| @chapter Demuxers |
| @c man begin DEMUXERS |
| |
| Demuxers are configured elements in FFmpeg which allow to read the |
| multimedia streams from a particular type of file. |
| |
| When you configure your FFmpeg build, all the supported demuxers |
| are enabled by default. You can list all available ones using the |
| configure option @code{--list-demuxers}. |
| |
| You can disable all the demuxers using the configure option |
| @code{--disable-demuxers}, and selectively enable a single demuxer with |
| the option @code{--enable-demuxer=@var{DEMUXER}}, or disable it |
| with the option @code{--disable-demuxer=@var{DEMUXER}}. |
| |
| The option @code{-formats} of the ff* tools will display the list of |
| enabled demuxers. |
| |
| The description of some of the currently available demuxers follows. |
| |
| @section applehttp |
| |
| Apple HTTP Live Streaming demuxer. |
| |
| This demuxer presents all AVStreams from all variant streams. |
| The id field is set to the bitrate variant index number. By setting |
| the discard flags on AVStreams (by pressing 'a' or 'v' in ffplay), |
| the caller can decide which variant streams to actually receive. |
| The total bitrate of the variant that the stream belongs to is |
| available in a metadata key named "variant_bitrate". |
| |
| @anchor{concat} |
| @section concat |
| |
| Virtual concatenation script demuxer. |
| |
| This demuxer reads a list of files and other directives from a text file and |
| demuxes them one after the other, as if all their packet had been muxed |
| together. |
| |
| The timestamps in the files are adjusted so that the first file starts at 0 |
| and each next file starts where the previous one finishes. Note that it is |
| done globally and may cause gaps if all streams do not have exactly the same |
| length. |
| |
| All files must have the same streams (same codecs, same time base, etc.). |
| |
| The duration of each file is used to adjust the timestamps of the next file: |
| if the duration is incorrect (because it was computed using the bit-rate or |
| because the file is truncated, for example), it can cause artifacts. The |
| @code{duration} directive can be used to override the duration stored in |
| each file. |
| |
| @subsection Syntax |
| |
| The script is a text file in extended-ASCII, with one directive per line. |
| Empty lines, leading spaces and lines starting with '#' are ignored. The |
| following directive is recognized: |
| |
| @table @option |
| |
| @item @code{file @var{path}} |
| Path to a file to read; special characters and spaces must be escaped with |
| backslash or single quotes. |
| |
| All subsequent directives apply to that file. |
| |
| @item @code{ffconcat version 1.0} |
| Identify the script type and version. It also sets the @option{safe} option |
| to 1 if it was to its default -1. |
| |
| To make FFmpeg recognize the format automatically, this directive must |
| appears exactly as is (no extra space or byte-order-mark) on the very first |
| line of the script. |
| |
| @item @code{duration @var{dur}} |
| Duration of the file. This information can be specified from the file; |
| specifying it here may be more efficient or help if the information from the |
| file is not available or accurate. |
| |
| If the duration is set for all files, then it is possible to seek in the |
| whole concatenated video. |
| |
| @end table |
| |
| @subsection Options |
| |
| This demuxer accepts the following option: |
| |
| @table @option |
| |
| @item safe |
| If set to 1, reject unsafe file paths. A file path is considered safe if it |
| does not contain a protocol specification and is relative and all components |
| only contain characters from the portable character set (letters, digits, |
| period, underscore and hyphen) and have no period at the beginning of a |
| component. |
| |
| If set to 0, any file name is accepted. |
| |
| The default is -1, it is equivalent to 1 if the format was automatically |
| probed and 0 otherwise. |
| |
| @end table |
| |
| @section libgme |
| |
| The Game Music Emu library is a collection of video game music file emulators. |
| |
| See @url{http://code.google.com/p/game-music-emu/} for more information. |
| |
| Some files have multiple tracks. The demuxer will pick the first track by |
| default. The @option{track_index} option can be used to select a different |
| track. Track indexes start at 0. The demuxer exports the number of tracks as |
| @var{tracks} meta data entry. |
| |
| For very large files, the @option{max_size} option may have to be adjusted. |
| |
| @section libquvi |
| |
| Play media from Internet services using the quvi project. |
| |
| The demuxer accepts a @option{format} option to request a specific quality. It |
| is by default set to @var{best}. |
| |
| See @url{http://quvi.sourceforge.net/} for more information. |
| |
| FFmpeg needs to be built with @code{--enable-libquvi} for this demuxer to be |
| enabled. |
| |
| @section image2 |
| |
| Image file demuxer. |
| |
| This demuxer reads from a list of image files specified by a pattern. |
| The syntax and meaning of the pattern is specified by the |
| option @var{pattern_type}. |
| |
| The pattern may contain a suffix which is used to automatically |
| determine the format of the images contained in the files. |
| |
| The size, the pixel format, and the format of each image must be the |
| same for all the files in the sequence. |
| |
| This demuxer accepts the following options: |
| @table @option |
| @item framerate |
| Set the frame rate for the video stream. It defaults to 25. |
| @item loop |
| If set to 1, loop over the input. Default value is 0. |
| @item pattern_type |
| Select the pattern type used to interpret the provided filename. |
| |
| @var{pattern_type} accepts one of the following values. |
| @table @option |
| @item sequence |
| Select a sequence pattern type, used to specify a sequence of files |
| indexed by sequential numbers. |
| |
| A sequence pattern may contain the string "%d" or "%0@var{N}d", which |
| specifies the position of the characters representing a sequential |
| number in each filename matched by the pattern. If the form |
| "%d0@var{N}d" is used, the string representing the number in each |
| filename is 0-padded and @var{N} is the total number of 0-padded |
| digits representing the number. The literal character '%' can be |
| specified in the pattern with the string "%%". |
| |
| If the sequence pattern contains "%d" or "%0@var{N}d", the first filename of |
| the file list specified by the pattern must contain a number |
| inclusively contained between @var{start_number} and |
| @var{start_number}+@var{start_number_range}-1, and all the following |
| numbers must be sequential. |
| |
| For example the pattern "img-%03d.bmp" will match a sequence of |
| filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ..., |
| @file{img-010.bmp}, etc.; the pattern "i%%m%%g-%d.jpg" will match a |
| sequence of filenames of the form @file{i%m%g-1.jpg}, |
| @file{i%m%g-2.jpg}, ..., @file{i%m%g-10.jpg}, etc. |
| |
| Note that the pattern must not necessarily contain "%d" or |
| "%0@var{N}d", for example to convert a single image file |
| @file{img.jpeg} you can employ the command: |
| @example |
| ffmpeg -i img.jpeg img.png |
| @end example |
| |
| @item glob |
| Select a glob wildcard pattern type. |
| |
| The pattern is interpreted like a @code{glob()} pattern. This is only |
| selectable if libavformat was compiled with globbing support. |
| |
| @item glob_sequence @emph{(deprecated, will be removed)} |
| Select a mixed glob wildcard/sequence pattern. |
| |
| If your version of libavformat was compiled with globbing support, and |
| the provided pattern contains at least one glob meta character among |
| @code{%*?[]@{@}} that is preceded by an unescaped "%", the pattern is |
| interpreted like a @code{glob()} pattern, otherwise it is interpreted |
| like a sequence pattern. |
| |
| All glob special characters @code{%*?[]@{@}} must be prefixed |
| with "%". To escape a literal "%" you shall use "%%". |
| |
| For example the pattern @code{foo-%*.jpeg} will match all the |
| filenames prefixed by "foo-" and terminating with ".jpeg", and |
| @code{foo-%?%?%?.jpeg} will match all the filenames prefixed with |
| "foo-", followed by a sequence of three characters, and terminating |
| with ".jpeg". |
| |
| This pattern type is deprecated in favor of @var{glob} and |
| @var{sequence}. |
| @end table |
| |
| Default value is @var{glob_sequence}. |
| @item pixel_format |
| Set the pixel format of the images to read. If not specified the pixel |
| format is guessed from the first image file in the sequence. |
| @item start_number |
| Set the index of the file matched by the image file pattern to start |
| to read from. Default value is 0. |
| @item start_number_range |
| Set the index interval range to check when looking for the first image |
| file in the sequence, starting from @var{start_number}. Default value |
| is 5. |
| @item ts_from_file |
| If set to 1, will set frame timestamp to modification time of image file. Note |
| that monotonity of timestamps is not provided: images go in the same order as |
| without this option. Default value is 0. |
| @item video_size |
| Set the video size of the images to read. If not specified the video |
| size is guessed from the first image file in the sequence. |
| @end table |
| |
| @subsection Examples |
| |
| @itemize |
| @item |
| Use @command{ffmpeg} for creating a video from the images in the file |
| sequence @file{img-001.jpeg}, @file{img-002.jpeg}, ..., assuming an |
| input frame rate of 10 frames per second: |
| @example |
| ffmpeg -i 'img-%03d.jpeg' -r 10 out.mkv |
| @end example |
| |
| @item |
| As above, but start by reading from a file with index 100 in the sequence: |
| @example |
| ffmpeg -start_number 100 -i 'img-%03d.jpeg' -r 10 out.mkv |
| @end example |
| |
| @item |
| Read images matching the "*.png" glob pattern , that is all the files |
| terminating with the ".png" suffix: |
| @example |
| ffmpeg -pattern_type glob -i "*.png" -r 10 out.mkv |
| @end example |
| @end itemize |
| |
| @section rawvideo |
| |
| Raw video demuxer. |
| |
| This demuxer allows to read raw video data. Since there is no header |
| specifying the assumed video parameters, the user must specify them |
| in order to be able to decode the data correctly. |
| |
| This demuxer accepts the following options: |
| @table @option |
| |
| @item framerate |
| Set input video frame rate. Default value is 25. |
| |
| @item pixel_format |
| Set the input video pixel format. Default value is @code{yuv420p}. |
| |
| @item video_size |
| Set the input video size. This value must be specified explicitly. |
| @end table |
| |
| For example to read a rawvideo file @file{input.raw} with |
| @command{ffplay}, assuming a pixel format of @code{rgb24}, a video |
| size of @code{320x240}, and a frame rate of 10 images per second, use |
| the command: |
| @example |
| ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw |
| @end example |
| |
| @section sbg |
| |
| SBaGen script demuxer. |
| |
| This demuxer reads the script language used by SBaGen |
| @url{http://uazu.net/sbagen/} to generate binaural beats sessions. A SBG |
| script looks like that: |
| @example |
| -SE |
| a: 300-2.5/3 440+4.5/0 |
| b: 300-2.5/0 440+4.5/3 |
| off: - |
| NOW == a |
| +0:07:00 == b |
| +0:14:00 == a |
| +0:21:00 == b |
| +0:30:00 off |
| @end example |
| |
| A SBG script can mix absolute and relative timestamps. If the script uses |
| either only absolute timestamps (including the script start time) or only |
| relative ones, then its layout is fixed, and the conversion is |
| straightforward. On the other hand, if the script mixes both kind of |
| timestamps, then the @var{NOW} reference for relative timestamps will be |
| taken from the current time of day at the time the script is read, and the |
| script layout will be frozen according to that reference. That means that if |
| the script is directly played, the actual times will match the absolute |
| timestamps up to the sound controller's clock accuracy, but if the user |
| somehow pauses the playback or seeks, all times will be shifted accordingly. |
| |
| @section tedcaptions |
| |
| JSON captions used for @url{http://www.ted.com/, TED Talks}. |
| |
| TED does not provide links to the captions, but they can be guessed from the |
| page. The file @file{tools/bookmarklets.html} from the FFmpeg source tree |
| contains a bookmarklet to expose them. |
| |
| This demuxer accepts the following option: |
| @table @option |
| @item start_time |
| Set the start time of the TED talk, in milliseconds. The default is 15000 |
| (15s). It is used to sync the captions with the downloadable videos, because |
| they include a 15s intro. |
| @end table |
| |
| Example: convert the captions to a format most players understand: |
| @example |
| ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt |
| @end example |
| |
| @c man end DEMUXERS |