FFmpeg
4.2.2
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Format I/O context. More...
#include <libavformat/avformat.h>
Data Fields | |
const AVClass * | av_class |
A class for logging and AVOptions. More... | |
ff_const59 struct AVInputFormat * | iformat |
The input container format. More... | |
ff_const59 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... | |
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 size of the data read from input for determining the input container format. 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... | |
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... | |
unsigned int | nb_chapters |
Number of chapters in AVChapter array. More... | |
AVChapter ** | chapters |
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... | |
int64_t | max_interleave_delta |
Maximum buffering duration for interleaving. More... | |
int | strict_std_compliance |
Allow non-standard and experimental extension. More... | |
int | event_flags |
Flags for the user to detect events happening on the file. More... | |
int | max_ts_probe |
Maximum number of packets to read while waiting for the first timestamp. More... | |
int | avoid_negative_ts |
Avoid negative timestamps during muxing. More... | |
int | ts_id |
Transport stream id. More... | |
int | audio_preload |
Audio preload in microseconds. 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 | 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 | 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 |
number of bytes to read maximally to identify format. More... | |
char * | codec_whitelist |
',' separated list of allowed decoders. More... | |
char * | format_whitelist |
',' separated list of allowed demuxers. More... | |
AVFormatInternal * | internal |
An opaque field for libavformat internal usage. More... | |
int | io_repositioned |
IO repositioned flag. More... | |
AVCodec * | video_codec |
Forced video codec. More... | |
AVCodec * | audio_codec |
Forced audio codec. More... | |
AVCodec * | subtitle_codec |
Forced subtitle codec. More... | |
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... | |
enum AVCodecID | data_codec_id |
Forced Data codec_id. More... | |
char * | protocol_whitelist |
',' separated list of allowed protocols. More... | |
int(* | io_open )(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, AVDictionary **options) |
A callback for opening new IO streams. More... | |
void(* | io_close )(struct AVFormatContext *s, AVIOContext *pb) |
A callback for closing the streams opened with AVFormatContext.io_open(). More... | |
char * | protocol_blacklist |
',' separated list of disallowed protocols. More... | |
int | max_streams |
The maximum number of streams. More... | |
int | skip_estimate_duration_from_pts |
Skip duration calcuation in estimate_timings_from_pts. More... | |
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.
Definition at line 1358 of file avformat.h.
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 1363 of file avformat.h.
ff_const59 struct AVInputFormat* AVFormatContext::iformat |
The input container format.
Demuxing only, set by avformat_open_input().
Definition at line 1370 of file avformat.h.
ff_const59 struct AVOutputFormat* AVFormatContext::oformat |
The output container format.
Muxing only, must be set by the caller before avformat_write_header().
Definition at line 1377 of file avformat.h.
Referenced by add_stream(), main(), and open_output_file().
void* AVFormatContext::priv_data |
Format private data.
This is an AVOptions-enabled struct if and only if iformat/oformat.priv_class is not NULL.
Definition at line 1386 of file avformat.h.
AVIOContext* AVFormatContext::pb |
I/O 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.
Definition at line 1400 of file avformat.h.
Referenced by main(), and open_output_file().
int AVFormatContext::ctx_flags |
Flags signalling stream properties.
A combination of AVFMTCTX_*. Set by libavformat.
Definition at line 1407 of file avformat.h.
unsigned int AVFormatContext::nb_streams |
Number of elements in AVFormatContext.streams.
Set by avformat_new_stream(), must not be modified by any other code.
Definition at line 1414 of file avformat.h.
Referenced by add_stream(), init_filters(), main(), open_input_file(), and open_output_file().
AVStream** AVFormatContext::streams |
A list of all streams in the file.
New streams are created with avformat_new_stream().
Freed by libavformat in avformat_free_context().
Definition at line 1426 of file avformat.h.
Referenced by encode_write_frame(), init_filters(), log_packet(), main(), open_codec_context(), open_input_file(), and open_output_file().
char* AVFormatContext::url |
input or output URL.
Unlike the old filename field, this field has no length restriction.
Freed by libavformat in avformat_free_context().
Definition at line 1454 of file avformat.h.
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 1463 of file avformat.h.
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 1473 of file avformat.h.
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 1480 of file avformat.h.
unsigned int AVFormatContext::packet_size |
Definition at line 1482 of file avformat.h.
int AVFormatContext::max_delay |
Definition at line 1483 of file avformat.h.
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 1489 of file avformat.h.
int64_t AVFormatContext::probesize |
Maximum size of the data read from input for determining the input container format.
Demuxing only, set by the caller before avformat_open_input().
Definition at line 1524 of file avformat.h.
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 1532 of file avformat.h.
const uint8_t* AVFormatContext::key |
Definition at line 1534 of file avformat.h.
int AVFormatContext::keylen |
Definition at line 1535 of file avformat.h.
unsigned int AVFormatContext::nb_programs |
Definition at line 1537 of file avformat.h.
AVProgram** AVFormatContext::programs |
Definition at line 1538 of file avformat.h.
enum AVCodecID AVFormatContext::video_codec_id |
enum AVCodecID AVFormatContext::audio_codec_id |
enum AVCodecID AVFormatContext::subtitle_codec_id |
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.
Definition at line 1568 of file avformat.h.
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 1574 of file avformat.h.
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.
Definition at line 1587 of file avformat.h.
AVChapter** AVFormatContext::chapters |
Definition at line 1588 of file avformat.h.
AVDictionary* AVFormatContext::metadata |
Metadata that applies to the whole file.
Freed by libavformat in avformat_free_context().
Definition at line 1598 of file avformat.h.
Referenced by main().
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.
Definition at line 1611 of file avformat.h.
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 1618 of file avformat.h.
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 1625 of file avformat.h.
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 1636 of file avformat.h.
int AVFormatContext::debug |
Flags to enable debugging.
Definition at line 1641 of file avformat.h.
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 1660 of file avformat.h.
int AVFormatContext::strict_std_compliance |
Allow non-standard and experimental extension.
Definition at line 1666 of file avformat.h.
int AVFormatContext::event_flags |
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_*.
Definition at line 1673 of file avformat.h.
int AVFormatContext::max_ts_probe |
Maximum number of packets to read while waiting for the first timestamp.
Decoding only.
Definition at line 1680 of file avformat.h.
int AVFormatContext::avoid_negative_ts |
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)
Definition at line 1689 of file avformat.h.
int AVFormatContext::ts_id |
Transport stream id.
This will be moved into demuxer private options. Thus no API/ABI compatibility
Definition at line 1698 of file avformat.h.
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.
Definition at line 1706 of file avformat.h.
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.
Definition at line 1714 of file avformat.h.
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.
Definition at line 1722 of file avformat.h.
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.
Definition at line 1730 of file avformat.h.
int AVFormatContext::avio_flags |
avio flags, used to force AVIO_FLAG_DIRECT.
Definition at line 1737 of file avformat.h.
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.
Definition at line 1745 of file avformat.h.
int64_t AVFormatContext::skip_initial_bytes |
Skip initial bytes when opening stream.
Definition at line 1752 of file avformat.h.
unsigned int AVFormatContext::correct_ts_overflow |
Correct single timestamp overflows.
Definition at line 1759 of file avformat.h.
int AVFormatContext::seek2any |
Force seeking to any (also non key) frames.
Definition at line 1766 of file avformat.h.
int AVFormatContext::flush_packets |
Flush the I/O context after each packet.
Definition at line 1773 of file avformat.h.
int AVFormatContext::probe_score |
format probing score.
The maximal score is AVPROBE_SCORE_MAX, its set when the demuxer probes the format.
Definition at line 1782 of file avformat.h.
int AVFormatContext::format_probesize |
number of bytes to read maximally to identify format.
Definition at line 1789 of file avformat.h.
char* AVFormatContext::codec_whitelist |
',' separated list of allowed decoders.
If NULL then all are allowed
Definition at line 1797 of file avformat.h.
char* AVFormatContext::format_whitelist |
',' separated list of allowed demuxers.
If NULL then all are allowed
Definition at line 1805 of file avformat.h.
AVFormatInternal* AVFormatContext::internal |
An opaque field for libavformat internal usage.
Must not be accessed in any way by callers.
Definition at line 1811 of file avformat.h.
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 1819 of file avformat.h.
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 1827 of file avformat.h.
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 1835 of file avformat.h.
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 1843 of file avformat.h.
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 1851 of file avformat.h.
int AVFormatContext::metadata_header_padding |
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.
Definition at line 1858 of file avformat.h.
void* AVFormatContext::opaque |
User data.
This is a place for some private data of the user.
Definition at line 1864 of file avformat.h.
av_format_control_message AVFormatContext::control_message_cb |
Callback used by devices to communicate with application.
Definition at line 1869 of file avformat.h.
int64_t AVFormatContext::output_ts_offset |
Output timestamp offset, in microseconds.
Muxing: set by user
Definition at line 1875 of file avformat.h.
uint8_t* AVFormatContext::dump_separator |
dump format separator.
can be ", " or "\n " or anything else
Definition at line 1883 of file avformat.h.
enum AVCodecID AVFormatContext::data_codec_id |
char* AVFormatContext::protocol_whitelist |
',' separated list of allowed protocols.
Definition at line 1918 of file avformat.h.
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.
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() |
Definition at line 1940 of file avformat.h.
void(* AVFormatContext::io_close) (struct AVFormatContext *s, AVIOContext *pb) |
A callback for closing the streams opened with AVFormatContext.io_open().
Definition at line 1946 of file avformat.h.
char* AVFormatContext::protocol_blacklist |
',' separated list of disallowed protocols.
Definition at line 1953 of file avformat.h.
int AVFormatContext::max_streams |
The maximum number of streams.
Definition at line 1960 of file avformat.h.
int AVFormatContext::skip_estimate_duration_from_pts |
Skip duration calcuation in estimate_timings_from_pts.
Definition at line 1967 of file avformat.h.