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							- \input texinfo @c -*- texinfo -*-
 - 
 - @settitle FFmpeg Documentation
 - @titlepage
 - @sp 7
 - @center @titlefont{FFmpeg Documentation}
 - @sp 3
 - @end titlepage
 - 
 - @chapter Synopsis
 - 
 - The generic syntax is:
 - 
 - @example
 - @c man begin SYNOPSIS
 - ffmpeg [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
 - @c man end
 - @end example
 - 
 - @chapter Description
 - @c man begin DESCRIPTION
 - 
 - 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.
 - 
 - 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:
 - @example
 - ffmpeg -i input.avi -b 64k output.avi
 - @end example
 - 
 - * To force the frame rate of the output file to 24 fps:
 - @example
 - ffmpeg -i input.avi -r 24 output.avi
 - @end example
 - 
 - * 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:
 - @example
 - ffmpeg -r 1 -i input.m2v -r 24 output.avi
 - @end example
 - 
 - 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.
 - 
 - @c man end DESCRIPTION
 - 
 - @chapter Options
 - @c man begin OPTIONS
 - 
 - @include fftools-common-opts.texi
 - 
 - @section Main options
 - 
 - @table @option
 - 
 - @item -f @var{fmt}
 - Force format.
 - 
 - @item -i @var{filename}
 - input file name
 - 
 - @item -y
 - Overwrite output files.
 - 
 - @item -t @var{duration}
 - Restrict the transcoded/captured video sequence
 - to the duration specified in seconds.
 - @code{hh:mm:ss[.xxx]} syntax is also supported.
 - 
 - @item -fs @var{limit_size}
 - Set the file size limit.
 - 
 - @item -ss @var{position}
 - Seek to given time position in seconds.
 - @code{hh:mm:ss[.xxx]} syntax is also supported.
 - 
 - @item -itsoffset @var{offset}
 - Set the input time offset in seconds.
 - @code{[-]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.
 - 
 - @item -timestamp @var{time}
 - Set the recording timestamp in the container.
 - The syntax for @var{time} is:
 - @example
 - now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
 - @end example
 - If the value is "now" it takes the current time.
 - Time is local time unless 'Z' or 'z' is appended, in which case it is
 - interpreted as UTC.
 - If the year-month-day part is not specified it takes the current
 - year-month-day.
 - 
 - @item -metadata @var{key}=@var{value}
 - Set a metadata key/value pair.
 - 
 - For example, for setting the title in the output file:
 - @example
 - ffmpeg -i in.avi -metadata title="my title" out.flv
 - @end example
 - 
 - @item -v @var{number}
 - Set the logging verbosity level.
 - 
 - @item -target @var{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:
 - 
 - @example
 - ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
 - @end example
 - 
 - Nevertheless you can specify additional options as long as you know
 - they do not conflict with the standard, as in:
 - 
 - @example
 - ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
 - @end example
 - 
 - @item -dframes @var{number}
 - Set the number of data frames to record.
 - 
 - @item -scodec @var{codec}
 - Force subtitle codec ('copy' to copy stream).
 - 
 - @item -newsubtitle
 - Add a new subtitle stream to the current output stream.
 - 
 - @item -slang @var{code}
 - Set the ISO 639 language code (3 letters) of the current subtitle stream.
 - 
 - @end table
 - 
 - @section Video Options
 - 
 - @table @option
 - @item -b @var{bitrate}
 - Set the video bitrate in bit/s (default = 200 kb/s).
 - @item -vframes @var{number}
 - Set the number of video frames to record.
 - @item -r @var{fps}
 - Set frame rate (Hz value, fraction or abbreviation), (default = 25).
 - @item -s @var{size}
 - Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
 - The following abbreviations are recognized:
 - @table @samp
 - @item sqcif
 - 128x96
 - @item qcif
 - 176x144
 - @item cif
 - 352x288
 - @item 4cif
 - 704x576
 - @item 16cif
 - 1408x1152
 - @item qqvga
 - 160x120
 - @item qvga
 - 320x240
 - @item vga
 - 640x480
 - @item svga
 - 800x600
 - @item xga
 - 1024x768
 - @item uxga
 - 1600x1200
 - @item qxga
 - 2048x1536
 - @item sxga
 - 1280x1024
 - @item qsxga
 - 2560x2048
 - @item hsxga
 - 5120x4096
 - @item wvga
 - 852x480
 - @item wxga
 - 1366x768
 - @item wsxga
 - 1600x1024
 - @item wuxga
 - 1920x1200
 - @item woxga
 - 2560x1600
 - @item wqsxga
 - 3200x2048
 - @item wquxga
 - 3840x2400
 - @item whsxga
 - 6400x4096
 - @item whuxga
 - 7680x4800
 - @item cga
 - 320x200
 - @item ega
 - 640x350
 - @item hd480
 - 852x480
 - @item hd720
 - 1280x720
 - @item hd1080
 - 1920x1080
 - @end table
 - 
 - @item -aspect @var{aspect}
 - Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).
 - @item -croptop @var{size} (deprecated - use -vf crop=x:y:width:height instead)
 - Set top crop band size (in pixels).
 - @item -cropbottom @var{size} (deprecated - use -vf crop=x:y:width:height instead)
 - Set bottom crop band size (in pixels).
 - @item -cropleft @var{size} (deprecated - use -vf crop=x:y:width:height instead)
 - Set left crop band size (in pixels).
 - @item -cropright @var{size} (deprecated - use -vf crop=x:y:width:height instead)
 - Set right crop band size (in pixels).
 - @item -padtop @var{size}
 - @item -padbottom @var{size}
 - @item -padleft @var{size}
 - @item -padright @var{size}
 - @item -padcolor @var{hex_color}
 - All the pad options have been removed. Use -vf
 - pad=width:height:x:y:color instead.
 - @item -vn
 - Disable video recording.
 - @item -bt @var{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.
 - @item -maxrate @var{bitrate}
 - Set max video bitrate (in bit/s).
 - Requires -bufsize to be set.
 - @item -minrate @var{bitrate}
 - Set min video bitrate (in bit/s).
 - Most useful in setting up a CBR encode:
 - @example
 - ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
 - @end example
 - It is of little use elsewise.
 - @item -bufsize @var{size}
 - Set video buffer verifier buffer size (in bits).
 - @item -vcodec @var{codec}
 - Force video codec to @var{codec}. Use the @code{copy} special value to
 - tell that the raw codec data must be copied as is.
 - @item -sameq
 - Use same video quality as source (implies VBR).
 - 
 - @item -pass @var{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:
 - @example
 - 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
 - @end example
 - 
 - @item -passlogfile @var{prefix}
 - Set two-pass log file name prefix to @var{prefix}, the default file name
 - prefix is ``ffmpeg2pass''. The complete file name will be
 - @file{PREFIX-N.log}, where N is a number specific to the output
 - stream.
 - 
 - @item -newvideo
 - Add a new video stream to the current output stream.
 - 
 - @item -vlang @var{code}
 - Set the ISO 639 language code (3 letters) of the current video stream.
 - 
 - @item -vf @var{filter_graph}
 - @var{filter_graph} is a description of the filter graph to apply to
 - the input video.
 - Use the option "-filters" to show all the available filters (including
 - also sources and sinks).
 - 
 - @end table
 - 
 - @section Advanced Video Options
 - 
 - @table @option
 - @item -pix_fmt @var{format}
 - Set pixel format. Use 'list' as parameter to show all the supported
 - pixel formats.
 - @item -sws_flags @var{flags}
 - Set SwScaler flags.
 - @item -g @var{gop_size}
 - Set the group of pictures size.
 - @item -intra
 - Use only intra frames.
 - @item -vdt @var{n}
 - Discard threshold.
 - @item -qscale @var{q}
 - Use fixed video quantizer scale (VBR).
 - @item -qmin @var{q}
 - minimum video quantizer scale (VBR)
 - @item -qmax @var{q}
 - maximum video quantizer scale (VBR)
 - @item -qdiff @var{q}
 - maximum difference between the quantizer scales (VBR)
 - @item -qblur @var{blur}
 - video quantizer scale blur (VBR) (range 0.0 - 1.0)
 - @item -qcomp @var{compression}
 - video quantizer scale compression (VBR) (default 0.5).
 - Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
 - 
 - @item -lmin @var{lambda}
 - minimum video lagrange factor (VBR)
 - @item -lmax @var{lambda}
 - max video lagrange factor (VBR)
 - @item -mblmin @var{lambda}
 - minimum macroblock quantizer scale (VBR)
 - @item -mblmax @var{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:
 - @example
 - ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
 - @end example
 - 
 - @item -rc_init_cplx @var{complexity}
 - initial complexity for single pass encoding
 - @item -b_qfactor @var{factor}
 - qp factor between P- and B-frames
 - @item -i_qfactor @var{factor}
 - qp factor between P- and I-frames
 - @item -b_qoffset @var{offset}
 - qp offset between P- and B-frames
 - @item -i_qoffset @var{offset}
 - qp offset between P- and I-frames
 - @item -rc_eq @var{equation}
 - Set rate control equation (@pxref{FFmpeg formula
 - evaluator}) (default = @code{tex^qComp}).
 - @item -rc_override @var{override}
 - rate control override for specific intervals
 - @item -me_method @var{method}
 - Set motion estimation method to @var{method}.
 - Available methods are (from lowest to best quality):
 - @table @samp
 - @item zero
 - Try just the (0, 0) vector.
 - @item phods
 - @item log
 - @item x1
 - @item hex
 - @item umh
 - @item epzs
 - (default method)
 - @item full
 - exhaustive search (slow and marginally better than epzs)
 - @end table
 - 
 - @item -dct_algo @var{algo}
 - Set DCT algorithm to @var{algo}. Available values are:
 - @table @samp
 - @item 0
 - FF_DCT_AUTO (default)
 - @item 1
 - FF_DCT_FASTINT
 - @item 2
 - FF_DCT_INT
 - @item 3
 - FF_DCT_MMX
 - @item 4
 - FF_DCT_MLIB
 - @item 5
 - FF_DCT_ALTIVEC
 - @end table
 - 
 - @item -idct_algo @var{algo}
 - Set IDCT algorithm to @var{algo}. Available values are:
 - @table @samp
 - @item 0
 - FF_IDCT_AUTO (default)
 - @item 1
 - FF_IDCT_INT
 - @item 2
 - FF_IDCT_SIMPLE
 - @item 3
 - FF_IDCT_SIMPLEMMX
 - @item 4
 - FF_IDCT_LIBMPEG2MMX
 - @item 5
 - FF_IDCT_PS2
 - @item 6
 - FF_IDCT_MLIB
 - @item 7
 - FF_IDCT_ARM
 - @item 8
 - FF_IDCT_ALTIVEC
 - @item 9
 - FF_IDCT_SH4
 - @item 10
 - FF_IDCT_SIMPLEARM
 - @end table
 - 
 - @item -er @var{n}
 - Set error resilience to @var{n}.
 - @table @samp
 - @item 1
 - FF_ER_CAREFUL (default)
 - @item 2
 - FF_ER_COMPLIANT
 - @item 3
 - FF_ER_AGGRESSIVE
 - @item 4
 - FF_ER_VERY_AGGRESSIVE
 - @end table
 - 
 - @item -ec @var{bit_mask}
 - Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
 - the following values:
 - @table @samp
 - @item 1
 - FF_EC_GUESS_MVS (default = enabled)
 - @item 2
 - FF_EC_DEBLOCK (default = enabled)
 - @end table
 - 
 - @item -bf @var{frames}
 - Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
 - @item -mbd @var{mode}
 - macroblock decision
 - @table @samp
 - @item 0
 - FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in FFmpeg).
 - @item 1
 - FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
 - @item 2
 - FF_MB_DECISION_RD: rate distortion
 - @end table
 - 
 - @item -4mv
 - Use four motion vector by macroblock (MPEG-4 only).
 - @item -part
 - Use data partitioning (MPEG-4 only).
 - @item -bug @var{param}
 - Work around encoder bugs that are not auto-detected.
 - @item -strict @var{strictness}
 - How strictly to follow the standards.
 - @item -aic
 - Enable Advanced intra coding (h263+).
 - @item -umv
 - Enable Unlimited Motion Vector (h263+)
 - 
 - @item -deinterlace
 - Deinterlace pictures.
 - @item -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
 - @option{-deinterlace}, but deinterlacing introduces losses.
 - @item -psnr
 - Calculate PSNR of compressed frames.
 - @item -vstats
 - Dump video coding statistics to @file{vstats_HHMMSS.log}.
 - @item -vstats_file @var{file}
 - Dump video coding statistics to @var{file}.
 - @item -top @var{n}
 - top=1/bottom=0/auto=-1 field first
 - @item -dc @var{precision}
 - Intra_dc_precision.
 - @item -vtag @var{fourcc/tag}
 - Force video tag/fourcc.
 - @item -qphist
 - Show QP histogram.
 - @item -vbsf @var{bitstream_filter}
 - Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump".
 - @example
 - ffmpeg -i h264.mp4 -vcodec copy -vbsf h264_mp4toannexb -an out.h264
 - @end example
 - @end table
 - 
 - @section Audio Options
 - 
 - @table @option
 - @item -aframes @var{number}
 - Set the number of audio frames to record.
 - @item -ar @var{freq}
 - Set the audio sampling frequency (default = 44100 Hz).
 - @item -ab @var{bitrate}
 - Set the audio bitrate in bit/s (default = 64k).
 - @item -aq @var{q}
 - Set the audio quality (codec-specific, VBR).
 - @item -ac @var{channels}
 - Set the number of audio channels (default = 1).
 - @item -an
 - Disable audio recording.
 - @item -acodec @var{codec}
 - Force audio codec to @var{codec}. Use the @code{copy} special value to
 - specify that the raw codec data must be copied as is.
 - @item -newaudio
 - Add a new audio track to the output file. If you want to specify parameters,
 - do so before @code{-newaudio} (@code{-acodec}, @code{-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 @code{-map} as usual.
 - 
 - Example:
 - @example
 - ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
 - @end example
 - @item -alang @var{code}
 - Set the ISO 639 language code (3 letters) of the current audio stream.
 - @end table
 - 
 - @section Advanced Audio options:
 - 
 - @table @option
 - @item -atag @var{fourcc/tag}
 - Force audio tag/fourcc.
 - @item -absf @var{bitstream_filter}
 - Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
 - @end table
 - 
 - @section Subtitle options:
 - 
 - @table @option
 - @item -scodec @var{codec}
 - Force subtitle codec ('copy' to copy stream).
 - @item -newsubtitle
 - Add a new subtitle stream to the current output stream.
 - @item -slang @var{code}
 - Set the ISO 639 language code (3 letters) of the current subtitle stream.
 - @item -sn
 - Disable subtitle recording.
 - @item -sbsf @var{bitstream_filter}
 - Bitstream filters available are "mov2textsub", "text2movsub".
 - @example
 - ffmpeg -i file.mov -an -vn -sbsf mov2textsub -scodec copy -f rawvideo sub.txt
 - @end example
 - @end table
 - 
 - @section Audio/Video grab options
 - 
 - @table @option
 - @item -vc @var{channel}
 - Set video grab channel (DV1394 only).
 - @item -tvstd @var{standard}
 - Set television standard (NTSC, PAL (SECAM)).
 - @item -isync
 - Synchronize read on input.
 - @end table
 - 
 - @section Advanced options
 - 
 - @table @option
 - @item -map @var{input_stream_id}[:@var{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.
 - @var{sync_stream_id} if specified sets the input stream to sync
 - against.
 - @item -map_meta_data @var{outfile}:@var{infile}
 - Set meta data information of @var{outfile} from @var{infile}.
 - @item -debug
 - Print specific debug info.
 - @item -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.
 - @item -dump
 - Dump each input packet.
 - @item -hex
 - When dumping packets, also dump the payload.
 - @item -bitexact
 - Only use bit exact algorithms (for codec testing).
 - @item -ps @var{size}
 - Set RTP payload size in bytes.
 - @item -re
 - Read input at native frame rate. Mainly used to simulate a grab device.
 - @item -loop_input
 - Loop over the input stream. Currently it works only for image
 - streams. This option is used for automatic FFserver testing.
 - @item -loop_output @var{number_of_times}
 - Repeatedly loop output for formats that support looping such as animated GIF
 - (0 will loop the output infinitely).
 - @item -threads @var{count}
 - Thread count.
 - @item -vsync @var{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.
 - @item -async @var{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.
 - @item -copyts
 - Copy timestamps from input to output.
 - @item -shortest
 - Finish encoding when the shortest input stream ends.
 - @item -dts_delta_threshold
 - Timestamp discontinuity delta threshold.
 - @item -muxdelay @var{seconds}
 - Set the maximum demux-decode delay.
 - @item -muxpreload @var{seconds}
 - Set the initial demux-decode delay.
 - @item -streamid @var{output-stream-index}:@var{new-value}
 - Assign a new value to a stream's stream-id field in the next output file.
 - All stream-id fields are reset to default for each output file.
 - 
 - For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
 - an output mpegts file:
 - @example
 - ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
 - @end example
 - @end table
 - 
 - @section Preset files
 - 
 - A preset file contains a sequence of @var{option}=@var{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 @file{ffpresets} directory in the FFmpeg source tree for examples.
 - 
 - Preset files are specified with the @code{vpre}, @code{apre},
 - @code{spre}, and @code{fpre} options. The @code{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 @code{vpre}, @code{apre}, and
 - @code{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 @code{vpre}, @code{apre}, and @code{spre}
 - preset options identifies the preset file to use according to the
 - following rules:
 - 
 - First ffmpeg searches for a file named @var{arg}.ffpreset in the
 - directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
 - the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
 - in that order. For example, if the argument is @code{libx264-max}, it will
 - search for the file @file{libx264-max.ffpreset}.
 - 
 - If no such file is found, then ffmpeg will search for a file named
 - @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
 - directories, where @var{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 @code{-vcodec libx264} and use @code{-vpre max},
 - then it will search for the file @file{libx264-max.ffpreset}.
 - 
 - @anchor{FFmpeg formula evaluator}
 - @section FFmpeg formula evaluator
 - 
 - When evaluating a rate control string, FFmpeg uses an internal formula
 - evaluator.
 - 
 - The following binary operators are available: @code{+}, @code{-},
 - @code{*}, @code{/}, @code{^}.
 - 
 - The following unary operators are available: @code{+}, @code{-},
 - @code{(...)}.
 - 
 - The following statements are available: @code{ld}, @code{st},
 - @code{while}.
 - 
 - The following functions are available:
 - @table @var
 - @item sinh(x)
 - @item cosh(x)
 - @item tanh(x)
 - @item sin(x)
 - @item cos(x)
 - @item tan(x)
 - @item atan(x)
 - @item asin(x)
 - @item acos(x)
 - @item exp(x)
 - @item log(x)
 - @item abs(x)
 - @item squish(x)
 - @item gauss(x)
 - @item mod(x, y)
 - @item max(x, y)
 - @item min(x, y)
 - @item eq(x, y)
 - @item gte(x, y)
 - @item gt(x, y)
 - @item lte(x, y)
 - @item lt(x, y)
 - @item bits2qp(bits)
 - @item qp2bits(qp)
 - @end table
 - 
 - The following constants are available:
 - @table @var
 - @item PI
 - @item E
 - @item iTex
 - @item pTex
 - @item tex
 - @item mv
 - @item fCode
 - @item iCount
 - @item mcVar
 - @item var
 - @item isI
 - @item isP
 - @item isB
 - @item avgQP
 - @item qComp
 - @item avgIITex
 - @item avgPITex
 - @item avgPPTex
 - @item avgBPTex
 - @item avgTex
 - @end table
 - 
 - @c man end
 - 
 - @section Protocols
 - 
 - The file name can be @file{-} to read from standard input or to write
 - to standard output.
 - 
 - FFmpeg also handles many protocols specified with an URL syntax.
 - 
 - Use 'ffmpeg -protocols' to see a list of the supported protocols.
 - 
 - The protocol @code{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 :-)
 - 
 - @chapter Tips
 - @c man begin TIPS
 - 
 - @itemize
 - @item
 - For streaming at very low bitrate application, use a low frame rate
 - and a small GOP size. This is especially true for RealVideo where
 - the Linux player does not seem to be very fast, so it can miss
 - frames. An example is:
 - 
 - @example
 - ffmpeg -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
 - @end example
 - 
 - @item
 - The parameter 'q' which is displayed while encoding is the current
 - quantizer. The value 1 indicates that a very good quality could
 - be achieved. The value 31 indicates the worst quality. If q=31 appears
 - too often, it means that the encoder cannot compress enough to meet
 - your bitrate. You must either increase the bitrate, decrease the
 - frame rate or decrease the frame size.
 - 
 - @item
 - If your computer is not fast enough, you can speed up the
 - compression at the expense of the compression ratio. You can use
 - '-me zero' to speed up motion estimation, and '-intra' to disable
 - motion estimation completely (you have only I-frames, which means it
 - is about as good as JPEG compression).
 - 
 - @item
 - To have very low audio bitrates, reduce the sampling frequency
 - (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
 - 
 - @item
 - To have a constant quality (but a variable bitrate), use the option
 - '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
 - quality).
 - 
 - @item
 - When converting video files, you can use the '-sameq' option which
 - uses the same quality factor in the encoder as in the decoder.
 - It allows almost lossless encoding.
 - 
 - @end itemize
 - @c man end TIPS
 - 
 - @chapter Examples
 - @c man begin EXAMPLES
 - 
 - @section Video and Audio grabbing
 - 
 - FFmpeg can grab video and audio from devices given that you specify the input
 - format and device.
 - 
 - @example
 - ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
 - @end example
 - 
 - Note that you must activate the right video source and channel before
 - launching FFmpeg with any TV viewer such as xawtv
 - (@url{http://linux.bytesex.org/xawtv/}) by Gerd Knorr. You also
 - have to set the audio recording levels correctly with a
 - standard mixer.
 - 
 - @section X11 grabbing
 - 
 - FFmpeg can grab the X11 display.
 - 
 - @example
 - ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
 - @end example
 - 
 - 0.0 is display.screen number of your X11 server, same as
 - the DISPLAY environment variable.
 - 
 - @example
 - ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
 - @end example
 - 
 - 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.
 - 
 - @section 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:
 - 
 - @example
 - ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
 - @end example
 - 
 - It will use the files:
 - @example
 - /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
 - /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
 - @end example
 - 
 - 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 @option{-s} option
 - if FFmpeg cannot guess it.
 - 
 - * You can input from a raw YUV420P file:
 - 
 - @example
 - ffmpeg -i /tmp/test.yuv /tmp/out.avi
 - @end example
 - 
 - 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:
 - 
 - @example
 - ffmpeg -i mydivx.avi hugefile.yuv
 - @end example
 - 
 - * You can set several input files and output files:
 - 
 - @example
 - ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
 - @end example
 - 
 - 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:
 - 
 - @example
 - ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
 - @end example
 - 
 - 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:
 - 
 - @example
 - ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
 - @end example
 - 
 - 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:
 - 
 - @example
 - ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
 - @end example
 - 
 - 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 @code{--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 @code{ffmpeg -formats}.
 - 
 - * You can extract images from a video, or create a video from many images:
 - 
 - For extracting images from a video:
 - @example
 - ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
 - @end example
 - 
 - This will extract one video frame per second from the video and will
 - output them in files named @file{foo-001.jpeg}, @file{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:
 - @example
 - ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
 - @end example
 - 
 - The syntax @code{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:
 - 
 - @example
 - ffmpeg -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio
 - @end example
 - 
 - In addition to the first video and audio streams, the resulting
 - output file @file{test12.avi} will contain the second video
 - and the second audio stream found in the input streams list.
 - 
 - The @code{-newvideo}, @code{-newaudio} and @code{-newsubtitle}
 - options have to be specified immediately after the name of the output
 - file to which you want to add them.
 - @c man end EXAMPLES
 - 
 - @include indevs.texi
 - @include outdevs.texi
 - @include filters.texi
 - 
 - @ignore
 - 
 - @setfilename ffmpeg
 - @settitle FFmpeg video converter
 - 
 - @c man begin SEEALSO
 - ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
 - @c man end
 - 
 - @c man begin AUTHORS
 - The FFmpeg developers
 - @c man end
 - 
 - @end ignore
 - 
 - @bye
 
 
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