ffmpeg (linux parancs)

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Verziószám: 3.2.14 (Debian 9-ben)
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Az ffmpeg linux parancs manual oldala és súgója. Az ffmpeg egy nagyon gyors video- és audio-konverter, amely élő audio / video forrásból is képes mintavételezni. Segítségével konvertálhatunk egyedi mintavételi frekvenciák között, vagy átméretezhetjük a videókat a kiváló minőségű többfázisú szűrő segítségével.

 

 

Man oldal kimenet

man ffmpeg
FFMPEG(1)                                                                     FFMPEG(1)

NAME
       ffmpeg - ffmpeg video converter

SYNOPSIS
       ffmpeg [global_options] {[input_file_options] -i input_url} ...
       {[output_file_options] output_url} ...

DESCRIPTION
       ffmpeg is a very fast video and audio converter that can also grab from a live
       audio/video source. It can also convert between arbitrary sample rates and
       resize video on the fly with a high quality polyphase filter.

       ffmpeg reads from an arbitrary number of input "files" (which can be regular
       files, pipes, network streams, grabbing devices, etc.), specified by the "-i"
       option, and writes to an arbitrary number of output "files", which are specified
       by a plain output url. Anything found on the command line which cannot be
       interpreted as an option is considered to be an output url.

       Each input or output url can, in principle, contain any number of streams of
       different types (video/audio/subtitle/attachment/data). The allowed number
       and/or types of streams may be limited by the container format. Selecting which
       streams from which inputs will go into which output is either done automatically
       or with the "-map" option (see the Stream selection chapter).

       To refer to input files in options, you must use their indices (0-based). E.g.
       the first input file is 0, the second is 1, etc. Similarly, streams within a
       file are referred to by their indices. E.g. "2:3" refers to the fourth stream in
       the third input file. Also see the Stream specifiers chapter.

       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.  Exceptions from this rule are the global options (e.g. verbosity level),
       which should be specified first.

       Do not mix input and output files -- first specify all input files, then all
       output files. Also do not mix options which belong to different files. All
       options apply ONLY to the next input or output file and are reset between files.

       ·   To set the video bitrate of the output file to 64 kbit/s:

                   ffmpeg -i input.avi -b:v 64k -bufsize 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.

DETAILED DESCRIPTION
       The transcoding process in ffmpeg for each output can be described by the
       following diagram:

                _______              ______________
               |       |            |              |
               | input |  demuxer   | encoded data |   decoder
               | file  | ---------> | packets      | -----+
               |_______|            |______________|      |
                                                          v
                                                      _________
                                                     |         |
                                                     | decoded |
                                                     | frames  |
                                                     |_________|
                ________             ______________       |
               |        |           |              |      |
               | output | <-------- | encoded data | <----+
               | file   |   muxer   | packets      |   encoder
               |________|           |______________|

       ffmpeg calls the libavformat library (containing demuxers) to read input files
       and get packets containing encoded data from them. When there are multiple input
       files, ffmpeg tries to keep them synchronized by tracking lowest timestamp on
       any active input stream.

       Encoded packets are then passed to the decoder (unless streamcopy is selected
       for the stream, see further for a description). The decoder produces
       uncompressed frames (raw video/PCM audio/...) which can be processed further by
       filtering (see next section). After filtering, the frames are passed to the
       encoder, which encodes them and outputs encoded packets. Finally those are
       passed to the muxer, which writes the encoded packets to the output file.

   Filtering
       Before encoding, ffmpeg can process raw audio and video frames using filters
       from the libavfilter library. Several chained filters form a filter graph.
       ffmpeg distinguishes between two types of filtergraphs: simple and complex.

       Simple filtergraphs

       Simple filtergraphs are those that have exactly one input and output, both of
       the same type. In the above diagram they can be represented by simply inserting
       an additional step between decoding and encoding:

                _________                        ______________
               |         |                      |              |
               | decoded |                      | encoded data |
               | frames  |\                   _ | packets      |
               |_________| \                  /||______________|
                            \   __________   /
                 simple     _\||          | /  encoder
                 filtergraph   | filtered |/
                               | frames   |
                               |__________|

       Simple filtergraphs are configured with the per-stream -filter option (with -vf
       and -af aliases for video and audio respectively).  A simple filtergraph for
       video can look for example like this:

                _______        _____________        _______        ________
               |       |      |             |      |       |      |        |
               | input | ---> | deinterlace | ---> | scale | ---> | output |
               |_______|      |_____________|      |_______|      |________|

       Note that some filters change frame properties but not frame contents. E.g. the
       "fps" filter in the example above changes number of frames, but does not touch
       the frame contents. Another example is the "setpts" filter, which only sets
       timestamps and otherwise passes the frames unchanged.

       Complex filtergraphs

       Complex filtergraphs are those which cannot be described as simply a linear
       processing chain applied to one stream. This is the case, for example, when the
       graph has more than one input and/or output, or when output stream type is
       different from input. They can be represented with the following diagram:

                _________
               |         |
               | input 0 |\                    __________
               |_________| \                  |          |
                            \   _________    /| output 0 |
                             \ |         |  / |__________|
                _________     \| complex | /
               |         |     |         |/
               | input 1 |---->| filter  |\
               |_________|     |         | \   __________
                              /| graph   |  \ |          |
                             / |         |   \| output 1 |
                _________   /  |_________|    |__________|
               |         | /
               | input 2 |/
               |_________|

       Complex filtergraphs are configured with the -filter_complex option.  Note that
       this option is global, since a complex filtergraph, by its nature, cannot be
       unambiguously associated with a single stream or file.

       The -lavfi option is equivalent to -filter_complex.

       A trivial example of a complex filtergraph is the "overlay" filter, which has
       two video inputs and one video output, containing one video overlaid on top of
       the other. Its audio counterpart is the "amix" filter.

   Stream copy
       Stream copy is a mode selected by supplying the "copy" parameter to the -codec
       option. It makes ffmpeg omit the decoding and encoding step for the specified
       stream, so it does only demuxing and muxing. It is useful for changing the
       container format or modifying container-level metadata. The diagram above will,
       in this case, simplify to this:

                _______              ______________            ________
               |       |            |              |          |        |
               | input |  demuxer   | encoded data |  muxer   | output |
               | file  | ---------> | packets      | -------> | file   |
               |_______|            |______________|          |________|

       Since there is no decoding or encoding, it is very fast and there is no quality
       loss. However, it might not work in some cases because of many factors. Applying
       filters is obviously also impossible, since filters work on uncompressed data.

STREAM SELECTION
       By default, ffmpeg includes only one stream of each type (video, audio,
       subtitle) present in the input files and adds them to each output file.  It
       picks the "best" of each based upon the following criteria: for video, it is the
       stream with the highest resolution, for audio, it is the stream with the most
       channels, for subtitles, it is the first subtitle stream. In the case where
       several streams of the same type rate equally, the stream with the lowest index
       is chosen.

       You can disable some of those defaults by using the "-vn/-an/-sn/-dn" options.
       For full manual control, use the "-map" option, which disables the defaults just
       described.

OPTIONS
       All the numerical options, if not specified otherwise, accept a string
       representing a number as input, which may be followed by one of the SI unit
       prefixes, for example: 'K', 'M', or 'G'.

       If 'i' is appended to the SI unit prefix, the complete prefix will be
       interpreted as a unit prefix for binary multiples, which are based on powers of
       1024 instead of powers of 1000. Appending 'B' to the SI unit prefix multiplies
       the value by 8. This allows using, for example: 'KB', 'MiB', 'G' and 'B' as
       number suffixes.

       Options which do not take arguments are boolean options, and set the
       corresponding value to true. They can be set to false by prefixing the option
       name with "no". For example using "-nofoo" will set the boolean option with name
       "foo" to false.

   Stream specifiers
       Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
       are used to precisely specify which stream(s) a given option belongs to.

       A stream specifier is a string generally appended to the option name and
       separated from it by a colon. E.g. "-codec:a:1 ac3" contains the "a:1" stream
       specifier, which matches the second audio stream. Therefore, it would select the
       ac3 codec for the second audio stream.

       A stream specifier can match several streams, so that the option is applied to
       all of them. E.g. the stream specifier in "-b:a 128k" matches all audio streams.

       An empty stream specifier matches all streams. For example, "-codec copy" or
       "-codec: copy" would copy all the streams without reencoding.

       Possible forms of stream specifiers are:

       stream_index
           Matches the stream with this index. E.g. "-threads:1 4" would set the thread
           count for the second stream to 4.

       stream_type[:stream_index]
           stream_type is one of following: 'v' or 'V' for video, 'a' for audio, 's'
           for subtitle, 'd' for data, and 't' for attachments. 'v' matches all video
           streams, 'V' only matches video streams which are not attached pictures,
           video thumbnails or cover arts.  If stream_index is given, then it matches
           stream number stream_index of this type. Otherwise, it matches all streams
           of this type.

       p:program_id[:stream_index]
           If stream_index is given, then it matches the stream with number
           stream_index in the program with the id program_id. Otherwise, it matches
           all streams in the program.

       #stream_id or i:stream_id
           Match the stream by stream id (e.g. PID in MPEG-TS container).

       m:key[:value]
           Matches streams with the metadata tag key having the specified value. If
           value is not given, matches streams that contain the given tag with any
           value.

       u   Matches streams with usable configuration, the codec must be defined and the
           essential information such as video dimension or audio sample rate must be
           present.

           Note that in ffmpeg, matching by metadata will only work properly for input
           files.

   Generic options
       These options are shared amongst the ff* tools.

       -L  Show license.

       -h, -?, -help, --help [arg]
           Show help. An optional parameter may be specified to print help about a
           specific item. If no argument is specified, only basic (non advanced) tool
           options are shown.

           Possible values of arg are:

           long
               Print advanced tool options in addition to the basic tool options.

           full
               Print complete list of options, including shared and private options for
               encoders, decoders, demuxers, muxers, filters, etc.

           decoder=decoder_name
               Print detailed information about the decoder named decoder_name. Use the
               -decoders option to get a list of all decoders.

           encoder=encoder_name
               Print detailed information about the encoder named encoder_name. Use the
               -encoders option to get a list of all encoders.

           demuxer=demuxer_name
               Print detailed information about the demuxer named demuxer_name. Use the
               -formats option to get a list of all demuxers and muxers.

           muxer=muxer_name
               Print detailed information about the muxer named muxer_name. Use the
               -formats option to get a list of all muxers and demuxers.

           filter=filter_name
               Print detailed information about the filter name filter_name. Use the
               -filters option to get a list of all filters.

       -version
           Show version.

       -formats
           Show available formats (including devices).

       -devices
           Show available devices.

       -codecs
           Show all codecs known to libavcodec.

           Note that the term 'codec' is used throughout this documentation as a
           shortcut for what is more correctly called a media bitstream format.

       -decoders
           Show available decoders.

       -encoders
           Show all available encoders.

       -bsfs
           Show available bitstream filters.

       -protocols
           Show available protocols.

       -filters
           Show available libavfilter filters.

       -pix_fmts
           Show available pixel formats.

       -sample_fmts
           Show available sample formats.

       -layouts
           Show channel names and standard channel layouts.

       -colors
           Show recognized color names.

       -sources device[,opt1=val1[,opt2=val2]...]
           Show autodetected sources of the intput device.  Some devices may provide
           system-dependent source names that cannot be autodetected.  The returned
           list cannot be assumed to be always complete.

                   ffmpeg -sources pulse,server=192.168.0.4

       -sinks device[,opt1=val1[,opt2=val2]...]
           Show autodetected sinks of the output device.  Some devices may provide
           system-dependent sink names that cannot be autodetected.  The returned list
           cannot be assumed to be always complete.

                   ffmpeg -sinks pulse,server=192.168.0.4

       -loglevel [repeat+]loglevel | -v [repeat+]loglevel
           Set the logging level used by the library.  Adding "repeat+" indicates that
           repeated log output should not be compressed to the first line and the "Last
           message repeated n times" line will be omitted. "repeat" can also be used
           alone.  If "repeat" is used alone, and with no prior loglevel set, the
           default loglevel will be used. If multiple loglevel parameters are given,
           using 'repeat' will not change the loglevel.  loglevel is a string or a
           number containing one of the following values:

           quiet, -8
               Show nothing at all; be silent.

           panic, 0
               Only show fatal errors which could lead the process to crash, such as an
               assertion failure. This is not currently used for anything.

           fatal, 8
               Only show fatal errors. These are errors after which the process
               absolutely cannot continue.

           error, 16
               Show all errors, including ones which can be recovered from.

           warning, 24
               Show all warnings and errors. Any message related to possibly incorrect
               or unexpected events will be shown.

           info, 32
               Show informative messages during processing. This is in addition to
               warnings and errors. This is the default value.

           verbose, 40
               Same as "info", except more verbose.

           debug, 48
               Show everything, including debugging information.

           trace, 56

           By default the program logs to stderr. If coloring is supported by the
           terminal, colors are used to mark errors and warnings. Log coloring can be
           disabled setting the environment variable AV_LOG_FORCE_NOCOLOR or NO_COLOR,
           or can be forced setting the environment variable AV_LOG_FORCE_COLOR.  The
           use of the environment variable NO_COLOR is deprecated and will be dropped
           in a future FFmpeg version.

       -report
           Dump full command line and console output to a file named
           "program-YYYYMMDD-HHMMSS.log" in the current directory.  This file can be
           useful for bug reports.  It also implies "-loglevel verbose".

           Setting the environment variable FFREPORT to any value has the same effect.
           If the value is a ':'-separated key=value sequence, these options will
           affect the report; option values must be escaped if they contain special
           characters or the options delimiter ':' (see the ``Quoting and escaping''
           section in the ffmpeg-utils manual).

           The following options are recognized:

           file
               set the file name to use for the report; %p is expanded to the name of
               the program, %t is expanded to a timestamp, "%%" is expanded to a plain
               "%"

           level
               set the log verbosity level using a numerical value (see "-loglevel").

           For example, to output a report to a file named ffreport.log using a log
           level of 32 (alias for log level "info"):

                   FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output

           Errors in parsing the environment variable are not fatal, and will not
           appear in the report.

       -hide_banner
           Suppress printing banner.

           All FFmpeg tools will normally show a copyright notice, build options and
           library versions. This option can be used to suppress printing this
           information.

       -cpuflags flags (global)
           Allows setting and clearing cpu flags. This option is intended for testing.
           Do not use it unless you know what you're doing.

                   ffmpeg -cpuflags -sse+mmx ...
                   ffmpeg -cpuflags mmx ...
                   ffmpeg -cpuflags 0 ...

           Possible flags for this option are:

           x86
               mmx
               mmxext
               sse
               sse2
               sse2slow
               sse3
               sse3slow
               ssse3
               atom
               sse4.1
               sse4.2
               avx
               avx2
               xop
               fma3
               fma4
               3dnow
               3dnowext
               bmi1
               bmi2
               cmov
           ARM
               armv5te
               armv6
               armv6t2
               vfp
               vfpv3
               neon
               setend
           AArch64
               armv8
               vfp
               neon
           PowerPC
               altivec
           Specific Processors
               pentium2
               pentium3
               pentium4
               k6
               k62
               athlon
               athlonxp
               k8
       -opencl_bench
           This option is used to benchmark all available OpenCL devices and print the
           results. This option is only available when FFmpeg has been compiled with
           "--enable-opencl".

           When FFmpeg is configured with "--enable-opencl", the options for the global
           OpenCL context are set via -opencl_options. See the "OpenCL Options" section
           in the ffmpeg-utils manual for the complete list of supported options.
           Amongst others, these options include the ability to select a specific
           platform and device to run the OpenCL code on. By default, FFmpeg will run
           on the first device of the first platform. While the options for the global
           OpenCL context provide flexibility to the user in selecting the OpenCL
           device of their choice, most users would probably want to select the fastest
           OpenCL device for their system.

           This option assists the selection of the most efficient configuration by
           identifying the appropriate device for the user's system. The built-in
           benchmark is run on all the OpenCL devices and the performance is measured
           for each device. The devices in the results list are sorted based on their
           performance with the fastest device listed first. The user can subsequently
           invoke ffmpeg using the device deemed most appropriate via -opencl_options
           to obtain the best performance for the OpenCL accelerated code.

           Typical usage to use the fastest OpenCL device involve the following steps.

           Run the command:

                   ffmpeg -opencl_bench

           Note down the platform ID (pidx) and device ID (didx) of the first i.e.
           fastest device in the list.  Select the platform and device using the
           command:

                   ffmpeg -opencl_options platform_idx=<pidx>:device_idx=<didx> ...

       -opencl_options options (global)
           Set OpenCL environment options. This option is only available when FFmpeg
           has been compiled with "--enable-opencl".

           options must be a list of key=value option pairs separated by ':'. See the
           ``OpenCL Options'' section in the ffmpeg-utils manual for the list of
           supported options.

   AVOptions
       These options are provided directly by the libavformat, libavdevice and
       libavcodec libraries. To see the list of available AVOptions, use the -help
       option. They are separated into two categories:

       generic
           These options can be set for any container, codec or device. Generic options
           are listed under AVFormatContext options for containers/devices and under
           AVCodecContext options for codecs.

       private
           These options are specific to the given container, device or codec. Private
           options are listed under their corresponding containers/devices/codecs.

       For example to write an ID3v2.3 header instead of a default ID3v2.4 to an MP3
       file, use the id3v2_version private option of the MP3 muxer:

               ffmpeg -i input.flac -id3v2_version 3 out.mp3

       All codec AVOptions are per-stream, and thus a stream specifier should be
       attached to them.

       Note: the -nooption syntax cannot be used for boolean AVOptions, use -option
       0/-option 1.

       Note: the old undocumented way of specifying per-stream AVOptions by prepending
       v/a/s to the options name is now obsolete and will be removed soon.

   Main options
       -f fmt (input/output)
           Force input or output file format. The format is normally auto detected for
           input files and guessed from the file extension for output files, so this
           option is not needed in most cases.

       -i url (input)
           input file url

       -y (global)
           Overwrite output files without asking.

       -n (global)
           Do not overwrite output files, and exit immediately if a specified output
           file already exists.

       -stream_loop number (input)
           Set number of times input stream shall be looped. Loop 0 means no loop, loop
           -1 means infinite loop.

       -c[:stream_specifier] codec (input/output,per-stream)
       -codec[:stream_specifier] codec (input/output,per-stream)
           Select an encoder (when used before an output file) or a decoder (when used
           before an input file) for one or more streams. codec is the name of a
           decoder/encoder or a special value "copy" (output only) to indicate that the
           stream is not to be re-encoded.

           For example

                   ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT

           encodes all video streams with libx264 and copies all audio streams.

           For each stream, the last matching "c" option is applied, so

                   ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT

           will copy all the streams except the second video, which will be encoded
           with libx264, and the 138th audio, which will be encoded with libvorbis.

       -t duration (input/output)
           When used as an input option (before "-i"), limit the duration of data read
           from the input file.

           When used as an output option (before an output url), stop writing the
           output after its duration reaches duration.

           duration must be a time duration specification, see the Time duration
           section in the ffmpeg-utils(1) manual.

           -to and -t are mutually exclusive and -t has priority.

       -to position (output)
           Stop writing the output at position.  position must be a time duration
           specification, see the Time duration section in the ffmpeg-utils(1) manual.

           -to and -t are mutually exclusive and -t has priority.

       -fs limit_size (output)
           Set the file size limit, expressed in bytes. No further chunk of bytes is
           written after the limit is exceeded. The size of the output file is slightly
           more than the requested file size.

       -ss position (input/output)
           When used as an input option (before "-i"), seeks in this input file to
           position. Note that in most formats it is not possible to seek exactly, so
           ffmpeg will seek to the closest seek point before position.  When
           transcoding and -accurate_seek is enabled (the default), this extra segment
           between the seek point and position will be decoded and discarded. When
           doing stream copy or when -noaccurate_seek is used, it will be preserved.

           When used as an output option (before an output url), decodes but discards
           input until the timestamps reach position.

           position must be a time duration specification, see the Time duration
           section in the ffmpeg-utils(1) manual.

       -sseof position (input/output)
           Like the "-ss" option but relative to the "end of file". That is negative
           values are earlier in the file, 0 is at EOF.

       -itsoffset offset (input)
           Set the input time offset.

           offset must be a time duration specification, see the Time duration section
           in the ffmpeg-utils(1) manual.

           The offset is added to the timestamps of the input files. Specifying a
           positive offset means that the corresponding streams are delayed by the time
           duration specified in offset.

       -timestamp date (output)
           Set the recording timestamp in the container.

           date must be a date specification, see the Date section in the
           ffmpeg-utils(1) manual.

       -metadata[:metadata_specifier] key=value (output,per-metadata)
           Set a metadata key/value pair.

           An optional metadata_specifier may be given to set metadata on streams,
           chapters or programs. See "-map_metadata" documentation for details.

           This option overrides metadata set with "-map_metadata". It is also possible
           to delete metadata by using an empty value.

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

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

           To set the language of the first audio stream:

                   ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT

       -program [title=title:][program_num=program_num:]st=stream[:st=stream...]
       (output)
           Creates a program with the specified title, program_num and adds the
           specified stream(s) to it.

       -target type (output)
           Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50"). type may be
           prefixed with "pal-", "ntsc-" or "film-" to use the corresponding standard.
           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 (output)
           Set the number of data frames to output. This is an alias for "-frames:d".

       -frames[:stream_specifier] framecount (output,per-stream)
           Stop writing to the stream after framecount frames.

       -q[:stream_specifier] q (output,per-stream)
       -qscale[:stream_specifier] q (output,per-stream)
           Use fixed quality scale (VBR). The meaning of q/qscale is codec-dependent.
           If qscale is used without a stream_specifier then it applies only to the
           video stream, this is to maintain compatibility with previous behavior and
           as specifying the same codec specific value to 2 different codecs that is
           audio and video generally is not what is intended when no stream_specifier
           is used.

       -filter[:stream_specifier] filtergraph (output,per-stream)
           Create the filtergraph specified by filtergraph and use it to filter the
           stream.

           filtergraph is a description of the filtergraph to apply to the stream, and
           must have a single input and a single output of the same type of the stream.
           In the filtergraph, the input is associated to the label "in", and the
           output to the label "out". See the ffmpeg-filters manual for more
           information about the filtergraph syntax.

           See the -filter_complex option if you want to create filtergraphs with
           multiple inputs and/or outputs.

       -filter_script[:stream_specifier] filename (output,per-stream)
           This option is similar to -filter, the only difference is that its argument
           is the name of the file from which a filtergraph description is to be read.

       -pre[:stream_specifier] preset_name (output,per-stream)
           Specify the preset for matching stream(s).

       -stats (global)
           Print encoding progress/statistics. It is on by default, to explicitly
           disable it you need to specify "-nostats".

       -progress url (global)
           Send program-friendly progress information to url.

           Progress information is written approximately every second and at the end of
           the encoding process. It is made of "key=value" lines. key consists of only
           alphanumeric characters. The last key of a sequence of progress information
           is always "progress".

       -stdin
           Enable interaction on standard input. On by default unless standard input is
           used as an input. To explicitly disable interaction you need to specify
           "-nostdin".

           Disabling interaction on standard input is useful, for example, if ffmpeg is
           in the background process group. Roughly the same result can be achieved
           with "ffmpeg ... < /dev/null" but it requires a shell.

       -debug_ts (global)
           Print timestamp information. It is off by default. This option is mostly
           useful for testing and debugging purposes, and the output format may change
           from one version to another, so it should not be employed by portable
           scripts.

           See also the option "-fdebug ts".

       -attach filename (output)
           Add an attachment to the output file. This is supported by a few formats
           like Matroska for e.g. fonts used in rendering subtitles. Attachments are
           implemented as a specific type of stream, so this option will add a new
           stream to the file. It is then possible to use per-stream options on this
           stream in the usual way. Attachment streams created with this option will be
           created after all the other streams (i.e. those created with "-map" or
           automatic mappings).

           Note that for Matroska you also have to set the mimetype metadata tag:

                   ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv

           (assuming that the attachment stream will be third in the output file).

       -dump_attachment[:stream_specifier] filename (input,per-stream)
           Extract the matching attachment stream into a file named filename. If
           filename is empty, then the value of the "filename" metadata tag will be
           used.

           E.g. to extract the first attachment to a file named 'out.ttf':

                   ffmpeg -dump_attachment:t:0 out.ttf -i INPUT

           To extract all attachments to files determined by the "filename" tag:

                   ffmpeg -dump_attachment:t "" -i INPUT

           Technical note -- attachments are implemented as codec extradata, so this
           option can actually be used to extract extradata from any stream, not just
           attachments.

       -noautorotate
           Disable automatically rotating video based on file metadata.

   Video Options
       -vframes number (output)
           Set the number of video frames to output. This is an alias for "-frames:v".

       -r[:stream_specifier] fps (input/output,per-stream)
           Set frame rate (Hz value, fraction or abbreviation).

           As an input option, ignore any timestamps stored in the file and instead
           generate timestamps assuming constant frame rate fps.  This is not the same
           as the -framerate option used for some input formats like image2 or v4l2 (it
           used to be the same in older versions of FFmpeg).  If in doubt use
           -framerate instead of the input option -r.

           As an output option, duplicate or drop input frames to achieve constant
           output frame rate fps.

       -s[:stream_specifier] size (input/output,per-stream)
           Set frame size.

           As an input option, this is a shortcut for the video_size private option,
           recognized by some demuxers for which the frame size is either not stored in
           the file or is configurable -- e.g. raw video or video grabbers.

           As an output option, this inserts the "scale" video filter to the end of the
           corresponding filtergraph. Please use the "scale" filter directly to insert
           it at the beginning or some other place.

           The format is wxh (default - same as source).

       -aspect[:stream_specifier] aspect (output,per-stream)
           Set the video display aspect ratio specified by aspect.

           aspect can be a floating point number string, or a string of the form
           num:den, where num and den are the numerator and denominator of the aspect
           ratio. For example "4:3", "16:9", "1.3333", and "1.7777" are valid argument
           values.

           If used together with -vcodec copy, it will affect the aspect ratio stored
           at container level, but not the aspect ratio stored in encoded frames, if it
           exists.

       -vn (output)
           Disable video recording.

       -vcodec codec (output)
           Set the video codec. This is an alias for "-codec:v".

       -pass[:stream_specifier] n (output,per-stream)
           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 -c:v libxvid -pass 1 -an -f rawvideo -y NUL
                   ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null

       -passlogfile[:stream_specifier] prefix (output,per-stream)
           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

       -vf filtergraph (output)
           Create the filtergraph specified by filtergraph and use it to filter the
           stream.

           This is an alias for "-filter:v", see the -filter option.

   Advanced Video options
       -pix_fmt[:stream_specifier] format (input/output,per-stream)
           Set pixel format. Use "-pix_fmts" to show all the supported pixel formats.
           If the selected pixel format can not be selected, ffmpeg will print a
           warning and select the best pixel format supported by the encoder.  If
           pix_fmt is prefixed by a "+", ffmpeg will exit with an error if the
           requested pixel format can not be selected, and automatic conversions inside
           filtergraphs are disabled.  If pix_fmt is a single "+", ffmpeg selects the
           same pixel format as the input (or graph output) and automatic conversions
           are disabled.

       -sws_flags flags (input/output)
           Set SwScaler flags.

       -vdt n
           Discard threshold.

       -rc_override[:stream_specifier] override (output,per-stream)
           Rate control override for specific intervals, formatted as "int,int,int"
           list separated with slashes. Two first values are the beginning and end
           frame numbers, last one is quantizer to use if positive, or quality factor
           if negative.

       -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[:stream_specifier] n (output,per-stream)
           top=1/bottom=0/auto=-1 field first

       -dc precision
           Intra_dc_precision.

       -vtag fourcc/tag (output)
           Force video tag/fourcc. This is an alias for "-tag:v".

       -qphist (global)
           Show QP histogram

       -vbsf bitstream_filter
           Deprecated see -bsf

       -force_key_frames[:stream_specifier] time[,time...] (output,per-stream)
       -force_key_frames[:stream_specifier] expr:expr (output,per-stream)
           Force key frames at the specified timestamps, more precisely at the first
           frames after each specified time.

           If the argument is prefixed with "expr:", the string expr is interpreted
           like an expression and is evaluated for each frame. A key frame is forced in
           case the evaluation is non-zero.

           If one of the times is ""chapters"[delta]", it is expanded into the time of
           the beginning of all chapters in the file, shifted by delta, expressed as a
           time in seconds.  This option can be useful to ensure that a seek point is
           present at a chapter mark or any other designated place in the output file.

           For example, to insert a key frame at 5 minutes, plus key frames 0.1 second
           before the beginning of every chapter:

                   -force_key_frames 0:05:00,chapters-0.1

           The expression in expr can contain the following constants:

           n   the number of current processed frame, starting from 0

           n_forced
               the number of forced frames

           prev_forced_n
               the number of the previous forced frame, it is "NAN" when no keyframe
               was forced yet

           prev_forced_t
               the time of the previous forced frame, it is "NAN" when no keyframe was
               forced yet

           t   the time of the current processed frame

           For example to force a key frame every 5 seconds, you can specify:

                   -force_key_frames expr:gte(t,n_forced*5)

           To force a key frame 5 seconds after the time of the last forced one,
           starting from second 13:

                   -force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))

           Note that forcing too many keyframes is very harmful for the lookahead
           algorithms of certain encoders: using fixed-GOP options or similar would be
           more efficient.

       -copyinkf[:stream_specifier] (output,per-stream)
           When doing stream copy, copy also non-key frames found at the beginning.

       -hwaccel[:stream_specifier] hwaccel (input,per-stream)
           Use hardware acceleration to decode the matching stream(s). The allowed
           values of hwaccel are:

           none
               Do not use any hardware acceleration (the default).

           auto
               Automatically select the hardware acceleration method.

           vda Use Apple VDA hardware acceleration.

           vdpau
               Use VDPAU (Video Decode and Presentation API for Unix) hardware
               acceleration.

           dxva2
               Use DXVA2 (DirectX Video Acceleration) hardware acceleration.

           qsv Use the Intel QuickSync Video acceleration for video transcoding.

               Unlike most other values, this option does not enable accelerated
               decoding (that is used automatically whenever a qsv decoder is
               selected), but accelerated transcoding, without copying the frames into
               the system memory.

               For it to work, both the decoder and the encoder must support QSV
               acceleration and no filters must be used.

           This option has no effect if the selected hwaccel is not available or not
           supported by the chosen decoder.

           Note that most acceleration methods are intended for playback and will not
           be faster than software decoding on modern CPUs. Additionally, ffmpeg will
           usually need to copy the decoded frames from the GPU memory into the system
           memory, resulting in further performance loss. This option is thus mainly
           useful for testing.

       -hwaccel_device[:stream_specifier] hwaccel_device (input,per-stream)
           Select a device to use for hardware acceleration.

           This option only makes sense when the -hwaccel option is also specified. Its
           exact meaning depends on the specific hardware acceleration method chosen.

           vdpau
               For VDPAU, this option specifies the X11 display/screen to use. If this
               option is not specified, the value of the DISPLAY environment variable
               is used

           dxva2
               For DXVA2, this option should contain the number of the display adapter
               to use.  If this option is not specified, the default adapter is used.

           qsv For QSV, this option corresponds to the values of MFX_IMPL_* . Allowed
               values are:

               auto
               sw
               hw
               auto_any
               hw_any
               hw2
               hw3
               hw4
       -hwaccels
           List all hardware acceleration methods supported in this build of ffmpeg.

   Audio Options
       -aframes number (output)
           Set the number of audio frames to output. This is an alias for "-frames:a".

       -ar[:stream_specifier] freq (input/output,per-stream)
           Set the audio sampling frequency. For output streams it is set by default to
           the frequency of the corresponding input stream. For input streams this
           option only makes sense for audio grabbing devices and raw demuxers and is
           mapped to the corresponding demuxer options.

       -aq q (output)
           Set the audio quality (codec-specific, VBR). This is an alias for -q:a.

       -ac[:stream_specifier] channels (input/output,per-stream)
           Set the number of audio channels. For output streams it is set by default to
           the number of input audio channels. For input streams this option only makes
           sense for audio grabbing devices and raw demuxers and is mapped to the
           corresponding demuxer options.

       -an (output)
           Disable audio recording.

       -acodec codec (input/output)
           Set the audio codec. This is an alias for "-codec:a".

       -sample_fmt[:stream_specifier] sample_fmt (output,per-stream)
           Set the audio sample format. Use "-sample_fmts" to get a list of supported
           sample formats.

       -af filtergraph (output)
           Create the filtergraph specified by filtergraph and use it to filter the
           stream.

           This is an alias for "-filter:a", see the -filter option.

   Advanced Audio options
       -atag fourcc/tag (output)
           Force audio tag/fourcc. This is an alias for "-tag:a".

       -absf bitstream_filter
           Deprecated, see -bsf

       -guess_layout_max channels (input,per-stream)
           If some input channel layout is not known, try to guess only if it
           corresponds to at most the specified number of channels. For example, 2
           tells to ffmpeg to recognize 1 channel as mono and 2 channels as stereo but
           not 6 channels as 5.1. The default is to always try to guess. Use 0 to
           disable all guessing.

   Subtitle options
       -scodec codec (input/output)
           Set the subtitle codec. This is an alias for "-codec:s".

       -sn (output)
           Disable subtitle recording.

       -sbsf bitstream_filter
           Deprecated, see -bsf

   Advanced Subtitle options
       -fix_sub_duration
           Fix subtitles durations. For each subtitle, wait for the next packet in the
           same stream and adjust the duration of the first to avoid overlap. This is
           necessary with some subtitles codecs, especially DVB subtitles, because the
           duration in the original packet is only a rough estimate and the end is
           actually marked by an empty subtitle frame. Failing to use this option when
           necessary can result in exaggerated durations or muxing failures due to non-
           monotonic timestamps.

           Note that this option will delay the output of all data until the next
           subtitle packet is decoded: it may increase memory consumption and latency a
           lot.

       -canvas_size size
           Set the size of the canvas used to render subtitles.

   Advanced options
       -map [-]input_file_id[:stream_specifier][,sync_file_id[:stream_specifier]] |
       [linklabel] (output)
           Designate one or more input streams as a source for the output file. Each
           input stream is identified by the input file index input_file_id and the
           input stream index input_stream_id within the input file. Both indices start
           at 0. If specified, sync_file_id:stream_specifier sets which input stream is
           used as a presentation sync reference.

           The first "-map" option on the command line specifies the source for output
           stream 0, the second "-map" option specifies the source for output stream 1,
           etc.

           A "-" character before the stream identifier creates a "negative" mapping.
           It disables matching streams from already created mappings.

           An alternative [linklabel] form will map outputs from complex filter graphs
           (see the -filter_complex option) to the output file.  linklabel must
           correspond to a defined output link label in the graph.

           For example, to map ALL streams from the first input file to output

                   ffmpeg -i INPUT -map 0 output

           For example, if you have two audio streams in the first input file, these
           streams are identified by "0:0" and "0:1". You can use "-map" to select
           which streams to place in an output file. For example:

                   ffmpeg -i INPUT -map 0:1 out.wav

           will map the input stream in INPUT identified by "0:1" to the (single)
           output stream in out.wav.

           For example, to select the stream with index 2 from input file a.mov
           (specified by the identifier "0:2"), and stream with index 6 from input
           b.mov (specified by the identifier "1:6"), and copy them to the output file
           out.mov:

                   ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov

           To select all video and the third audio stream from an input file:

                   ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT

           To map all the streams except the second audio, use negative mappings

                   ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT

           To pick the English audio stream:

                   ffmpeg -i INPUT -map 0:m:language:eng OUTPUT

           Note that using this option disables the default mappings for this output
           file.

       -ignore_unknown
           Ignore input streams with unknown type instead of failing if copying such
           streams is attempted.

       -copy_unknown
           Allow input streams with unknown type to be copied instead of failing if
           copying such streams is attempted.

       -map_channel
       [input_file_id.stream_specifier.channel_id|-1][:output_file_id.stream_specifier]
           Map an audio channel from a given input to an output. If
           output_file_id.stream_specifier is not set, the audio channel will be mapped
           on all the audio streams.

           Using "-1" instead of input_file_id.stream_specifier.channel_id will map a
           muted channel.

           For example, assuming INPUT is a stereo audio file, you can switch the two
           audio channels with the following command:

                   ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT

           If you want to mute the first channel and keep the second:

                   ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT

           The order of the "-map_channel" option specifies the order of the channels
           in the output stream. The output channel layout is guessed from the number
           of channels mapped (mono if one "-map_channel", stereo if two, etc.). Using
           "-ac" in combination of "-map_channel" makes the channel gain levels to be
           updated if input and output channel layouts don't match (for instance two
           "-map_channel" options and "-ac 6").

           You can also extract each channel of an input to specific outputs; the
           following command extracts two channels of the INPUT audio stream (file 0,
           stream 0) to the respective OUTPUT_CH0 and OUTPUT_CH1 outputs:

                   ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1

           The following example splits the channels of a stereo input into two
           separate streams, which are put into the same output file:

                   ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg

           Note that currently each output stream can only contain channels from a
           single input stream; you can't for example use "-map_channel" to pick
           multiple input audio channels contained in different streams (from the same
           or different files) and merge them into a single output stream. It is
           therefore not currently possible, for example, to turn two separate mono
           streams into a single stereo stream. However splitting a stereo stream into
           two single channel mono streams is possible.

           If you need this feature, a possible workaround is to use the amerge filter.
           For example, if you need to merge a media (here input.mkv) with 2 mono audio
           streams into one single stereo channel audio stream (and keep the video
           stream), you can use the following command:

                   ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv

       -map_metadata[:metadata_spec_out] infile[:metadata_spec_in]
       (output,per-metadata)
           Set metadata information of the next output file from infile. Note that
           those are file indices (zero-based), not filenames.  Optional
           metadata_spec_in/out parameters specify, which metadata to copy.  A metadata
           specifier can have the following forms:

           g   global metadata, i.e. metadata that applies to the whole file

           s[:stream_spec]
               per-stream metadata. stream_spec is a stream specifier as described in
               the Stream specifiers chapter. In an input metadata specifier, the first
               matching stream is copied from. In an output metadata specifier, all
               matching streams are copied to.

           c:chapter_index
               per-chapter metadata. chapter_index is the zero-based chapter index.

           p:program_index
               per-program metadata. program_index is the zero-based program index.

           If metadata specifier is omitted, it defaults to global.

           By default, global metadata is copied from the first input file, per-stream
           and per-chapter metadata is copied along with streams/chapters. These
           default mappings are disabled by creating any mapping of the relevant type.
           A negative file index can be used to create a dummy mapping that just
           disables automatic copying.

           For example to copy metadata from the first stream of the input file to
           global metadata of the output file:

                   ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3

           To do the reverse, i.e. copy global metadata to all audio streams:

                   ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv

           Note that simple 0 would work as well in this example, since global metadata
           is assumed by default.

       -map_chapters input_file_index (output)
           Copy chapters from input file with index input_file_index to the next output
           file. If no chapter mapping is specified, then chapters are copied from the
           first input file with at least one chapter. Use a negative file index to
           disable any chapter copying.

       -benchmark (global)
           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.

       -benchmark_all (global)
           Show benchmarking information during the encode.  Shows CPU time used in
           various steps (audio/video encode/decode).

       -timelimit duration (global)
           Exit after ffmpeg has been running for duration seconds.

       -dump (global)
           Dump each input packet to stderr.

       -hex (global)
           When dumping packets, also dump the payload.

       -re (input)
           Read input at native frame rate. Mainly used to simulate a grab device, or
           live input stream (e.g. when reading from a file). Should not be used with
           actual grab devices or live input streams (where it can cause packet loss).
           By default ffmpeg attempts to read the input(s) as fast as possible.  This
           option will slow down the reading of the input(s) to the native frame rate
           of the input(s). It is useful for real-time output (e.g. live streaming).

       -loop_input
           Loop over the input stream. Currently it works only for image streams. This
           option is used for automatic FFserver testing.  This option is deprecated,
           use -loop 1.

       -loop_output number_of_times
           Repeatedly loop output for formats that support looping such as animated GIF
           (0 will loop the output infinitely).  This option is deprecated, use -loop.

       -vsync parameter
           Video sync method.  For compatibility reasons old values can be specified as
           numbers.  Newly added values will have to be specified as strings always.

           0, passthrough
               Each frame is passed with its timestamp from the demuxer to the muxer.

           1, cfr
               Frames will be duplicated and dropped to achieve exactly the requested
               constant frame rate.

           2, vfr
               Frames are passed through with their timestamp or dropped so as to
               prevent 2 frames from having the same timestamp.

           drop
               As passthrough but destroys all timestamps, making the muxer generate
               fresh timestamps based on frame-rate.

           -1, auto
               Chooses between 1 and 2 depending on muxer capabilities. This is the
               default method.

           Note that the timestamps may be further modified by the muxer, after this.
           For example, in the case that the format option avoid_negative_ts is
           enabled.

           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.

       -frame_drop_threshold parameter
           Frame drop threshold, which specifies how much behind video frames can be
           before they are dropped. In frame rate units, so 1.0 is one frame.  The
           default is -1.1. One possible usecase is to avoid framedrops in case of
           noisy timestamps or to increase frame drop precision in case of exact
           timestamps.

       -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.

           Note that the timestamps may be further modified by the muxer, after this.
           For example, in the case that the format option avoid_negative_ts is
           enabled.

           This option has been deprecated. Use the "aresample" audio filter instead.

       -copyts
           Do not process input timestamps, but keep their values without trying to
           sanitize them. In particular, do not remove the initial start time offset
           value.

           Note that, depending on the vsync option or on specific muxer processing
           (e.g. in case the format option avoid_negative_ts is enabled) the output
           timestamps may mismatch with the input timestamps even when this option is
           selected.

       -start_at_zero
           When used with copyts, shift input timestamps so they start at zero.

           This means that using e.g. "-ss 50" will make output timestamps start at 50
           seconds, regardless of what timestamp the input file started at.

       -copytb mode
           Specify how to set the encoder timebase when stream copying.  mode is an
           integer numeric value, and can assume one of the following values:

           1   Use the demuxer timebase.

               The time base is copied to the output encoder from the corresponding
               input demuxer. This is sometimes required to avoid non monotonically
               increasing timestamps when copying video streams with variable frame
               rate.

           0   Use the decoder timebase.

               The time base is copied to the output encoder from the corresponding
               input decoder.

           -1  Try to make the choice automatically, in order to generate a sane
               output.

           Default value is -1.

       -shortest (output)
           Finish encoding when the shortest input stream ends.

       -dts_delta_threshold
           Timestamp discontinuity delta threshold.

       -muxdelay seconds (input)
           Set the maximum demux-decode delay.

       -muxpreload seconds (input)
           Set the initial demux-decode delay.

       -streamid output-stream-index:new-value (output)
           Assign a new stream-id value to an output stream. This option should be
           specified prior to the output filename to which it applies.  For the
           situation where multiple output files exist, a streamid may be reassigned to
           a different value.

           For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for an
           output mpegts file:

                   ffmpeg -i inurl -streamid 0:33 -streamid 1:36 out.ts

       -bsf[:stream_specifier] bitstream_filters (output,per-stream)
           Set bitstream filters for matching streams. bitstream_filters is a comma-
           separated list of bitstream filters. Use the "-bsfs" option to get the list
           of bitstream filters.

                   ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264

                   ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt

       -tag[:stream_specifier] codec_tag (input/output,per-stream)
           Force a tag/fourcc for matching streams.

       -timecode hh:mm:ssSEPff
           Specify Timecode for writing. SEP is ':' for non drop timecode and ';' (or
           '.') for drop.

                   ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg

       -filter_complex filtergraph (global)
           Define a complex filtergraph, i.e. one with arbitrary number of inputs
           and/or outputs. For simple graphs -- those with one input and one output of
           the same type -- see the -filter options. filtergraph is a description of
           the filtergraph, as described in the ``Filtergraph syntax'' section of the
           ffmpeg-filters manual.

           Input link labels must refer to input streams using the
           "[file_index:stream_specifier]" syntax (i.e. the same as -map uses). If
           stream_specifier matches multiple streams, the first one will be used. An
           unlabeled input will be connected to the first unused input stream of the
           matching type.

           Output link labels are referred to with -map. Unlabeled outputs are added to
           the first output file.

           Note that with this option it is possible to use only lavfi sources without
           normal input files.

           For example, to overlay an image over video

                   ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
                   '[out]' out.mkv

           Here "[0:v]" refers to the first video stream in the first input file, which
           is linked to the first (main) input of the overlay filter. Similarly the
           first video stream in the second input is linked to the second (overlay)
           input of overlay.

           Assuming there is only one video stream in each input file, we can omit
           input labels, so the above is equivalent to

                   ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
                   '[out]' out.mkv

           Furthermore we can omit the output label and the single output from the
           filter graph will be added to the output file automatically, so we can
           simply write

                   ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv

           To generate 5 seconds of pure red video using lavfi "color" source:

                   ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv

       -lavfi filtergraph (global)
           Define a complex filtergraph, i.e. one with arbitrary number of inputs
           and/or outputs. Equivalent to -filter_complex.

       -filter_complex_script filename (global)
           This option is similar to -filter_complex, the only difference is that its
           argument is the name of the file from which a complex filtergraph
           description is to be read.

       -accurate_seek (input)
           This option enables or disables accurate seeking in input files with the -ss
           option. It is enabled by default, so seeking is accurate when transcoding.
           Use -noaccurate_seek to disable it, which may be useful e.g. when copying
           some streams and transcoding the others.

       -seek_timestamp (input)
           This option enables or disables seeking by timestamp in input files with the
           -ss option. It is disabled by default. If enabled, the argument to the -ss
           option is considered an actual timestamp, and is not offset by the start
           time of the file. This matters only for files which do not start from
           timestamp 0, such as transport streams.

       -thread_queue_size size (input)
           This option sets the maximum number of queued packets when reading from the
           file or device. With low latency / high rate live streams, packets may be
           discarded if they are not read in a timely manner; raising this value can
           avoid it.

       -override_ffserver (global)
           Overrides the input specifications from ffserver. Using this option you can
           map any input stream to ffserver and control many aspects of the encoding
           from ffmpeg. Without this option ffmpeg will transmit to ffserver what is
           requested by ffserver.

           The option is intended for cases where features are needed that cannot be
           specified to ffserver but can be to ffmpeg.

       -sdp_file file (global)
           Print sdp information for an output stream to file.  This allows dumping sdp
           information when at least one output isn't an rtp stream. (Requires at least
           one of the output formats to be rtp).

       -discard (input)
           Allows discarding specific streams or frames of streams at the demuxer.  Not
           all demuxers support this.

           none
               Discard no frame.

           default
               Default, which discards no frames.

           noref
               Discard all non-reference frames.

           bidir
               Discard all bidirectional frames.

           nokey
               Discard all frames excepts keyframes.

           all Discard all frames.

       -abort_on flags (global)
           Stop and abort on various conditions. The following flags are available:

           empty_output
               No packets were passed to the muxer, the output is empty.

       -xerror (global)
           Stop and exit on error

       -max_muxing_queue_size packets (output,per-stream)
           When transcoding audio and/or video streams, ffmpeg will not begin writing
           into the output until it has one packet for each such stream. While waiting
           for that to happen, packets for other streams are buffered. This option sets
           the size of this buffer, in packets, for the matching output stream.

           The default value of this option should be high enough for most uses, so
           only touch this option if you are sure that you need it.

       As a special exception, you can use a bitmap subtitle stream as input: it will
       be converted into a video with the same size as the largest video in the file,
       or 720x576 if no video is present. Note that this is an experimental and
       temporary solution. It will be removed once libavfilter has proper support for
       subtitles.

       For example, to hardcode subtitles on top of a DVB-T recording stored in MPEG-TS
       format, delaying the subtitles by 1 second:

               ffmpeg -i input.ts -filter_complex \
                 '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
                 -sn -map '#0x2dc' output.mkv

       (0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video, audio
       and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)

   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 presets directory in the FFmpeg source tree
       for examples.

       There are two types of preset files: ffpreset and avpreset files.

       ffpreset files

       ffpreset 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) or in a ffpresets folder along
       the executable on win32, in that order. For example, if the argument is
       "libvpx-1080p", it will search for the file libvpx-1080p.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 libvpx" and use "-vpre
       1080p", then it will search for the file libvpx-1080p.ffpreset.

       avpreset files

       avpreset files are specified with the "pre" option. They work similar to
       ffpreset files, but they only allow encoder- specific options. Therefore, an
       option=value pair specifying an encoder cannot be used.

       When the "pre" option is specified, ffmpeg will look for files with the suffix
       .avpreset in the directories $AVCONV_DATADIR (if set), and $HOME/.avconv, and in
       the datadir defined at configuration time (usually PREFIX/share/ffmpeg), in that
       order.

       First ffmpeg searches for a file named codec_name-arg.avpreset 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 libvpx" and use "-pre 1080p", then it will search for the file
       libvpx-1080p.avpreset.

       If no such file is found, then ffmpeg will search for a file named arg.avpreset
       in the same directories.

EXAMPLES
   Video and Audio grabbing
       If you specify the input format and device then ffmpeg can grab video and audio
       directly.

               ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg

       Or with an ALSA audio source (mono input, card id 1) instead of OSS:

               ffmpeg -f alsa -ac 1 -i hw:1 -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 <http://linux.bytesex.org/xawtv/> by Gerd
       Knorr. You also have to set the audio recording levels correctly with a standard
       mixer.

   X11 grabbing
       Grab the X11 display with ffmpeg via

               ffmpeg -f x11grab -video_size cif -framerate 25 -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 -video_size cif -framerate 25 -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
       Any supported file format and protocol can serve as input to ffmpeg:

       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 -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2

           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 -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 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 -framerate 12 -i foo-%03d.jpeg -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.

           When importing an image sequence, -i also supports expanding shell-like
           wildcard patterns (globbing) internally, by selecting the image2-specific
           "-pattern_type glob" option.

           For example, for creating a video from filenames matching the glob pattern
           "foo-*.jpeg":

                   ffmpeg -f image2 -pattern_type glob -framerate 12 -i 'foo-*.jpeg' -s WxH foo.avi

       ·   You can put many streams of the same type in the output:

                   ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut

           The resulting output file test12.nut will contain the first four streams
           from the input files in reverse order.

       ·   To force CBR video output:

                   ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v

       ·   The four options lmin, lmax, mblmin and 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

SEE ALSO
       ffmpeg-all(1), ffplay(1), ffprobe(1), ffserver(1), ffmpeg-utils(1),
       ffmpeg-scaler(1), ffmpeg-resampler(1), ffmpeg-codecs(1),
       ffmpeg-bitstream-filters(1), ffmpeg-formats(1), ffmpeg-devices(1),
       ffmpeg-protocols(1), ffmpeg-filters(1)

AUTHORS
       The FFmpeg developers.

       For details about the authorship, see the Git history of the project
       (git://source.ffmpeg.org/ffmpeg), e.g. by typing the command git log in the
       FFmpeg source directory, or browsing the online repository at
       <http://source.ffmpeg.org>.

       Maintainers for the specific components are listed in the file MAINTAINERS in
       the source code tree.

                                                                              FFMPEG(1)

 

 

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ffmpeg --help
ffmpeg version 3.2.14-1~deb9u1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
  configuration: --prefix=/usr --extra-version='1~deb9u1' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libebur128 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  libavutil      55. 34.101 / 55. 34.101
  libavcodec     57. 64.101 / 57. 64.101
  libavformat    57. 56.101 / 57. 56.101
  libavdevice    57.  1.100 / 57.  1.100
  libavfilter     6. 65.100 /  6. 65.100
  libavresample   3.  1.  0 /  3.  1.  0
  libswscale      4.  2.100 /  4.  2.100
  libswresample   2.  3.100 /  2.  3.100
  libpostproc    54.  1.100 / 54.  1.100
Hyper fast Audio and Video encoder
usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

Getting help:
    -h      -- print basic options
    -h long -- print more options
    -h full -- print all options (including all format and codec specific options, very long)
    -h type=name -- print all options for the named decoder/encoder/demuxer/muxer/filter
    See man ffmpeg for detailed description of the options.

Print help / information / capabilities:
-L                  show license
-h topic            show help
-? topic            show help
-help topic         show help
--help topic        show help
-version            show version
-buildconf          show build configuration
-formats            show available formats
-devices            show available devices
-codecs             show available codecs
-decoders           show available decoders
-encoders           show available encoders
-bsfs               show available bit stream filters
-protocols          show available protocols
-filters            show available filters
-pix_fmts           show available pixel formats
-layouts            show standard channel layouts
-sample_fmts        show available audio sample formats
-colors             show available color names
-sources device     list sources of the input device
-sinks device       list sinks of the output device
-hwaccels           show available HW acceleration methods

Global options (affect whole program instead of just one file:
-loglevel loglevel  set logging level
-v loglevel         set logging level
-report             generate a report
-max_alloc bytes    set maximum size of a single allocated block
-y                  overwrite output files
-n                  never overwrite output files
-ignore_unknown     Ignore unknown stream types
-stats              print progress report during encoding
-max_error_rate ratio of errors (0.0: no errors, 1.0: 100% error  maximum error rate
-bits_per_raw_sample number  set the number of bits per raw sample
-vol volume         change audio volume (256=normal)

Per-file main options:
-f fmt              force format
-c codec            codec name
-codec codec        codec name
-pre preset         preset name
-map_metadata outfile[,metadata]:infile[,metadata]  set metadata information of outfile from infile
-t duration         record or transcode "duration" seconds of audio/video
-to time_stop       record or transcode stop time
-fs limit_size      set the limit file size in bytes
-ss time_off        set the start time offset
-sseof time_off     set the start time offset relative to EOF
-seek_timestamp     enable/disable seeking by timestamp with -ss
-timestamp time     set the recording timestamp ('now' to set the current time)
-metadata string=string  add metadata
-program title=string:st=number...  add program with specified streams
-target type        specify target file type ("vcd", "svcd", "dvd", "dv" or "dv50" with optional prefixes "pal-", "ntsc-" or "film-")
-apad               audio pad
-frames number      set the number of frames to output
-filter filter_graph  set stream filtergraph
-filter_script filename  read stream filtergraph description from a file
-reinit_filter      reinit filtergraph on input parameter changes
-discard            discard
-disposition        disposition

Video options:
-vframes number     set the number of video frames to output
-r rate             set frame rate (Hz value, fraction or abbreviation)
-s size             set frame size (WxH or abbreviation)
-aspect aspect      set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
-bits_per_raw_sample number  set the number of bits per raw sample
-vn                 disable video
-vcodec codec       force video codec ('copy' to copy stream)
-timecode hh:mm:ss[:;.]ff  set initial TimeCode value.
-pass n             select the pass number (1 to 3)
-vf filter_graph    set video filters
-ab bitrate         audio bitrate (please use -b:a)
-b bitrate          video bitrate (please use -b:v)
-dn                 disable data

Audio options:
-aframes number     set the number of audio frames to output
-aq quality         set audio quality (codec-specific)
-ar rate            set audio sampling rate (in Hz)
-ac channels        set number of audio channels
-an                 disable audio
-acodec codec       force audio codec ('copy' to copy stream)
-vol volume         change audio volume (256=normal)
-af filter_graph    set audio filters

Subtitle options:
-s size             set frame size (WxH or abbreviation)
-sn                 disable subtitle
-scodec codec       force subtitle codec ('copy' to copy stream)
-stag fourcc/tag    force subtitle tag/fourcc
-fix_sub_duration   fix subtitles duration
-canvas_size size   set canvas size (WxH or abbreviation)
-spre preset        set the subtitle options to the indicated preset

 

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