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diff --git a/doc/demuxers.texi b/doc/demuxers.texi index c3049ddfc4..aea4c54c0b 100644 --- a/doc/demuxers.texi +++ b/doc/demuxers.texi @@ -1,10 +1,10 @@ @chapter Demuxers @c man begin DEMUXERS -Demuxers are configured elements in Libav which allow to read the +Demuxers are configured elements in FFmpeg which allow to read the multimedia streams from a particular type of file. -When you configure your Libav build, all the supported demuxers +When you configure your FFmpeg build, all the supported demuxers are enabled by default. You can list all available ones using the configure option "--list-demuxers". @@ -23,8 +23,31 @@ The description of some of the currently available demuxers follows. 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 the string "%d" or "%0@var{N}d", which +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 framerate 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 @@ -32,13 +55,11 @@ 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 pattern contains "%d" or "%0@var{N}d", the first filename of +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 0 and 4, all the following numbers must -be sequential. This limitation may be hopefully fixed. - -The pattern may contain a suffix which is used to automatically -determine the format of the images contained in the files. +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}, ..., @@ -46,23 +67,81 @@ filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ..., 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. -The size, the pixel format, and the format of each image must be the -same for all the files in the sequence. +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 -The following example shows how to use @command{avconv} for creating a -video from the images in the file sequence @file{img-001.jpeg}, -@file{img-002.jpeg}, ..., assuming an input framerate of 10 frames per -second: +@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 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 -avconv -i 'img-%03d.jpeg' -r 10 out.mkv +ffmpeg -i 'img-%03d.jpeg' -r 10 out.mkv @end example -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: +@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 -avconv -i img.jpeg img.png +ffmpeg -pattern_type glob -i "*.png" -r 10 out.mkv @end example +@end itemize @section applehttp @@ -70,9 +149,39 @@ 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 avplay), +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". +@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. + @c man end INPUT DEVICES |