FFMPEG

ffmpeg − FFmpeg video converter

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.

Generic options

These options are shared amongst the ff* tools.

−L

Show license.

−h, −?, −help, −−help

Show help.

−version

Show version.

−formats

Show available formats.

The fields preceding the format names have the following meanings:

D

Decoding available

E

Encoding available

−codecs

Show available codecs.

The fields preceding the codec names have the following meanings:

D

Decoding available

E

Encoding available

V/A/S

Video/audio/subtitle codec

S

Codec supports slices

D

Codec supports direct rendering

T

Codec can handle input truncated at random locations instead of only at frame boundaries

−bsfs

Show available bitstream filters.

−protocols

Show available protocols.

−filters

Show available libavfilter filters.

−pix_fmts

Show available pixel formats.

−loglevel loglevel

Set the logging level used by the library. loglevel is a number or a string containing one of the following values:

quiet

panic

fatal

error

warning

info

verbose

debug

Main options

−f fmt

Force format.

−i filename

input file name

−y

Overwrite output files.

−t duration

Restrict the transcoded/captured video sequence to the duration specified in seconds. "hh:mm:ss[.xxx]" syntax is also supported.

−fs limit_size

Set the file size limit.

−ss position

Seek to given time position in seconds. "hh:mm:ss[.xxx]" syntax is also supported.

−itsoffset offset

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.

−timestamp time

Set the timestamp.

−metadata key=value

Set a metadata key/value pair.

For example, for setting the title in the output file:

        ffmpeg −i in.avi −metadata title="my title" out.flv

−v number

Set the logging verbosity level.

−target type

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

−dframes number

Set the number of data frames to record.

−scodec codec

Force subtitle codec (’copy’ to copy stream).

−newsubtitle

Add a new subtitle stream to the current output stream.

−slang code

Set the ISO 639 language code (3 letters) of the current subtitle stream.

Video Options

−b bitrate

Set the video bitrate in bit/s (default = 200 kb/s).

−vframes number

Set the number of video frames to record.

−r fps

Set frame rate (Hz value, fraction or abbreviation), (default = 25).

−s size

Set frame size. The format is wxh (ffserver default = 160x128, ffmpeg default = same as source). The following abbreviations are recognized:

sqcif

128x96

qcif

176x144

cif

352x288

4cif

704x576

16cif

1408x1152

qqvga

160x120

qvga

320x240

vga

640x480

svga

800x600

xga

1024x768

uxga

1600x1200

qxga

2048x1536

sxga

1280x1024

qsxga

2560x2048

hsxga

5120x4096

wvga

852x480

wxga

1366x768

wsxga

1600x1024

wuxga

1920x1200

woxga

2560x1600

wqsxga

3200x2048

wquxga

3840x2400

whsxga

6400x4096

whuxga

7680x4800

cga

320x200

ega

640x350

hd480

852x480

hd720

1280x720

hd1080

1920x1080

−aspect aspect

Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).

−croptop size

Set top crop band size (in pixels).

−cropbottom size

Set bottom crop band size (in pixels).

−cropleft size

Set left crop band size (in pixels).

−cropright size

Set right crop band size (in pixels).

−padtop size

Set top pad band size (in pixels).

−padbottom size

Set bottom pad band size (in pixels).

−padleft size

Set left pad band size (in pixels).

−padright size

Set right pad band size (in pixels).

−padcolor hex_color

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)).

−vn

Disable video recording.

−bt tolerance

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.

−maxrate bitrate

Set max video bitrate (in bit/s). Requires −bufsize to be set.

−minrate bitrate

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.

−bufsize size

Set video buffer verifier buffer size (in bits).

−vcodec codec

Force video codec to codec. Use the "copy" special value to tell that the raw codec data must be copied as is.

−sameq

Use same video quality as source (implies VBR ).

−pass n

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

−passlogfile prefix

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.

−newvideo

Add a new video stream to the current output stream.

−vlang code

Set the ISO 639 language code (3 letters) of the current video stream.

Advanced Video Options

−pix_fmt format

Set pixel format. Use ’list’ as parameter to show all the supported pixel formats.

−sws_flags flags

Set SwScaler flags.

−g gop_size

Set the group of pictures size.

−intra

Use only intra frames.

−vdt n

Discard threshold.

−qscale q

Use fixed video quantizer scale ( VBR ).

−qmin q

minimum video quantizer scale ( VBR )

−qmax q

maximum video quantizer scale ( VBR )

−qdiff q

maximum difference between the quantizer scales ( VBR )

−qblur blur

video quantizer scale blur ( VBR ) (range 0.0 − 1.0)

−qcomp compression

video quantizer scale compression ( VBR ) (default 0.5). Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0−1.0

−lmin lambda

minimum video lagrange factor ( VBR )

−lmax lambda

max video lagrange factor ( VBR )

−mblmin lambda

minimum macroblock quantizer scale ( VBR )

−mblmax lambda

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

−rc_init_cplx complexity

initial complexity for single pass encoding

−b_qfactor factor

qp factor between P− and B−frames

−i_qfactor factor

qp factor between P− and I−frames

−b_qoffset offset

qp offset between P− and B−frames

−i_qoffset offset

qp offset between P− and I−frames

−rc_eq equation

Set rate control equation (default = "tex^qComp").

−rc_override override

rate control override for specific intervals

−me_method method

Set motion estimation method to method. Available methods are (from lowest to best quality):

zero

Try just the (0, 0) vector.

phods

log

x1

hex

umh

epzs

(default method)

full

exhaustive search (slow and marginally better than epzs)

−dct_algo algo

Set DCT algorithm to algo. Available values are:

0

FF_DCT_AUTO (default)

1

FF_DCT_FASTINT

2

FF_DCT_INT

3

FF_DCT_MMX

4

FF_DCT_MLIB

5

FF_DCT_ALTIVEC

−idct_algo algo

Set IDCT algorithm to algo. Available values are:

0

FF_IDCT_AUTO (default)

1

FF_IDCT_INT

2

FF_IDCT_SIMPLE

3

FF_IDCT_SIMPLEMMX

4

FF_IDCT_LIBMPEG2MMX

5

FF_IDCT_PS2

6

FF_IDCT_MLIB

7

FF_IDCT_ARM

8

FF_IDCT_ALTIVEC

9

FF_IDCT_SH4

10

FF_IDCT_SIMPLEARM

−er n

Set error resilience to n.

1

FF_ER_CAREFUL (default)

2

FF_ER_COMPLIANT

3

FF_ER_AGGRESSIVE

4

FF_ER_VERY_AGGRESSIVE

−ec bit_mask

Set error concealment to bit_mask. bit_mask is a bit mask of the following values:

1

FF_EC_GUESS_MVS (default = enabled)

2

FF_EC_DEBLOCK (default = enabled)

−bf frames

Use ’frames’ B−frames (supported for MPEG−1 , MPEG−2 and MPEG−4 ).

−mbd mode

macroblock decision

0

FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).

1

FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.

2

FF_MB_DECISION_RD: rate distortion

−4mv

Use four motion vector by macroblock ( MPEG−4 only).

−part

Use data partitioning ( MPEG−4 only).

−bug param

Work around encoder bugs that are not auto-detected.

−strict strictness

How strictly to follow the standards.

−aic

Enable Advanced intra coding (h263+).

−umv

Enable Unlimited Motion Vector (h263+)

−deinterlace

Deinterlace pictures.

−ilme

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.

−psnr

Calculate PSNR of compressed frames.

−vstats

Dump video coding statistics to vstats_HHMMSS.log.

−vstats_file file

Dump video coding statistics to file.

−top n

top=1/bottom=0/auto=−1 field first

−dc precision

Intra_dc_precision.

−vtag fourcc/tag

Force video tag/fourcc.

−qphist

Show QP histogram.

−vbsf bitstream_filter

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

Audio Options

−aframes number

Set the number of audio frames to record.

−ar freq

Set the audio sampling frequency (default = 44100 Hz).

−ab bitrate

Set the audio bitrate in bit/s (default = 64k).

−aq q

Set the audio quality (codec-specific, VBR ).

−ac channels

Set the number of audio channels (default = 1).

−an

Disable audio recording.

−acodec codec

Force audio codec to codec. Use the "copy" special value to specify that the raw codec data must be copied as is.

−newaudio

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

−alang code

Set the ISO 639 language code (3 letters) of the current audio stream.

Advanced Audio options:

−atag fourcc/tag

Force audio tag/fourcc.

−absf bitstream_filter

Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".

Subtitle options:

−scodec codec

Force subtitle codec (’copy’ to copy stream).

−newsubtitle

Add a new subtitle stream to the current output stream.

−slang code

Set the ISO 639 language code (3 letters) of the current subtitle stream.

−sn

Disable subtitle recording.

−sbsf bitstream_filter

Bitstream filters available are "mov2textsub", "text2movsub".

        ffmpeg −i file.mov −an −vn −sbsf mov2textsub −scodec copy −f rawvideo sub.txt

Audio/Video grab options

−vc channel

Set video grab channel ( DV1394 only).

−tvstd standard

Set television standard ( NTSC , PAL ( SECAM )).

−isync

Synchronize read on input.

Advanced options

−map input_stream_id[:sync_stream_id]

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.

−map_meta_data outfile:infile

Set meta data information of outfile from infile.

−debug

Print specific debug info.

−benchmark

Show benchmarking information at the end of an encode. Shows CPU time used and maximum memory consumption. Maximum memory consumption is not supported on all systems, it will usually display as 0 if not supported.

−dump

Dump each input packet.

−hex

When dumping packets, also dump the payload.

−bitexact

Only use bit exact algorithms (for codec testing).

−ps size

Set RTP payload size in bytes.

−re

Read input at native frame rate. Mainly used to simulate a grab device.

−loop_input

Loop over the input stream. Currently it works only for image streams. This option is used for automatic FFserver testing.

−loop_output number_of_times

Repeatedly loop output for formats that support looping such as animated GIF (0 will loop the output infinitely).

−threads count

Thread count.

−vsync parameter

Video sync method. 0 Each frame is passed with its timestamp from the demuxer to the muxer 1 Frames will be duplicated and dropped to achieve exactly the requested constant framerate. 2 Frames are passed through with their timestamp or dropped so as to prevent 2 frames from having the same timestamp −1 Chooses between 1 and 2 depending on muxer capabilities. This is the default method.

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.

−async samples_per_second

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.

−copyts

Copy timestamps from input to output.

−shortest

Finish encoding when the shortest input stream ends.

−dts_delta_threshold

Timestamp discontinuity delta threshold.

−muxdelay seconds

Set the maximum demux-decode delay.

−muxpreload seconds

Set the initial demux-decode delay.

Preset files

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", "spre", and "fpre" options. The "fpre" option takes the filename of the preset instead of a preset name as input and can be used for any kind of codec. For 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 "vpre", "apre", and "spre" 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 $FFMPEG_DATADIR (if set), and $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.

@anchor{FFmpeg formula evaluator}

FFmpeg formula evaluator

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:

sinh(x)

cosh(x)

tanh(x)

sin(x)

cos(x)

tan(x)

atan(x)

asin(x)

acos(x)

exp(x)

log(x)

abs(x)

squish(x)

gauss(x)

mod(x, y)

max(x, y)

min(x, y)

eq(x, y)

gte(x, y)

gt(x, y)

lte(x, y)

lt(x, y)

bits2qp(bits)

qp2bits(qp)

The following constants are available:

PI

E

iTex

pTex

tex

mv

fCode

iCount

mcVar

var

isI

isP

isB

avgQP

qComp

avgIITex

avgPITex

avgPPTex

avgBPTex

avgTex

Video and Audio grabbing

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.

X11 grabbing

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.

Video and Audio file format conversion

* 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, or create a video from many images:

For extracting 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.

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.

For creating a video from many images:

        ffmpeg −f image2 −i foo−%03d.jpeg −r 12 −s WxH foo.avi

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.

* 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.

ffserver(1), ffplay(1) and the HTML documentation of ffmpeg.

Fabrice Bellard