypt_ecb(), and xtea_le_crypt_ecb().

◆ keylen

int AVFormatContext::keylen

Definition at line 1453 of file avformat.h.

◆ nb_programs

unsigned int AVFormatContext::nb_programs

Definition at line 1455 of file avformat.h.

Referenced by av_dump_format(), av_find_program_from_stream(), av_new_program(), av_program_add_stream_index(), clear_avprogram(), discard_pid(), discard_unused_programs(), ff_metadata_conv_ctx(), of_add_metadata(), pat_cb(), show_format(), show_programs(), and update_stream_timings().

◆ programs

AVProgram** AVFormatContext::programs

Definition at line 1456 of file avformat.h.

Referenced by av_dump_format(), av_find_program_from_stream(), av_new_program(), av_program_add_stream_index(), clear_avprogram(), discard_pid(), discard_unused_programs(), ff_metadata_conv_ctx(), of_add_metadata(), pat_cb(), show_programs(), and update_stream_timings().

◆ video_codec_id

enum AVCodecID AVFormatContext::video_codec_id

Forced video codec_id.

Demuxing: Set by user.

Definition at line 1462 of file avformat.h.

Referenced by device_try_init(), dshow_cycle_formats(), dshow_read_header(), dshow_should_set_format(), ifile_open(), mmap_read_frame(), and v4l2_read_header().

◆ audio_codec_id

enum AVCodecID AVFormatContext::audio_codec_id

Forced audio codec_id.

Demuxing: Set by user.

Definition at line 1468 of file avformat.h.

Referenced by ifile_open().

◆ subtitle_codec_id

enum AVCodecID AVFormatContext::subtitle_codec_id

Forced subtitle codec_id.

Demuxing: Set by user.

Definition at line 1474 of file avformat.h.

Referenced by ifile_open().

◆ data_codec_id

enum AVCodecID AVFormatContext::data_codec_id

Forced Data codec_id.

Demuxing: Set by user.

Definition at line 1480 of file avformat.h.

Referenced by ifile_open().

◆ metadata

AVDictionary* AVFormatContext::metadata

Metadata that applies to the whole file.

demuxing: set by libavformat in avformat_open_input()
muxing: may be set by the caller before avformat_write_header()

Freed by libavformat in avformat_free_context().

Examples: show_metadata.c.

Definition at line 1490 of file avformat.h.

Referenced by av_dump_format(), copy_meta(), ff_decklink_read_packet(), ff_metadata_conv_ctx(), ff_sauce_read(), ff_wms_parse_sdp_a_line(), fifo_mux_init(), handle_id3(), hls_mux_init(), hls_read_header(), hls_read_packet(), main(), metadata_obu(), mxf_parse_structural_metadata(), of_add_metadata(), open_slave(), read_header(), read_string(), read_thread(), read_uint16(), read_uint32(), read_uint64(), read_uint8(), rtp_mpegts_write_header(), rv10_write_header(), scan_file(), segment_mux_init(), show_format(), var_read_metadata(), and webm_chunk_init().

◆ start_time_realtime

int64_t AVFormatContext::start_time_realtime

Start time of the stream in real world time, in microseconds since the Unix epoch (00:00 1st January 1970).

That is, pts=0 in the stream was captured at this real world time.

muxing: Set by the caller before avformat_write_header(). If set to either 0 or AV_NOPTS_VALUE, then the current wall-time will be used.
demuxing: Set by libavformat. AV_NOPTS_VALUE if unknown. Note that the value may become known after some number of frames have been received.

Definition at line 1503 of file avformat.h.

Referenced by ff_rtp_chain_mux_open().

◆ fps_probe_size

int AVFormatContext::fps_probe_size

The number of frames used for determining the framerate in avformat_find_stream_info().

Demuxing only, set by the caller before avformat_find_stream_info().

Definition at line 1510 of file avformat.h.

Referenced by avformat_find_stream_info().

◆ error_recognition

int AVFormatContext::error_recognition

Error recognition; higher values will detect more errors but may misdetect some more or less valid parts as errors.

Demuxing only, set by the caller before avformat_open_input().

Definition at line 1517 of file avformat.h.

◆ interrupt_callback

AVIOInterruptCB AVFormatContext::interrupt_callback

Custom interrupt callbacks for the I/O layer.

demuxing: set by the user before avformat_open_input(). muxing: set by the user before avformat_write_header() (mainly useful for AVFMT_NOFILE formats). The callback should also be passed to avio_open2() if it's used to open the file.

Definition at line 1528 of file avformat.h.

Referenced by avformat_find_stream_info(), dash_init(), ff_rtp_chain_mux_open(), fifo_mux_init(), fifo_test_packet(), hds_write_header(), hls_mux_init(), hls_read_header(), ifile_open(), ism_seek(), ism_write_header(), lavfi_read_header(), LLVMFuzzerTestOneInput(), of_open(), open_file(), open_slave(), read_thread(), reopen_demux_for_component(), sap_read_header(), segment_mux_init(), and webm_chunk_init().

◆ debug

int AVFormatContext::debug

Flags to enable debugging.

Definition at line 1533 of file avformat.h.

Referenced by amf_load_library(), ff_amf_encode_close(), and LLVMFuzzerTestOneInput().

◆ max_streams

int AVFormatContext::max_streams

The maximum number of streams.

encoding: unused
decoding: set by user

Definition at line 1541 of file avformat.h.

◆ max_index_size

unsigned int AVFormatContext::max_index_size

Maximum amount of memory in bytes to use for the index of each stream.

If the index exceeds this size, entries will be discarded as needed to maintain a smaller size. This can lead to slower or less accurate seeking (depends on demuxer). Demuxers for which a full in-memory index is mandatory will ignore this.

muxing: unused
demuxing: set by user

Definition at line 1553 of file avformat.h.

◆ max_picture_buffer

unsigned int AVFormatContext::max_picture_buffer

Maximum amount of memory in bytes to use for buffering frames obtained from realtime capture devices.

Definition at line 1559 of file avformat.h.

◆ max_interleave_delta

int64_t AVFormatContext::max_interleave_delta

Maximum buffering duration for interleaving.

To ensure all the streams are interleaved correctly, av_interleaved_write_frame() will wait until it has at least one packet for each stream before actually writing any packets to the output file. When some streams are "sparse" (i.e. there are large gaps between successive packets), this can result in excessive buffering.

This field specifies the maximum difference between the timestamps of the first and the last packet in the muxing queue, above which libavformat will output a packet regardless of whether it has queued a packet for all the streams.

Muxing only, set by the caller before avformat_write_header().

Definition at line 1577 of file avformat.h.

◆ max_ts_probe

int AVFormatContext::max_ts_probe

Maximum number of packets to read while waiting for the first timestamp.

Decoding only.

Definition at line 1583 of file avformat.h.

Referenced by avformat_find_stream_info().

◆ max_chunk_duration

int AVFormatContext::max_chunk_duration

Max chunk time in microseconds.

Note, not all formats support this and unpredictable things may happen if it is used when not supported.

encoding: Set by user
decoding: unused

Definition at line 1591 of file avformat.h.

◆ max_chunk_size

int AVFormatContext::max_chunk_size

Max chunk size in bytes Note, not all formats support this and unpredictable things may happen if it is used when not supported.

encoding: Set by user
decoding: unused

Definition at line 1599 of file avformat.h.

◆ max_probe_packets

int AVFormatContext::max_probe_packets

Maximum number of packets that can be probed.

encoding: unused
decoding: set by user

Definition at line 1606 of file avformat.h.

◆ strict_std_compliance

int AVFormatContext::strict_std_compliance

Allow non-standard and experimental extension.

See also: AVCodecContext.strict_std_compliance

Definition at line 1612 of file avformat.h.

Referenced by dash_init(), ff_rtp_chain_mux_open(), hls_mux_init(), LLVMFuzzerTestOneInput(), mov_write_video_tag(), open_slave(), and webm_chunk_init().

◆ event_flags

int AVFormatContext::event_flags

Flags indicating events happening on the file, a combination of AVFMT_EVENT_FLAG_*.

demuxing: may be set by the demuxer in avformat_open_input(), avformat_find_stream_info() and av_read_frame(). Flags must be cleared by the user once the event has been handled.
muxing: may be set by the user after avformat_write_header() to indicate a user-triggered event. The muxer will clear the flags for events it has handled in av_[interleaved]_write_frame().

Definition at line 1625 of file avformat.h.

Referenced by hls_read_packet().

◆ avoid_negative_ts

int AVFormatContext::avoid_negative_ts

Avoid negative timestamps during muxing.

Any value of the AVFMT_AVOID_NEG_TS_* constants. Note, this works better when using av_interleaved_write_frame().

muxing: Set by user
demuxing: unused

Definition at line 1642 of file avformat.h.

Referenced by dash_init(), seg_init(), and webm_chunk_init().

◆ audio_preload

int AVFormatContext::audio_preload

Audio preload in microseconds.

Note, not all formats support this and unpredictable things may happen if it is used when not supported.

encoding: Set by user
decoding: unused

Definition at line 1654 of file avformat.h.

◆ use_wallclock_as_timestamps

int AVFormatContext::use_wallclock_as_timestamps

forces the use of wallclock timestamps as pts/dts of packets This has undefined results in the presence of B frames.

encoding: unused
decoding: Set by user

Definition at line 1662 of file avformat.h.

◆ skip_estimate_duration_from_pts

int AVFormatContext::skip_estimate_duration_from_pts

Skip duration calcuation in estimate_timings_from_pts.

encoding: unused
decoding: set by user

Definition at line 1669 of file avformat.h.

Referenced by estimate_timings_from_pts().

◆ avio_flags

int AVFormatContext::avio_flags

avio flags, used to force AVIO_FLAG_DIRECT.

encoding: unused
decoding: Set by user

Definition at line 1676 of file avformat.h.

◆ duration_estimation_method

enum AVDurationEstimationMethod AVFormatContext::duration_estimation_method

The duration field can be estimated through various ways, and this field can be used to know how the duration was estimated.

encoding: unused
decoding: Read by user

Definition at line 1684 of file avformat.h.

Referenced by estimate_timings().

◆ skip_initial_bytes

int64_t AVFormatContext::skip_initial_bytes

Skip initial bytes when opening stream.

encoding: unused
decoding: Set by user

Definition at line 1691 of file avformat.h.

◆ correct_ts_overflow

unsigned int AVFormatContext::correct_ts_overflow

Correct single timestamp overflows.

encoding: unused
decoding: Set by user

Definition at line 1698 of file avformat.h.

◆ seek2any

int AVFormatContext::seek2any

Force seeking to any (also non key) frames.

encoding: unused
decoding: Set by user

Definition at line 1705 of file avformat.h.

◆ flush_packets

int AVFormatContext::flush_packets

Flush the I/O context after each packet.

encoding: Set by user
decoding: unused

Definition at line 1712 of file avformat.h.

Referenced by webm_chunk_init().

◆ probe_score

int AVFormatContext::probe_score

format probing score.

The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes the format.

encoding: unused
decoding: set by avformat, read by user

Definition at line 1721 of file avformat.h.

Referenced by show_format().

◆ format_probesize

int AVFormatContext::format_probesize

Maximum number of bytes read from input in order to identify the input format.

Only used when the format is not set explicitly by the caller.

Demuxing only, set by the caller before avformat_open_input().

See also: probesize

Definition at line 1732 of file avformat.h.

◆ codec_whitelist

char* AVFormatContext::codec_whitelist

',' separated list of allowed decoders.

If NULL then all are allowed

encoding: unused
decoding: set by user

Definition at line 1740 of file avformat.h.

Referenced by avformat_find_stream_info(), and ff_copy_whiteblacklists().

◆ format_whitelist

char* AVFormatContext::format_whitelist

',' separated list of allowed demuxers.

If NULL then all are allowed

encoding: unused
decoding: set by user

Definition at line 1748 of file avformat.h.

Referenced by ff_copy_whiteblacklists().

◆ protocol_whitelist

char* AVFormatContext::protocol_whitelist

',' separated list of allowed protocols.

encoding: unused
decoding: set by user

Definition at line 1755 of file avformat.h.

Referenced by ff_copy_whiteblacklists(), ism_seek(), and lavfi_read_header().

◆ protocol_blacklist

char* AVFormatContext::protocol_blacklist

',' separated list of disallowed protocols.

encoding: unused
decoding: set by user

Definition at line 1762 of file avformat.h.

Referenced by ff_copy_whiteblacklists(), and ism_seek().

◆ io_repositioned

int AVFormatContext::io_repositioned

IO repositioned flag.

This is set by avformat when the underlaying IO context read pointer is repositioned, for example when doing byte based seeking. Demuxers can use the flag to detect such changes.

Definition at line 1770 of file avformat.h.

◆ video_codec

const struct AVCodec* AVFormatContext::video_codec

Forced video codec.

This allows forcing a specific decoder, even when there are multiple with the same codec_id. Demuxing: Set by user

Definition at line 1778 of file avformat.h.

Referenced by ifile_open().

◆ audio_codec

const struct AVCodec* AVFormatContext::audio_codec

Forced audio codec.

This allows forcing a specific decoder, even when there are multiple with the same codec_id. Demuxing: Set by user

Definition at line 1786 of file avformat.h.

Referenced by dss_read_header(), dss_read_packet(), dss_read_seek(), and ifile_open().

◆ subtitle_codec

const struct AVCodec* AVFormatContext::subtitle_codec

Forced subtitle codec.

This allows forcing a specific decoder, even when there are multiple with the same codec_id. Demuxing: Set by user

Definition at line 1794 of file avformat.h.

Referenced by ifile_open().

◆ data_codec

const struct AVCodec* AVFormatContext::data_codec

Forced data codec.

This allows forcing a specific decoder, even when there are multiple with the same codec_id. Demuxing: Set by user

Definition at line 1802 of file avformat.h.

Referenced by ifile_open().

◆ metadata_header_padding

int AVFormatContext::metadata_header_padding

Number of bytes to be written as padding in a metadata header.

Demuxing: Unused. Muxing: Set by user.

Definition at line 1809 of file avformat.h.

◆ opaque

void* AVFormatContext::opaque

User data.

This is a place for some private data of the user.

Definition at line 1815 of file avformat.h.

Referenced by dash_init(), fifo_mux_init(), hls_mux_init(), open_slave(), program_opencl_config_output(), and segment_mux_init().

◆ control_message_cb

av_format_control_message AVFormatContext::control_message_cb

Callback used by devices to communicate with application.

Definition at line 1820 of file avformat.h.

◆ output_ts_offset

int64_t AVFormatContext::output_ts_offset

Output timestamp offset, in microseconds.

Muxing: set by user

Definition at line 1826 of file avformat.h.

◆ dump_separator

uint8_t* AVFormatContext::dump_separator

dump format separator.

can be ", " or "\n " or anything else

muxing: Set by user.
demuxing: Set by user.

Definition at line 1834 of file avformat.h.

Referenced by dump_stream_format(), and dump_stream_group().

◆ io_open

int(* AVFormatContext::io_open) (struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, AVDictionary **options)

A callback for opening new IO streams.

Whenever a muxer or a demuxer needs to open an IO stream (typically from avformat_open_input() for demuxers, but for certain formats can happen at other times as well), it will call this callback to obtain an IO context.

Parameters

s	the format context
pb	on success, the newly opened IO context should be returned here
url	the url to open
flags	a combination of AVIO_FLAG_*
options	a dictionary of additional options, with the same semantics as in avio_open2()

Returns: 0 on success, a negative AVERROR code on failure

Note: Certain muxers and demuxers do nesting, i.e. they open one or more additional internal format contexts. Thus the AVFormatContext pointer passed to this callback may be different from the one facing the caller. It will, however, have the same 'opaque' field.

Definition at line 1856 of file avformat.h.

Referenced by dash_init(), fifo_mux_init(), hls_mux_init(), hls_read_header(), open_slave(), open_track_resource_context(), read_header(), reopen_demux_for_component(), seg_write_header(), and segment_mux_init().

◆ io_close2

int(* AVFormatContext::io_close2) (struct AVFormatContext *s, AVIOContext *pb)

A callback for closing the streams opened with AVFormatContext.io_open().

Using this is preferred over io_close, because this can return an error. Therefore this callback is used instead of io_close by the generic libavformat code if io_close is NULL or the default.

Parameters

s	the format context
pb	IO context to be closed and freed

Returns: 0 on success, a negative AVERROR code on failure

Definition at line 1870 of file avformat.h.

Referenced by dash_init(), fifo_mux_init(), hls_mux_init(), open_slave(), open_track_resource_context(), and segment_mux_init().

The documentation for this struct was generated from the following file:

libavformat/avformat.h

Data Fields

Detailed Description

Field Documentation

◆ av_class

◆ iformat

◆ oformat

◆ priv_data

◆ pb

◆ ctx_flags

◆ nb_streams

◆ streams

◆ nb_stream_groups

◆ stream_groups

◆ nb_chapters

◆ chapters

◆ url

◆ start_time

◆ duration

◆ bit_rate

◆ packet_size

◆ max_delay

◆ flags

◆ probesize

◆ max_analyze_duration

◆ key

◆ keylen

◆ nb_programs

◆ programs

◆ video_codec_id

◆ audio_codec_id

◆ subtitle_codec_id

◆ data_codec_id

◆ metadata

◆ start_time_realtime

◆ fps_probe_size

◆ error_recognition

◆ interrupt_callback

◆ debug

◆ max_streams

◆ max_index_size

◆ max_picture_buffer

◆ max_interleave_delta

◆ max_ts_probe

◆ max_chunk_duration

◆ max_chunk_size

◆ max_probe_packets

◆ strict_std_compliance

◆ event_flags

◆ avoid_negative_ts

◆ audio_preload

◆ use_wallclock_as_timestamps

◆ skip_estimate_duration_from_pts

◆ avio_flags

◆ duration_estimation_method

◆ skip_initial_bytes

◆ correct_ts_overflow

◆ seek2any

◆ flush_packets

◆ probe_score

◆ format_probesize

◆ codec_whitelist

◆ format_whitelist

◆ protocol_whitelist

◆ protocol_blacklist

◆ io_repositioned

◆ video_codec

◆ audio_codec

◆ subtitle_codec

◆ data_codec

◆ metadata_header_padding

◆ opaque

◆ control_message_cb

◆ output_ts_offset

◆ dump_separator

◆ io_open

◆ io_close2