| @chapter Muxers |
| @c man begin MUXERS |
| |
| Muxers are configured elements in FFmpeg which allow writing |
| multimedia streams to a particular type of file. |
| |
| When you configure your FFmpeg build, all the supported muxers |
| are enabled by default. You can list all available muxers using the |
| configure option @code{--list-muxers}. |
| |
| You can disable all the muxers with the configure option |
| @code{--disable-muxers} and selectively enable / disable single muxers |
| with the options @code{--enable-muxer=@var{MUXER}} / |
| @code{--disable-muxer=@var{MUXER}}. |
| |
| The option @code{-formats} of the ff* tools will display the list of |
| enabled muxers. |
| |
| A description of some of the currently available muxers follows. |
| |
| @anchor{crc} |
| @section crc |
| |
| CRC (Cyclic Redundancy Check) testing format. |
| |
| This muxer computes and prints the Adler-32 CRC of all the input audio |
| and video frames. By default audio frames are converted to signed |
| 16-bit raw audio and video frames to raw video before computing the |
| CRC. |
| |
| The output of the muxer consists of a single line of the form: |
| CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to |
| 8 digits containing the CRC for all the decoded input frames. |
| |
| For example to compute the CRC of the input, and store it in the file |
| @file{out.crc}: |
| @example |
| ffmpeg -i INPUT -f crc out.crc |
| @end example |
| |
| You can print the CRC to stdout with the command: |
| @example |
| ffmpeg -i INPUT -f crc - |
| @end example |
| |
| You can select the output format of each frame with @command{ffmpeg} by |
| specifying the audio and video codec and format. For example to |
| compute the CRC of the input audio converted to PCM unsigned 8-bit |
| and the input video converted to MPEG-2 video, use the command: |
| @example |
| ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc - |
| @end example |
| |
| See also the @ref{framecrc} muxer. |
| |
| @anchor{framecrc} |
| @section framecrc |
| |
| Per-frame CRC (Cyclic Redundancy Check) testing format. |
| |
| This muxer computes and prints the Adler-32 CRC for each decoded audio |
| and video frame. By default audio frames are converted to signed |
| 16-bit raw audio and video frames to raw video before computing the |
| CRC. |
| |
| The output of the muxer consists of a line for each audio and video |
| frame of the form: @var{stream_index}, @var{frame_dts}, |
| @var{frame_size}, 0x@var{CRC}, where @var{CRC} is a hexadecimal |
| number 0-padded to 8 digits containing the CRC of the decoded frame. |
| |
| For example to compute the CRC of each decoded frame in the input, and |
| store it in the file @file{out.crc}: |
| @example |
| ffmpeg -i INPUT -f framecrc out.crc |
| @end example |
| |
| You can print the CRC of each decoded frame to stdout with the command: |
| @example |
| ffmpeg -i INPUT -f framecrc - |
| @end example |
| |
| You can select the output format of each frame with @command{ffmpeg} by |
| specifying the audio and video codec and format. For example, to |
| compute the CRC of each decoded input audio frame converted to PCM |
| unsigned 8-bit and of each decoded input video frame converted to |
| MPEG-2 video, use the command: |
| @example |
| ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc - |
| @end example |
| |
| See also the @ref{crc} muxer. |
| |
| @anchor{image2} |
| @section image2 |
| |
| Image file muxer. |
| |
| The image file muxer writes video frames to image files. |
| |
| The output filenames are specified by a pattern, which can be used to |
| produce sequentially numbered series of files. |
| The pattern may contain the string "%d" or "%0@var{N}d", this string |
| specifies the position of the characters representing a numbering in |
| the filenames. If the form "%0@var{N}d" is used, the string |
| representing the number in each filename is 0-padded to @var{N} |
| digits. 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 |
| the file list specified will contain the number 1, all the following |
| numbers will be sequential. |
| |
| The pattern may contain a suffix which is used to automatically |
| determine the format of the image files to write. |
| |
| For example the pattern "img-%03d.bmp" will specify a sequence of |
| filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ..., |
| @file{img-010.bmp}, etc. |
| The pattern "img%%-%d.jpg" will specify a sequence of filenames of the |
| form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg}, |
| etc. |
| |
| The following example shows how to use @command{ffmpeg} for creating a |
| sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ..., |
| taking one image every second from the input video: |
| @example |
| ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg' |
| @end example |
| |
| Note that with @command{ffmpeg}, if the format is not specified with the |
| @code{-f} option and the output filename specifies an image file |
| format, the image2 muxer is automatically selected, so the previous |
| command can be written as: |
| @example |
| ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg' |
| @end example |
| |
| Note also that the pattern must not necessarily contain "%d" or |
| "%0@var{N}d", for example to create a single image file |
| @file{img.jpeg} from the input video you can employ the command: |
| @example |
| ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg |
| @end example |
| |
| The image muxer supports the .Y.U.V image file format. This format is |
| special in that that each image frame consists of three files, for |
| each of the YUV420P components. To read or write this image file format, |
| specify the name of the '.Y' file. The muxer will automatically open the |
| '.U' and '.V' files as required. |
| |
| @section mov |
| |
| MOV / MP4 muxer |
| |
| The muxer options are: |
| |
| @table @option |
| @item -moov_size @var{bytes} |
| Reserves space for the moov atom at the beginning of the file instead of placing the |
| moov atom at the end. If the space reserved is insufficient, muxing will fail. |
| @end table |
| |
| @section mpegts |
| |
| MPEG transport stream muxer. |
| |
| This muxer implements ISO 13818-1 and part of ETSI EN 300 468. |
| |
| The muxer options are: |
| |
| @table @option |
| @item -mpegts_original_network_id @var{number} |
| Set the original_network_id (default 0x0001). This is unique identifier |
| of a network in DVB. Its main use is in the unique identification of a |
| service through the path Original_Network_ID, Transport_Stream_ID. |
| @item -mpegts_transport_stream_id @var{number} |
| Set the transport_stream_id (default 0x0001). This identifies a |
| transponder in DVB. |
| @item -mpegts_service_id @var{number} |
| Set the service_id (default 0x0001) also known as program in DVB. |
| @item -mpegts_pmt_start_pid @var{number} |
| Set the first PID for PMT (default 0x1000, max 0x1f00). |
| @item -mpegts_start_pid @var{number} |
| Set the first PID for data packets (default 0x0100, max 0x0f00). |
| @end table |
| |
| The recognized metadata settings in mpegts muxer are @code{service_provider} |
| and @code{service_name}. If they are not set the default for |
| @code{service_provider} is "FFmpeg" and the default for |
| @code{service_name} is "Service01". |
| |
| @example |
| ffmpeg -i file.mpg -c copy \ |
| -mpegts_original_network_id 0x1122 \ |
| -mpegts_transport_stream_id 0x3344 \ |
| -mpegts_service_id 0x5566 \ |
| -mpegts_pmt_start_pid 0x1500 \ |
| -mpegts_start_pid 0x150 \ |
| -metadata service_provider="Some provider" \ |
| -metadata service_name="Some Channel" \ |
| -y out.ts |
| @end example |
| |
| @section null |
| |
| Null muxer. |
| |
| This muxer does not generate any output file, it is mainly useful for |
| testing or benchmarking purposes. |
| |
| For example to benchmark decoding with @command{ffmpeg} you can use the |
| command: |
| @example |
| ffmpeg -benchmark -i INPUT -f null out.null |
| @end example |
| |
| Note that the above command does not read or write the @file{out.null} |
| file, but specifying the output file is required by the @command{ffmpeg} |
| syntax. |
| |
| Alternatively you can write the command as: |
| @example |
| ffmpeg -benchmark -i INPUT -f null - |
| @end example |
| |
| @section matroska |
| |
| Matroska container muxer. |
| |
| This muxer implements the matroska and webm container specs. |
| |
| The recognized metadata settings in this muxer are: |
| |
| @table @option |
| |
| @item title=@var{title name} |
| Name provided to a single track |
| @end table |
| |
| @table @option |
| |
| @item language=@var{language name} |
| Specifies the language of the track in the Matroska languages form |
| @end table |
| |
| @table @option |
| |
| @item stereo_mode=@var{mode} |
| Stereo 3D video layout of two views in a single video track |
| @table @option |
| @item mono |
| video is not stereo |
| @item left_right |
| Both views are arranged side by side, Left-eye view is on the left |
| @item bottom_top |
| Both views are arranged in top-bottom orientation, Left-eye view is at bottom |
| @item top_bottom |
| Both views are arranged in top-bottom orientation, Left-eye view is on top |
| @item checkerboard_rl |
| Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first |
| @item checkerboard_lr |
| Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first |
| @item row_interleaved_rl |
| Each view is constituted by a row based interleaving, Right-eye view is first row |
| @item row_interleaved_lr |
| Each view is constituted by a row based interleaving, Left-eye view is first row |
| @item col_interleaved_rl |
| Both views are arranged in a column based interleaving manner, Right-eye view is first column |
| @item col_interleaved_lr |
| Both views are arranged in a column based interleaving manner, Left-eye view is first column |
| @item anaglyph_cyan_red |
| All frames are in anaglyph format viewable through red-cyan filters |
| @item right_left |
| Both views are arranged side by side, Right-eye view is on the left |
| @item anaglyph_green_magenta |
| All frames are in anaglyph format viewable through green-magenta filters |
| @item block_lr |
| Both eyes laced in one Block, Left-eye view is first |
| @item block_rl |
| Both eyes laced in one Block, Right-eye view is first |
| @end table |
| @end table |
| |
| For example a 3D WebM clip can be created using the following command line: |
| @example |
| ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm |
| @end example |
| |
| @section segment |
| |
| Basic stream segmenter. |
| |
| The segmenter muxer outputs streams to a number of separate files of nearly |
| fixed duration. Output filename pattern can be set in a fashion similar to |
| @ref{image2}. |
| |
| Every segment starts with a video keyframe, if a video stream is present. |
| The segment muxer works best with a single constant frame rate video. |
| |
| Optionally it can generate a flat list of the created segments, one segment |
| per line. |
| |
| @table @option |
| @item segment_format @var{format} |
| Override the inner container format, by default it is guessed by the filename |
| extension. |
| @item segment_time @var{t} |
| Set segment duration to @var{t} seconds. |
| @item segment_list @var{name} |
| Generate also a listfile named @var{name}. |
| @item segment_list_size @var{size} |
| Overwrite the listfile once it reaches @var{size} entries. |
| @end table |
| |
| @example |
| ffmpeg -i in.mkv -c copy -map 0 -f segment -list out.list out%03d.nut |
| @end example |
| |
| |
| @c man end MUXERS |