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FFmpeg is a very fast video and audio converter. It can also grab from a live audio/video source.
The command line interface is designed to be intuitive, in the sense that FFmpeg tries to figure out all parameters that can possibly be derived automatically. You usually only have to specify the target bitrate you want.
FFmpeg can also convert from any sample rate to any other, and resize video on the fly with a high quality polyphase filter.
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FFmpeg can grab video and audio from devices given that you specify the input format and device.
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg |
Note that you must activate the right video source and channel before launching FFmpeg with any TV viewer such as xawtv (http://linux.bytesex.org/xawtv/) by Gerd Knorr. You also have to set the audio recording levels correctly with a standard mixer.
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FFmpeg can grab the X11 display.
ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg |
0.0 is display.screen number of your X11 server, same as the DISPLAY environment variable.
ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg |
0.0 is display.screen number of your X11 server, same as the DISPLAY environment variable. 10 is the x-offset and 20 the y-offset for the grabbing.
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* FFmpeg can use any supported file format and protocol as input:
Examples:
* You can use YUV files as input:
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg |
It will use the files:
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V, /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc... |
The Y files use twice the resolution of the U and V files. They are raw files, without header. They can be generated by all decent video decoders. You must specify the size of the image with the ‘-s’ option if FFmpeg cannot guess it.
* You can input from a raw YUV420P file:
ffmpeg -i /tmp/test.yuv /tmp/out.avi |
test.yuv is a file containing raw YUV planar data. Each frame is composed of the Y plane followed by the U and V planes at half vertical and horizontal resolution.
* You can output to a raw YUV420P file:
ffmpeg -i mydivx.avi hugefile.yuv |
* You can set several input files and output files:
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg |
Converts the audio file a.wav and the raw YUV video file a.yuv to MPEG file a.mpg.
* You can also do audio and video conversions at the same time:
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2 |
Converts a.wav to MPEG audio at 22050 Hz sample rate.
* You can encode to several formats at the same time and define a mapping from input stream to output streams:
ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0 |
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map file:index' specifies which input stream is used for each output stream, in the order of the definition of output streams.
* You can transcode decrypted VOBs:
ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi |
This is a typical DVD ripping example; the input is a VOB file, the
output an AVI file with MPEG-4 video and MP3 audio. Note that in this
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
input video. Furthermore, the audio stream is MP3-encoded so you need
to enable LAME support by passing --enable-libmp3lame
to configure.
The mapping is particularly useful for DVD transcoding
to get the desired audio language.
NOTE: To see the supported input formats, use ffmpeg -formats
.
* You can extract images from a video:
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg |
This will extract one video frame per second from the video and will output them in files named ‘foo-001.jpeg’, ‘foo-002.jpeg’, etc. Images will be rescaled to fit the new WxH values.
The syntax foo-%03d.jpeg
specifies to use a decimal number
composed of three digits padded with zeroes to express the sequence
number. It is the same syntax supported by the C printf function, but
only formats accepting a normal integer are suitable.
If you want to extract just a limited number of frames, you can use the above command in combination with the -vframes or -t option, or in combination with -ss to start extracting from a certain point in time.
* You can put many streams of the same type in the output:
ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio |
In addition to the first video and audio streams, the resulting output file ‘test12.avi’ will contain the second video and the second audio stream found in the input streams list.
The -newvideo
, -newaudio
and -newsubtitle
options have to be specified immediately after the name of the output
file to which you want to add them.
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The generic syntax is:
ffmpeg [[infile options][‘-i’ infile]]... {[outfile options] outfile}... |
As a general rule, options are applied to the next specified file. Therefore, order is important, and you can have the same option on the command line multiple times. Each occurrence is then applied to the next input or output file.
* To set the video bitrate of the output file to 64kbit/s:
ffmpeg -i input.avi -b 64k output.avi |
* To force the frame rate of the output file to 24 fps:
ffmpeg -i input.avi -r 24 output.avi |
* To force the frame rate of the input file (valid for raw formats only) to 1 fps and the frame rate of the output file to 24 fps:
ffmpeg -r 1 -i input.m2v -r 24 output.avi |
The format option may be needed for raw input files.
By default, FFmpeg tries to convert as losslessly as possible: It uses the same audio and video parameters for the outputs as the one specified for the inputs.
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Show license.
Show help.
Show version.
Show available formats, codecs, bitstream filters, protocols, and frame size and frame rate abbreviations.
The fields preceding the format and codec names have the following meanings:
Decoding available
Encoding available
Video/audio/subtitle codec
Codec supports slices
Codec supports direct rendering
Codec can handle input truncated at random locations instead of only at frame boundaries
Force format.
input file name
Overwrite output files.
Restrict the transcoded/captured video sequence
to the duration specified in seconds.
hh:mm:ss[.xxx]
syntax is also supported.
Set the file size limit.
Seek to given time position in seconds.
hh:mm:ss[.xxx]
syntax is also supported.
Set the input time offset in seconds.
[-]hh:mm:ss[.xxx]
syntax is also supported.
This option affects all the input files that follow it.
The offset is added to the timestamps of the input files.
Specifying a positive offset means that the corresponding
streams are delayed by 'offset' seconds.
Set the title.
Set the timestamp.
Set the author.
Set the copyright.
Set the comment.
Set the album.
Set the track.
Set the year.
Set the logging verbosity level.
Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd", "ntsc-svcd", ... ). All the format options (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg |
Nevertheless you can specify additional options as long as you know they do not conflict with the standard, as in:
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg |
Set the number of data frames to record.
Force subtitle codec ('copy' to copy stream).
Add a new subtitle stream to the current output stream.
Set the ISO 639 language code (3 letters) of the current subtitle stream.
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Set the video bitrate in bit/s (default = 200 kb/s).
Set the number of video frames to record.
Set frame rate (Hz value, fraction or abbreviation), (default = 25).
Set frame size. The format is ‘wxh’ (ffserver default = 160x128, ffmpeg default = same as source). The following abbreviations are recognized:
128x96
176x144
352x288
704x576
160x120
320x240
640x480
800x600
1024x768
1600x1200
2048x1536
1280x1024
2560x2048
5120x4096
852x480
1366x768
1600x1024
1920x1200
2560x1600
3200x2048
3840x2400
6400x4096
7680x4800
320x200
640x350
852x480
1280x720
1920x1080
Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
Set top crop band size (in pixels).
Set bottom crop band size (in pixels).
Set left crop band size (in pixels).
Set right crop band size (in pixels).
Set top pad band size (in pixels).
Set bottom pad band size (in pixels).
Set left pad band size (in pixels).
Set right pad band size (in pixels).
Set color of padded bands. The value for padcolor is expressed as a six digit hexadecimal number where the first two digits represent red, the middle two digits green and last two digits blue (default = 000000 (black)).
Disable video recording.
Set video bitrate tolerance (in bits, default 4000k). Has a minimum value of: (target_bitrate/target_framerate). In 1-pass mode, bitrate tolerance specifies how far ratecontrol is willing to deviate from the target average bitrate value. This is not related to min/max bitrate. Lowering tolerance too much has an adverse effect on quality.
Set max video bitrate (in bit/s). Requires -bufsize to be set.
Set min video bitrate (in bit/s). Most useful in setting up a CBR encode:
ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v |
It is of little use elsewise.
Set video buffer verifier buffer size (in bits).
Force video codec to codec. Use the copy
special value to
tell that the raw codec data must be copied as is.
Use same video quality as source (implies VBR).
Select the pass number (1 or 2). It is used to do two-pass video encoding. The statistics of the video are recorded in the first pass into a log file (see also the option -passlogfile), and in the second pass that log file is used to generate the video at the exact requested bitrate. On pass 1, you may just deactivate audio and set output to null, examples for Windows and Unix:
ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y NUL ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y /dev/null |
Set two-pass log file name prefix to prefix, the default file name prefix is “ffmpeg2pass”. The complete file name will be ‘PREFIX-N.log’, where N is a number specific to the output stream.
Add a new video stream to the current output stream.
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Set pixel format. Use 'list' as parameter to show all the supported pixel formats.
Set SwScaler flags (only available when compiled with swscale support).
Set the group of pictures size.
Use only intra frames.
Discard threshold.
Use fixed video quantizer scale (VBR).
minimum video quantizer scale (VBR)
maximum video quantizer scale (VBR)
maximum difference between the quantizer scales (VBR)
video quantizer scale blur (VBR) (range 0.0 - 1.0)
video quantizer scale compression (VBR) (default 0.5). Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
minimum video lagrange factor (VBR)
max video lagrange factor (VBR)
minimum macroblock quantizer scale (VBR)
maximum macroblock quantizer scale (VBR)
These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units, but you may use the QP2LAMBDA constant to easily convert from 'q' units:
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext |
initial complexity for single pass encoding
qp factor between P- and B-frames
qp factor between P- and I-frames
qp offset between P- and B-frames
qp offset between P- and I-frames
Set rate control equation (see section FFmpeg formula evaluator) (default = tex^qComp
).
rate control override for specific intervals
Set motion estimation method to method. Available methods are (from lowest to best quality):
Try just the (0, 0) vector.
(default method)
exhaustive search (slow and marginally better than epzs)
Set DCT algorithm to algo. Available values are:
FF_DCT_AUTO (default)
FF_DCT_FASTINT
FF_DCT_INT
FF_DCT_MMX
FF_DCT_MLIB
FF_DCT_ALTIVEC
Set IDCT algorithm to algo. Available values are:
FF_IDCT_AUTO (default)
FF_IDCT_INT
FF_IDCT_SIMPLE
FF_IDCT_SIMPLEMMX
FF_IDCT_LIBMPEG2MMX
FF_IDCT_PS2
FF_IDCT_MLIB
FF_IDCT_ARM
FF_IDCT_ALTIVEC
FF_IDCT_SH4
FF_IDCT_SIMPLEARM
Set error resilience to n.
FF_ER_CAREFUL (default)
FF_ER_COMPLIANT
FF_ER_AGGRESSIVE
FF_ER_VERY_AGGRESSIVE
Set error concealment to bit_mask. bit_mask is a bit mask of the following values:
FF_EC_GUESS_MVS (default = enabled)
FF_EC_DEBLOCK (default = enabled)
Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
macroblock decision
FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
FF_MB_DECISION_RD: rate distortion
Use four motion vector by macroblock (MPEG-4 only).
Use data partitioning (MPEG-4 only).
Work around encoder bugs that are not auto-detected.
How strictly to follow the standards.
Enable Advanced intra coding (h263+).
Enable Unlimited Motion Vector (h263+)
Deinterlace pictures.
Force interlacing support in encoder (MPEG-2 and MPEG-4 only). Use this option if your input file is interlaced and you want to keep the interlaced format for minimum losses. The alternative is to deinterlace the input stream with ‘-deinterlace’, but deinterlacing introduces losses.
Calculate PSNR of compressed frames.
Dump video coding statistics to ‘vstats_HHMMSS.log’.
Dump video coding statistics to file.
Insert video processing module. module contains the module name and its parameters separated by spaces.
top=1/bottom=0/auto=-1 field first
Intra_dc_precision.
Force video tag/fourcc.
Show QP histogram.
Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump".
ffmpeg -i h264.mp4 -vcodec copy -vbsf h264_mp4toannexb -an out.h264 |
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Set the number of audio frames to record.
Set the audio sampling frequency (default = 44100 Hz).
Set the audio bitrate in bit/s (default = 64k).
Set the number of audio channels (default = 1).
Disable audio recording.
Force audio codec to codec. Use the copy
special value to
specify that the raw codec data must be copied as is.
Add a new audio track to the output file. If you want to specify parameters,
do so before -newaudio
(-acodec
, -ab
, etc..).
Mapping will be done automatically, if the number of output streams is equal to
the number of input streams, else it will pick the first one that matches. You
can override the mapping using -map
as usual.
Example:
ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio |
Set the ISO 639 language code (3 letters) of the current audio stream.
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Force audio tag/fourcc.
Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
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Force subtitle codec ('copy' to copy stream).
Add a new subtitle stream to the current output stream.
Set the ISO 639 language code (3 letters) of the current subtitle stream.
Bitstream filters available are "mov2textsub", "text2movsub".
ffmpeg -i file.mov -an -vn -sbsf mov2textsub -scodec copy -f rawvideo sub.txt |
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Set video grab channel (DV1394 only).
Set television standard (NTSC, PAL (SECAM)).
Synchronize read on input.
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Set stream mapping from input streams to output streams. Just enumerate the input streams in the order you want them in the output. sync_stream_id if specified sets the input stream to sync against.
Set meta data information of outfile from infile.
Print specific debug info.
Add timings for benchmarking.
Dump each input packet.
When dumping packets, also dump the payload.
Only use bit exact algorithms (for codec testing).
Set packet size in bits.
Read input at native frame rate. Mainly used to simulate a grab device.
Loop over the input stream. Currently it works only for image streams. This option is used for automatic FFserver testing.
Repeatedly loop output for formats that support looping such as animated GIF (0 will loop the output infinitely).
Thread count.
Video sync method. Video will be stretched/squeezed to match the timestamps, it is done by duplicating and dropping frames. With -map you can select from which stream the timestamps should be taken. You can leave either video or audio unchanged and sync the remaining stream(s) to the unchanged one.
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps, the parameter is the maximum samples per second by which the audio is changed. -async 1 is a special case where only the start of the audio stream is corrected without any later correction.
Copy timestamps from input to output.
Finish encoding when the shortest input stream ends.
Timestamp discontinuity delta threshold.
Set the maximum demux-decode delay.
Set the initial demux-decode delay.
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A preset file contains a sequence of option=value pairs, one for each line, specifying a sequence of options which would be awkward to specify on the command line. Lines starting with the hash ('#') character are ignored and are used to provide comments. Check the ‘ffpresets’ directory in the FFmpeg source tree for examples.
Preset files are specified with the vpre
, apre
and
spre
options. The options specified in a preset file are
applied to the currently selected codec of the same type as the preset
option.
The argument passed to the preset options identifies the preset file to use according to the following rules.
First ffmpeg searches for a file named arg.ffpreset in the
directories ‘$HOME/.ffmpeg’, and in the datadir defined at
configuration time (usually ‘PREFIX/share/ffmpeg’) in that
order. For example, if the argument is libx264-max
, it will
search for the file ‘libx264-max.ffpreset’.
If no such file is found, then ffmpeg will search for a file named
codec_name-arg.ffpreset in the above-mentioned
directories, where codec_name is the name of the codec to which
the preset file options will be applied. For example, if you select
the video codec with -vcodec libx264
and use -vpre max
,
then it will search for the file ‘libx264-max.ffpreset’.
Finally, if the above rules failed and the argument specifies an absolute pathname, ffmpeg will search for that filename. This way you can specify the absolute and complete filename of the preset file, for example ‘./ffpresets/libx264-max.ffpreset’.
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When evaluating a rate control string, FFmpeg uses an internal formula evaluator.
The following binary operators are available: +
, -
,
*
, /
, ^
.
The following unary operators are available: +
, -
,
(...)
.
The following statements are available: ld
, st
,
while
.
The following functions are available:
The following constants are available:
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The file name can be ‘-’ to read from standard input or to write to standard output.
FFmpeg also handles many protocols specified with an URL syntax.
Use 'ffmpeg -formats' to see a list of the supported protocols.
The protocol http:
is currently used only to communicate with
FFserver (see the FFserver documentation). When FFmpeg will be a
video player it will also be used for streaming :-)
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ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm |
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