@end table
-@section libwavpack
+@anchor{flac}
+@section flac
-A wrapper providing WavPack encoding through libwavpack.
+FLAC (Free Lossless Audio Codec) Encoder
-Only lossless mode using 32-bit integer samples is supported currently.
-The @option{compression_level} option can be used to control speed vs.
-compression tradeoff, with the values mapped to libwavpack as follows:
+@subsection Options
+
+The following options are supported by FFmpeg's flac encoder.
@table @option
+@item compression_level
+Sets the compression level, which chooses defaults for many other options
+if they are not set explicitly.
-@item 0
-Fast mode - corresponding to the wavpack @option{-f} option.
+@item frame_size
+Sets the size of the frames in samples per channel.
-@item 1
-Normal (default) settings.
+@item lpc_coeff_precision
+Sets the LPC coefficient precision, valid values are from 1 to 15, 15 is the
+default.
-@item 2
-High quality - corresponding to the wavpack @option{-h} option.
+@item lpc_type
+Sets the first stage LPC algorithm
+@table @samp
+@item none
+LPC is not used
-@item 3
-Very high quality - corresponding to the wavpack @option{-hh} option.
+@item fixed
+fixed LPC coefficients
-@item 4-8
-Same as 3, but with extra processing enabled - corresponding to the wavpack
-@option{-x} option. I.e. 4 is the same as @option{-x2} and 8 is the same as
-@option{-x6}.
+@item levinson
+@item cholesky
@end table
-@c man end AUDIO ENCODERS
+@item lpc_passes
+Number of passes to use for Cholesky factorization during LPC analysis
-@chapter Video Encoders
-@c man begin VIDEO ENCODERS
+@item min_partition_order
+The minimum partition order
-@section libwebp
+@item max_partition_order
+The maximum partition order
-libwebp WebP Image encoder wrapper
+@item prediction_order_method
+@table @samp
+@item estimation
+@item 2level
+@item 4level
+@item 8level
+@item search
+Bruteforce search
+@item log
+@end table
-libwebp is Google's official encoder for WebP images. It can encode in either
-lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
-frame. Lossless images are a separate codec developed by Google.
+@item ch_mode
+Channel mode
+@table @samp
+@item auto
+The mode is chosen automatically for each frame
+@item indep
+Chanels are independently coded
+@item left_side
+@item right_side
+@item mid_side
+@end table
-@subsection Pixel Format
+@item exact_rice_parameters
+Chooses if rice parameters are calculated exactly or approximately.
+if set to 1 then they are chosen exactly, which slows the code down slightly and
+improves compression slightly.
-Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
-to limitations of the format and libwebp. Alpha is supported for either mode.
-Because of API limitations, if RGB is passed in when encoding lossy or YUV is
-passed in for encoding lossless, the pixel format will automatically be
-converted using functions from libwebp. This is not ideal and is done only for
-convenience.
+@item multi_dim_quant
+Multi Dimensional Quantization. If set to 1 then a 2nd stage LPC algorithm is
+applied after the first stage to finetune the coefficients. This is quite slow
+and slightly improves compression.
-@subsection Options
+@end table
-@table @option
+@anchor{libfaac}
+@section libfaac
-@item -lossless @var{boolean}
-Enables/Disables use of lossless mode. Default is 0.
+libfaac AAC (Advanced Audio Coding) encoder wrapper.
-@item -compression_level @var{integer}
-For lossy, this is a quality/speed tradeoff. Higher values give better quality
-for a given size at the cost of increased encoding time. For lossless, this is
-a size/speed tradeoff. Higher values give smaller size at the cost of increased
-encoding time. More specifically, it controls the number of extra algorithms
-and compression tools used, and varies the combination of these tools. This
-maps to the @var{method} option in libwebp. The valid range is 0 to 6.
-Default is 4.
+Requires the presence of the libfaac headers and library during
+configuration. You need to explicitly configure the build with
+@code{--enable-libfaac --enable-nonfree}.
-@item -qscale @var{float}
-For lossy encoding, this controls image quality, 0 to 100. For lossless
-encoding, this controls the effort and time spent at compressing more. The
-default value is 75. Note that for usage via libavcodec, this option is called
-@var{global_quality} and must be multiplied by @var{FF_QP2LAMBDA}.
+This encoder is considered to be of higher quality with respect to the
+@ref{aacenc,,the native experimental FFmpeg AAC encoder}.
-@item -preset @var{type}
-Configuration preset. This does some automatic settings based on the general
-type of the image.
-@table @option
-@item none
-Do not use a preset.
-@item default
-Use the encoder default.
-@item picture
-Digital picture, like portrait, inner shot
-@item photo
-Outdoor photograph, with natural lighting
-@item drawing
-Hand or line drawing, with high-contrast details
-@item icon
-Small-sized colorful images
-@item text
-Text-like
-@end table
+For more information see the libfaac project at
+@url{http://www.audiocoding.com/faac.html/}.
-@item lumi_aq
-Enable lumi masking adaptive quantization when set to 1. Default is 0
-(disabled).
+@subsection Options
-@item variance_aq
-Enable variance adaptive quantization when set to 1. Default is 0
-(disabled).
+The following shared FFmpeg codec options are recognized.
-When combined with @option{lumi_aq}, the resulting quality will not
-be better than any of the two specified individually. In other
-words, the resulting quality will be the worse one of the two
-effects.
+The following options are supported by the libfaac wrapper. The
+@command{faac}-equivalent of the options are listed in parentheses.
-@item ssim
-Set structural similarity (SSIM) displaying method. Possible values:
+@table @option
+@item b (@emph{-b})
+Set bit rate in bits/s for ABR (Average Bit Rate) mode. If the bit rate
+is not explicitly specified, it is automatically set to a suitable
+value depending on the selected profile. @command{faac} bitrate is
+expressed in kilobits/s.
-@table @samp
-@item off
-Disable displaying of SSIM information.
+Note that libfaac does not support CBR (Constant Bit Rate) but only
+ABR (Average Bit Rate).
-@item avg
-Output average SSIM at the end of encoding to stdout. The format of
-showing the average SSIM is:
+If VBR mode is enabled this option is ignored.
-@example
-Average SSIM: %f
-@end example
+@item ar (@emph{-R})
+Set audio sampling rate (in Hz).
-For users who are not familiar with C, %f means a float number, or
-a decimal (e.g. 0.939232).
+@item ac (@emph{-c})
+Set the number of audio channels.
-@item frame
-Output both per-frame SSIM data during encoding and average SSIM at
-the end of encoding to stdout. The format of per-frame information
-is:
+@item cutoff (@emph{-C})
+Set cutoff frequency. If not specified (or explicitly set to 0) it
+will use a value automatically computed by the library. Default value
+is 0.
-@example
- SSIM: avg: %1.3f min: %1.3f max: %1.3f
-@end example
+@item profile
+Set audio profile.
-For users who are not familiar with C, %1.3f means a float number
-rounded to 3 digits after the dot (e.g. 0.932).
+The following profiles are recognized:
+@table @samp
+@item aac_main
+Main AAC (Main)
-@end table
+@item aac_low
+Low Complexity AAC (LC)
-@item ssim_acc
-Set SSIM accuracy. Valid options are integers within the range of
-0-4, while 0 gives the most accurate result and 4 computes the
-fastest.
+@item aac_ssr
+Scalable Sample Rate (SSR)
+@item aac_ltp
+Long Term Prediction (LTP)
@end table
-@section libx264
+If not specified it is set to @samp{aac_low}.
-x264 H.264/MPEG-4 AVC encoder wrapper
+@item flags +qscale
+Set constant quality VBR (Variable Bit Rate) mode.
-x264 supports an impressive number of features, including 8x8 and 4x4 adaptive
-spatial transform, adaptive B-frame placement, CAVLC/CABAC entropy coding,
-interlacing (MBAFF), lossless mode, psy optimizations for detail retention
-(adaptive quantization, psy-RD, psy-trellis).
+@item global_quality
+Set quality in VBR mode as an integer number of lambda units.
-The Libav wrapper provides a mapping for most of them using global options
-that match those of the encoders and provides private options for the unique
-encoder options. Additionally an expert override is provided to directly pass
-a list of key=value tuples as accepted by x264_param_parse.
+Only relevant when VBR mode is enabled with @code{flags +qscale}. The
+value is converted to QP units by dividing it by @code{FF_QP2LAMBDA},
+and used to set the quality value used by libfaac. A reasonable range
+for the option value in QP units is [10-500], the higher the value the
+higher the quality.
-@subsection Option Mapping
-
-The following options are supported by the x264 wrapper, the x264-equivalent
-options follow the Libav ones.
-
-@multitable { } { } { }
-@item b @tab bitrate
-@tab Libav @code{b} option is expressed in bits/s, x264 @code{bitrate} in kilobits/s.
-@item bf @tab bframes
-@tab Maximum number of B-frames.
-@item g @tab keyint
-@tab Maximum GOP size.
-@item qmin @tab qpmin
-@tab Minimum quantizer scale.
-@item qmax @tab qpmax
-@tab Maximum quantizer scale.
-@item qdiff @tab qpstep
-@tab Maximum difference between quantizer scales.
-@item qblur @tab qblur
-@tab Quantizer curve blur
-@item qcomp @tab qcomp
-@tab Quantizer curve compression factor
-@item refs @tab ref
-@tab Number of reference frames each P-frame can use. The range is from @var{0-16}.
-@item sc_threshold @tab scenecut
-@tab Sets the threshold for the scene change detection.
-@item trellis @tab trellis
-@tab Performs Trellis quantization to increase efficiency. Enabled by default.
-@item nr @tab nr
-@tab Noise reduction.
-@item me_range @tab merange
-@tab Maximum range of the motion search in pixels.
-@item subq @tab subme
-@tab Sub-pixel motion estimation method.
-@item b_strategy @tab b-adapt
-@tab Adaptive B-frame placement decision algorithm. Use only on first-pass.
-@item keyint_min @tab min-keyint
-@tab Minimum GOP size.
-@item coder @tab cabac
-@tab Set coder to @code{ac} to use CABAC.
-@item cmp @tab chroma-me
-@tab Set to @code{chroma} to use chroma motion estimation.
-@item threads @tab threads
-@tab Number of encoding threads.
-@item thread_type @tab sliced_threads
-@tab Set to @code{slice} to use sliced threading instead of frame threading.
-@item flags -cgop @tab open-gop
-@tab Set @code{-cgop} to use recovery points to close GOPs.
-@item rc_init_occupancy @tab vbv-init
-@tab Initial buffer occupancy.
-@end multitable
-
-@subsection Private Options
-@table @option
-@item -preset @var{string}
-Set the encoding preset (cf. x264 --fullhelp).
-@item -tune @var{string}
-Tune the encoding params (cf. x264 --fullhelp).
-@item -profile @var{string}
-Set profile restrictions (cf. x264 --fullhelp).
-@item -fastfirstpass @var{integer}
-Use fast settings when encoding first pass.
-@item -crf @var{float}
-Select the quality for constant quality mode.
-@item -crf_max @var{float}
-In CRF mode, prevents VBV from lowering quality beyond this point.
-@item -qp @var{integer}
-Constant quantization parameter rate control method.
-@item -aq-mode @var{integer}
-AQ method
+@item q (@emph{-q})
+Enable VBR mode when set to a non-negative value, and set constant
+quality value as a double floating point value in QP units.
-Possible values:
-@table @samp
-@item none
+The value sets the quality value used by libfaac. A reasonable range
+for the option value is [10-500], the higher the value the higher the
+quality.
-@item variance
-Variance AQ (complexity mask).
-@item autovariance
-Auto-variance AQ (experimental).
+This option is valid only using the @command{ffmpeg} command-line
+tool. For library interface users, use @option{global_quality}.
@end table
-@item -aq-strength @var{float}
-AQ strength, reduces blocking and blurring in flat and textured areas.
-@item -psy @var{integer}
-Use psychovisual optimizations.
-@item -psy-rd @var{string}
-Strength of psychovisual optimization, in <psy-rd>:<psy-trellis> format.
-@item -rc-lookahead @var{integer}
-Number of frames to look ahead for frametype and ratecontrol.
-@item -weightb @var{integer}
-Weighted prediction for B-frames.
-@item -weightp @var{integer}
-Weighted prediction analysis method.
-Possible values:
-@table @samp
-@item none
+@subsection Examples
-@item simple
+@itemize
+@item
+Use @command{ffmpeg} to convert an audio file to ABR 128 kbps AAC in an M4A (MP4)
+container:
+@example
+ffmpeg -i input.wav -codec:a libfaac -b:a 128k -output.m4a
+@end example
-@item smart
+@item
+Use @command{ffmpeg} to convert an audio file to VBR AAC, using the
+LTP AAC profile:
+@example
+ffmpeg -i input.wav -c:a libfaac -profile:a aac_ltp -q:a 100 output.m4a
+@end example
+@end itemize
-@end table
-@item -ssim @var{integer}
-Calculate and print SSIM stats.
-@item -intra-refresh @var{integer}
-Use Periodic Intra Refresh instead of IDR frames.
-@item -bluray-compat @var{integer}
-Configure the encoder to be compatible with the bluray standard.
-It is a shorthand for setting "bluray-compat=1 force-cfr=1".
-@item -b-bias @var{integer}
-Influences how often B-frames are used.
-@item -b-pyramid @var{integer}
-Keep some B-frames as references.
+@anchor{libfdk-aac-enc}
+@section libfdk_aac
-Possible values:
-@table @samp
-@item none
+libfdk-aac AAC (Advanced Audio Coding) encoder wrapper.
-@item strict
-Strictly hierarchical pyramid.
-@item normal
-Non-strict (not Blu-ray compatible).
-@end table
-@item -mixed-refs @var{integer}
-One reference per partition, as opposed to one reference per macroblock.
-@item -8x8dct @var{integer}
-High profile 8x8 transform.
-@item -fast-pskip @var{integer}
-@item -aud @var{integer}
-Use access unit delimiters.
-@item -mbtree @var{integer}
-Use macroblock tree ratecontrol.
-@item -deblock @var{string}
-Loop filter parameters, in <alpha:beta> form.
-@item -cplxblur @var{float}
-Reduce fluctuations in QP (before curve compression).
-@item -partitions @var{string}
-A comma-separated list of partitions to consider, possible values: p8x8, p4x4, b8x8, i8x8, i4x4, none, all.
-@item -direct-pred @var{integer}
-Direct MV prediction mode
+The libfdk-aac library is based on the Fraunhofer FDK AAC code from
+the Android project.
-Possible values:
-@table @samp
-@item none
+Requires the presence of the libfdk-aac headers and library during
+configuration. You need to explicitly configure the build with
+@code{--enable-libfdk-aac}. The library is also incompatible with GPL,
+so if you allow the use of GPL, you should configure with
+@code{--enable-gpl --enable-nonfree --enable-libfdk-aac}.
-@item spatial
+This encoder is considered to be of higher quality with respect to
+both @ref{aacenc,,the native experimental FFmpeg AAC encoder} and
+@ref{libfaac}.
-@item temporal
+VBR encoding, enabled through the @option{vbr} or @option{flags
++qscale} options, is experimental and only works with some
+combinations of parameters.
-@item auto
+Support for encoding 7.1 audio is only available with libfdk-aac 0.1.3 or
+higher.
-@end table
-@item -slice-max-size @var{integer}
-Limit the size of each slice in bytes.
-@item -stats @var{string}
-Filename for 2 pass stats.
-@item -nal-hrd @var{integer}
-Signal HRD information (requires vbv-bufsize; cbr not allowed in .mp4).
+For more information see the fdk-aac project at
+@url{http://sourceforge.net/p/opencore-amr/fdk-aac/}.
-Possible values:
-@table @samp
-@item none
+@subsection Options
-@item vbr
+The following options are mapped on the shared FFmpeg codec options.
-@item cbr
+@table @option
+@item b
+Set bit rate in bits/s. If the bitrate is not explicitly specified, it
+is automatically set to a suitable value depending on the selected
+profile.
-@end table
-@item -x264-params @var{string}
-Override the x264 configuration using a :-separated list of key=value parameters.
-@example
--x264-params level=30:bframes=0:weightp=0:cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:no-fast-pskip=1:subq=6:8x8dct=0:trellis=0
-@end example
-@end table
+In case VBR mode is enabled the option is ignored.
-Encoding avpresets for common usages are provided so they can be used with the
-general presets system (e.g. passing the @code{-pre} option).
+@item ar
+Set audio sampling rate (in Hz).
-@section ProRes
+@item channels
+Set the number of audio channels.
-Apple ProRes encoder.
+@item flags +qscale
+Enable fixed quality, VBR (Variable Bit Rate) mode.
+Note that VBR is implicitly enabled when the @option{vbr} value is
+positive.
-@subsection Private Options
+@item cutoff
+Set cutoff frequency. If not specified (or explicitly set to 0) it
+will use a value automatically computed by the library. Default value
+is 0.
-@table @option
-@item profile @var{integer}
-Select the ProRes profile to encode
-@table @samp
-@item proxy
-@item lt
-@item standard
-@item hq
-@item 4444
-@end table
+@item profile
+Set audio profile.
-@item quant_mat @var{integer}
-Select quantization matrix.
+The following profiles are recognized:
@table @samp
-@item auto
-@item default
-@item proxy
-@item lt
-@item standard
-@item hq
-@end table
-If set to @var{auto}, the matrix matching the profile will be picked.
-If not set, the matrix providing the highest quality, @var{default}, will be
-picked.
+@item aac_low
+Low Complexity AAC (LC)
-@item bits_per_mb @var{integer}
-How many bits to allot for coding one macroblock. Different profiles use
-between 200 and 2400 bits per macroblock, the maximum is 8000.
+@item aac_he
+High Efficiency AAC (HE-AAC)
-@item mbs_per_slice @var{integer}
-Number of macroblocks in each slice (1-8); the default value (8)
-should be good in almost all situations.
+@item aac_he_v2
+High Efficiency AAC version 2 (HE-AACv2)
-@item vendor @var{string}
-Override the 4-byte vendor ID.
-A custom vendor ID like @var{apl0} would claim the stream was produced by
-the Apple encoder.
+@item aac_ld
+Low Delay AAC (LD)
-@item alpha_bits @var{integer}
-Specify number of bits for alpha component.
-Possible values are @var{0}, @var{8} and @var{16}.
-Use @var{0} to disable alpha plane coding.
+@item aac_eld
+Enhanced Low Delay AAC (ELD)
+@end table
+If not specified it is set to @samp{aac_low}.
@end table
-@subsection Speed considerations
+The following are private options of the libfdk_aac encoder.
-In the default mode of operation the encoder has to honor frame constraints
-(i.e. not produc frames with size bigger than requested) while still making
-output picture as good as possible.
-A frame containing a lot of small details is harder to compress and the encoder
-would spend more time searching for appropriate quantizers for each slice.
+@table @option
+@item afterburner
+Enable afterburner feature if set to 1, disabled if set to 0. This
+improves the quality but also the required processing power.
-Setting a higher @option{bits_per_mb} limit will improve the speed.
+Default value is 1.
-For the fastest encoding speed set the @option{qscale} parameter (4 is the
-recommended value) and do not set a size constraint.
+@item eld_sbr
+Enable SBR (Spectral Band Replication) for ELD if set to 1, disabled
+if set to 0.
-@section libkvazaar
+Default value is 0.
-Kvazaar H.265/HEVC encoder.
+@item signaling
+Set SBR/PS signaling style.
-Requires the presence of the libkvazaar headers and library during
-configuration. You need to explicitly configure the build with
-@option{--enable-libkvazaar}.
+It can assume one of the following values:
+@table @samp
+@item default
+choose signaling implicitly (explicit hierarchical by default,
+implicit if global header is disabled)
-@subsection Options
+@item implicit
+implicit backwards compatible signaling
-@table @option
+@item explicit_sbr
+explicit SBR, implicit PS signaling
-@item b
-Set target video bitrate in bit/s and enable rate control.
+@item explicit_hierarchical
+explicit hierarchical signaling
+@end table
-@item kvazaar-params
-Set kvazaar parameters as a list of @var{name}=@var{value} pairs separated
-by commas (,). See kvazaar documentation for a list of options.
+Default value is @samp{default}.
-@end table
+@item latm
+Output LATM/LOAS encapsulated data if set to 1, disabled if set to 0.
-@section QSV encoders
+Default value is 0.
-The family of Intel QuickSync Video encoders (MPEG-2, H.264 and HEVC)
+@item header_period
+Set StreamMuxConfig and PCE repetition period (in frames) for sending
+in-band configuration buffers within LATM/LOAS transport layer.
+
+Must be a 16-bits non-negative integer.
+
+Default value is 0.
+
+@item vbr
+Set VBR mode, from 1 to 5. 1 is lowest quality (though still pretty
+good) and 5 is highest quality. A value of 0 will disable VBR, and CBR
+(Constant Bit Rate) is enabled.
+
+Currently only the @samp{aac_low} profile supports VBR encoding.
+
+VBR modes 1-5 correspond to roughly the following average bit rates:
+
+@table @samp
+@item 1
+32 kbps/channel
+@item 2
+40 kbps/channel
+@item 3
+48-56 kbps/channel
+@item 4
+64 kbps/channel
+@item 5
+about 80-96 kbps/channel
+@end table
+
+Default value is 0.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Use @command{ffmpeg} to convert an audio file to VBR AAC in an M4A (MP4)
+container:
+@example
+ffmpeg -i input.wav -codec:a libfdk_aac -vbr 3 output.m4a
+@end example
+
+@item
+Use @command{ffmpeg} to convert an audio file to CBR 64k kbps AAC, using the
+High-Efficiency AAC profile:
+@example
+ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a
+@end example
+@end itemize
+
+@anchor{libmp3lame}
+@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}.
+
+See @ref{libshine} for a fixed-point MP3 encoder, although with a
+lower quality.
+
+@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 or ABR. 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 overridden by use
+@option{--nores} option.
+
+@item joint_stereo (@emph{-m j})
+Enable the encoder to use (on a frame by frame basis) either L/R
+stereo or mid/side stereo. Default value is 1.
+
+@item abr (@emph{--abr})
+Enable the encoder to use ABR when set to 1. The @command{lame}
+@option{--abr} sets the target bitrate, while this options only
+tells FFmpeg to use ABR still relies on @option{b} to set bitrate.
+
+@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
+
+@anchor{libshine}
+@section libshine
+
+Shine Fixed-Point MP3 encoder wrapper.
+
+Shine is a fixed-point MP3 encoder. It has a far better performance on
+platforms without an FPU, e.g. armel CPUs, and some phones and tablets.
+However, as it is more targeted on performance than quality, it is not on par
+with LAME and other production-grade encoders quality-wise. Also, according to
+the project's homepage, this encoder may not be free of bugs as the code was
+written a long time ago and the project was dead for at least 5 years.
+
+This encoder only supports stereo and mono input. This is also CBR-only.
+
+The original project (last updated in early 2007) is at
+@url{http://sourceforge.net/projects/libshine-fxp/}. We only support the
+updated fork by the Savonet/Liquidsoap project at @url{https://github.com/savonet/shine}.
+
+Requires the presence of the libshine headers and library during
+configuration. You need to explicitly configure the build with
+@code{--enable-libshine}.
+
+See also @ref{libmp3lame}.
+
+@subsection Options
+
+The following options are supported by the libshine wrapper. The
+@command{shineenc}-equivalent of the options are listed in parentheses.
+
+@table @option
+@item b (@emph{-b})
+Set bitrate expressed in bits/s for CBR. @command{shineenc} @option{-b} option
+is expressed in kilobits/s.
+
+@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 modelled 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 @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
+
+@section libvorbis
+
+libvorbis encoder wrapper.
+
+Requires the presence of the libvorbisenc headers and library during
+configuration. You need to explicitly configure the build with
+@code{--enable-libvorbis}.
+
+@subsection Options
+
+The following options are supported by the libvorbis wrapper. The
+@command{oggenc}-equivalent of the options are listed in parentheses.
+
+To get a more accurate and extensive documentation of the libvorbis
+options, consult the libvorbisenc's and @command{oggenc}'s documentations.
+See @url{http://xiph.org/vorbis/},
+@url{http://wiki.xiph.org/Vorbis-tools}, and oggenc(1).
+
+@table @option
+@item b (@emph{-b})
+Set bitrate expressed in bits/s for ABR. @command{oggenc} @option{-b} is
+expressed in kilobits/s.
+
+@item q (@emph{-q})
+Set constant quality setting for VBR. The value should be a float
+number in the range of -1.0 to 10.0. The higher the value, the better
+the quality. The default value is @samp{3.0}.
+
+This option is valid only using the @command{ffmpeg} command-line tool.
+For library interface users, use @option{global_quality}.
+
+@item cutoff (@emph{--advanced-encode-option lowpass_frequency=N})
+Set cutoff bandwidth in Hz, a value of 0 disables cutoff. @command{oggenc}'s
+related option is expressed in kHz. The default value is @samp{0} (cutoff
+disabled).
+
+@item minrate (@emph{-m})
+Set minimum bitrate expressed in bits/s. @command{oggenc} @option{-m} is
+expressed in kilobits/s.
+
+@item maxrate (@emph{-M})
+Set maximum bitrate expressed in bits/s. @command{oggenc} @option{-M} is
+expressed in kilobits/s. This only has effect on ABR mode.
+
+@item iblock (@emph{--advanced-encode-option impulse_noisetune=N})
+Set noise floor bias for impulse blocks. The value is a float number from
+-15.0 to 0.0. A negative bias instructs the encoder to pay special attention
+to the crispness of transients in the encoded audio. The tradeoff for better
+transient response is a higher bitrate.
+
+@end table
+
+@anchor{libwavpack}
+@section libwavpack
+
+A wrapper providing WavPack encoding through libwavpack.
+
+Only lossless mode using 32-bit integer samples is supported currently.
+
+Requires the presence of the libwavpack headers and library during
+configuration. You need to explicitly configure the build with
+@code{--enable-libwavpack}.
+
+Note that a libavcodec-native encoder for the WavPack codec exists so users can
+encode audios with this codec without using this encoder. See @ref{wavpackenc}.
+
+@subsection Options
+
+@command{wavpack} command line utility's corresponding options are listed in
+parentheses, if any.
+
+@table @option
+@item frame_size (@emph{--blocksize})
+Default is 32768.
+
+@item compression_level
+Set speed vs. compression tradeoff. Acceptable arguments are listed below:
+
+@table @samp
+@item 0 (@emph{-f})
+Fast mode.
+
+@item 1
+Normal (default) settings.
+
+@item 2 (@emph{-h})
+High quality.
+
+@item 3 (@emph{-hh})
+Very high quality.
+
+@item 4-8 (@emph{-hh -x}@var{EXTRAPROC})
+Same as @samp{3}, but with extra processing enabled.
+
+@samp{4} is the same as @option{-x2} and @samp{8} is the same as @option{-x6}.
+
+@end table
+@end table
+
+@anchor{wavpackenc}
+@section wavpack
+
+WavPack lossless audio encoder.
+
+This is a libavcodec-native WavPack encoder. There is also an encoder based on
+libwavpack, but there is virtually no reason to use that encoder.
+
+See also @ref{libwavpack}.
+
+@subsection Options
+
+The equivalent options for @command{wavpack} command line utility are listed in
+parentheses.
+
+@subsubsection Shared options
+
+The following shared options are effective for this encoder. Only special notes
+about this particular encoder will be documented here. For the general meaning
+of the options, see @ref{codec-options,,the Codec Options chapter}.
+
+@table @option
+@item frame_size (@emph{--blocksize})
+For this encoder, the range for this option is between 128 and 131072. Default
+is automatically decided based on sample rate and number of channel.
+
+For the complete formula of calculating default, see
+@file{libavcodec/wavpackenc.c}.
+
+@item compression_level (@emph{-f}, @emph{-h}, @emph{-hh}, and @emph{-x})
+This option's syntax is consistent with @ref{libwavpack}'s.
+@end table
+
+@subsubsection Private options
+
+@table @option
+@item joint_stereo (@emph{-j})
+Set whether to enable joint stereo. Valid values are:
+
+@table @samp
+@item on (@emph{1})
+Force mid/side audio encoding.
+@item off (@emph{0})
+Force left/right audio encoding.
+@item auto
+Let the encoder decide automatically.
+@end table
+
+@item optimize_mono
+Set whether to enable optimization for mono. This option is only effective for
+non-mono streams. Available values:
+
+@table @samp
+@item on
+enabled
+@item off
+disabled
+@end table
+
+@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 libopenh264
+
+Cisco libopenh264 H.264/MPEG-4 AVC encoder wrapper.
+
+This encoder requires the presence of the libopenh264 headers and
+library during configuration. You need to explicitly configure the
+build with @code{--enable-libopenh264}. The library is detected using
+@command{pkg-config}.
+
+For more information about the library see
+@url{http://www.openh264.org}.
+
+@subsection Options
+
+The following FFmpeg global options affect the configurations of the
+libopenh264 encoder.
+
+@table @option
+@item b
+Set the bitrate (as a number of bits per second).
+
+@item g
+Set the GOP size.
+
+@item maxrate
+Set the max bitrate (as a number of bits per second).
+
+@item flags +global_header
+Set global header in the bitstream.
+
+@item slices
+Set the number of slices, used in parallelized encoding. Default value
+is 0. This is only used when @option{slice_mode} is set to
+@samp{fixed}.
+
+@item slice_mode
+Set slice mode. Can assume one of the follwing possible values:
+
+@table @samp
+@item fixed
+a fixed number of slices
+@item rowmb
+one slice per row of macroblocks
+@item auto
+automatic number of slices according to number of thread
+@end table
+
+Default value is @samp{auto}.
+
+@item loopfilter
+Enable loop filter, if set to 1 (automatically enabled). To disable
+set a value of 0.
+
+@item profile
+Set profile restrictions. If set to the value of @samp{main} enable
+CABAC (set the @code{SEncParamExt.iEntropyCodingModeFlag} flag to 1).
+@end table
+
+@section jpeg2000
+
+The native jpeg 2000 encoder is lossy by default, the @code{-q:v}
+option can be used to set the encoding quality. Lossless encoding
+can be selected with @code{-pred 1}.
+
+@subsection Options
+
+@table @option
+@item format
+Can be set to either @code{j2k} or @code{jp2} (the default) that
+makes it possible to store non-rgb pix_fmts.
+
+@end table
+
+@section snow
+
+@subsection Options
+
+@table @option
+@item iterative_dia_size
+dia size for the iterative motion estimation
+@end table
+
+@section libtheora
+
+libtheora Theora encoder wrapper.
+
+Requires the presence of the libtheora headers and library during
+configuration. You need to explicitly configure the build with
+@code{--enable-libtheora}.
+
+For more information about the libtheora project see
+@url{http://www.theora.org/}.
+
+@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 in bit/s for CBR (Constant Bit Rate) mode. In
+case VBR (Variable Bit Rate) mode is enabled this option is ignored.
+
+@item flags
+Used to enable constant quality mode (VBR) 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 as an integer in lambda units.
+
+Only relevant when VBR mode is enabled with @code{flags +qscale}. The
+value is converted to QP units by dividing it by @code{FF_QP2LAMBDA},
+clipped in the [0 - 10] range, and then multiplied by 6.3 to get a
+value in the native libtheora range [0-63]. A higher value corresponds
+to a higher quality.
+
+@item q
+Enable VBR mode when set to a non-negative value, and set constant
+quality value as a double floating point value in QP units.
+
+The value is clipped in the [0-10] range, and then multiplied by 6.3
+to get a value in the native libtheora range [0-63].
+
+This option is valid only using the @command{ffmpeg} command-line
+tool. For library interface users, use @option{global_quality}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Set maximum constant quality (VBR) encoding with @command{ffmpeg}:
+@example
+ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
+@end example
+
+@item
+Use @command{ffmpeg} to convert a CBR 1000 kbps Theora video stream:
+@example
+ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
+@end example
+@end itemize
+
+@section libvpx
+
+VP8/VP9 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
+
+The following options are supported by the libvpx wrapper. The
+@command{vpxenc}-equivalent options or values are listed in parentheses
+for easy migration.
+
+To reduce the duplication of documentation, only the private options
+and some others requiring special attention are documented here. For
+the documentation of the undocumented generic options, see
+@ref{codec-options,,the Codec Options chapter}.
+
+To get more documentation of the libvpx options, invoke the command
+@command{ffmpeg -h encoder=libvpx}, @command{ffmpeg -h encoder=libvpx-vp9} or
+@command{vpxenc --help}. Further information is available in the libvpx API
+documentation.
+
+@table @option
+
+@item b (@emph{target-bitrate})
+Set bitrate in bits/s. Note that FFmpeg's @option{b} option is
+expressed in bits/s, while @command{vpxenc}'s @option{target-bitrate} is in
+kilobits/s.
+
+@item g (@emph{kf-max-dist})
+
+@item keyint_min (@emph{kf-min-dist})
+
+@item qmin (@emph{min-q})
+
+@item qmax (@emph{max-q})
+
+@item bufsize (@emph{buf-sz}, @emph{buf-optimal-sz})
+Set ratecontrol buffer size (in bits). Note @command{vpxenc}'s options are
+specified in milliseconds, the libvpx wrapper converts this value as follows:
+@code{buf-sz = bufsize * 1000 / bitrate},
+@code{buf-optimal-sz = bufsize * 1000 / bitrate * 5 / 6}.
+
+@item rc_init_occupancy (@emph{buf-initial-sz})
+Set number of bits which should be loaded into the rc buffer before decoding
+starts. Note @command{vpxenc}'s option is specified in milliseconds, the libvpx
+wrapper converts this value as follows:
+@code{rc_init_occupancy * 1000 / bitrate}.
+
+@item undershoot-pct
+Set datarate undershoot (min) percentage of the target bitrate.
+
+@item overshoot-pct
+Set datarate overshoot (max) percentage of the target bitrate.
+
+@item skip_threshold (@emph{drop-frame})
+
+@item qcomp (@emph{bias-pct})
+
+@item maxrate (@emph{maxsection-pct})
+Set GOP max bitrate in bits/s. Note @command{vpxenc}'s option is specified as a
+percentage of the target bitrate, the libvpx wrapper converts this value as
+follows: @code{(maxrate * 100 / bitrate)}.
+
+@item minrate (@emph{minsection-pct})
+Set GOP min bitrate in bits/s. Note @command{vpxenc}'s option is specified as a
+percentage of the target bitrate, the libvpx wrapper converts this value as
+follows: @code{(minrate * 100 / bitrate)}.
+
+@item minrate, maxrate, b @emph{end-usage=cbr}
+@code{(minrate == maxrate == bitrate)}.
+
+@item crf (@emph{end-usage=cq}, @emph{cq-level})
+
+@item quality, deadline (@emph{deadline})
+@table @samp
+@item best
+Use best quality deadline. Poorly named and quite slow, this option should be
+avoided as it may give worse quality output than good.
+@item good
+Use good quality deadline. This is a good trade-off between speed and quality
+when used with the @option{cpu-used} option.
+@item realtime
+Use realtime quality deadline.
+@end table
+
+@item speed, cpu-used (@emph{cpu-used})
+Set quality/speed ratio modifier. Higher values speed up the encode at the cost
+of quality.
+
+@item nr (@emph{noise-sensitivity})
+
+@item static-thresh
+Set a change threshold on blocks below which they will be skipped by the
+encoder.
+
+@item slices (@emph{token-parts})
+Note that FFmpeg's @option{slices} option gives the total number of partitions,
+while @command{vpxenc}'s @option{token-parts} is given as
+@code{log2(partitions)}.
+
+@item max-intra-rate
+Set maximum I-frame bitrate as a percentage of the target bitrate. A value of 0
+means unlimited.
+
+@item force_key_frames
+@code{VPX_EFLAG_FORCE_KF}
+
+@item Alternate reference frame related
+@table @option
+@item auto-alt-ref
+Enable use of alternate reference frames (2-pass only).
+@item arnr-max-frames
+Set altref noise reduction max frame count.
+@item arnr-type
+Set altref noise reduction filter type: backward, forward, centered.
+@item arnr-strength
+Set altref noise reduction filter strength.
+@item rc-lookahead, lag-in-frames (@emph{lag-in-frames})
+Set number of frames to look ahead for frametype and ratecontrol.
+@end table
+
+@item error-resilient
+Enable error resiliency features.
+
+@item VP9-specific options
+@table @option
+@item lossless
+Enable lossless mode.
+@item tile-columns
+Set number of tile columns to use. Note this is given as
+@code{log2(tile_columns)}. For example, 8 tile columns would be requested by
+setting the @option{tile-columns} option to 3.
+@item tile-rows
+Set number of tile rows to use. Note this is given as @code{log2(tile_rows)}.
+For example, 4 tile rows would be requested by setting the @option{tile-rows}
+option to 2.
+@item frame-parallel
+Enable frame parallel decodability features.
+@item aq-mode
+Set adaptive quantization mode (0: off (default), 1: variance 2: complexity, 3:
+cyclic refresh).
+@item colorspace @emph{color-space}
+Set input color space. The VP9 bitstream supports signaling the following
+colorspaces:
+@table @option
+@item @samp{rgb} @emph{sRGB}
+@item @samp{bt709} @emph{bt709}
+@item @samp{unspecified} @emph{unknown}
+@item @samp{bt470bg} @emph{bt601}
+@item @samp{smpte170m} @emph{smpte170}
+@item @samp{smpte240m} @emph{smpte240}
+@item @samp{bt2020_ncl} @emph{bt2020}
+@end table
+@end table
+
+@end table
+
+For more information about libvpx see:
+@url{http://www.webmproject.org/}
+
+
+@section libwebp
+
+libwebp WebP Image encoder wrapper
+
+libwebp is Google's official encoder for WebP images. It can encode in either
+lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
+frame. Lossless images are a separate codec developed by Google.
+
+@subsection Pixel Format
+
+Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
+to limitations of the format and libwebp. Alpha is supported for either mode.
+Because of API limitations, if RGB is passed in when encoding lossy or YUV is
+passed in for encoding lossless, the pixel format will automatically be
+converted using functions from libwebp. This is not ideal and is done only for
+convenience.
+
+@subsection Options
+
+@table @option
+
+@item -lossless @var{boolean}
+Enables/Disables use of lossless mode. Default is 0.
+
+@item -compression_level @var{integer}
+For lossy, this is a quality/speed tradeoff. Higher values give better quality
+for a given size at the cost of increased encoding time. For lossless, this is
+a size/speed tradeoff. Higher values give smaller size at the cost of increased
+encoding time. More specifically, it controls the number of extra algorithms
+and compression tools used, and varies the combination of these tools. This
+maps to the @var{method} option in libwebp. The valid range is 0 to 6.
+Default is 4.
+
+@item -qscale @var{float}
+For lossy encoding, this controls image quality, 0 to 100. For lossless
+encoding, this controls the effort and time spent at compressing more. The
+default value is 75. Note that for usage via libavcodec, this option is called
+@var{global_quality} and must be multiplied by @var{FF_QP2LAMBDA}.
+
+@item -preset @var{type}
+Configuration preset. This does some automatic settings based on the general
+type of the image.
+@table @option
+@item none
+Do not use a preset.
+@item default
+Use the encoder default.
+@item picture
+Digital picture, like portrait, inner shot
+@item photo
+Outdoor photograph, with natural lighting
+@item drawing
+Hand or line drawing, with high-contrast details
+@item icon
+Small-sized colorful images
+@item text
+Text-like
+@end table
+
+@end table
+
+@section libx264, libx264rgb
+
+x264 H.264/MPEG-4 AVC encoder wrapper.
+
+This encoder requires the presence of the libx264 headers and library
+during configuration. You need to explicitly configure the build with
+@code{--enable-libx264}.
+
+libx264 supports an impressive number of features, including 8x8 and
+4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
+entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
+for detail retention (adaptive quantization, psy-RD, psy-trellis).
+
+Many libx264 encoder options are mapped to FFmpeg global codec
+options, while unique encoder options are provided through private
+options. Additionally the @option{x264opts} and @option{x264-params}
+private options allows one to pass a list of key=value tuples as accepted
+by the libx264 @code{x264_param_parse} function.
+
+The x264 project website is at
+@url{http://www.videolan.org/developers/x264.html}.
+
+The libx264rgb encoder is the same as libx264, except it accepts packed RGB
+pixel formats as input instead of YUV.
+
+@subsection Supported Pixel Formats
+
+x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at
+x264's configure time. FFmpeg only supports one bit depth in one particular
+build. In other words, it is not possible to build one FFmpeg with multiple
+versions of x264 with different bit depths.
+
+@subsection Options
+
+The following options are supported by the libx264 wrapper. The
+@command{x264}-equivalent options or values are listed in parentheses
+for easy migration.
+
+To reduce the duplication of documentation, only the private options
+and some others requiring special attention are documented here. For
+the documentation of the undocumented generic options, see
+@ref{codec-options,,the Codec Options chapter}.
+
+To get a more accurate and extensive documentation of the libx264
+options, invoke the command @command{x264 --full-help} or consult
+the libx264 documentation.
+
+@table @option
+@item b (@emph{bitrate})
+Set bitrate in bits/s. Note that FFmpeg's @option{b} option is
+expressed in bits/s, while @command{x264}'s @option{bitrate} is in
+kilobits/s.
+
+@item bf (@emph{bframes})
+
+@item g (@emph{keyint})
+
+@item qmin (@emph{qpmin})
+Minimum quantizer scale.
+
+@item qmax (@emph{qpmax})
+Maximum quantizer scale.
+
+@item qdiff (@emph{qpstep})
+Maximum difference between quantizer scales.
+
+@item qblur (@emph{qblur})
+Quantizer curve blur
+
+@item qcomp (@emph{qcomp})
+Quantizer curve compression factor
+
+@item refs (@emph{ref})
+Number of reference frames each P-frame can use. The range is from @var{0-16}.
+
+@item sc_threshold (@emph{scenecut})
+Sets the threshold for the scene change detection.
+
+@item trellis (@emph{trellis})
+Performs Trellis quantization to increase efficiency. Enabled by default.
+
+@item nr (@emph{nr})
+
+@item me_range (@emph{merange})
+Maximum range of the motion search in pixels.
+
+@item me_method (@emph{me})
+Set motion estimation method. Possible values in the decreasing order
+of speed:
+
+@table @samp
+@item dia (@emph{dia})
+@item epzs (@emph{dia})
+Diamond search with radius 1 (fastest). @samp{epzs} is an alias for
+@samp{dia}.
+@item hex (@emph{hex})
+Hexagonal search with radius 2.
+@item umh (@emph{umh})
+Uneven multi-hexagon search.
+@item esa (@emph{esa})
+Exhaustive search.
+@item tesa (@emph{tesa})
+Hadamard exhaustive search (slowest).
+@end table
+
+@item subq (@emph{subme})
+Sub-pixel motion estimation method.
+
+@item b_strategy (@emph{b-adapt})
+Adaptive B-frame placement decision algorithm. Use only on first-pass.
+
+@item keyint_min (@emph{min-keyint})
+Minimum GOP size.
+
+@item coder
+Set entropy encoder. Possible values:
+
+@table @samp
+@item ac
+Enable CABAC.
+
+@item vlc
+Enable CAVLC and disable CABAC. It generates the same effect as
+@command{x264}'s @option{--no-cabac} option.
+@end table
+
+@item cmp
+Set full pixel motion estimation comparation algorithm. Possible values:
+
+@table @samp
+@item chroma
+Enable chroma in motion estimation.
+
+@item sad
+Ignore chroma in motion estimation. It generates the same effect as
+@command{x264}'s @option{--no-chroma-me} option.
+@end table
+
+@item threads (@emph{threads})
+Number of encoding threads.
+
+@item thread_type
+Set multithreading technique. Possible values:
+
+@table @samp
+@item slice
+Slice-based multithreading. It generates the same effect as
+@command{x264}'s @option{--sliced-threads} option.
+@item frame
+Frame-based multithreading.
+@end table
+
+@item flags
+Set encoding flags. It can be used to disable closed GOP and enable
+open GOP by setting it to @code{-cgop}. The result is similar to
+the behavior of @command{x264}'s @option{--open-gop} option.
+
+@item rc_init_occupancy (@emph{vbv-init})
+
+@item preset (@emph{preset})
+Set the encoding preset.
+
+@item tune (@emph{tune})
+Set tuning of the encoding params.
+
+@item profile (@emph{profile})
+Set profile restrictions.
+
+@item fastfirstpass
+Enable fast settings when encoding first pass, when set to 1. When set
+to 0, it has the same effect of @command{x264}'s
+@option{--slow-firstpass} option.
+
+@item crf (@emph{crf})
+Set the quality for constant quality mode.
+
+@item crf_max (@emph{crf-max})
+In CRF mode, prevents VBV from lowering quality beyond this point.
+
+@item qp (@emph{qp})
+Set constant quantization rate control method parameter.
+
+@item aq-mode (@emph{aq-mode})
+Set AQ method. Possible values:
+
+@table @samp
+@item none (@emph{0})
+Disabled.
+
+@item variance (@emph{1})
+Variance AQ (complexity mask).
+
+@item autovariance (@emph{2})
+Auto-variance AQ (experimental).
+@end table
+
+@item aq-strength (@emph{aq-strength})
+Set AQ strength, reduce blocking and blurring in flat and textured areas.
+
+@item psy
+Use psychovisual optimizations when set to 1. When set to 0, it has the
+same effect as @command{x264}'s @option{--no-psy} option.
+
+@item psy-rd (@emph{psy-rd})
+Set strength of psychovisual optimization, in
+@var{psy-rd}:@var{psy-trellis} format.
+
+@item rc-lookahead (@emph{rc-lookahead})
+Set number of frames to look ahead for frametype and ratecontrol.
+
+@item weightb
+Enable weighted prediction for B-frames when set to 1. When set to 0,
+it has the same effect as @command{x264}'s @option{--no-weightb} option.
+
+@item weightp (@emph{weightp})
+Set weighted prediction method for P-frames. Possible values:
+
+@table @samp
+@item none (@emph{0})
+Disabled
+@item simple (@emph{1})
+Enable only weighted refs
+@item smart (@emph{2})
+Enable both weighted refs and duplicates
+@end table
+
+@item ssim (@emph{ssim})
+Enable calculation and printing SSIM stats after the encoding.
+
+@item intra-refresh (@emph{intra-refresh})
+Enable the use of Periodic Intra Refresh instead of IDR frames when set
+to 1.
+
+@item avcintra-class (@emph{class})
+Configure the encoder to generate AVC-Intra.
+Valid values are 50,100 and 200
+
+@item bluray-compat (@emph{bluray-compat})
+Configure the encoder to be compatible with the bluray standard.
+It is a shorthand for setting "bluray-compat=1 force-cfr=1".
+
+@item b-bias (@emph{b-bias})
+Set the influence on how often B-frames are used.
+
+@item b-pyramid (@emph{b-pyramid})
+Set method for keeping of some B-frames as references. Possible values:
+
+@table @samp
+@item none (@emph{none})
+Disabled.
+@item strict (@emph{strict})
+Strictly hierarchical pyramid.
+@item normal (@emph{normal})
+Non-strict (not Blu-ray compatible).
+@end table
+
+@item mixed-refs
+Enable the use of one reference per partition, as opposed to one
+reference per macroblock when set to 1. When set to 0, it has the
+same effect as @command{x264}'s @option{--no-mixed-refs} option.
+
+@item 8x8dct
+Enable adaptive spatial transform (high profile 8x8 transform)
+when set to 1. When set to 0, it has the same effect as
+@command{x264}'s @option{--no-8x8dct} option.
+
+@item fast-pskip
+Enable early SKIP detection on P-frames when set to 1. When set
+to 0, it has the same effect as @command{x264}'s
+@option{--no-fast-pskip} option.
+
+@item aud (@emph{aud})
+Enable use of access unit delimiters when set to 1.
+
+@item mbtree
+Enable use macroblock tree ratecontrol when set to 1. When set
+to 0, it has the same effect as @command{x264}'s
+@option{--no-mbtree} option.
+
+@item deblock (@emph{deblock})
+Set loop filter parameters, in @var{alpha}:@var{beta} form.
+
+@item cplxblur (@emph{cplxblur})
+Set fluctuations reduction in QP (before curve compression).
+
+@item partitions (@emph{partitions})
+Set partitions to consider as a comma-separated list of. Possible
+values in the list:
+
+@table @samp
+@item p8x8
+8x8 P-frame partition.
+@item p4x4
+4x4 P-frame partition.
+@item b8x8
+4x4 B-frame partition.
+@item i8x8
+8x8 I-frame partition.
+@item i4x4
+4x4 I-frame partition.
+(Enabling @samp{p4x4} requires @samp{p8x8} to be enabled. Enabling
+@samp{i8x8} requires adaptive spatial transform (@option{8x8dct}
+option) to be enabled.)
+@item none (@emph{none})
+Do not consider any partitions.
+@item all (@emph{all})
+Consider every partition.
+@end table
+
+@item direct-pred (@emph{direct})
+Set direct MV prediction mode. Possible values:
+
+@table @samp
+@item none (@emph{none})
+Disable MV prediction.
+@item spatial (@emph{spatial})
+Enable spatial predicting.
+@item temporal (@emph{temporal})
+Enable temporal predicting.
+@item auto (@emph{auto})
+Automatically decided.
+@end table
+
+@item slice-max-size (@emph{slice-max-size})
+Set the limit of the size of each slice in bytes. If not specified
+but RTP payload size (@option{ps}) is specified, that is used.
+
+@item stats (@emph{stats})
+Set the file name for multi-pass stats.
+
+@item nal-hrd (@emph{nal-hrd})
+Set signal HRD information (requires @option{vbv-bufsize} to be set).
+Possible values:
+
+@table @samp
+@item none (@emph{none})
+Disable HRD information signaling.
+@item vbr (@emph{vbr})
+Variable bit rate.
+@item cbr (@emph{cbr})
+Constant bit rate (not allowed in MP4 container).
+@end table
+
+@item x264opts (N.A.)
+Set any x264 option, see @command{x264 --fullhelp} for a list.
+
+Argument 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.
+
+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
+
+@item a53cc @var{boolean}
+Import closed captions (which must be ATSC compatible format) into output.
+Only the mpeg2 and h264 decoders provide these. Default is 0 (off).
+
+@item x264-params (N.A.)
+Override the x264 configuration using a :-separated list of key=value
+parameters.
+
+This option is functionally the same as the @option{x264opts}, but is
+duplicated for compatibility with the Libav fork.
+
+For example to specify libx264 encoding options with @command{ffmpeg}:
+@example
+ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
+cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
+no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
+@end example
+@end table
+
+Encoding ffpresets for common usages are provided so they can be used with the
+general presets system (e.g. passing the @option{pre} option).
+
+@section libx265
+
+x265 H.265/HEVC encoder wrapper.
+
+This encoder requires the presence of the libx265 headers and library
+during configuration. You need to explicitly configure the build with
+@option{--enable-libx265}.
+
+@subsection Options
+
+@table @option
+@item preset
+Set the x265 preset.
+
+@item tune
+Set the x265 tune parameter.
+
+@item x265-params
+Set x265 options using a list of @var{key}=@var{value} couples separated
+by ":". See @command{x265 --help} for a list of options.
+
+For example to specify libx265 encoding options with @option{-x265-params}:
+
+@example
+ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
+@end example
+@end table
+
+@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
+
+@item lumi_aq
+Enable lumi masking adaptive quantization when set to 1. Default is 0
+(disabled).
+
+@item variance_aq
+Enable variance adaptive quantization when set to 1. Default is 0
+(disabled).
+
+When combined with @option{lumi_aq}, the resulting quality will not
+be better than any of the two specified individually. In other
+words, the resulting quality will be the worse one of the two
+effects.
+
+@item ssim
+Set structural similarity (SSIM) displaying method. Possible values:
+
+@table @samp
+@item off
+Disable displaying of SSIM information.
+
+@item avg
+Output average SSIM at the end of encoding to stdout. The format of
+showing the average SSIM is:
+
+@example
+Average SSIM: %f
+@end example
+
+For users who are not familiar with C, %f means a float number, or
+a decimal (e.g. 0.939232).
+
+@item frame
+Output both per-frame SSIM data during encoding and average SSIM at
+the end of encoding to stdout. The format of per-frame information
+is:
+
+@example
+ SSIM: avg: %1.3f min: %1.3f max: %1.3f
+@end example
+
+For users who are not familiar with C, %1.3f means a float number
+rounded to 3 digits after the dot (e.g. 0.932).
+
+@end table
+
+@item ssim_acc
+Set SSIM accuracy. Valid options are integers within the range of
+0-4, while 0 gives the most accurate result and 4 computes the
+fastest.
+
+@end table
+
+@section mpeg2
+
+MPEG-2 video encoder.
+
+@subsection Options
+
+@table @option
+@item seq_disp_ext @var{integer}
+Specifies if the encoder should write a sequence_display_extension to the
+output.
+@table @option
+@item -1
+@itemx auto
+Decide automatically to write it or not (this is the default) by checking if
+the data to be written is different from the default or unspecified values.
+@item 0
+@itemx never
+Never write it.
+@item 1
+@itemx always
+Always write it.
+@end table
+@end table
+
+@section png
+
+PNG image encoder.
+
+@subsection Private options
+
+@table @option
+@item dpi @var{integer}
+Set physical density of pixels, in dots per inch, unset by default
+@item dpm @var{integer}
+Set physical density of pixels, in dots per meter, unset by default
+@end table
+
+@section ProRes
+
+Apple ProRes encoder.
+
+FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
+The used encoder can be chosen with the @code{-vcodec} option.
+
+@subsection Private Options for prores-ks
+
+@table @option
+@item profile @var{integer}
+Select the ProRes profile to encode
+@table @samp
+@item proxy
+@item lt
+@item standard
+@item hq
+@item 4444
+@end table
+
+@item quant_mat @var{integer}
+Select quantization matrix.
+@table @samp
+@item auto
+@item default
+@item proxy
+@item lt
+@item standard
+@item hq
+@end table
+If set to @var{auto}, the matrix matching the profile will be picked.
+If not set, the matrix providing the highest quality, @var{default}, will be
+picked.
+
+@item bits_per_mb @var{integer}
+How many bits to allot for coding one macroblock. Different profiles use
+between 200 and 2400 bits per macroblock, the maximum is 8000.
+
+@item mbs_per_slice @var{integer}
+Number of macroblocks in each slice (1-8); the default value (8)
+should be good in almost all situations.
+
+@item vendor @var{string}
+Override the 4-byte vendor ID.
+A custom vendor ID like @var{apl0} would claim the stream was produced by
+the Apple encoder.
+
+@item alpha_bits @var{integer}
+Specify number of bits for alpha component.
+Possible values are @var{0}, @var{8} and @var{16}.
+Use @var{0} to disable alpha plane coding.
+
+@end table
+
+@subsection Speed considerations
+
+In the default mode of operation the encoder has to honor frame constraints
+(i.e. not produce frames with size bigger than requested) while still making
+output picture as good as possible.
+A frame containing a lot of small details is harder to compress and the encoder
+would spend more time searching for appropriate quantizers for each slice.
+
+Setting a higher @option{bits_per_mb} limit will improve the speed.
+
+For the fastest encoding speed set the @option{qscale} parameter (4 is the
+recommended value) and do not set a size constraint.
+
+@section libkvazaar
+
+Kvazaar H.265/HEVC encoder.
+
+Requires the presence of the libkvazaar headers and library during
+configuration. You need to explicitly configure the build with
+@option{--enable-libkvazaar}.
+
+@subsection Options
+
+@table @option
+
+@item b
+Set target video bitrate in bit/s and enable rate control.
+
+@item kvazaar-params
+Set kvazaar parameters as a list of @var{name}=@var{value} pairs separated
+by commas (,). See kvazaar documentation for a list of options.
+
+@end table
+
++@section QSV encoders
++
++The family of Intel QuickSync Video encoders (MPEG-2, H.264 and HEVC)
+
+ The ratecontrol method is selected as follows:
+
+ @itemize @bullet
+ @item
+ When @option{global_quality} is specified, a quality-based mode is used.
+ Specifically this means either
+ @itemize @minus
+ @item
+ @var{CQP} - constant quantizer scale, when the @option{qscale} codec flag is
+ also set (the @option{-qscale} avconv option).
+
+ @item
+ @var{LA_ICQ} - intelligent constant quality with lookahead, when the
-@option{la_depth} option is also set.
++@option{look_ahead} option is also set.
+
+ @item
+ @var{ICQ} -- intelligent constant quality otherwise.
+ @end itemize
+
+ @item
+ Otherwise, a bitrate-based mode is used. For all of those, you should specify at
+ least the desired average bitrate with the @option{b} option.
+ @itemize @minus
+ @item
-@var{LA} - VBR with lookahead, when the @option{la_depth} option is specified.
++@var{LA} - VBR with lookahead, when the @option{look_ahead} option is specified.
+
+ @item
+ @var{VCM} - video conferencing mode, when the @option{vcm} option is set.
+
+ @item
+ @var{CBR} - constant bitrate, when @option{maxrate} is specified and equal to
+ the average bitrate.
+
+ @item
+ @var{VBR} - variable bitrate, when @option{maxrate} is specified, but is higher
+ than the average bitrate.
+
+ @item
+ @var{AVBR} - average VBR mode, when @option{maxrate} is not specified. This mode
+ is further configured by the @option{avbr_accuracy} and
+ @option{avbr_convergence} options.
+ @end itemize
+ @end itemize
+
+ Note that depending on your system, a different mode than the one you specified
+ may be selected by the encoder. Set the verbosity level to @var{verbose} or
+ higher to see the actual settings used by the QSV runtime.
+
+ Additional libavcodec global options are mapped to MSDK options as follows:
+
+ @itemize
+ @item
+ @option{g/gop_size} -> @option{GopPicSize}
+
+ @item
+ @option{bf/max_b_frames}+1 -> @option{GopRefDist}
+
+ @item
+ @option{rc_init_occupancy/rc_initial_buffer_occupancy} ->
+ @option{InitialDelayInKB}
+
+ @item
+ @option{slices} -> @option{NumSlice}
+
+ @item
+ @option{refs} -> @option{NumRefFrame}
+
+ @item
+ @option{b_strategy/b_frame_strategy} -> @option{BRefType}
+
+ @item
+ @option{cgop/CLOSED_GOP} codec flag -> @option{GopOptFlag}
+
+ @item
+ For the @var{CQP} mode, the @option{i_qfactor/i_qoffset} and
+ @option{b_qfactor/b_qoffset} set the difference between @var{QPP} and @var{QPI},
+ and @var{QPP} and @var{QPB} respectively.
+
+ @item
+ Setting the @option{coder} option to the value @var{vlc} will make the H.264
+ encoder use CAVLC instead of CABAC.
+
+ @end itemize
+
@c man end VIDEO ENCODERS
+
+@chapter Subtitles Encoders
+@c man begin SUBTITLES ENCODERS
+
+@section dvdsub
+
+This codec encodes the bitmap subtitle format that is used in DVDs.
+Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
+and they can also be used in Matroska files.
+
+@subsection Options
+
+@table @option
+@item even_rows_fix
+When set to 1, enable a work-around that makes the number of pixel rows
+even in all subtitles. This fixes a problem with some players that
+cut off the bottom row if the number is odd. The work-around just adds
+a fully transparent row if needed. The overhead is low, typically
+one byte per subtitle on average.
+
+By default, this work-around is disabled.
+@end table
+
+@c man end SUBTITLES ENCODERS
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