Forced audio codec. This allows forcing a specific decoder, even when there are multiple with the same codec_id. Demuxing: Set by user
Forced audio codec_id. Demuxing: Set by user.
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
A class for logging and @ref avoptions. Set by avformat_alloc_context(). Exports (de)muxer private options if they exist.
avio flags, used to force AVIO_FLAG_DIRECT. - encoding: unused - decoding: Set by user
Avoid negative timestamps during muxing. Any value of the AVFMT_AVOID_NEG_TS_* constants. Note, this only works when using av_interleaved_write_frame. (interleave_packet_per_dts is in use) - muxing: Set by user - demuxing: unused
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.
',' separated list of allowed decoders. If NULL then all are allowed - encoding: unused - decoding: set by user
Callback used by devices to communicate with application.
Correct single timestamp overflows - encoding: unused - decoding: Set by user
Flags signalling stream properties. A combination of AVFMTCTX_*. Set by libavformat.
Forced data codec. This allows forcing a specific decoder, even when there are multiple with the same codec_id. Demuxing: Set by user
Forced Data codec_id. Demuxing: Set by user.
Flags to enable debugging.
dump format separator. can be ", " or "\n " or anything else - muxing: Set by user. - demuxing: Set by user.
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.
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
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().
Flags for the user to detect events happening on the file. Flags must be cleared by the user once the event has been handled. A combination of AVFMT_EVENT_FLAG_*.
input or output filename
Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*. Set by the user before avformat_open_input() / avformat_write_header().
Flush the I/O context after each packet. - encoding: Set by user - decoding: unused
number of bytes to read maximally to identify format. - encoding: unused - decoding: set by user
',' separated list of allowed demuxers. If NULL then all are allowed - encoding: unused - decoding: set by user
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().
The input container format.
An opaque field for libavformat internal usage. Must not be accessed in any way by callers.
Custom interrupt callbacks for the I/O layer.
A callback for closing the streams opened with AVFormatContext.io_open().
A callback for opening new IO streams.
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.
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.
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
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
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
Maximum buffering duration for interleaving.
Maximum amount of memory in bytes to use for buffering frames obtained from realtime capture devices.
The maximum number of streams. - encoding: unused - decoding: set by user
Maximum number of packets to read while waiting for the first timestamp. Decoding only.
Metadata that applies to the whole file.
Number of bytes to be written as padding in a metadata header. Demuxing: Unused. Muxing: Set by user via av_format_set_metadata_header_padding.
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
Number of elements in AVFormatContext.streams.
The output container format.
User data. This is a place for some private data of the user.
Called to open further IO contexts when needed for demuxing.
Output timestamp offset, in microseconds. Muxing: set by user
I/O context.
Format private data. This is an AVOptions-enabled struct if and only if iformat/oformat.priv_class is not NULL.
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
Maximum size of the data read from input for determining the input container format. Demuxing only, set by the caller before avformat_open_input().
',' separated list of disallowed protocols. - encoding: unused - decoding: set by user
',' separated list of allowed protocols. - encoding: unused - decoding: set by user
Force seeking to any (also non key) frames. - encoding: unused - decoding: Set by user
Skip duration calcuation in estimate_timings_from_pts. - encoding: unused - decoding: set by user
Skip initial bytes when opening stream - encoding: unused - decoding: Set by user
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.
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.
A list of all streams in the file. New streams are created with avformat_new_stream().
Allow non-standard and experimental extension @see AVCodecContext.strict_std_compliance
Forced subtitle codec. This allows forcing a specific decoder, even when there are multiple with the same codec_id. Demuxing: Set by user
Forced subtitle codec_id. Demuxing: Set by user.
Transport stream id. This will be moved into demuxer private options. Thus no API/ABI compatibility
input or output URL. Unlike the old filename field, this field has no length restriction.
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
Forced video codec. This allows forcing a specific decoder, even when there are multiple with the same codec_id. Demuxing: Set by user
Forced video codec_id. Demuxing: Set by user.
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.