+ * @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).
+ *
+ * @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 frames which belong a single
+ * elementary stream. In 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.
+ *
+ * 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
+ *
+ * @section lavf_decoding_seek Seeking
+ * @}
+ *
+ * @defgroup lavf_encoding Muxing
+ * @{
+ * @}
+ *
+ * @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
+ * @{
+ * @}
+ * @}
+ *