4 Muxers are configured elements in FFmpeg which allow writing
5 multimedia streams to a particular type of file.
7 When you configure your FFmpeg build, all the supported muxers
8 are enabled by default. You can list all available muxers using the
9 configure option @code{--list-muxers}.
11 You can disable all the muxers with the configure option
12 @code{--disable-muxers} and selectively enable / disable single muxers
13 with the options @code{--enable-muxer=@var{MUXER}} /
14 @code{--disable-muxer=@var{MUXER}}.
16 The option @code{-formats} of the ff* tools will display the list of
19 A description of some of the currently available muxers follows.
24 CRC (Cyclic Redundancy Check) testing format.
26 This muxer computes and prints the Adler-32 CRC of all the input audio
27 and video frames. By default audio frames are converted to signed
28 16-bit raw audio and video frames to raw video before computing the
31 The output of the muxer consists of a single line of the form:
32 CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to
33 8 digits containing the CRC for all the decoded input frames.
35 For example to compute the CRC of the input, and store it in the file
38 ffmpeg -i INPUT -f crc out.crc
41 You can print the CRC to stdout with the command:
43 ffmpeg -i INPUT -f crc -
46 You can select the output format of each frame with @command{ffmpeg} by
47 specifying the audio and video codec and format. For example to
48 compute the CRC of the input audio converted to PCM unsigned 8-bit
49 and the input video converted to MPEG-2 video, use the command:
51 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
54 See also the @ref{framecrc} muxer.
59 Per-frame CRC (Cyclic Redundancy Check) testing format.
61 This muxer computes and prints the Adler-32 CRC for each decoded audio
62 and video frame. By default audio frames are converted to signed
63 16-bit raw audio and video frames to raw video before computing the
66 The output of the muxer consists of a line for each audio and video
67 frame of the form: @var{stream_index}, @var{frame_dts},
68 @var{frame_size}, 0x@var{CRC}, where @var{CRC} is a hexadecimal
69 number 0-padded to 8 digits containing the CRC of the decoded frame.
71 For example to compute the CRC of each decoded frame in the input, and
72 store it in the file @file{out.crc}:
74 ffmpeg -i INPUT -f framecrc out.crc
77 You can print the CRC of each decoded frame to stdout with the command:
79 ffmpeg -i INPUT -f framecrc -
82 You can select the output format of each frame with @command{ffmpeg} by
83 specifying the audio and video codec and format. For example, to
84 compute the CRC of each decoded input audio frame converted to PCM
85 unsigned 8-bit and of each decoded input video frame converted to
86 MPEG-2 video, use the command:
88 ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
91 See also the @ref{crc} muxer.
98 The image file muxer writes video frames to image files.
100 The output filenames are specified by a pattern, which can be used to
101 produce sequentially numbered series of files.
102 The pattern may contain the string "%d" or "%0@var{N}d", this string
103 specifies the position of the characters representing a numbering in
104 the filenames. If the form "%0@var{N}d" is used, the string
105 representing the number in each filename is 0-padded to @var{N}
106 digits. The literal character '%' can be specified in the pattern with
109 If the pattern contains "%d" or "%0@var{N}d", the first filename of
110 the file list specified will contain the number 1, all the following
111 numbers will be sequential.
113 The pattern may contain a suffix which is used to automatically
114 determine the format of the image files to write.
116 For example the pattern "img-%03d.bmp" will specify a sequence of
117 filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
118 @file{img-010.bmp}, etc.
119 The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
120 form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg},
123 The following example shows how to use @command{ffmpeg} for creating a
124 sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ...,
125 taking one image every second from the input video:
127 ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
130 Note that with @command{ffmpeg}, if the format is not specified with the
131 @code{-f} option and the output filename specifies an image file
132 format, the image2 muxer is automatically selected, so the previous
133 command can be written as:
135 ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
138 Note also that the pattern must not necessarily contain "%d" or
139 "%0@var{N}d", for example to create a single image file
140 @file{img.jpeg} from the input video you can employ the command:
142 ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
145 The image muxer supports the .Y.U.V image file format. This format is
146 special in that that each image frame consists of three files, for
147 each of the YUV420P components. To read or write this image file format,
148 specify the name of the '.Y' file. The muxer will automatically open the
149 '.U' and '.V' files as required.
155 The muxer options are:
158 @item -moov_size @var{bytes}
159 Reserves space for the moov atom at the beginning of the file instead of placing the
160 moov atom at the end. If the space reserved is insufficient, muxing will fail.
165 MPEG transport stream muxer.
167 This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
169 The muxer options are:
172 @item -mpegts_original_network_id @var{number}
173 Set the original_network_id (default 0x0001). This is unique identifier
174 of a network in DVB. Its main use is in the unique identification of a
175 service through the path Original_Network_ID, Transport_Stream_ID.
176 @item -mpegts_transport_stream_id @var{number}
177 Set the transport_stream_id (default 0x0001). This identifies a
179 @item -mpegts_service_id @var{number}
180 Set the service_id (default 0x0001) also known as program in DVB.
181 @item -mpegts_pmt_start_pid @var{number}
182 Set the first PID for PMT (default 0x1000, max 0x1f00).
183 @item -mpegts_start_pid @var{number}
184 Set the first PID for data packets (default 0x0100, max 0x0f00).
187 The recognized metadata settings in mpegts muxer are @code{service_provider}
188 and @code{service_name}. If they are not set the default for
189 @code{service_provider} is "FFmpeg" and the default for
190 @code{service_name} is "Service01".
193 ffmpeg -i file.mpg -c copy \
194 -mpegts_original_network_id 0x1122 \
195 -mpegts_transport_stream_id 0x3344 \
196 -mpegts_service_id 0x5566 \
197 -mpegts_pmt_start_pid 0x1500 \
198 -mpegts_start_pid 0x150 \
199 -metadata service_provider="Some provider" \
200 -metadata service_name="Some Channel" \
208 This muxer does not generate any output file, it is mainly useful for
209 testing or benchmarking purposes.
211 For example to benchmark decoding with @command{ffmpeg} you can use the
214 ffmpeg -benchmark -i INPUT -f null out.null
217 Note that the above command does not read or write the @file{out.null}
218 file, but specifying the output file is required by the @command{ffmpeg}
221 Alternatively you can write the command as:
223 ffmpeg -benchmark -i INPUT -f null -
228 Matroska container muxer.
230 This muxer implements the matroska and webm container specs.
232 The recognized metadata settings in this muxer are:
236 @item title=@var{title name}
237 Name provided to a single track
242 @item language=@var{language name}
243 Specifies the language of the track in the Matroska languages form
248 @item stereo_mode=@var{mode}
249 Stereo 3D video layout of two views in a single video track
254 Both views are arranged side by side, Left-eye view is on the left
256 Both views are arranged in top-bottom orientation, Left-eye view is at bottom
258 Both views are arranged in top-bottom orientation, Left-eye view is on top
259 @item checkerboard_rl
260 Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
261 @item checkerboard_lr
262 Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
263 @item row_interleaved_rl
264 Each view is constituted by a row based interleaving, Right-eye view is first row
265 @item row_interleaved_lr
266 Each view is constituted by a row based interleaving, Left-eye view is first row
267 @item col_interleaved_rl
268 Both views are arranged in a column based interleaving manner, Right-eye view is first column
269 @item col_interleaved_lr
270 Both views are arranged in a column based interleaving manner, Left-eye view is first column
271 @item anaglyph_cyan_red
272 All frames are in anaglyph format viewable through red-cyan filters
274 Both views are arranged side by side, Right-eye view is on the left
275 @item anaglyph_green_magenta
276 All frames are in anaglyph format viewable through green-magenta filters
278 Both eyes laced in one Block, Left-eye view is first
280 Both eyes laced in one Block, Right-eye view is first
284 For example a 3D WebM clip can be created using the following command line:
286 ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
291 Basic stream segmenter.
293 The segmenter muxer outputs streams to a number of separate files of nearly
294 fixed duration. Output filename pattern can be set in a fashion similar to
297 Every segment starts with a video keyframe, if a video stream is present.
298 The segment muxer works best with a single constant frame rate video.
300 Optionally it can generate a flat list of the created segments, one segment
304 @item segment_format @var{format}
305 Override the inner container format, by default it is guessed by the filename
307 @item segment_time @var{t}
308 Set segment duration to @var{t} seconds.
309 @item segment_list @var{name}
310 Generate also a listfile named @var{name}.
311 @item segment_list_size @var{size}
312 Overwrite the listfile once it reaches @var{size} entries.
316 ffmpeg -i in.mkv -c copy -map 0 -f segment -list out.list out%03d.nut