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. 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 parameter for the outputs as the one
specified for the inputs.
OPTIONS
"Main options"
show license
show help
show available formats, codecs, protocols, ...
force format
input file name
overwrite output files
set the recording time in seconds. hh:mm:ss[.xxx] syntax is also
supported.
set the title
set the author
set the copyright
set the comment
activate high quality settings
"Video Options"
set the video bitrate in kbit/s (default = 200 kb/s)
set frame rate (default = 25)
set frame size. The format is WxH (default 160x128). The
following abbreviations are recognized:
128x96
176x144
352x288
704x576
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)
disable video recording
set video bitrate tolerance (in kbit/s)
set max video bitrate tolerance (in kbit/s)
set min video bitrate tolerance (in kbit/s)
set ratecontrol buffere size (in kbit)
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 useful to do two pass
encoding. The statistics of the video are recorded in the first pass and
the video at the exact requested bit rate is generated in the second
pass.
select two pass log file name to file.
"Advanced Video Options"
set the group of picture size
use only intra frames
use fixed video quantiser scale (VBR)
min video quantiser scale (VBR)
max video quantiser scale (VBR)
max difference between the quantiser scale (VBR)
video quantiser scale blur (VBR)
video quantiser scale compression (VBR)
initial complexity for 1-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. Default is tex^qComp.
rate control override for specific intervals
set motion estimation method to method. Available methods are
(from lower 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_CAREFULL (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 (only MPEG-4)
macroblock decision
FF_MB_DECISION_SIMPLE: use mb_cmp (cannot change it yet in ffmpeg)
FF_MB_DECISION_BITS: chooses the one which needs the fewest bits
FF_MB_DECISION_RD: rate distoration
use four motion vector by macroblock (only MPEG-4)
use data partitioning (only MPEG-4)
workaround not auto detected encoder bugs
how strictly to follow the standarts
enable Advanced intra coding (h263+)
enable Unlimited Motion Vector (h263+)
deinterlace pictures
calculate PSNR of compressed frames
dump video coding statistics to vstats_HHMMSS.log.
insert video processing module. module contains the module
name and its parameters separated by spaces.
"Audio Options"
set audio bitrate (in kbit/s)
set the audio sampling freq (default = 44100 Hz)
set the audio bitrate in kbit/s (default = 64)
set the number of audio channels (default = 1)
disable audio recording
force audio codec to codec. Use the copy special value to
tell that the raw codec data must be copied as is.
"Audio/Video grab options"
set video grab device (e.g. /dev/video0)
set video grab channel (DV1394 only)
set television standard (NTSC, PAL (SECAM))
set DV1394 grab
set audio device (e.g. /dev/dsp)
"Advanced options"
set input stream mapping
print specific debug info
add timings for benchmarking
dump each input packet
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 ffserver automatic testing.
"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:
The following constants are available:
EXAMPLES
"Video and Audio grabbing"
FFmpeg can use a video4linux compatible video source and any Open Sound
System audio source:
ffmpeg /tmp/out.mpg
Note that you must activate the right video source and channel before
launching ffmpeg. You can use any TV viewer such as xawtv
(<http://bytesex.org/xawtv/>) by Gerd Knorr which I find very
good. You must also set correctly the audio recording levels with a
standard mixer.
"Video and Audio file format conversion"
* ffmpeg can use any supported file format and protocol as input:
Examples:
* You can input from YUV files:
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
The RAW YUV420P is a file containing RAW YUV planar, for each frame first
come the Y plane followed by U and V planes, which are half vertical and
horizontal resolution.
* You can output to a RAW YUV420P file:
ffmpeg -i mydivx.avi -o hugefile.yuv
* You can set several input files and output files:
Convert a.wav to a.mp2 at 64 kbits and b.mp2 at 128 kbits. "-map
file:index" specify which input stream is used for each output
stream, in the order of the definition of output streams.
This is a typical DVD ripper example, input from a VOB file, output
to 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, GOP
size is 300 that means an INTRA frame every 10 seconds for 29.97 fps
input video. Also the audio stream is MP3 encoded so you need LAME
support which is enabled using --enable-mp3lame when
configuring. The mapping is particularly useful for DVD transcoding
to get the desired audio language.
NOTE: to see the supported input formats, use ffmpeg -formats.
