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- @chapter Encoders
- @c man begin ENCODERS
- Encoders are configured elements in FFmpeg which allow the encoding of
- multimedia streams.
- When you configure your FFmpeg build, all the supported native encoders
- are enabled by default. Encoders requiring an external library must be enabled
- manually via the corresponding @code{--enable-lib} option. You can list all
- available encoders using the configure option @code{--list-encoders}.
- You can disable all the encoders with the configure option
- @code{--disable-encoders} and selectively enable / disable single encoders
- with the options @code{--enable-encoder=@var{ENCODER}} /
- @code{--disable-encoder=@var{ENCODER}}.
- The option @code{-codecs} of the ff* tools will display the list of
- enabled encoders.
- @c man end ENCODERS
- @chapter Audio Encoders
- @c man begin AUDIO ENCODERS
- A description of some of the currently available audio encoders
- follows.
- @anchor{aacenc}
- @section aac
- Advanced Audio Coding (AAC) encoder.
- This encoder is an experimental FFmpeg-native AAC encoder. Currently only the
- low complexity (AAC-LC) profile is supported. To use this encoder, you must set
- @option{strict} option to @samp{experimental} or lower.
- As this encoder is experimental, unexpected behavior may exist from time to
- time. For a more stable AAC encoder, see @ref{libvo-aacenc}. However, be warned
- that it has a worse quality reported by some users.
- @c Comment this out until somebody writes the respective documentation.
- @c See also @ref{libfaac}, @ref{libaacplus}, and @ref{libfdk-aac-enc}.
- @subsection Options
- @table @option
- @item b
- Set bit rate in bits/s. Setting this automatically activates constant bit rate
- (CBR) mode.
- @item q
- Set quality for variable bit rate (VBR) mode. This option is valid only using
- the @command{ffmpeg} command-line tool. For library interface users, use
- @option{global_quality}.
- @item stereo_mode
- Set stereo encoding mode. Possible values:
- @table @samp
- @item auto
- Automatically selected by the encoder.
- @item ms_off
- Disable middle/side encoding. This is the default.
- @item ms_force
- Force middle/side encoding.
- @end table
- @item aac_coder
- Set AAC encoder coding method. Possible values:
- @table @samp
- @item 0
- FAAC-inspired method.
- This method is a simplified reimplementation of the method used in FAAC, which
- sets thresholds proportional to the band energies, and then decreases all the
- thresholds with quantizer steps to find the appropriate quantization with
- distortion below threshold band by band.
- The quality of this method is comparable to the two loop searching method
- descibed below, but somewhat a little better and slower.
- @item 1
- Average noise to mask ratio (ANMR) trellis-based solution.
- This has a theoretic best quality out of all the coding methods, but at the
- cost of the slowest speed.
- @item 2
- Two loop searching (TLS) method.
- This method first sets quantizers depending on band thresholds and then tries
- to find an optimal combination by adding or subtracting a specific value from
- all quantizers and adjusting some individual quantizer a little.
- This method produces similar quality with the FAAC method and is the default.
- @item 3
- Constant quantizer method.
- This method sets a constant quantizer for all bands. This is the fastest of all
- the methods, yet produces the worst quality.
- @end table
- @end table
- @subsection Tips and Tricks
- According to some reports
- (e.g. @url{http://d.hatena.ne.jp/kamedo2/20120729/1343545890}), setting the
- @option{cutoff} option to 15000 Hz greatly improves the quality of the output
- quality. As a result, we encourage you to do the same.
- @section ac3 and ac3_fixed
- AC-3 audio encoders.
- These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366, as well as
- the undocumented RealAudio 3 (a.k.a. dnet).
- The @var{ac3} encoder uses floating-point math, while the @var{ac3_fixed}
- encoder only uses fixed-point integer math. This does not mean that one is
- always faster, just that one or the other may be better suited to a
- particular system. The floating-point encoder will generally produce better
- quality audio for a given bitrate. The @var{ac3_fixed} encoder is not the
- default codec for any of the output formats, so it must be specified explicitly
- using the option @code{-acodec ac3_fixed} in order to use it.
- @subsection AC-3 Metadata
- The AC-3 metadata options are used to set parameters that describe the audio,
- but in most cases do not affect the audio encoding itself. Some of the options
- do directly affect or influence the decoding and playback of the resulting
- bitstream, while others are just for informational purposes. A few of the
- options will add bits to the output stream that could otherwise be used for
- audio data, and will thus affect the quality of the output. Those will be
- indicated accordingly with a note in the option list below.
- These parameters are described in detail in several publicly-available
- documents.
- @itemize
- @item @uref{http://www.atsc.org/cms/standards/a_52-2010.pdf,A/52:2010 - Digital Audio Compression (AC-3) (E-AC-3) Standard}
- @item @uref{http://www.atsc.org/cms/standards/a_54a_with_corr_1.pdf,A/54 - Guide to the Use of the ATSC Digital Television Standard}
- @item @uref{http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/18_Metadata.Guide.pdf,Dolby Metadata Guide}
- @item @uref{http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/46_DDEncodingGuidelines.pdf,Dolby Digital Professional Encoding Guidelines}
- @end itemize
- @subsubsection Metadata Control Options
- @table @option
- @item -per_frame_metadata @var{boolean}
- Allow Per-Frame Metadata. Specifies if the encoder should check for changing
- metadata for each frame.
- @table @option
- @item 0
- The metadata values set at initialization will be used for every frame in the
- stream. (default)
- @item 1
- Metadata values can be changed before encoding each frame.
- @end table
- @end table
- @subsubsection Downmix Levels
- @table @option
- @item -center_mixlev @var{level}
- Center Mix Level. The amount of gain the decoder should apply to the center
- channel when downmixing to stereo. This field will only be written to the
- bitstream if a center channel is present. The value is specified as a scale
- factor. There are 3 valid values:
- @table @option
- @item 0.707
- Apply -3dB gain
- @item 0.595
- Apply -4.5dB gain (default)
- @item 0.500
- Apply -6dB gain
- @end table
- @item -surround_mixlev @var{level}
- Surround Mix Level. The amount of gain the decoder should apply to the surround
- channel(s) when downmixing to stereo. This field will only be written to the
- bitstream if one or more surround channels are present. The value is specified
- as a scale factor. There are 3 valid values:
- @table @option
- @item 0.707
- Apply -3dB gain
- @item 0.500
- Apply -6dB gain (default)
- @item 0.000
- Silence Surround Channel(s)
- @end table
- @end table
- @subsubsection Audio Production Information
- Audio Production Information is optional information describing the mixing
- environment. Either none or both of the fields are written to the bitstream.
- @table @option
- @item -mixing_level @var{number}
- Mixing Level. Specifies peak sound pressure level (SPL) in the production
- environment when the mix was mastered. Valid values are 80 to 111, or -1 for
- unknown or not indicated. The default value is -1, but that value cannot be
- used if the Audio Production Information is written to the bitstream. Therefore,
- if the @code{room_type} option is not the default value, the @code{mixing_level}
- option must not be -1.
- @item -room_type @var{type}
- Room Type. Describes the equalization used during the final mixing session at
- the studio or on the dubbing stage. A large room is a dubbing stage with the
- industry standard X-curve equalization; a small room has flat equalization.
- This field will not be written to the bitstream if both the @code{mixing_level}
- option and the @code{room_type} option have the default values.
- @table @option
- @item 0
- @itemx notindicated
- Not Indicated (default)
- @item 1
- @itemx large
- Large Room
- @item 2
- @itemx small
- Small Room
- @end table
- @end table
- @subsubsection Other Metadata Options
- @table @option
- @item -copyright @var{boolean}
- Copyright Indicator. Specifies whether a copyright exists for this audio.
- @table @option
- @item 0
- @itemx off
- No Copyright Exists (default)
- @item 1
- @itemx on
- Copyright Exists
- @end table
- @item -dialnorm @var{value}
- Dialogue Normalization. Indicates how far the average dialogue level of the
- program is below digital 100% full scale (0 dBFS). This parameter determines a
- level shift during audio reproduction that sets the average volume of the
- dialogue to a preset level. The goal is to match volume level between program
- sources. A value of -31dB will result in no volume level change, relative to
- the source volume, during audio reproduction. Valid values are whole numbers in
- the range -31 to -1, with -31 being the default.
- @item -dsur_mode @var{mode}
- Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround
- (Pro Logic). This field will only be written to the bitstream if the audio
- stream is stereo. Using this option does @b{NOT} mean the encoder will actually
- apply Dolby Surround processing.
- @table @option
- @item 0
- @itemx notindicated
- Not Indicated (default)
- @item 1
- @itemx off
- Not Dolby Surround Encoded
- @item 2
- @itemx on
- Dolby Surround Encoded
- @end table
- @item -original @var{boolean}
- Original Bit Stream Indicator. Specifies whether this audio is from the
- original source and not a copy.
- @table @option
- @item 0
- @itemx off
- Not Original Source
- @item 1
- @itemx on
- Original Source (default)
- @end table
- @end table
- @subsection Extended Bitstream Information
- The extended bitstream options are part of the Alternate Bit Stream Syntax as
- specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts.
- If any one parameter in a group is specified, all values in that group will be
- written to the bitstream. Default values are used for those that are written
- but have not been specified. If the mixing levels are written, the decoder
- will use these values instead of the ones specified in the @code{center_mixlev}
- and @code{surround_mixlev} options if it supports the Alternate Bit Stream
- Syntax.
- @subsubsection Extended Bitstream Information - Part 1
- @table @option
- @item -dmix_mode @var{mode}
- Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt
- (Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
- @table @option
- @item 0
- @itemx notindicated
- Not Indicated (default)
- @item 1
- @itemx ltrt
- Lt/Rt Downmix Preferred
- @item 2
- @itemx loro
- Lo/Ro Downmix Preferred
- @end table
- @item -ltrt_cmixlev @var{level}
- Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the
- center channel when downmixing to stereo in Lt/Rt mode.
- @table @option
- @item 1.414
- Apply +3dB gain
- @item 1.189
- Apply +1.5dB gain
- @item 1.000
- Apply 0dB gain
- @item 0.841
- Apply -1.5dB gain
- @item 0.707
- Apply -3.0dB gain
- @item 0.595
- Apply -4.5dB gain (default)
- @item 0.500
- Apply -6.0dB gain
- @item 0.000
- Silence Center Channel
- @end table
- @item -ltrt_surmixlev @var{level}
- Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the
- surround channel(s) when downmixing to stereo in Lt/Rt mode.
- @table @option
- @item 0.841
- Apply -1.5dB gain
- @item 0.707
- Apply -3.0dB gain
- @item 0.595
- Apply -4.5dB gain
- @item 0.500
- Apply -6.0dB gain (default)
- @item 0.000
- Silence Surround Channel(s)
- @end table
- @item -loro_cmixlev @var{level}
- Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the
- center channel when downmixing to stereo in Lo/Ro mode.
- @table @option
- @item 1.414
- Apply +3dB gain
- @item 1.189
- Apply +1.5dB gain
- @item 1.000
- Apply 0dB gain
- @item 0.841
- Apply -1.5dB gain
- @item 0.707
- Apply -3.0dB gain
- @item 0.595
- Apply -4.5dB gain (default)
- @item 0.500
- Apply -6.0dB gain
- @item 0.000
- Silence Center Channel
- @end table
- @item -loro_surmixlev @var{level}
- Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the
- surround channel(s) when downmixing to stereo in Lo/Ro mode.
- @table @option
- @item 0.841
- Apply -1.5dB gain
- @item 0.707
- Apply -3.0dB gain
- @item 0.595
- Apply -4.5dB gain
- @item 0.500
- Apply -6.0dB gain (default)
- @item 0.000
- Silence Surround Channel(s)
- @end table
- @end table
- @subsubsection Extended Bitstream Information - Part 2
- @table @option
- @item -dsurex_mode @var{mode}
- Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX
- (7.1 matrixed to 5.1). Using this option does @b{NOT} mean the encoder will actually
- apply Dolby Surround EX processing.
- @table @option
- @item 0
- @itemx notindicated
- Not Indicated (default)
- @item 1
- @itemx on
- Dolby Surround EX Off
- @item 2
- @itemx off
- Dolby Surround EX On
- @end table
- @item -dheadphone_mode @var{mode}
- Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone
- encoding (multi-channel matrixed to 2.0 for use with headphones). Using this
- option does @b{NOT} mean the encoder will actually apply Dolby Headphone
- processing.
- @table @option
- @item 0
- @itemx notindicated
- Not Indicated (default)
- @item 1
- @itemx on
- Dolby Headphone Off
- @item 2
- @itemx off
- Dolby Headphone On
- @end table
- @item -ad_conv_type @var{type}
- A/D Converter Type. Indicates whether the audio has passed through HDCD A/D
- conversion.
- @table @option
- @item 0
- @itemx standard
- Standard A/D Converter (default)
- @item 1
- @itemx hdcd
- HDCD A/D Converter
- @end table
- @end table
- @subsection Other AC-3 Encoding Options
- @table @option
- @item -stereo_rematrixing @var{boolean}
- Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
- is an optional AC-3 feature that increases quality by selectively encoding
- the left/right channels as mid/side. This option is enabled by default, and it
- is highly recommended that it be left as enabled except for testing purposes.
- @end table
- @subsection Floating-Point-Only AC-3 Encoding Options
- These options are only valid for the floating-point encoder and do not exist
- for the fixed-point encoder due to the corresponding features not being
- implemented in fixed-point.
- @table @option
- @item -channel_coupling @var{boolean}
- Enables/Disables use of channel coupling, which is an optional AC-3 feature
- that increases quality by combining high frequency information from multiple
- channels into a single channel. The per-channel high frequency information is
- sent with less accuracy in both the frequency and time domains. This allows
- more bits to be used for lower frequencies while preserving enough information
- to reconstruct the high frequencies. This option is enabled by default for the
- floating-point encoder and should generally be left as enabled except for
- testing purposes or to increase encoding speed.
- @table @option
- @item -1
- @itemx auto
- Selected by Encoder (default)
- @item 0
- @itemx off
- Disable Channel Coupling
- @item 1
- @itemx on
- Enable Channel Coupling
- @end table
- @item -cpl_start_band @var{number}
- Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
- value higher than the bandwidth is used, it will be reduced to 1 less than the
- coupling end band. If @var{auto} is used, the start band will be determined by
- the encoder based on the bit rate, sample rate, and channel layout. This option
- has no effect if channel coupling is disabled.
- @table @option
- @item -1
- @itemx auto
- Selected by Encoder (default)
- @end table
- @end table
- @section libmp3lame
- LAME (Lame Ain't an MP3 Encoder) MP3 encoder wrapper
- Requires the presence of the libmp3lame headers and library during
- configuration. You need to explicitly configure the build with
- @code{--enable-libmp3lame}.
- @subsection Options
- The following options are supported by the libmp3lame wrapper. The
- @command{lame}-equivalent of the options are listed in parentheses.
- @table @option
- @item b (@emph{-b})
- Set bitrate expressed in bits/s for CBR. LAME @code{bitrate} is
- expressed in kilobits/s.
- @item q (@emph{-V})
- Set constant quality setting for VBR. This option is valid only
- using the @command{ffmpeg} command-line tool. For library interface
- users, use @option{global_quality}.
- @item compression_level (@emph{-q})
- Set algorithm quality. Valid arguments are integers in the 0-9 range,
- with 0 meaning highest quality but slowest, and 9 meaning fastest
- while producing the worst quality.
- @item reservoir
- Enable use of bit reservoir when set to 1. Default value is 1. LAME
- has this enabled by default, but can be overriden by use
- @option{--nores} option.
- @end table
- @section libopencore-amrnb
- OpenCORE Adaptive Multi-Rate Narrowband encoder.
- Requires the presence of the libopencore-amrnb headers and library during
- configuration. You need to explicitly configure the build with
- @code{--enable-libopencore-amrnb --enable-version3}.
- This is a mono-only encoder. Officially it only supports 8000Hz sample rate,
- but you can override it by setting @option{strict} to @samp{unofficial} or
- lower.
- @subsection Options
- @table @option
- @item b
- Set bitrate in bits per second. Only the following bitrates are supported,
- otherwise libavcodec will round to the nearest valid bitrate.
- @table @option
- @item 4750
- @item 5150
- @item 5900
- @item 6700
- @item 7400
- @item 7950
- @item 10200
- @item 12200
- @end table
- @item dtx
- Allow discontinuous transmission (generate comfort noise) when set to 1. The
- default value is 0 (disabled).
- @end table
- @section libtwolame
- TwoLAME MP2 encoder wrapper
- Requires the presence of the libtwolame headers and library during
- configuration. You need to explicitly configure the build with
- @code{--enable-libtwolame}.
- @subsection Options
- The following options are supported by the libtwolame wrapper. The
- @command{twolame}-equivalent options follow the FFmpeg ones and are in
- parentheses.
- @table @option
- @item b (@emph{-b})
- Set bitrate expressed in bits/s for CBR. @command{twolame} @option{b}
- option is expressed in kilobits/s. Default value is 128k.
- @item q (@emph{-V})
- Set quality for experimental VBR support. Maximum value range is
- from -50 to 50, useful range is from -10 to 10. The higher the
- value, the better the quality. This option is valid only using the
- @command{ffmpeg} command-line tool. For library interface users,
- use @option{global_quality}.
- @item mode (@emph{--mode})
- Set the mode of the resulting audio. Possible values:
- @table @samp
- @item auto
- Choose mode automatically based on the input. This is the default.
- @item stereo
- Stereo
- @item joint_stereo
- Joint stereo
- @item dual_channel
- Dual channel
- @item mono
- Mono
- @end table
- @item psymodel (@emph{--psyc-mode})
- Set psychoacoustic model to use in encoding. The argument must be
- an integer between -1 and 4, inclusive. The higher the value, the
- better the quality. The default value is 3.
- @item energy_levels (@emph{--energy})
- Enable energy levels extensions when set to 1. The default value is
- 0 (disabled).
- @item error_protection (@emph{--protect})
- Enable CRC error protection when set to 1. The default value is 0
- (disabled).
- @item copyright (@emph{--copyright})
- Set MPEG audio copyright flag when set to 1. The default value is 0
- (disabled).
- @item original (@emph{--original})
- Set MPEG audio original flag when set to 1. The default value is 0
- (disabled).
- @end table
- @anchor{libvo-aacenc}
- @section libvo-aacenc
- VisualOn AAC encoder
- Requires the presence of the libvo-aacenc headers and library during
- configuration. You need to explicitly configure the build with
- @code{--enable-libvo-aacenc --enable-version3}.
- This encoder is considered to be worse than the
- @ref{aacenc,,native experimental FFmpeg AAC encoder}, according to
- multiple sources.
- @subsection Options
- The VisualOn AAC encoder only support encoding AAC-LC and up to 2
- channels. It is also CBR-only.
- @table @option
- @item b
- Set bit rate in bits/s.
- @end table
- @section libvo-amrwbenc
- VisualOn Adaptive Multi-Rate Wideband encoder
- Requires the presence of the libvo-amrwbenc headers and library during
- configuration. You need to explicitly configure the build with
- @code{--enable-libvo-amrwbenc --enable-version3}.
- This is a mono-only encoder. Officially it only supports 16000Hz sample
- rate, but you can override it by setting @option{strict} to
- @samp{unofficial} or lower.
- @subsection Options
- @table @option
- @item b
- Set bitrate in bits/s. Only the following bitrates are supported, otherwise
- libavcodec will round to the nearest valid bitrate.
- @table @samp
- @item 6600
- @item 8850
- @item 12650
- @item 14250
- @item 15850
- @item 18250
- @item 19850
- @item 23050
- @item 23850
- @end table
- @item dtx
- Allow discontinuous transmission (generate comfort noise) when set to 1. The
- default value is 0 (disabled).
- @end table
- @section libopus
- libopus Opus Interactive Audio Codec encoder wrapper.
- Requires the presence of the libopus headers and library during
- configuration. You need to explicitly configure the build with
- @code{--enable-libopus}.
- @subsection Option Mapping
- Most libopus options are modeled after the @command{opusenc} utility from
- opus-tools. The following is an option mapping chart describing options
- supported by the libopus wrapper, and their @command{opusenc}-equivalent
- in parentheses.
- @table @option
- @item b (@emph{bitrate})
- Set the bit rate in bits/s. FFmpeg's @option{b} option is
- expressed in bits/s, while @command{opusenc}'s @option{bitrate} in
- kilobits/s.
- @item vbr (@emph{vbr}, @emph{hard-cbr}, and @emph{cvbr})
- Set VBR mode. The FFmpeg @option{vbr} option has the following
- valid arguments, with the their @command{opusenc} equivalent options
- in parentheses:
- @table @samp
- @item off (@emph{hard-cbr})
- Use constant bit rate encoding.
- @item on (@emph{vbr})
- Use variable bit rate encoding (the default).
- @item constrained (@emph{cvbr})
- Use constrained variable bit rate encoding.
- @end table
- @item compression_level (@emph{comp})
- Set encoding algorithm complexity. Valid options are integers in
- the 0-10 range. 0 gives the fastest encodes but lower quality, while 10
- gives the highest quality but slowest encoding. The default is 10.
- @item frame_duration (@emph{framesize})
- Set maximum frame size, or duration of a frame in milliseconds. The
- argument must be exactly the following: 2.5, 5, 10, 20, 40, 60. Smaller
- frame sizes achieve lower latency but less quality at a given bitrate.
- Sizes greater than 20ms are only interesting at fairly low bitrates.
- The default is 20ms.
- @item packet_loss (@emph{expect-loss})
- Set expected packet loss percentage. The default is 0.
- @item application (N.A.)
- Set intended application type. Valid options are listed below:
- @table @samp
- @item voip
- Favor improved speech intelligibility.
- @item audio
- Favor faithfulness to the input (the default).
- @item lowdelay
- Restrict to only the lowest delay modes.
- @end table
- @item cutoff (N.A.)
- Set cutoff bandwidth in Hz. The argument must be exactly one of the
- following: 4000, 6000, 8000, 12000, or 20000, corresponding to
- narrowband, mediumband, wideband, super wideband, and fullband
- respectively. The default is 0 (cutoff disabled).
- @end table
- @c man end AUDIO ENCODERS
- @chapter Video Encoders
- @c man begin VIDEO ENCODERS
- A description of some of the currently available video encoders
- follows.
- @section libtheora
- Theora format supported through libtheora.
- Requires the presence of the libtheora headers and library during
- configuration. You need to explicitly configure the build with
- @code{--enable-libtheora}.
- @subsection Options
- The following global options are mapped to internal libtheora options
- which affect the quality and the bitrate of the encoded stream.
- @table @option
- @item b
- Set the video bitrate, only works if the @code{qscale} flag in
- @option{flags} is not enabled.
- @item flags
- Used to enable constant quality mode encoding through the
- @option{qscale} flag, and to enable the @code{pass1} and @code{pass2}
- modes.
- @item g
- Set the GOP size.
- @item global_quality
- Set the global quality in lambda units, only works if the
- @code{qscale} flag in @option{flags} is enabled. The value is clipped
- in the [0 - 10*@code{FF_QP2LAMBDA}] range, and then multiplied for 6.3
- to get a value in the native libtheora range [0-63]. A higher value
- corresponds to a higher quality.
- For example, to set maximum constant quality encoding with
- @command{ffmpeg}:
- @example
- ffmpeg -i INPUT -flags:v qscale -global_quality:v "10*QP2LAMBDA" -codec:v libtheora OUTPUT.ogg
- @end example
- @end table
- @section libvpx
- VP8 format supported through libvpx.
- Requires the presence of the libvpx headers and library during configuration.
- You need to explicitly configure the build with @code{--enable-libvpx}.
- @subsection Options
- Mapping from FFmpeg to libvpx options with conversion notes in parentheses.
- @table @option
- @item threads
- g_threads
- @item profile
- g_profile
- @item vb
- rc_target_bitrate
- @item g
- kf_max_dist
- @item keyint_min
- kf_min_dist
- @item qmin
- rc_min_quantizer
- @item qmax
- rc_max_quantizer
- @item bufsize, vb
- rc_buf_sz
- @code{(bufsize * 1000 / vb)}
- rc_buf_optimal_sz
- @code{(bufsize * 1000 / vb * 5 / 6)}
- @item rc_init_occupancy, vb
- rc_buf_initial_sz
- @code{(rc_init_occupancy * 1000 / vb)}
- @item rc_buffer_aggressivity
- rc_undershoot_pct
- @item skip_threshold
- rc_dropframe_thresh
- @item qcomp
- rc_2pass_vbr_bias_pct
- @item maxrate, vb
- rc_2pass_vbr_maxsection_pct
- @code{(maxrate * 100 / vb)}
- @item minrate, vb
- rc_2pass_vbr_minsection_pct
- @code{(minrate * 100 / vb)}
- @item minrate, maxrate, vb
- @code{VPX_CBR}
- @code{(minrate == maxrate == vb)}
- @item crf
- @code{VPX_CQ}, @code{VP8E_SET_CQ_LEVEL}
- @item quality
- @table @option
- @item @var{best}
- @code{VPX_DL_BEST_QUALITY}
- @item @var{good}
- @code{VPX_DL_GOOD_QUALITY}
- @item @var{realtime}
- @code{VPX_DL_REALTIME}
- @end table
- @item speed
- @code{VP8E_SET_CPUUSED}
- @item nr
- @code{VP8E_SET_NOISE_SENSITIVITY}
- @item mb_threshold
- @code{VP8E_SET_STATIC_THRESHOLD}
- @item slices
- @code{VP8E_SET_TOKEN_PARTITIONS}
- @item max-intra-rate
- @code{VP8E_SET_MAX_INTRA_BITRATE_PCT}
- @item force_key_frames
- @code{VPX_EFLAG_FORCE_KF}
- @item Alternate reference frame related
- @table @option
- @item vp8flags altref
- @code{VP8E_SET_ENABLEAUTOALTREF}
- @item @var{arnr_max_frames}
- @code{VP8E_SET_ARNR_MAXFRAMES}
- @item @var{arnr_type}
- @code{VP8E_SET_ARNR_TYPE}
- @item @var{arnr_strength}
- @code{VP8E_SET_ARNR_STRENGTH}
- @item @var{rc_lookahead}
- g_lag_in_frames
- @end table
- @item vp8flags error_resilient
- g_error_resilient
- @end table
- For more information about libvpx see:
- @url{http://www.webmproject.org/}
- @section libx264
- H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 format supported through
- libx264.
- Requires the presence of the libx264 headers and library during
- configuration. You need to explicitly configure the build with
- @code{--enable-libx264}.
- @subsection Options
- @table @option
- @item preset @var{preset_name}
- Set the encoding preset.
- @item tune @var{tune_name}
- Tune the encoding params.
- @item fastfirstpass @var{bool}
- Use fast settings when encoding first pass, default value is 1.
- @item profile @var{profile_name}
- Set profile restrictions.
- @item level @var{level}
- Specify level (as defined by Annex A).
- Deprecated in favor of @var{x264opts}.
- @item passlogfile @var{filename}
- Specify filename for 2 pass stats.
- Deprecated in favor of @var{x264opts} (see @var{stats} libx264 option).
- @item wpredp @var{wpred_type}
- Specify Weighted prediction for P-frames.
- Deprecated in favor of @var{x264opts} (see @var{weightp} libx264 option).
- @item x264opts @var{options}
- Allow to set any x264 option, see @code{x264 --fullhelp} for a list.
- @var{options} is a list of @var{key}=@var{value} couples separated by
- ":". In @var{filter} and @var{psy-rd} options that use ":" as a separator
- themselves, use "," instead. They accept it as well since long ago but this
- is kept undocumented for some reason.
- @end table
- For example to specify libx264 encoding options with @command{ffmpeg}:
- @example
- ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
- @end example
- For more information about libx264 and the supported options see:
- @url{http://www.videolan.org/developers/x264.html}
- @section libxvid
- Xvid MPEG-4 Part 2 encoder wrapper.
- This encoder requires the presence of the libxvidcore headers and library
- during configuration. You need to explicitly configure the build with
- @code{--enable-libxvid --enable-gpl}.
- The native @code{mpeg4} encoder supports the MPEG-4 Part 2 format, so
- users can encode to this format without this library.
- @subsection Options
- The following options are supported by the libxvid wrapper. Some of
- the following options are listed but are not documented, and
- correspond to shared codec options. See @ref{codec-options,,the Codec
- Options chapter} for their documentation. The other shared options
- which are not listed have no effect for the libxvid encoder.
- @table @option
- @item b
- @item g
- @item qmin
- @item qmax
- @item mpeg_quant
- @item threads
- @item bf
- @item b_qfactor
- @item b_qoffset
- @item flags
- Set specific encoding flags. Possible values:
- @table @samp
- @item mv4
- Use four motion vector by macroblock.
- @item aic
- Enable high quality AC prediction.
- @item gray
- Only encode grayscale.
- @item gmc
- Enable the use of global motion compensation (GMC).
- @item qpel
- Enable quarter-pixel motion compensation.
- @item cgop
- Enable closed GOP.
- @item global_header
- Place global headers in extradata instead of every keyframe.
- @end table
- @item trellis
- @item me_method
- Set motion estimation method. Possible values in decreasing order of
- speed and increasing order of quality:
- @table @samp
- @item zero
- Use no motion estimation (default).
- @item phods
- @item x1
- @item log
- Enable advanced diamond zonal search for 16x16 blocks and half-pixel
- refinement for 16x16 blocks. @samp{x1} and @samp{log} are aliases for
- @samp{phods}.
- @item epzs
- Enable all of the things described above, plus advanced diamond zonal
- search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
- estimation on chroma planes.
- @item full
- Enable all of the things described above, plus extended 16x16 and 8x8
- blocks search.
- @end table
- @item mbd
- Set macroblock decision algorithm. Possible values in the increasing
- order of quality:
- @table @samp
- @item simple
- Use macroblock comparing function algorithm (default).
- @item bits
- Enable rate distortion-based half pixel and quarter pixel refinement for
- 16x16 blocks.
- @item rd
- Enable all of the things described above, plus rate distortion-based
- half pixel and quarter pixel refinement for 8x8 blocks, and rate
- distortion-based search using square pattern.
- @end table
- @end table
- @c man end VIDEO ENCODERS
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