/* * copyright (c) 2001 Fabrice Bellard * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVFORMAT_AVFORMAT_H #define AVFORMAT_AVFORMAT_H /** * @file * @ingroup libavf * Main libavformat public API header */ /** * @defgroup libavf I/O and Muxing/Demuxing Library * @{ * * Libavformat (lavf) is a library for dealing with various media container * formats. Its main two purposes are demuxing - i.e. splitting a media file * into component streams, and the reverse process of muxing - writing supplied * data in a specified container format. It also has an @ref lavf_io * "I/O module" which supports a number of protocols for accessing the data (e.g. * file, tcp, http and others). Before using lavf, you need to call * av_register_all() to register all compiled muxers, demuxers and protocols. * Unless you are absolutely sure you won't use libavformat's network * capabilities, you should also call avformat_network_init(). * * A supported input format is described by an AVInputFormat struct, conversely * an output format is described by AVOutputFormat. You can iterate over all * registered input/output formats using the av_iformat_next() / * av_oformat_next() functions. The protocols layer is not part of the public * API, so you can only get the names of supported protocols with the * avio_enum_protocols() function. * * Main lavf structure used for both muxing and demuxing is AVFormatContext, * which exports all information about the file being read or written. As with * most Libav structures, its size is not part of public ABI, so it cannot be * allocated on stack or directly with av_malloc(). To create an * AVFormatContext, use avformat_alloc_context() (some functions, like * avformat_open_input() might do that for you). * * Most importantly an AVFormatContext contains: * @li the @ref AVFormatContext.iformat "input" or @ref AVFormatContext.oformat * "output" format. It is either autodetected or set by user for input; * always set by user for output. * @li an @ref AVFormatContext.streams "array" of AVStreams, which describe all * elementary streams stored in the file. AVStreams are typically referred to * using their index in this array. * @li an @ref AVFormatContext.pb "I/O context". It is either opened by lavf or * set by user for input, always set by user for output (unless you are dealing * with an AVFMT_NOFILE format). * * @section lavf_options Passing options to (de)muxers * Lavf allows to configure muxers and demuxers using the @ref avoptions * mechanism. Generic (format-independent) libavformat options are provided by * AVFormatContext, they can be examined from a user program by calling * av_opt_next() / av_opt_find() on an allocated AVFormatContext (or its AVClass * from avformat_get_class()). Private (format-specific) options are provided by * AVFormatContext.priv_data if and only if AVInputFormat.priv_class / * AVOutputFormat.priv_class of the corresponding format struct is non-NULL. * Further options may be provided by the @ref AVFormatContext.pb "I/O context", * if its AVClass is non-NULL, and the protocols layer. See the discussion on * nesting in @ref avoptions documentation to learn how to access those. * * @defgroup lavf_decoding Demuxing * @{ * Demuxers read a media file and split it into chunks of data (@em packets). A * @ref AVPacket "packet" contains one or more encoded frames which belongs to a * single elementary stream. In the lavf API this process is represented by the * avformat_open_input() function for opening a file, av_read_frame() for * reading a single packet and finally avformat_close_input(), which does the * cleanup. * * @section lavf_decoding_open Opening a media file * The minimum information required to open a file is its URL or filename, which * is passed to avformat_open_input(), as in the following code: * @code * const char *url = "in.mp3"; * AVFormatContext *s = NULL; * int ret = avformat_open_input(&s, url, NULL, NULL); * if (ret < 0) * abort(); * @endcode * The above code attempts to allocate an AVFormatContext, open the * specified file (autodetecting the format) and read the header, exporting the * information stored there into s. Some formats do not have a header or do not * store enough information there, so it is recommended that you call the * avformat_find_stream_info() function which tries to read and decode a few * frames to find missing information. * * In some cases you might want to preallocate an AVFormatContext yourself with * avformat_alloc_context() and do some tweaking on it before passing it to * avformat_open_input(). One such case is when you want to use custom functions * for reading input data instead of lavf internal I/O layer. * To do that, create your own AVIOContext with avio_alloc_context(), passing * your reading callbacks to it. Then set the @em pb field of your * AVFormatContext to newly created AVIOContext. * * Since the format of the opened file is in general not known until after * avformat_open_input() has returned, it is not possible to set demuxer private * options on a preallocated context. Instead, the options should be passed to * avformat_open_input() wrapped in an AVDictionary: * @code * AVDictionary *options = NULL; * av_dict_set(&options, "video_size", "640x480", 0); * av_dict_set(&options, "pixel_format", "rgb24", 0); * * if (avformat_open_input(&s, url, NULL, &options) < 0) * abort(); * av_dict_free(&options); * @endcode * This code passes the private options 'video_size' and 'pixel_format' to the * demuxer. They would be necessary for e.g. the rawvideo demuxer, since it * cannot know how to interpret raw video data otherwise. If the format turns * out to be something different than raw video, those options will not be * recognized by the demuxer and therefore will not be applied. Such unrecognized * options are then returned in the options dictionary (recognized options are * consumed). The calling program can handle such unrecognized options as it * wishes, e.g. * @code * AVDictionaryEntry *e; * if (e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX)) { * fprintf(stderr, "Option %s not recognized by the demuxer.\n", e->key); * abort(); * } * @endcode * * After you have finished reading the file, you must close it with * avformat_close_input(). It will free everything associated with the file. * * @section lavf_decoding_read Reading from an opened file * Reading data from an opened AVFormatContext is done by repeatedly calling * av_read_frame() on it. Each call, if successful, will return an AVPacket * containing encoded data for one AVStream, identified by * AVPacket.stream_index. This packet may be passed straight into the libavcodec * decoding functions avcodec_send_packet() or avcodec_decode_subtitle2() if the * caller wishes to decode the data. * * AVPacket.pts, AVPacket.dts and AVPacket.duration timing information will be * set if known. They may also be unset (i.e. AV_NOPTS_VALUE for * pts/dts, 0 for duration) if the stream does not provide them. The timing * information will be in AVStream.time_base units, i.e. it has to be * multiplied by the timebase to convert them to seconds. * * If AVPacket.buf is set on the returned packet, then the packet is * allocated dynamically and the user may keep it indefinitely. * Otherwise, if AVPacket.buf is NULL, the packet data is backed by a * static storage somewhere inside the demuxer and the packet is only valid * until the next av_read_frame() call or closing the file. If the caller * requires a longer lifetime, av_dup_packet() will make an av_malloc()ed copy * of it. * In both cases, the packet must be freed with av_packet_unref() when it is no * longer needed. * * @section lavf_decoding_seek Seeking * @} * * @defgroup lavf_encoding Muxing * @{ * Muxers take encoded data in the form of @ref AVPacket "AVPackets" and write * it into files or other output bytestreams in the specified container format. * * The main API functions for muxing are avformat_write_header() for writing the * file header, av_write_frame() / av_interleaved_write_frame() for writing the * packets and av_write_trailer() for finalizing the file. * * At the beginning of the muxing process, the caller must first call * avformat_alloc_context() to create a muxing context. The caller then sets up * the muxer by filling the various fields in this context: * * - The @ref AVFormatContext.oformat "oformat" field must be set to select the * muxer that will be used. * - Unless the format is of the AVFMT_NOFILE type, the @ref AVFormatContext.pb * "pb" field must be set to an opened IO context, either returned from * avio_open2() or a custom one. * - Unless the format is of the AVFMT_NOSTREAMS type, at least one stream must * be created with the avformat_new_stream() function. The caller should fill * the @ref AVStream.codecpar "stream codec parameters" information, such as the * codec @ref AVCodecParameters.codec_type "type", @ref AVCodecParameters.codec_id * "id" and other parameters (e.g. width / height, the pixel or sample format, * etc.) as known. The @ref AVStream.time_base "stream timebase" should * be set to the timebase that the caller desires to use for this stream (note * that the timebase actually used by the muxer can be different, as will be * described later). * - It is advised to manually initialize only the relevant fields in * AVCodecParameters, rather than using @ref avcodec_parameters_copy() during * remuxing: there is no guarantee that the codec context values remain valid * for both input and output format contexts. * - The caller may fill in additional information, such as @ref * AVFormatContext.metadata "global" or @ref AVStream.metadata "per-stream" * metadata, @ref AVFormatContext.chapters "chapters", @ref * AVFormatContext.programs "programs", etc. as described in the * AVFormatContext documentation. Whether such information will actually be * stored in the output depends on what the container format and the muxer * support. * * When the muxing context is fully set up, the caller must call * avformat_write_header() to initialize the muxer internals and write the file * header. Whether anything actually is written to the IO context at this step * depends on the muxer, but this function must always be called. Any muxer * private options must be passed in the options parameter to this function. * * The data is then sent to the muxer by repeatedly calling av_write_frame() or * av_interleaved_write_frame() (consult those functions' documentation for * discussion on the difference between them; only one of them may be used with * a single muxing context, they should not be mixed). Do note that the timing * information on the packets sent to the muxer must be in the corresponding * AVStream's timebase. That timebase is set by the muxer (in the * avformat_write_header() step) and may be different from the timebase * requested by the caller. * * Once all the data has been written, the caller must call av_write_trailer() * to flush any buffered packets and finalize the output file, then close the IO * context (if any) and finally free the muxing context with * avformat_free_context(). * @} * * @defgroup lavf_io I/O Read/Write * @{ * @} * * @defgroup lavf_codec Demuxers * @{ * @defgroup lavf_codec_native Native Demuxers * @{ * @} * @defgroup lavf_codec_wrappers External library wrappers * @{ * @} * @} * @defgroup lavf_protos I/O Protocols * @{ * @} * @defgroup lavf_internal Internal * @{ * @} * @} */ #include #include /* FILE */ #include "libavcodec/avcodec.h" #include "libavutil/dict.h" #include "libavutil/log.h" #include "avio.h" #include "libavformat/version.h" struct AVFormatContext; /** * @defgroup metadata_api Public Metadata API * @{ * @ingroup libavf * The metadata API allows libavformat to export metadata tags to a client * application when demuxing. Conversely it allows a client application to * set metadata when muxing. * * Metadata is exported or set as pairs of key/value strings in the 'metadata' * fields of the AVFormatContext, AVStream, AVChapter and AVProgram structs * using the @ref lavu_dict "AVDictionary" API. Like all strings in Libav, * metadata is assumed to be UTF-8 encoded Unicode. Note that metadata * exported by demuxers isn't checked to be valid UTF-8 in most cases. * * Important concepts to keep in mind: * - Keys are unique; there can never be 2 tags with the same key. This is * also meant semantically, i.e., a demuxer should not knowingly produce * several keys that are literally different but semantically identical. * E.g., key=Author5, key=Author6. In this example, all authors must be * placed in the same tag. * - Metadata is flat, not hierarchical; there are no subtags. If you * want to store, e.g., the email address of the child of producer Alice * and actor Bob, that could have key=alice_and_bobs_childs_email_address. * - Several modifiers can be applied to the tag name. This is done by * appending a dash character ('-') and the modifier name in the order * they appear in the list below -- e.g. foo-eng-sort, not foo-sort-eng. * - language -- a tag whose value is localized for a particular language * is appended with the ISO 639-2/B 3-letter language code. * For example: Author-ger=Michael, Author-eng=Mike * The original/default language is in the unqualified "Author" tag. * A demuxer should set a default if it sets any translated tag. * - sorting -- a modified version of a tag that should be used for * sorting will have '-sort' appended. E.g. artist="The Beatles", * artist-sort="Beatles, The". * - Some protocols and demuxers support metadata updates. After a successful * call to av_read_packet(), AVFormatContext.event_flags or AVStream.event_flags * will be updated to indicate if metadata changed. In order to detect metadata * changes on a stream, you need to loop through all streams in the AVFormatContext * and check their individual event_flags. * * - Demuxers attempt to export metadata in a generic format, however tags * with no generic equivalents are left as they are stored in the container. * Follows a list of generic tag names: * @verbatim album -- name of the set this work belongs to album_artist -- main creator of the set/album, if different from artist. e.g. "Various Artists" for compilation albums. artist -- main creator of the work comment -- any additional description of the file. composer -- who composed the work, if different from artist. copyright -- name of copyright holder. creation_time-- date when the file was created, preferably in ISO 8601. date -- date when the work was created, preferably in ISO 8601. disc -- number of a subset, e.g. disc in a multi-disc collection. encoder -- name/settings of the software/hardware that produced the file. encoded_by -- person/group who created the file. filename -- original name of the file. genre -- . language -- main language in which the work is performed, preferably in ISO 639-2 format. Multiple languages can be specified by separating them with commas. performer -- artist who performed the work, if different from artist. E.g for "Also sprach Zarathustra", artist would be "Richard Strauss" and performer "London Philharmonic Orchestra". publisher -- name of the label/publisher. service_name -- name of the service in broadcasting (channel name). service_provider -- name of the service provider in broadcasting. title -- name of the work. track -- number of this work in the set, can be in form current/total. variant_bitrate -- the total bitrate of the bitrate variant that the current stream is part of @endverbatim * * Look in the examples section for an application example how to use the Metadata API. * * @} */ /* packet functions */ /** * Allocate and read the payload of a packet and initialize its * fields with default values. * * @param s associated IO context * @param pkt packet * @param size desired payload size * @return >0 (read size) if OK, AVERROR_xxx otherwise */ int av_get_packet(AVIOContext *s, AVPacket *pkt, int size); /** * Read data and append it to the current content of the AVPacket. * If pkt->size is 0 this is identical to av_get_packet. * Note that this uses av_grow_packet and thus involves a realloc * which is inefficient. Thus this function should only be used * when there is no reasonable way to know (an upper bound of) * the final size. * * @param s associated IO context * @param pkt packet * @param size amount of data to read * @return >0 (read size) if OK, AVERROR_xxx otherwise, previous data * will not be lost even if an error occurs. */ int av_append_packet(AVIOContext *s, AVPacket *pkt, int size); #if FF_API_LAVF_FRAC /*************************************************/ /* fractional numbers for exact pts handling */ /** * The exact value of the fractional number is: 'val + num / den'. * num is assumed to be 0 <= num < den. */ typedef struct AVFrac { int64_t val, num, den; } AVFrac; #endif /*************************************************/ /* input/output formats */ struct AVCodecTag; /** * This structure contains the data a format has to probe a file. */ typedef struct AVProbeData { const char *filename; unsigned char *buf; /**< Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero. */ int buf_size; /**< Size of buf except extra allocated bytes */ const char *mime_type; /**< mime_type, when known. */ } AVProbeData; #define AVPROBE_SCORE_EXTENSION 50 ///< score for file extension #define AVPROBE_SCORE_MIME 75 ///< score for file mime type #define AVPROBE_SCORE_MAX 100 ///< maximum score #define AVPROBE_PADDING_SIZE 32 ///< extra allocated bytes at the end of the probe buffer /// Demuxer will use avio_open, no opened file should be provided by the caller. #define AVFMT_NOFILE 0x0001 #define AVFMT_NEEDNUMBER 0x0002 /**< Needs '%d' in filename. */ #define AVFMT_SHOW_IDS 0x0008 /**< Show format stream IDs numbers. */ #if FF_API_LAVF_FMT_RAWPICTURE #define AVFMT_RAWPICTURE 0x0020 /**< Format wants AVPicture structure for raw picture data. @deprecated Not used anymore */ #endif #define AVFMT_GLOBALHEADER 0x0040 /**< Format wants global header. */ #define AVFMT_NOTIMESTAMPS 0x0080 /**< Format does not need / have any timestamps. */ #define AVFMT_GENERIC_INDEX 0x0100 /**< Use generic index building code. */ #define AVFMT_TS_DISCONT 0x0200 /**< Format allows timestamp discontinuities. Note, muxers always require valid (monotone) timestamps */ #define AVFMT_VARIABLE_FPS 0x0400 /**< Format allows variable fps. */ #define AVFMT_NODIMENSIONS 0x0800 /**< Format does not need width/height */ #define AVFMT_NOSTREAMS 0x1000 /**< Format does not require any streams */ #define AVFMT_NOBINSEARCH 0x2000 /**< Format does not allow to fall back on binary search via read_timestamp */ #define AVFMT_NOGENSEARCH 0x4000 /**< Format does not allow to fall back on generic search */ #define AVFMT_NO_BYTE_SEEK 0x8000 /**< Format does not allow seeking by bytes */ #define AVFMT_ALLOW_FLUSH 0x10000 /**< Format allows flushing. If not set, the muxer will not receive a NULL packet in the write_packet function. */ #define AVFMT_TS_NONSTRICT 0x20000 /**< Format does not require strictly increasing timestamps, but they must still be monotonic */ #define AVFMT_TS_NEGATIVE 0x40000 /**< Format allows muxing negative timestamps. If not set the timestamp will be shifted in av_write_frame and av_interleaved_write_frame so they start from 0. */ /** * @addtogroup lavf_encoding * @{ */ typedef struct AVOutputFormat { const char *name; /** * Descriptive name for the format, meant to be more human-readable * than name. You should use the NULL_IF_CONFIG_SMALL() macro * to define it. */ const char *long_name; const char *mime_type; const char *extensions; /**< comma-separated filename extensions */ /* output support */ enum AVCodecID audio_codec; /**< default audio codec */ enum AVCodecID video_codec; /**< default video codec */ enum AVCodecID subtitle_codec; /**< default subtitle codec */ /** * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS, * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH, * AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE */ int flags; /** * List of supported codec_id-codec_tag pairs, ordered by "better * choice first". The arrays are all terminated by AV_CODEC_ID_NONE. */ const struct AVCodecTag * const *codec_tag; const AVClass *priv_class; ///< AVClass for the private context /***************************************************************** * No fields below this line are part of the public API. They * may not be used outside of libavformat and can be changed and * removed at will. * New public fields should be added right above. ***************************************************************** */ struct AVOutputFormat *next; /** * size of private data so that it can be allocated in the wrapper */ int priv_data_size; int (*write_header)(struct AVFormatContext *); /** * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags, * pkt can be NULL in order to flush data buffered in the muxer. * When flushing, return 0 if there still is more data to flush, * or 1 if everything was flushed and there is no more buffered * data. */ int (*write_packet)(struct AVFormatContext *, AVPacket *pkt); int (*write_trailer)(struct AVFormatContext *); /** * Currently only used to set pixel format if not YUV420P. */ int (*interleave_packet)(struct AVFormatContext *, AVPacket *out, AVPacket *in, int flush); /** * Test if the given codec can be stored in this container. * * @return 1 if the codec is supported, 0 if it is not. * A negative number if unknown. */ int (*query_codec)(enum AVCodecID id, int std_compliance); } AVOutputFormat; /** * @} */ /** * @addtogroup lavf_decoding * @{ */ typedef struct AVInputFormat { /** * A comma separated list of short names for the format. New names * may be appended with a minor bump. */ const char *name; /** * Descriptive name for the format, meant to be more human-readable * than name. You should use the NULL_IF_CONFIG_SMALL() macro * to define it. */ const char *long_name; /** * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS, * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH, * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK. */ int flags; /** * If extensions are defined, then no probe is done. You should * usually not use extension format guessing because it is not * reliable enough */ const char *extensions; const struct AVCodecTag * const *codec_tag; const AVClass *priv_class; ///< AVClass for the private context /** * Comma-separated list of mime types. * It is used check for matching mime types while probing. * @see av_probe_input_format2 */ const char *mime_type; /***************************************************************** * No fields below this line are part of the public API. They * may not be used outside of libavformat and can be changed and * removed at will. * New public fields should be added right above. ***************************************************************** */ struct AVInputFormat *next; /** * Raw demuxers store their codec ID here. */ int raw_codec_id; /** * Size of private data so that it can be allocated in the wrapper. */ int priv_data_size; /** * Tell if a given file has a chance of being parsed as this format. * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes * big so you do not have to check for that unless you need more. */ int (*read_probe)(AVProbeData *); /** * Read the format header and initialize the AVFormatContext * structure. Return 0 if OK. 'avformat_new_stream' should be * called to create new streams. */ int (*read_header)(struct AVFormatContext *); /** * Read one packet and put it in 'pkt'. pts and flags are also * set. 'avformat_new_stream' can be called only if the flag * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a * background thread). * @return 0 on success, < 0 on error. * When returning an error, pkt must not have been allocated * or must be freed before returning */ int (*read_packet)(struct AVFormatContext *, AVPacket *pkt); /** * Close the stream. The AVFormatContext and AVStreams are not * freed by this function */ int (*read_close)(struct AVFormatContext *); /** * Seek to a given timestamp relative to the frames in * stream component stream_index. * @param stream_index Must not be -1. * @param flags Selects which direction should be preferred if no exact * match is available. * @return >= 0 on success (but not necessarily the new offset) */ int (*read_seek)(struct AVFormatContext *, int stream_index, int64_t timestamp, int flags); /** * Get the next timestamp in stream[stream_index].time_base units. * @return the timestamp or AV_NOPTS_VALUE if an error occurred */ int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index, int64_t *pos, int64_t pos_limit); /** * Start/resume playing - only meaningful if using a network-based format * (RTSP). */ int (*read_play)(struct AVFormatContext *); /** * Pause playing - only meaningful if using a network-based format * (RTSP). */ int (*read_pause)(struct AVFormatContext *); /** * Seek to timestamp ts. * Seeking will be done so that the point from which all active streams * can be presented successfully will be closest to ts and within min/max_ts. * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL. */ int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags); } AVInputFormat; /** * @} */ enum AVStreamParseType { AVSTREAM_PARSE_NONE, AVSTREAM_PARSE_FULL, /**< full parsing and repack */ AVSTREAM_PARSE_HEADERS, /**< Only parse headers, do not repack. */ AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on a packet boundary */ AVSTREAM_PARSE_FULL_ONCE, /**< full parsing and repack of the first frame only, only implemented for H.264 currently */ }; typedef struct AVIndexEntry { int64_t pos; int64_t timestamp; #define AVINDEX_KEYFRAME 0x0001 int flags:2; int size:30; //Yeah, trying to keep the size of this small to reduce memory requirements (it is 24 vs. 32 bytes due to possible 8-byte alignment). int min_distance; /**< Minimum distance between this and the previous keyframe, used to avoid unneeded searching. */ } AVIndexEntry; #define AV_DISPOSITION_DEFAULT 0x0001 #define AV_DISPOSITION_DUB 0x0002 #define AV_DISPOSITION_ORIGINAL 0x0004 #define AV_DISPOSITION_COMMENT 0x0008 #define AV_DISPOSITION_LYRICS 0x0010 #define AV_DISPOSITION_KARAOKE 0x0020 /** * Track should be used during playback by default. * Useful for subtitle track that should be displayed * even when user did not explicitly ask for subtitles. */ #define AV_DISPOSITION_FORCED 0x0040 #define AV_DISPOSITION_HEARING_IMPAIRED 0x0080 /**< stream for hearing impaired audiences */ #define AV_DISPOSITION_VISUAL_IMPAIRED 0x0100 /**< stream for visual impaired audiences */ #define AV_DISPOSITION_CLEAN_EFFECTS 0x0200 /**< stream without voice */ /** * The stream is stored in the file as an attached picture/"cover art" (e.g. * APIC frame in ID3v2). The single packet associated with it will be returned * among the first few packets read from the file unless seeking takes place. * It can also be accessed at any time in AVStream.attached_pic. */ #define AV_DISPOSITION_ATTACHED_PIC 0x0400 typedef struct AVStreamInternal AVStreamInternal; /** * Stream structure. * 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(AVStream) must not be used outside libav*. */ typedef struct AVStream { int index; /**< stream index in AVFormatContext */ /** * Format-specific stream ID. * decoding: set by libavformat * encoding: set by the user, replaced by libavformat if left unset */ int id; #if FF_API_LAVF_AVCTX /** * @deprecated use the codecpar struct instead */ attribute_deprecated AVCodecContext *codec; #endif void *priv_data; #if FF_API_LAVF_FRAC /** * @deprecated this field is unused */ attribute_deprecated struct AVFrac pts; #endif /** * This is the fundamental unit of time (in seconds) in terms * of which frame timestamps are represented. * * decoding: set by libavformat * encoding: May be set by the caller before avformat_write_header() to * provide a hint to the muxer about the desired timebase. In * avformat_write_header(), the muxer will overwrite this field * with the timebase that will actually be used for the timestamps * written into the file (which may or may not be related to the * user-provided one, depending on the format). */ AVRational time_base; /** * Decoding: pts of the first frame of the stream, in stream time base. * Only set this if you are absolutely 100% sure that the value you set * it to really is the pts of the first frame. * This may be undefined (AV_NOPTS_VALUE). */ int64_t start_time; /** * Decoding: duration of the stream, in stream time base. * If a source file does not specify a duration, but does specify * a bitrate, this value will be estimated from bitrate and file size. */ int64_t duration; int64_t nb_frames; ///< number of frames in this stream if known or 0 int disposition; /**< AV_DISPOSITION_* bit field */ enum AVDiscard discard; ///< Selects which packets can be discarded at will and do not need to be demuxed. /** * sample aspect ratio (0 if unknown) * - encoding: Set by user. * - decoding: Set by libavformat. */ AVRational sample_aspect_ratio; AVDictionary *metadata; /** * Average framerate * * - demuxing: May be set by libavformat when creating the stream or in * avformat_find_stream_info(). * - muxing: May be set by the caller before avformat_write_header(). */ AVRational avg_frame_rate; /** * For streams with AV_DISPOSITION_ATTACHED_PIC disposition, this packet * will contain the attached picture. * * decoding: set by libavformat, must not be modified by the caller. * encoding: unused */ AVPacket attached_pic; /** * An array of side data that applies to the whole stream (i.e. the * container does not allow it to change between packets). * * There may be no overlap between the side data in this array and side data * in the packets. I.e. a given side data is either exported by the muxer * (demuxing) / set by the caller (muxing) in this array, then it never * appears in the packets, or the side data is exported / sent through * the packets (always in the first packet where the value becomes known or * changes), then it does not appear in this array. * * - demuxing: Set by libavformat when the stream is created. * - muxing: May be set by the caller before avformat_write_header(). * * Freed by libavformat in avformat_free_context(). */ AVPacketSideData *side_data; /** * The number of elements in the AVStream.side_data array. */ int nb_side_data; /** * Flags for the user to detect events happening on the stream. Flags must * be cleared by the user once the event has been handled. * A combination of AVSTREAM_EVENT_FLAG_*. */ int event_flags; #define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata. /* * Codec parameters associated with this stream. Allocated and freed by * libavformat in avformat_new_stream() and avformat_free_context() * respectively. * * - demuxing: filled by libavformat on stream creation or in * avformat_find_stream_info() * - muxing: filled by the caller before avformat_write_header() */ AVCodecParameters *codecpar; /***************************************************************** * All fields below this line are not part of the public API. They * may not be used outside of libavformat and can be changed and * removed at will. * New public fields should be added right above. ***************************************************************** */ /** * Stream information used internally by av_find_stream_info() */ #define MAX_STD_TIMEBASES (60*12+5) struct { int nb_decoded_frames; int found_decoder; /** * Those are used for average framerate estimation. */ int64_t fps_first_dts; int fps_first_dts_idx; int64_t fps_last_dts; int fps_last_dts_idx; } *info; int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */ // Timestamp generation support: int64_t first_dts; int64_t cur_dts; int64_t last_IP_pts; int last_IP_duration; /** * Number of packets to buffer for codec probing */ #define MAX_PROBE_PACKETS 2500 int probe_packets; /** * Number of frames that have been demuxed during av_find_stream_info() */ int codec_info_nb_frames; /* av_read_frame() support */ enum AVStreamParseType need_parsing; struct AVCodecParserContext *parser; /** * last packet in packet_buffer for this stream when muxing. */ struct AVPacketList *last_in_packet_buffer; AVProbeData probe_data; #define MAX_REORDER_DELAY 16 int64_t pts_buffer[MAX_REORDER_DELAY+1]; AVIndexEntry *index_entries; /**< Only used if the format does not support seeking natively. */ int nb_index_entries; unsigned int index_entries_allocated_size; /** * An opaque field for libavformat internal usage. * Must not be accessed in any way by callers. */ AVStreamInternal *internal; } AVStream; #define AV_PROGRAM_RUNNING 1 /** * 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(AVProgram) must not be used outside libav*. */ typedef struct AVProgram { int id; int flags; enum AVDiscard discard; ///< selects which program to discard and which to feed to the caller unsigned int *stream_index; unsigned int nb_stream_indexes; AVDictionary *metadata; } AVProgram; #define AVFMTCTX_NOHEADER 0x0001 /**< signal that no header is present (streams are added dynamically) */ typedef struct AVChapter { int id; ///< unique ID to identify the chapter AVRational time_base; ///< time base in which the start/end timestamps are specified int64_t start, end; ///< chapter start/end time in time_base units AVDictionary *metadata; } AVChapter; typedef struct AVFormatInternal AVFormatInternal; /** * 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. */ typedef struct AVFormatContext { /** * A class for logging and @ref avoptions. Set by avformat_alloc_context(). * Exports (de)muxer private options if they exist. */ const AVClass *av_class; /** * The input container format. * * Demuxing only, set by avformat_open_input(). */ struct AVInputFormat *iformat; /** * The output container format. * * Muxing only, must be set by the caller before avformat_write_header(). */ struct AVOutputFormat *oformat; /** * 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() */ void *priv_data; /** * 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. */ AVIOContext *pb; /* stream info */ /** * Flags signalling stream properties. A combination of AVFMTCTX_*. * Set by libavformat. */ int ctx_flags; /** * Number of elements in AVFormatContext.streams. * * Set by avformat_new_stream(), must not be modified by any other code. */ unsigned int nb_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(). */ AVStream **streams; /** * input or output filename * * - demuxing: set by avformat_open_input() * - muxing: may be set by the caller before avformat_write_header() */ char filename[1024]; /** * 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. */ int64_t start_time; /** * 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. */ int64_t duration; /** * Total stream bitrate in bit/s, 0 if not * available. Never set it directly if the file_size and the * duration are known as Libav can compute it automatically. */ int bit_rate; unsigned int packet_size; int max_delay; /** * Flags modifying the (de)muxer behaviour. A combination of AVFMT_FLAG_*. * Set by the user before avformat_open_input() / avformat_write_header(). */ int flags; #define AVFMT_FLAG_GENPTS 0x0001 ///< Generate missing pts even if it requires parsing future frames. #define AVFMT_FLAG_IGNIDX 0x0002 ///< Ignore index. #define AVFMT_FLAG_NONBLOCK 0x0004 ///< Do not block when reading packets from input. #define AVFMT_FLAG_IGNDTS 0x0008 ///< Ignore DTS on frames that contain both DTS & PTS #define AVFMT_FLAG_NOFILLIN 0x0010 ///< Do not infer any values from other values, just return what is stored in the container #define AVFMT_FLAG_NOPARSE 0x0020 ///< Do not use AVParsers, you also must set AVFMT_FLAG_NOFILLIN as the fillin code works on frames and no parsing -> no frames. Also seeking to frames can not work if parsing to find frame boundaries has been disabled #define AVFMT_FLAG_NOBUFFER 0x0040 ///< Do not buffer frames when possible #define AVFMT_FLAG_CUSTOM_IO 0x0080 ///< The caller has supplied a custom AVIOContext, don't avio_close() it. #define AVFMT_FLAG_DISCARD_CORRUPT 0x0100 ///< Discard frames marked corrupted #define AVFMT_FLAG_FLUSH_PACKETS 0x0200 ///< Flush the AVIOContext every packet. /** * When muxing, try to avoid writing any random/volatile data to the output. * This includes any random IDs, real-time timestamps/dates, muxer version, etc. * * This flag is mainly intended for testing. */ #define AVFMT_FLAG_BITEXACT 0x0400 /** * Maximum size of the data read from input for determining * the input container format. * Demuxing only, set by the caller before avformat_open_input(). */ unsigned int probesize; /** * 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(). */ int max_analyze_duration; const uint8_t *key; int keylen; unsigned int nb_programs; AVProgram **programs; /** * Forced video codec_id. * Demuxing: Set by user. */ enum AVCodecID video_codec_id; /** * Forced audio codec_id. * Demuxing: Set by user. */ enum AVCodecID audio_codec_id; /** * Forced subtitle codec_id. * Demuxing: Set by user. */ enum AVCodecID subtitle_codec_id; /** * 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 */ unsigned int max_index_size; /** * Maximum amount of memory in bytes to use for buffering frames * obtained from realtime capture devices. */ unsigned int max_picture_buffer; /** * 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 */ unsigned int nb_chapters; AVChapter **chapters; /** * 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(). */ AVDictionary *metadata; /** * 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 only, set by the caller before avformat_write_header(). */ int64_t start_time_realtime; /** * 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(). */ int fps_probe_size; /** * 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(). */ int error_recognition; /** * 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. */ AVIOInterruptCB interrupt_callback; /** * Flags to enable debugging. */ int debug; #define FF_FDEBUG_TS 0x0001 /** * 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(). */ int64_t max_interleave_delta; /** * Allow non-standard and experimental extension * @see AVCodecContext.strict_std_compliance */ int strict_std_compliance; /** * 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_*. */ int event_flags; #define AVFMT_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata. /** * Maximum number of packets to read while waiting for the first timestamp. * Decoding only. */ int max_ts_probe; /** * Avoid negative timestamps during muxing. * Any value of the AVFMT_AVOID_NEG_TS_* constants. * Note, this only works when using av_interleaved_write_frame. * - muxing: Set by user * - demuxing: unused */ int avoid_negative_ts; #define AVFMT_AVOID_NEG_TS_AUTO -1 ///< Enabled when required by target format #define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE 1 ///< Shift timestamps so they are non negative #define AVFMT_AVOID_NEG_TS_MAKE_ZERO 2 ///< Shift timestamps so that they start at 0 /** * An opaque field for libavformat internal usage. * Must not be accessed in any way by callers. */ AVFormatInternal *internal; /** * Arbitrary user data set by the caller. */ void *opaque; /** * 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. * * @param s the format context * @param pb on success, the newly opened IO context should be returned here * @param url the url to open * @param flags a combination of AVIO_FLAG_* * @param options a dictionary of additional options, with the same * semantics as in avio_open2() * @return 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. */ int (*io_open)(struct AVFormatContext *s, AVIOContext **pb, const char *url, int flags, AVDictionary **options); /** * A callback for closing the streams opened with AVFormatContext.io_open(). */ void (*io_close)(struct AVFormatContext *s, AVIOContext *pb); /** * A comma-separated list of protocol names that will not be used internally * by libavformat. If this field is a non-empty string, then protocols * listed here will be forbidden. * * This field should be set using AVOptions. */ char *protocol_blacklist; /** * A comma-separated list of protocol names that can be used internally by * libavformat. If this field is a non-empty string, all protocols not * listed here will be forbidden. * * This field should be set using AVOptions. */ char *protocol_whitelist; } AVFormatContext; typedef struct AVPacketList { AVPacket pkt; struct AVPacketList *next; } AVPacketList; /** * @defgroup lavf_core Core functions * @ingroup libavf * * Functions for querying libavformat capabilities, allocating core structures, * etc. * @{ */ /** * Return the LIBAVFORMAT_VERSION_INT constant. */ unsigned avformat_version(void); /** * Return the libavformat build-time configuration. */ const char *avformat_configuration(void); /** * Return the libavformat license. */ const char *avformat_license(void); /** * Initialize libavformat and register all the muxers, demuxers and * protocols. If you do not call this function, then you can select * exactly which formats you want to support. * * @see av_register_input_format() * @see av_register_output_format() * @see av_register_protocol() */ void av_register_all(void); void av_register_input_format(AVInputFormat *format); void av_register_output_format(AVOutputFormat *format); /** * Do global initialization of network components. This is optional, * but recommended, since it avoids the overhead of implicitly * doing the setup for each session. * * Calling this function will become mandatory if using network * protocols at some major version bump. */ int avformat_network_init(void); /** * Undo the initialization done by avformat_network_init. */ int avformat_network_deinit(void); /** * If f is NULL, returns the first registered input format, * if f is non-NULL, returns the next registered input format after f * or NULL if f is the last one. */ AVInputFormat *av_iformat_next(const AVInputFormat *f); /** * If f is NULL, returns the first registered output format, * if f is non-NULL, returns the next registered output format after f * or NULL if f is the last one. */ AVOutputFormat *av_oformat_next(const AVOutputFormat *f); /** * Allocate an AVFormatContext. * avformat_free_context() can be used to free the context and everything * allocated by the framework within it. */ AVFormatContext *avformat_alloc_context(void); /** * Free an AVFormatContext and all its streams. * @param s context to free */ void avformat_free_context(AVFormatContext *s); /** * Get the AVClass for AVFormatContext. It can be used in combination with * AV_OPT_SEARCH_FAKE_OBJ for examining options. * * @see av_opt_find(). */ const AVClass *avformat_get_class(void); /** * Add a new stream to a media file. * * When demuxing, it is called by the demuxer in read_header(). If the * flag AVFMTCTX_NOHEADER is set in s.ctx_flags, then it may also * be called in read_packet(). * * When muxing, should be called by the user before avformat_write_header(). * * @param s media file handle * @param c If non-NULL, the AVCodecContext corresponding to the new stream * will be initialized to use this codec. This is needed for e.g. codec-specific * defaults to be set, so codec should be provided if it is known. * * @return newly created stream or NULL on error. */ AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c); /** * Allocate new information from stream. * * @param stream stream * @param type desired side information type * @param size side information size * @return pointer to fresh allocated data or NULL otherwise */ uint8_t *av_stream_new_side_data(AVStream *stream, enum AVPacketSideDataType type, int size); /** * Get side information from stream. * * @param stream stream * @param type desired side information type * @param size pointer for side information size to store (optional) * @return pointer to data if present or NULL otherwise */ uint8_t *av_stream_get_side_data(AVStream *stream, enum AVPacketSideDataType type, int *size); AVProgram *av_new_program(AVFormatContext *s, int id); /** * @} */ /** * @addtogroup lavf_decoding * @{ */ /** * Find AVInputFormat based on the short name of the input format. */ AVInputFormat *av_find_input_format(const char *short_name); /** * Guess the file format. * * @param pd data to be probed * @param is_opened Whether the file is already opened; determines whether * demuxers with or without AVFMT_NOFILE are probed. */ AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened); /** * Guess the file format. * * @param pd data to be probed * @param is_opened Whether the file is already opened; determines whether * demuxers with or without AVFMT_NOFILE are probed. * @param score_max A probe score larger that this is required to accept a * detection, the variable is set to the actual detection * score afterwards. * If the score is <= AVPROBE_SCORE_MAX / 4 it is recommended * to retry with a larger probe buffer. */ AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max); /** * Probe a bytestream to determine the input format. Each time a probe returns * with a score that is too low, the probe buffer size is increased and another * attempt is made. When the maximum probe size is reached, the input format * with the highest score is returned. * * @param pb the bytestream to probe * @param fmt the input format is put here * @param filename the filename of the stream * @param logctx the log context * @param offset the offset within the bytestream to probe from * @param max_probe_size the maximum probe buffer size (zero for default) * @return 0 in case of success, a negative value corresponding to an * AVERROR code otherwise */ int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt, const char *filename, void *logctx, unsigned int offset, unsigned int max_probe_size); /** * Open an input stream and read the header. The codecs are not opened. * The stream must be closed with avformat_close_input(). * * @param ps Pointer to user-supplied AVFormatContext (allocated by avformat_alloc_context). * May be a pointer to NULL, in which case an AVFormatContext is allocated by this * function and written into ps. * Note that a user-supplied AVFormatContext will be freed on failure. * @param filename Name of the stream to open. * @param fmt If non-NULL, this parameter forces a specific input format. * Otherwise the format is autodetected. * @param options A dictionary filled with AVFormatContext and demuxer-private options. * On return this parameter will be destroyed and replaced with a dict containing * options that were not found. May be NULL. * * @return 0 on success, a negative AVERROR on failure. * * @note If you want to use custom IO, preallocate the format context and set its pb field. */ int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options); /** * Read packets of a media file to get stream information. This * is useful for file formats with no headers such as MPEG. This * function also computes the real framerate in case of MPEG-2 repeat * frame mode. * The logical file position is not changed by this function; * examined packets may be buffered for later processing. * * @param ic media file handle * @param options If non-NULL, an ic.nb_streams long array of pointers to * dictionaries, where i-th member contains options for * codec corresponding to i-th stream. * On return each dictionary will be filled with options that were not found. * @return >=0 if OK, AVERROR_xxx on error * * @note this function isn't guaranteed to open all the codecs, so * options being non-empty at return is a perfectly normal behavior. * * @todo Let the user decide somehow what information is needed so that * we do not waste time getting stuff the user does not need. */ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options); /** * Find the "best" stream in the file. * The best stream is determined according to various heuristics as the most * likely to be what the user expects. * If the decoder parameter is non-NULL, av_find_best_stream will find the * default decoder for the stream's codec; streams for which no decoder can * be found are ignored. * * @param ic media file handle * @param type stream type: video, audio, subtitles, etc. * @param wanted_stream_nb user-requested stream number, * or -1 for automatic selection * @param related_stream try to find a stream related (eg. in the same * program) to this one, or -1 if none * @param decoder_ret if non-NULL, returns the decoder for the * selected stream * @param flags flags; none are currently defined * @return the non-negative stream number in case of success, * AVERROR_STREAM_NOT_FOUND if no stream with the requested type * could be found, * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder * @note If av_find_best_stream returns successfully and decoder_ret is not * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec. */ int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, AVCodec **decoder_ret, int flags); /** * Return the next frame of a stream. * This function returns what is stored in the file, and does not validate * that what is there are valid frames for the decoder. It will split what is * stored in the file into frames and return one for each call. It will not * omit invalid data between valid frames so as to give the decoder the maximum * information possible for decoding. * * If pkt->buf is NULL, then the packet is valid until the next * av_read_frame() or until avformat_close_input(). Otherwise the packet * is valid indefinitely. In both cases the packet must be freed with * av_packet_unref when it is no longer needed. For video, the packet contains * exactly one frame. For audio, it contains an integer number of frames if each * frame has a known fixed size (e.g. PCM or ADPCM data). If the audio frames * have a variable size (e.g. MPEG audio), then it contains one frame. * * pkt->pts, pkt->dts and pkt->duration are always set to correct * values in AVStream.time_base units (and guessed if the format cannot * provide them). pkt->pts can be AV_NOPTS_VALUE if the video format * has B-frames, so it is better to rely on pkt->dts if you do not * decompress the payload. * * @return 0 if OK, < 0 on error or end of file */ int av_read_frame(AVFormatContext *s, AVPacket *pkt); /** * Seek to the keyframe at timestamp. * 'timestamp' in 'stream_index'. * * @param s media file handle * @param stream_index If stream_index is (-1), a default * stream is selected, and timestamp is automatically converted * from AV_TIME_BASE units to the stream specific time_base. * @param timestamp Timestamp in AVStream.time_base units * or, if no stream is specified, in AV_TIME_BASE units. * @param flags flags which select direction and seeking mode * @return >= 0 on success */ int av_seek_frame(AVFormatContext *s, int stream_index, int64_t timestamp, int flags); /** * Seek to timestamp ts. * Seeking will be done so that the point from which all active streams * can be presented successfully will be closest to ts and within min/max_ts. * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL. * * If flags contain AVSEEK_FLAG_BYTE, then all timestamps are in bytes and * are the file position (this may not be supported by all demuxers). * If flags contain AVSEEK_FLAG_FRAME, then all timestamps are in frames * in the stream with stream_index (this may not be supported by all demuxers). * Otherwise all timestamps are in units of the stream selected by stream_index * or if stream_index is -1, in AV_TIME_BASE units. * If flags contain AVSEEK_FLAG_ANY, then non-keyframes are treated as * keyframes (this may not be supported by all demuxers). * * @param s media file handle * @param stream_index index of the stream which is used as time base reference * @param min_ts smallest acceptable timestamp * @param ts target timestamp * @param max_ts largest acceptable timestamp * @param flags flags * @return >=0 on success, error code otherwise * * @note This is part of the new seek API which is still under construction. * Thus do not use this yet. It may change at any time, do not expect * ABI compatibility yet! */ int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags); /** * Start playing a network-based stream (e.g. RTSP stream) at the * current position. */ int av_read_play(AVFormatContext *s); /** * Pause a network-based stream (e.g. RTSP stream). * * Use av_read_play() to resume it. */ int av_read_pause(AVFormatContext *s); /** * Close an opened input AVFormatContext. Free it and all its contents * and set *s to NULL. */ void avformat_close_input(AVFormatContext **s); /** * @} */ #define AVSEEK_FLAG_BACKWARD 1 ///< seek backward #define AVSEEK_FLAG_BYTE 2 ///< seeking based on position in bytes #define AVSEEK_FLAG_ANY 4 ///< seek to any frame, even non-keyframes #define AVSEEK_FLAG_FRAME 8 ///< seeking based on frame number /** * @addtogroup lavf_encoding * @{ */ /** * Allocate the stream private data and write the stream header to * an output media file. * * @param s Media file handle, must be allocated with avformat_alloc_context(). * Its oformat field must be set to the desired output format; * Its pb field must be set to an already opened AVIOContext. * @param options An AVDictionary filled with AVFormatContext and muxer-private options. * On return this parameter will be destroyed and replaced with a dict containing * options that were not found. May be NULL. * * @return 0 on success, negative AVERROR on failure. * * @see av_opt_find, av_dict_set, avio_open, av_oformat_next. */ int avformat_write_header(AVFormatContext *s, AVDictionary **options); /** * Write a packet to an output media file. * * This function passes the packet directly to the muxer, without any buffering * or reordering. The caller is responsible for correctly interleaving the * packets if the format requires it. Callers that want libavformat to handle * the interleaving should call av_interleaved_write_frame() instead of this * function. * * @param s media file handle * @param pkt The packet containing the data to be written. Note that unlike * av_interleaved_write_frame(), this function does not take * ownership of the packet passed to it (though some muxers may make * an internal reference to the input packet). *
* This parameter can be NULL (at any time, not just at the end), in * order to immediately flush data buffered within the muxer, for * muxers that buffer up data internally before writing it to the * output. *
* Packet's @ref AVPacket.stream_index "stream_index" field must be * set to the index of the corresponding stream in @ref * AVFormatContext.streams "s->streams". *
* The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts") * must be set to correct values in the stream's timebase (unless the * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then * they can be set to AV_NOPTS_VALUE). * The dts for subsequent packets passed to this function must be strictly * increasing when compared in their respective timebases (unless the * output format is flagged with the AVFMT_TS_NONSTRICT, then they * merely have to be nondecreasing). @ref AVPacket.duration * "duration") should also be set if known. * @return < 0 on error, = 0 if OK, 1 if flushed and there is no more data to flush * * @see av_interleaved_write_frame() */ int av_write_frame(AVFormatContext *s, AVPacket *pkt); /** * Write a packet to an output media file ensuring correct interleaving. * * This function will buffer the packets internally as needed to make sure the * packets in the output file are properly interleaved in the order of * increasing dts. Callers doing their own interleaving should call * av_write_frame() instead of this function. * * Using this function instead of av_write_frame() can give muxers advance * knowledge of future packets, improving e.g. the behaviour of the mp4 * muxer for VFR content in fragmenting mode. * * @param s media file handle * @param pkt The packet containing the data to be written. *
* If the packet is reference-counted, this function will take * ownership of this reference and unreference it later when it sees * fit. * The caller must not access the data through this reference after * this function returns. If the packet is not reference-counted, * libavformat will make a copy. *
* This parameter can be NULL (at any time, not just at the end), to * flush the interleaving queues. *
* Packet's @ref AVPacket.stream_index "stream_index" field must be * set to the index of the corresponding stream in @ref * AVFormatContext.streams "s->streams". *
* The timestamps (@ref AVPacket.pts "pts", @ref AVPacket.dts "dts") * must be set to correct values in the stream's timebase (unless the * output format is flagged with the AVFMT_NOTIMESTAMPS flag, then * they can be set to AV_NOPTS_VALUE). * The dts for subsequent packets in one stream must be strictly * increasing (unless the output format is flagged with the * AVFMT_TS_NONSTRICT, then they merely have to be nondecreasing). * @ref AVPacket.duration "duration") should also be set if known. * * @return 0 on success, a negative AVERROR on error. Libavformat will always * take care of freeing the packet, even if this function fails. * * @see av_write_frame(), AVFormatContext.max_interleave_delta */ int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt); /** * Write the stream trailer to an output media file and free the * file private data. * * May only be called after a successful call to avformat_write_header. * * @param s media file handle * @return 0 if OK, AVERROR_xxx on error */ int av_write_trailer(AVFormatContext *s); /** * Return the output format in the list of registered output formats * which best matches the provided parameters, or return NULL if * there is no match. * * @param short_name if non-NULL checks if short_name matches with the * names of the registered formats * @param filename if non-NULL checks if filename terminates with the * extensions of the registered formats * @param mime_type if non-NULL checks if mime_type matches with the * MIME type of the registered formats */ AVOutputFormat *av_guess_format(const char *short_name, const char *filename, const char *mime_type); /** * Guess the codec ID based upon muxer and filename. */ enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name, const char *filename, const char *mime_type, enum AVMediaType type); /** * @} */ /** * @defgroup lavf_misc Utility functions * @ingroup libavf * @{ * * Miscellaneous utility functions related to both muxing and demuxing * (or neither). */ /** * Send a nice hexadecimal dump of a buffer to the specified file stream. * * @param f The file stream pointer where the dump should be sent to. * @param buf buffer * @param size buffer size * * @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2 */ void av_hex_dump(FILE *f, const uint8_t *buf, int size); /** * Send a nice hexadecimal dump of a buffer to the log. * * @param avcl A pointer to an arbitrary struct of which the first field is a * pointer to an AVClass struct. * @param level The importance level of the message, lower values signifying * higher importance. * @param buf buffer * @param size buffer size * * @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2 */ void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size); /** * Send a nice dump of a packet to the specified file stream. * * @param f The file stream pointer where the dump should be sent to. * @param pkt packet to dump * @param dump_payload True if the payload must be displayed, too. * @param st AVStream that the packet belongs to */ void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st); /** * Send a nice dump of a packet to the log. * * @param avcl A pointer to an arbitrary struct of which the first field is a * pointer to an AVClass struct. * @param level The importance level of the message, lower values signifying * higher importance. * @param pkt packet to dump * @param dump_payload True if the payload must be displayed, too. * @param st AVStream that the packet belongs to */ void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload, AVStream *st); /** * Get the AVCodecID for the given codec tag tag. * If no codec id is found returns AV_CODEC_ID_NONE. * * @param tags list of supported codec_id-codec_tag pairs, as stored * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag * @param tag codec tag to match to a codec ID */ enum AVCodecID av_codec_get_id(const struct AVCodecTag * const *tags, unsigned int tag); /** * Get the codec tag for the given codec id id. * If no codec tag is found returns 0. * * @param tags list of supported codec_id-codec_tag pairs, as stored * in AVInputFormat.codec_tag and AVOutputFormat.codec_tag * @param id codec ID to match to a codec tag */ unsigned int av_codec_get_tag(const struct AVCodecTag * const *tags, enum AVCodecID id); int av_find_default_stream_index(AVFormatContext *s); /** * Get the index for a specific timestamp. * * @param st stream that the timestamp belongs to * @param timestamp timestamp to retrieve the index for * @param flags if AVSEEK_FLAG_BACKWARD then the returned index will correspond * to the timestamp which is <= the requested one, if backward * is 0, then it will be >= * if AVSEEK_FLAG_ANY seek to any frame, only keyframes otherwise * @return < 0 if no such timestamp could be found */ int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags); /** * Add an index entry into a sorted list. Update the entry if the list * already contains it. * * @param timestamp timestamp in the time base of the given stream */ int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags); /** * Split a URL string into components. * * The pointers to buffers for storing individual components may be null, * in order to ignore that component. Buffers for components not found are * set to empty strings. If the port is not found, it is set to a negative * value. * * @param proto the buffer for the protocol * @param proto_size the size of the proto buffer * @param authorization the buffer for the authorization * @param authorization_size the size of the authorization buffer * @param hostname the buffer for the host name * @param hostname_size the size of the hostname buffer * @param port_ptr a pointer to store the port number in * @param path the buffer for the path * @param path_size the size of the path buffer * @param url the URL to split */ void av_url_split(char *proto, int proto_size, char *authorization, int authorization_size, char *hostname, int hostname_size, int *port_ptr, char *path, int path_size, const char *url); /** * Print detailed information about the input or output format, such as * duration, bitrate, streams, container, programs, metadata, side data, * codec and time base. * * @param ic the context to analyze * @param index the index to print, if you have multiple inputs or outputs * @param url the URL to print, such as source or destination file * @param is_output whether the context is input or output */ void av_dump_format(AVFormatContext *ic, int index, const char *url, int is_output); /** * Return in 'buf' the path with '%d' replaced by a number. * * Also handles the '%0nd' format where 'n' is the total number * of digits and '%%'. * * @param buf destination buffer * @param buf_size destination buffer size * @param path numbered sequence string * @param number frame number * @return 0 if OK, -1 on format error */ int av_get_frame_filename(char *buf, int buf_size, const char *path, int number); /** * Check whether filename actually is a numbered sequence generator. * * @param filename possible numbered sequence string * @return 1 if a valid numbered sequence string, 0 otherwise */ int av_filename_number_test(const char *filename); /** * Generate an SDP for an RTP session. * * Note, this overwrites the id values of AVStreams in the muxer contexts * for getting unique dynamic payload types. * * @param ac array of AVFormatContexts describing the RTP streams. If the * array is composed by only one context, such context can contain * multiple AVStreams (one AVStream per RTP stream). Otherwise, * all the contexts in the array (an AVCodecContext per RTP stream) * must contain only one AVStream. * @param n_files number of AVCodecContexts contained in ac * @param buf buffer where the SDP will be stored (must be allocated by * the caller) * @param size the size of the buffer * @return 0 if OK, AVERROR_xxx on error */ int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size); /** * Return a positive value if the given filename has one of the given * extensions, 0 otherwise. * * @param filename file name to check against the given extensions * @param extensions a comma-separated list of filename extensions */ int av_match_ext(const char *filename, const char *extensions); /** * Test if the given container can store a codec. * * @param ofmt container to check for compatibility * @param codec_id codec to potentially store in container * @param std_compliance standards compliance level, one of FF_COMPLIANCE_* * * @return 1 if codec with ID codec_id can be stored in ofmt, 0 if it cannot. * A negative number if this information is not available. */ int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id, int std_compliance); /** * @defgroup riff_fourcc RIFF FourCCs * @{ * Get the tables mapping RIFF FourCCs to libavcodec AVCodecIDs. The tables are * meant to be passed to av_codec_get_id()/av_codec_get_tag() as in the * following code: * @code * uint32_t tag = MKTAG('H', '2', '6', '4'); * const struct AVCodecTag *table[] = { avformat_get_riff_video_tags(), 0 }; * enum AVCodecID id = av_codec_get_id(table, tag); * @endcode */ /** * @return the table mapping RIFF FourCCs for video to libavcodec AVCodecID. */ const struct AVCodecTag *avformat_get_riff_video_tags(void); /** * @return the table mapping RIFF FourCCs for audio to AVCodecID. */ const struct AVCodecTag *avformat_get_riff_audio_tags(void); /** * @} */ /** * @} */ #endif /* AVFORMAT_AVFORMAT_H */