Ffmpeg 옵션

Syntax

The generic syntax is:

ffmpeg [[infile options][`-i' infile]]... {[outfile options] outfile}...

If no input file is given, audio/video grabbing is done.

As a general rule, options are applied to the next specified file. For example, if you give the `-b 64' option, it sets the video bitrate of the next file. 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.

Main options

`-L'

Show license.

`-h'

Show help.

`-formats'

Show available formats, codecs, protocols, ...

`-f fmt'

Force format.

`-i filename'

input filename

`-y'

Overwrite output files.

`-t duration'

Set the recording time in seconds. hh:mm:ss[.xxx] syntax is also supported.

`-ss position'

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

`-title string'

Set the title.

`-author string'

Set the author.

`-copyright string'

Set the copyright.

`-comment string'

Set the comment.

`-target type'

Specify target file type ("vcd", "svcd", "dvd", "dv", "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

`-hq'

Activate high quality settings.

`-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.

Video Options

`-b bitrate'

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

`-r fps'

Set frame rate (default = 25).

`-s size'

Set frame size. The format is `wxh' (default = 160x128). The following abbreviations are recognized:

   `sqcif'
       128x96 
   `qcif'
       176x144 
   `cif'
       352x288 
   `4cif'
       704x576 

`-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 kbit/s). 

`-maxrate bitrate'

   Set max video bitrate tolerance (in kbit/s). 

`-minrate bitrate'

   Set min video bitrate tolerance (in kbit/s). 

`-bufsize size'

   Set rate control buffer size (in kbit). 

`-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 useful to do two pass encoding. The statistics of the video are recorded in the first pass and the video is generated at the exact requested bitrate in the second pass. 

`-passlogfile file'

   Set two pass logfile name to file. 

Advanced Video Options

`-g gop_size'

   Set the group of pictures size. 

`-intra'

   Use only intra frames. 

`-qscale q'

   Use fixed video quantiser scale (VBR). 

`-qmin q'

   minimum video quantiser scale (VBR) 

`-qmax q'

   maximum video quantiser scale (VBR) 

`-qdiff q'

   maximum difference between the quantiser scales (VBR) 

`-qblur blur'

   video quantiser scale blur (VBR) 

`-qcomp compression'

   video quantiser scale compression (VBR) 

`-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 (see section 3.8 FFmpeg formula evaluator) (default = tex^qComp). 

`-rc_override override'

   rate control override for specific intervals 

`-me 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'
   `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. 

`-interlace'

   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'. 

`-vhook module'

   Insert video processing module. module contains the module name and its parameters separated by spaces. 

Audio Options

`-ar freq'

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

`-ab bitrate'

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

`-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. 

Audio/Video grab options

`-vd device'

   sEt video grab device (e.g. `/dev/video0'). 

`-vc channel'

   Set video grab channel (DV1394 only). 

`-tvstd standard'

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

`-dv1394'

   Set DV1394 grab. 

`-ad device'

   Set audio device (e.g. `/dev/dsp'). 

Advanced options

`-map file:stream'

   Set input stream mapping. 

`-debug'

   Print specific debug info. 

`-benchmark'

   Add timings for benchmarking. 

`-hex'

   Dump each input packet. 

`-bitexact'

   Only use bit exact algorithms (for codec testing). 

`-ps size'

   Set packet size in bits. 

`-re'

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

`-loop'

   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). 

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 functions are available:

sinh(x) cosh(x) tanh(x) sin(x) cos(x) tan(x) exp(x) log(x) squish(x) gauss(x) abs(x) max(x, y) min(x, y) gt(x, y) lt(x, y) eq(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

Protocols

The filename 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 :-)