Bytestream IO Context. More...

#include <avio.h>

Data Fields
const AVClass *	av_class
	A class for private options. More...

unsigned char *	buffer
	Start of the buffer. More...

int	buffer_size
	Maximum buffer size. More...

unsigned char *	buf_ptr
	Current position in the buffer. More...

unsigned char *	buf_end
	End of the data, may be less than buffer+buffer_size if the read function returned less data than requested, e.g. More...

void *	opaque
	A private pointer, passed to the read/write/seek/... More...

int(*	read_packet )(void opaque, uint8_t buf, int buf_size)

int(*	write_packet )(void opaque, uint8_t buf, int buf_size)

int64_t(*	seek )(void *opaque, int64_t offset, int whence)

int64_t	pos
	position in the file of the current buffer More...

int	must_flush
	true if the next seek should flush More...

int	eof_reached
	true if eof reached More...

int	write_flag
	true if open for writing More...

int	max_packet_size

unsigned long	checksum

unsigned char *	checksum_ptr

unsigned long(*	update_checksum )(unsigned long checksum, const uint8_t *buf, unsigned int size)

int	error
	contains the error code or 0 if no error happened More...

int(*	read_pause )(void *opaque, int pause)
	Pause or resume playback for network streaming protocols - e.g. More...

int64_t(*	read_seek )(void *opaque, int stream_index, int64_t timestamp, int flags)
	Seek to a given timestamp in stream with the specified stream_index. More...

int	seekable
	A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable. More...

int64_t	maxsize
	max filesize, used to limit allocations This field is internal to libavformat and access from outside is not allowed. More...

int	direct
	avio_read and avio_write should if possible be satisfied directly instead of going through a buffer, and avio_seek will always call the underlying seek function directly. More...

int64_t	bytes_read
	Bytes read statistic This field is internal to libavformat and access from outside is not allowed. More...

int	seek_count
	seek statistic This field is internal to libavformat and access from outside is not allowed. More...

int	writeout_count
	writeout statistic This field is internal to libavformat and access from outside is not allowed. More...

int	orig_buffer_size
	Original buffer size used internally after probing and ensure seekback to reset the buffer size This field is internal to libavformat and access from outside is not allowed. More...

int	short_seek_threshold
	Threshold to favor readahead over seek. More...

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

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

int(*	write_data_type )(void opaque, uint8_t buf, int buf_size, enum AVIODataMarkerType type, int64_t time)
	A callback that is used instead of write_packet. More...

int	ignore_boundary_point
	If set, don't call write_data_type separately for AVIO_DATA_MARKER_BOUNDARY_POINT, but ignore them and treat them as AVIO_DATA_MARKER_UNKNOWN (to avoid needlessly small chunks of data returned from the callback). More...

enum AVIODataMarkerType	current_type
	Internal, not meant to be used from outside of AVIOContext. More...

int64_t	last_time

int(*	short_seek_get )(void *opaque)
	A callback that is used instead of short_seek_threshold. More...

Detailed Description

Bytestream IO 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(AVIOContext) must not be used outside libav*.

Note: None of the function pointers in AVIOContext should be called directly, they should only be set by the client application when implementing custom I/O. Normally these are set to the function pointers specified in avio_alloc_context()

Examples:: avio_reading.c, http_multiclient.c, qsvdec.c, and transcode_aac.c.

Definition at line 155 of file avio.h.

Field Documentation

const AVClass* AVIOContext::av_class

A class for private options.

If this AVIOContext is created by avio_open2(), av_class is set and passes the options down to protocols.

If this AVIOContext is manually allocated, then av_class may be set by the caller.

warning – this field can be NULL, be sure to not pass this AVIOContext to any av_opt_* functions in that case.

Definition at line 168 of file avio.h.

Referenced by av_probe_input_buffer2(), and format_child_next().

unsigned char* AVIOContext::buffer

Start of the buffer.

Examples:: avio_reading.c.

Definition at line 216 of file avio.h.

Referenced by asf_write_trailer(), avio_close(), avio_read(), avio_seek(), ffio_ensure_seekback(), ffio_init_context(), ffio_read_partial(), ffio_rewind_with_probe_data(), ffio_set_buf_size(), fill_buffer(), flush_buffer(), free_playlist_list(), hls_read_seek(), main(), url_resetbuf(), and wtvfile_close().

int AVIOContext::buffer_size

Maximum buffer size.

Definition at line 217 of file avio.h.

Referenced by avio_read(), ff_configure_buffers_for_index(), ffio_ensure_seekback(), ffio_init_context(), ffio_rewind_with_probe_data(), ffio_set_buf_size(), ffm_read_data(), fill_buffer(), and url_resetbuf().

unsigned char* AVIOContext::buf_ptr

Current position in the buffer.

Definition at line 218 of file avio.h.

Referenced by asf_write_trailer(), avio_r8(), avio_read(), avio_seek(), avio_seek_time(), avio_w8(), avio_write(), ffio_ensure_seekback(), ffio_fill(), ffio_get_checksum(), ffio_init_checksum(), ffio_init_context(), ffio_read_indirect(), ffio_read_partial(), ffio_rewind_with_probe_data(), ffio_set_buf_size(), fill_buffer(), flush_buffer(), hls_read_seek(), mxf_write_content_storage(), mxf_write_identification(), mxf_write_multi_descriptor(), mxf_write_package(), mxf_write_preface(), mxf_write_sequence(), mxf_write_structural_component(), mxf_write_track(), read_gab2_sub(), and rv10_write_header().

unsigned char* AVIOContext::buf_end

End of the data, may be less than buffer+buffer_size if the read function returned less data than requested, e.g.

for streams where no more data has been received yet.

Definition at line 219 of file avio.h.

Referenced by avio_r8(), avio_read(), avio_seek(), avio_seek_time(), avio_w8(), avio_write(), ffio_ensure_seekback(), ffio_fill(), ffio_init_context(), ffio_read_indirect(), ffio_read_partial(), ffio_rewind_with_probe_data(), fill_buffer(), flush_buffer(), hls_read_seek(), init_packetizer(), read_gab2_sub(), and url_resetbuf().

void* AVIOContext::opaque

A private pointer, passed to the read/write/seek/...

functions.

Definition at line 223 of file avio.h.

Referenced by avio_accept(), avio_close(), avio_close_dyn_buf(), avio_get_dyn_buf(), avio_handshake(), avio_pause(), avio_read(), avio_seek(), avio_seek_time(), avio_size(), ff_avio_child_next(), ffio_close_null_buf(), ffio_init_context(), ffio_read_partial(), fill_buffer(), writeout(), and wtvfile_close().

int(* AVIOContext::read_packet)(void *opaque, uint8_t *buf, int buf_size)

Definition at line 225 of file avio.h.

Referenced by avio_read(), ffio_ensure_seekback(), ffio_init_context(), ffio_read_partial(), and fill_buffer().

int(* AVIOContext::write_packet)(void *opaque, uint8_t *buf, int buf_size)

Definition at line 226 of file avio.h.

Referenced by ffio_init_context(), ffio_open_null_buf(), and writeout().

int64_t(* AVIOContext::seek)(void *opaque, int64_t offset, int whence)

Definition at line 227 of file avio.h.

Referenced by avio_seek(), avio_seek_time(), avio_size(), ffio_init_context(), and nut_read_header().

int64_t AVIOContext::pos

position in the file of the current buffer

Definition at line 228 of file avio.h.

Referenced by asfrtp_parse_packet(), avio_read(), avio_seek(), avio_seek_time(), avio_size(), ffio_init_context(), ffio_read_partial(), ffio_rewind_with_probe_data(), ffm_read_packet(), fill_buffer(), hls_read_seek(), init_packetizer(), read_header(), and writeout().

int AVIOContext::must_flush

true if the next seek should flush

Definition at line 229 of file avio.h.

Referenced by avio_flush(), avio_seek(), ffio_init_context(), and ffio_rewind_with_probe_data().

int AVIOContext::eof_reached

true if eof reached

Definition at line 230 of file avio.h.

Referenced by amf_skip_tag(), ape_read_header(), asf_read_packet(), asfrtp_parse_packet(), avio_feof(), avio_read(), avio_seek(), bmv_read_packet(), decode_frame_header(), decode_main_header(), ebml_level_end(), ebml_parse(), ff_mov_read_chan(), ff_mov_read_stsd_entries(), ff_read_riff_info(), ffio_init_context(), ffio_rewind_with_probe_data(), ffm2_read_header(), ffm_read_header(), fill_buffer(), find_sidx(), get_line(), get_str(), gxf_packet(), hls_read_seek(), hnm_read_packet(), id3v2_parse(), idcin_read_header(), idcin_read_packet(), mov_metadata_hmmt(), mov_read_chap(), mov_read_ctts(), mov_read_elst(), mov_read_sbgp(), mov_read_stco(), mov_read_stps(), mov_read_stsc(), mov_read_stss(), mov_read_stsz(), mov_read_stts(), mov_read_trun(), new_output_stream(), parse_multipart_header(), read_packet(), read_thread(), recheck_discard_flags(), skip_reserved(), xwma_read_header(), and yuv4_read_packet().

int AVIOContext::write_flag

true if open for writing

Definition at line 231 of file avio.h.

Referenced by avio_close(), avio_read(), avio_seek(), ffio_ensure_seekback(), ffio_read_indirect(), ffio_read_partial(), ffio_rewind_with_probe_data(), ffio_set_buf_size(), flush_buffer(), and url_resetbuf().

int AVIOContext::max_packet_size

Definition at line 232 of file avio.h.

Referenced by avio_close_dyn_buf(), ffio_ensure_seekback(), ffio_init_context(), fill_buffer(), and rtp_write_header().

unsigned long AVIOContext::checksum

Definition at line 233 of file avio.h.

Referenced by ffio_get_checksum(), ffio_init_checksum(), fill_buffer(), and flush_buffer().

unsigned char* AVIOContext::checksum_ptr

Definition at line 234 of file avio.h.

Referenced by ffio_ensure_seekback(), ffio_get_checksum(), ffio_init_checksum(), fill_buffer(), and flush_buffer().

unsigned long(* AVIOContext::update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size)

Definition at line 235 of file avio.h.

Referenced by avio_read(), avio_write(), ffio_get_checksum(), ffio_init_checksum(), ffio_init_context(), fill_buffer(), and flush_buffer().

int AVIOContext::error

contains the error code or 0 if no error happened

Definition at line 236 of file avio.h.

Referenced by asf_get_packet(), av_interleaved_write_frame(), av_write_frame(), av_write_trailer(), avi_sync(), avio_read(), cin_read_frame_header(), ebml_read_num(), ffio_init_context(), ffio_read_partial(), fill_buffer(), flv_write_packet(), get_line(), idcin_read_header(), idcin_read_packet(), mxg_read_packet(), read_thread(), write_header_internal(), write_packet(), writeout(), wtvfile_read_packet(), and yuv4_read_packet().

int(* AVIOContext::read_pause)(void *opaque, int pause)

Pause or resume playback for network streaming protocols - e.g.

MMS.

Definition at line 240 of file avio.h.

Referenced by avio_pause(), and ffio_init_context().

int64_t(* AVIOContext::read_seek)(void *opaque, int stream_index, int64_t timestamp, int flags)

Seek to a given timestamp in stream with the specified stream_index.

Needed for some network streaming protocols which don't support seeking to byte position.

Definition at line 246 of file avio.h.

Referenced by avio_seek_time(), and ffio_init_context().

int AVIOContext::seekable

A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.

Definition at line 251 of file avio.h.

Referenced by adp_read_header(), adts_aac_read_header(), aiff_read_header(), aiff_write_trailer(), amf_parse_object(), ape_read_header(), apng_write_trailer(), asf_read_data(), asf_read_header(), asf_write_header1(), asf_write_trailer(), ast_write_trailer(), avi_read_header(), avi_write_header(), avi_write_idx1(), avi_write_ix(), avi_write_packet(), avi_write_packet_internal(), avi_write_trailer(), avio_seek(), caf_write_header(), caf_write_trailer(), cine_read_seek(), dsf_read_header(), dtshd_read_header(), end_ebml_master_crc32(), end_ebml_master_crc32_preliminary(), estimate_timings(), ff_id3v1_read(), ff_voc_get_packet(), ffio_init_context(), ffm2_read_header(), ffm_read_header(), flac_write_trailer(), flv_read_packet(), flv_write_header(), gxf_write_header(), hls_read_header(), http_prepare_data(), http_receive_data(), ico_write_header(), ivf_write_trailer(), matroska_execute_seekhead(), mkv_check_new_extra_data(), mkv_start_new_cluster(), mkv_write_flush_packet(), mkv_write_header(), mkv_write_packet_internal(), mkv_write_tags(), mkv_write_tracks(), mkv_write_trailer(), mov_find_next_sample(), mov_init(), mov_read_cmov(), mov_read_default(), mov_read_header(), mov_read_moof(), mp3_read_header(), mp3_write_xing(), mpc8_read_header(), mpc_read_header(), mpegps_read_pes_header(), mv_read_packet(), mv_read_seek(), mxf_parse_handle_essence(), mxf_read_random_index_pack(), mxf_write_footer(), nut_read_header(), ogg_get_length(), ogg_read_page(), ogg_replace_stream(), put_id3v2_tags(), r3d_read_header(), read_header(), read_seek(), rm_read_header(), rm_write_trailer(), rsd_read_header(), rso_write_header(), seek_back(), seg_init(), seg_write_header(), segment_start(), smjpeg_write_trailer(), sox_write_trailer(), start_ebml_master_crc32(), swf_write_trailer(), tak_read_header(), tta_read_header(), vc1test_write_trailer(), webm_chunk_write_header(), wv_read_block_header(), wv_read_header(), and wv_write_trailer().

int64_t AVIOContext::maxsize

max filesize, used to limit allocations This field is internal to libavformat and access from outside is not allowed.

Definition at line 257 of file avio.h.

Referenced by append_packet_chunked(), ffio_limit(), mp3_read_header(), and thp_read_header().

int AVIOContext::direct

avio_read and avio_write should if possible be satisfied directly instead of going through a buffer, and avio_seek will always call the underlying seek function directly.

Definition at line 264 of file avio.h.

Referenced by avio_read(), avio_seek(), avio_write(), and ffio_init_context().

int64_t AVIOContext::bytes_read

Bytes read statistic This field is internal to libavformat and access from outside is not allowed.

Definition at line 270 of file avio.h.

Referenced by avformat_find_stream_info(), avio_close(), avio_read(), and fill_buffer().

int AVIOContext::seek_count

seek statistic This field is internal to libavformat and access from outside is not allowed.

Definition at line 276 of file avio.h.

Referenced by avformat_find_stream_info(), avio_close(), and avio_seek().

int AVIOContext::writeout_count

writeout statistic This field is internal to libavformat and access from outside is not allowed.

Definition at line 282 of file avio.h.

Referenced by avio_close(), and writeout().

int AVIOContext::orig_buffer_size

Original buffer size used internally after probing and ensure seekback to reset the buffer size This field is internal to libavformat and access from outside is not allowed.

Definition at line 289 of file avio.h.

Referenced by ffio_init_context(), ffio_set_buf_size(), and fill_buffer().

int AVIOContext::short_seek_threshold

Threshold to favor readahead over seek.

This is current internal only, do not use from outside.

Definition at line 295 of file avio.h.

Referenced by avio_seek(), ff_configure_buffers_for_index(), and ffio_init_context().

const char* AVIOContext::protocol_whitelist

',' separated list of allowed protocols.

Definition at line 300 of file avio.h.

Referenced by avformat_open_input().

const char* AVIOContext::protocol_blacklist

',' separated list of disallowed protocols.

Definition at line 305 of file avio.h.

Referenced by avformat_open_input().

int(* AVIOContext::write_data_type)(void *opaque, uint8_t *buf, int buf_size, enum AVIODataMarkerType type, int64_t time)

A callback that is used instead of write_packet.

Definition at line 310 of file avio.h.

Referenced by avio_write_marker(), ffio_init_context(), init_fps(), and writeout().

int AVIOContext::ignore_boundary_point

If set, don't call write_data_type separately for AVIO_DATA_MARKER_BOUNDARY_POINT, but ignore them and treat them as AVIO_DATA_MARKER_UNKNOWN (to avoid needlessly small chunks of data returned from the callback).

Definition at line 317 of file avio.h.

Referenced by avio_write_marker(), and ffio_init_context().

enum AVIODataMarkerType AVIOContext::current_type

Internal, not meant to be used from outside of AVIOContext.

Definition at line 322 of file avio.h.

Referenced by avio_write_marker(), ffio_init_context(), and writeout().

int64_t AVIOContext::last_time

Definition at line 323 of file avio.h.

Referenced by avio_write_marker(), ffio_init_context(), and writeout().

int(* AVIOContext::short_seek_get)(void *opaque)

A callback that is used instead of short_seek_threshold.

This is current internal only, do not use from outside.