4 Encoders are configured elements in FFmpeg which allow the encoding of
7 When you configure your FFmpeg build, all the supported native encoders
8 are enabled by default. Encoders requiring an external library must be enabled
9 manually via the corresponding @code{--enable-lib} option. You can list all
10 available encoders using the configure option @code{--list-encoders}.
12 You can disable all the encoders with the configure option
13 @code{--disable-encoders} and selectively enable / disable single encoders
14 with the options @code{--enable-encoder=@var{ENCODER}} /
15 @code{--disable-encoder=@var{ENCODER}}.
17 The option @code{-encoders} of the ff* tools will display the list of
22 @chapter Audio Encoders
23 @c man begin AUDIO ENCODERS
25 A description of some of the currently available audio encoders
31 Advanced Audio Coding (AAC) encoder.
33 This encoder is the default AAC encoder, natively implemented into FFmpeg.
39 Set bit rate in bits/s. Setting this automatically activates constant bit rate
40 (CBR) mode. If this option is unspecified it is set to 128kbps.
43 Set quality for variable bit rate (VBR) mode. This option is valid only using
44 the @command{ffmpeg} command-line tool. For library interface users, use
45 @option{global_quality}.
48 Set cutoff frequency. If unspecified will allow the encoder to dynamically
49 adjust the cutoff to improve clarity on low bitrates.
52 Set AAC encoder coding method. Possible values:
56 Two loop searching (TLS) method.
58 This method first sets quantizers depending on band thresholds and then tries
59 to find an optimal combination by adding or subtracting a specific value from
60 all quantizers and adjusting some individual quantizer a little. Will tune
61 itself based on whether @option{aac_is}, @option{aac_ms} and @option{aac_pns}
65 Average noise to mask ratio (ANMR) trellis-based solution.
67 This is an experimental coder which currently produces a lower quality, is more
68 unstable and is slower than the default twoloop coder but has potential.
69 Currently has no support for the @option{aac_is} or @option{aac_pns} options.
70 Not currently recommended.
73 Constant quantizer method.
75 Uses a cheaper version of twoloop algorithm that doesn't try to do as many
76 clever adjustments. Worse with low bitrates (less than 64kbps), but is better
77 and much faster at higher bitrates.
78 This is the default choice for a coder
83 Sets mid/side coding mode. The default value of "auto" will automatically use
84 M/S with bands which will benefit from such coding. Can be forced for all bands
85 using the value "enable", which is mainly useful for debugging or disabled using
89 Sets intensity stereo coding tool usage. By default, it's enabled and will
90 automatically toggle IS for similar pairs of stereo bands if it's beneficial.
91 Can be disabled for debugging by setting the value to "disable".
94 Uses perceptual noise substitution to replace low entropy high frequency bands
95 with imperceptible white noise during the decoding process. By default, it's
96 enabled, but can be disabled for debugging purposes by using "disable".
99 Enables the use of a multitap FIR filter which spans through the high frequency
100 bands to hide quantization noise during the encoding process and is reverted
101 by the decoder. As well as decreasing unpleasant artifacts in the high range
102 this also reduces the entropy in the high bands and allows for more bits to
103 be used by the mid-low bands. By default it's enabled but can be disabled for
104 debugging by setting the option to "disable".
107 Enables the use of the long term prediction extension which increases coding
108 efficiency in very low bandwidth situations such as encoding of voice or
109 solo piano music by extending constant harmonic peaks in bands throughout
110 frames. This option is implied by profile:a aac_low and is incompatible with
111 aac_pred. Use in conjunction with @option{-ar} to decrease the samplerate.
114 Enables the use of a more traditional style of prediction where the spectral
115 coefficients transmitted are replaced by the difference of the current
116 coefficients minus the previous "predicted" coefficients. In theory and sometimes
117 in practice this can improve quality for low to mid bitrate audio.
118 This option implies the aac_main profile and is incompatible with aac_ltp.
121 Sets the encoding profile, possible values:
125 The default, AAC "Low-complexity" profile. Is the most compatible and produces
129 Equivalent to @code{-profile:a aac_low -aac_pns 0}. PNS was introduced with the
130 MPEG4 specifications.
133 Long term prediction profile, is enabled by and will enable the @option{aac_ltp}
134 option. Introduced in MPEG4.
137 Main-type prediction profile, is enabled by and will enable the @option{aac_pred}
138 option. Introduced in MPEG2.
141 If this option is unspecified it is set to @samp{aac_low}.
144 @section ac3 and ac3_fixed
148 These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366, as well as
149 the undocumented RealAudio 3 (a.k.a. dnet).
151 The @var{ac3} encoder uses floating-point math, while the @var{ac3_fixed}
152 encoder only uses fixed-point integer math. This does not mean that one is
153 always faster, just that one or the other may be better suited to a
154 particular system. The @var{ac3_fixed} encoder is not the default codec for
155 any of the output formats, so it must be specified explicitly using the option
156 @code{-acodec ac3_fixed} in order to use it.
158 @subsection AC-3 Metadata
160 The AC-3 metadata options are used to set parameters that describe the audio,
161 but in most cases do not affect the audio encoding itself. Some of the options
162 do directly affect or influence the decoding and playback of the resulting
163 bitstream, while others are just for informational purposes. A few of the
164 options will add bits to the output stream that could otherwise be used for
165 audio data, and will thus affect the quality of the output. Those will be
166 indicated accordingly with a note in the option list below.
168 These parameters are described in detail in several publicly-available
171 @item @uref{http://www.atsc.org/cms/standards/a_52-2010.pdf,A/52:2010 - Digital Audio Compression (AC-3) (E-AC-3) Standard}
172 @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}
173 @item @uref{http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/18_Metadata.Guide.pdf,Dolby Metadata Guide}
174 @item @uref{http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/46_DDEncodingGuidelines.pdf,Dolby Digital Professional Encoding Guidelines}
177 @subsubsection Metadata Control Options
181 @item -per_frame_metadata @var{boolean}
182 Allow Per-Frame Metadata. Specifies if the encoder should check for changing
183 metadata for each frame.
186 The metadata values set at initialization will be used for every frame in the
189 Metadata values can be changed before encoding each frame.
194 @subsubsection Downmix Levels
198 @item -center_mixlev @var{level}
199 Center Mix Level. The amount of gain the decoder should apply to the center
200 channel when downmixing to stereo. This field will only be written to the
201 bitstream if a center channel is present. The value is specified as a scale
202 factor. There are 3 valid values:
207 Apply -4.5dB gain (default)
212 @item -surround_mixlev @var{level}
213 Surround Mix Level. The amount of gain the decoder should apply to the surround
214 channel(s) when downmixing to stereo. This field will only be written to the
215 bitstream if one or more surround channels are present. The value is specified
216 as a scale factor. There are 3 valid values:
221 Apply -6dB gain (default)
223 Silence Surround Channel(s)
228 @subsubsection Audio Production Information
229 Audio Production Information is optional information describing the mixing
230 environment. Either none or both of the fields are written to the bitstream.
234 @item -mixing_level @var{number}
235 Mixing Level. Specifies peak sound pressure level (SPL) in the production
236 environment when the mix was mastered. Valid values are 80 to 111, or -1 for
237 unknown or not indicated. The default value is -1, but that value cannot be
238 used if the Audio Production Information is written to the bitstream. Therefore,
239 if the @code{room_type} option is not the default value, the @code{mixing_level}
240 option must not be -1.
242 @item -room_type @var{type}
243 Room Type. Describes the equalization used during the final mixing session at
244 the studio or on the dubbing stage. A large room is a dubbing stage with the
245 industry standard X-curve equalization; a small room has flat equalization.
246 This field will not be written to the bitstream if both the @code{mixing_level}
247 option and the @code{room_type} option have the default values.
251 Not Indicated (default)
262 @subsubsection Other Metadata Options
266 @item -copyright @var{boolean}
267 Copyright Indicator. Specifies whether a copyright exists for this audio.
271 No Copyright Exists (default)
277 @item -dialnorm @var{value}
278 Dialogue Normalization. Indicates how far the average dialogue level of the
279 program is below digital 100% full scale (0 dBFS). This parameter determines a
280 level shift during audio reproduction that sets the average volume of the
281 dialogue to a preset level. The goal is to match volume level between program
282 sources. A value of -31dB will result in no volume level change, relative to
283 the source volume, during audio reproduction. Valid values are whole numbers in
284 the range -31 to -1, with -31 being the default.
286 @item -dsur_mode @var{mode}
287 Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround
288 (Pro Logic). This field will only be written to the bitstream if the audio
289 stream is stereo. Using this option does @b{NOT} mean the encoder will actually
290 apply Dolby Surround processing.
294 Not Indicated (default)
297 Not Dolby Surround Encoded
300 Dolby Surround Encoded
303 @item -original @var{boolean}
304 Original Bit Stream Indicator. Specifies whether this audio is from the
305 original source and not a copy.
312 Original Source (default)
317 @subsection Extended Bitstream Information
318 The extended bitstream options are part of the Alternate Bit Stream Syntax as
319 specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts.
320 If any one parameter in a group is specified, all values in that group will be
321 written to the bitstream. Default values are used for those that are written
322 but have not been specified. If the mixing levels are written, the decoder
323 will use these values instead of the ones specified in the @code{center_mixlev}
324 and @code{surround_mixlev} options if it supports the Alternate Bit Stream
327 @subsubsection Extended Bitstream Information - Part 1
331 @item -dmix_mode @var{mode}
332 Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt
333 (Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
337 Not Indicated (default)
340 Lt/Rt Downmix Preferred
343 Lo/Ro Downmix Preferred
346 @item -ltrt_cmixlev @var{level}
347 Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the
348 center channel when downmixing to stereo in Lt/Rt mode.
361 Apply -4.5dB gain (default)
365 Silence Center Channel
368 @item -ltrt_surmixlev @var{level}
369 Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the
370 surround channel(s) when downmixing to stereo in Lt/Rt mode.
379 Apply -6.0dB gain (default)
381 Silence Surround Channel(s)
384 @item -loro_cmixlev @var{level}
385 Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the
386 center channel when downmixing to stereo in Lo/Ro mode.
399 Apply -4.5dB gain (default)
403 Silence Center Channel
406 @item -loro_surmixlev @var{level}
407 Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the
408 surround channel(s) when downmixing to stereo in Lo/Ro mode.
417 Apply -6.0dB gain (default)
419 Silence Surround Channel(s)
424 @subsubsection Extended Bitstream Information - Part 2
428 @item -dsurex_mode @var{mode}
429 Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX
430 (7.1 matrixed to 5.1). Using this option does @b{NOT} mean the encoder will actually
431 apply Dolby Surround EX processing.
435 Not Indicated (default)
438 Dolby Surround EX Off
444 @item -dheadphone_mode @var{mode}
445 Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone
446 encoding (multi-channel matrixed to 2.0 for use with headphones). Using this
447 option does @b{NOT} mean the encoder will actually apply Dolby Headphone
452 Not Indicated (default)
461 @item -ad_conv_type @var{type}
462 A/D Converter Type. Indicates whether the audio has passed through HDCD A/D
467 Standard A/D Converter (default)
475 @subsection Other AC-3 Encoding Options
479 @item -stereo_rematrixing @var{boolean}
480 Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
481 is an optional AC-3 feature that increases quality by selectively encoding
482 the left/right channels as mid/side. This option is enabled by default, and it
483 is highly recommended that it be left as enabled except for testing purposes.
485 @item cutoff @var{frequency}
486 Set lowpass cutoff frequency. If unspecified, the encoder selects a default
487 determined by various other encoding parameters.
491 @subsection Floating-Point-Only AC-3 Encoding Options
493 These options are only valid for the floating-point encoder and do not exist
494 for the fixed-point encoder due to the corresponding features not being
495 implemented in fixed-point.
499 @item -channel_coupling @var{boolean}
500 Enables/Disables use of channel coupling, which is an optional AC-3 feature
501 that increases quality by combining high frequency information from multiple
502 channels into a single channel. The per-channel high frequency information is
503 sent with less accuracy in both the frequency and time domains. This allows
504 more bits to be used for lower frequencies while preserving enough information
505 to reconstruct the high frequencies. This option is enabled by default for the
506 floating-point encoder and should generally be left as enabled except for
507 testing purposes or to increase encoding speed.
511 Selected by Encoder (default)
514 Disable Channel Coupling
517 Enable Channel Coupling
520 @item -cpl_start_band @var{number}
521 Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
522 value higher than the bandwidth is used, it will be reduced to 1 less than the
523 coupling end band. If @var{auto} is used, the start band will be determined by
524 the encoder based on the bit rate, sample rate, and channel layout. This option
525 has no effect if channel coupling is disabled.
529 Selected by Encoder (default)
537 FLAC (Free Lossless Audio Codec) Encoder
541 The following options are supported by FFmpeg's flac encoder.
544 @item compression_level
545 Sets the compression level, which chooses defaults for many other options
546 if they are not set explicitly. Valid values are from 0 to 12, 5 is the
550 Sets the size of the frames in samples per channel.
552 @item lpc_coeff_precision
553 Sets the LPC coefficient precision, valid values are from 1 to 15, 15 is the
557 Sets the first stage LPC algorithm
563 fixed LPC coefficients
571 Number of passes to use for Cholesky factorization during LPC analysis
573 @item min_partition_order
574 The minimum partition order
576 @item max_partition_order
577 The maximum partition order
579 @item prediction_order_method
594 The mode is chosen automatically for each frame
596 Channels are independently coded
602 @item exact_rice_parameters
603 Chooses if rice parameters are calculated exactly or approximately.
604 if set to 1 then they are chosen exactly, which slows the code down slightly and
605 improves compression slightly.
607 @item multi_dim_quant
608 Multi Dimensional Quantization. If set to 1 then a 2nd stage LPC algorithm is
609 applied after the first stage to finetune the coefficients. This is quite slow
610 and slightly improves compression.
619 This is a native FFmpeg encoder for the Opus format. Currently its in development and
620 only implements the CELT part of the codec. Its quality is usually worse and at best
621 is equal to the libopus encoder.
627 Set bit rate in bits/s. If unspecified it uses the number of channels and the layout
628 to make a good guess.
631 Sets the maximum delay in milliseconds. Lower delays than 20ms will very quickly
635 @anchor{libfdk-aac-enc}
638 libfdk-aac AAC (Advanced Audio Coding) encoder wrapper.
640 The libfdk-aac library is based on the Fraunhofer FDK AAC code from
643 Requires the presence of the libfdk-aac headers and library during
644 configuration. You need to explicitly configure the build with
645 @code{--enable-libfdk-aac}. The library is also incompatible with GPL,
646 so if you allow the use of GPL, you should configure with
647 @code{--enable-gpl --enable-nonfree --enable-libfdk-aac}.
649 This encoder has support for the AAC-HE profiles.
651 VBR encoding, enabled through the @option{vbr} or @option{flags
652 +qscale} options, is experimental and only works with some
653 combinations of parameters.
655 Support for encoding 7.1 audio is only available with libfdk-aac 0.1.3 or
658 For more information see the fdk-aac project at
659 @url{http://sourceforge.net/p/opencore-amr/fdk-aac/}.
663 The following options are mapped on the shared FFmpeg codec options.
667 Set bit rate in bits/s. If the bitrate is not explicitly specified, it
668 is automatically set to a suitable value depending on the selected
671 In case VBR mode is enabled the option is ignored.
674 Set audio sampling rate (in Hz).
677 Set the number of audio channels.
680 Enable fixed quality, VBR (Variable Bit Rate) mode.
681 Note that VBR is implicitly enabled when the @option{vbr} value is
685 Set cutoff frequency. If not specified (or explicitly set to 0) it
686 will use a value automatically computed by the library. Default value
692 The following profiles are recognized:
695 Low Complexity AAC (LC)
698 High Efficiency AAC (HE-AAC)
701 High Efficiency AAC version 2 (HE-AACv2)
707 Enhanced Low Delay AAC (ELD)
710 If not specified it is set to @samp{aac_low}.
713 The following are private options of the libfdk_aac encoder.
717 Enable afterburner feature if set to 1, disabled if set to 0. This
718 improves the quality but also the required processing power.
723 Enable SBR (Spectral Band Replication) for ELD if set to 1, disabled
729 Enable ELDv2 (LD-MPS extension for ELD stereo signals) for ELDv2 if set to 1,
730 disabled if set to 0.
732 Note that option is available when fdk-aac version (AACENCODER_LIB_VL0.AACENCODER_LIB_VL1.AACENCODER_LIB_VL2) > (4.0.0).
737 Set SBR/PS signaling style.
739 It can assume one of the following values:
742 choose signaling implicitly (explicit hierarchical by default,
743 implicit if global header is disabled)
746 implicit backwards compatible signaling
749 explicit SBR, implicit PS signaling
751 @item explicit_hierarchical
752 explicit hierarchical signaling
755 Default value is @samp{default}.
758 Output LATM/LOAS encapsulated data if set to 1, disabled if set to 0.
763 Set StreamMuxConfig and PCE repetition period (in frames) for sending
764 in-band configuration buffers within LATM/LOAS transport layer.
766 Must be a 16-bits non-negative integer.
771 Set VBR mode, from 1 to 5. 1 is lowest quality (though still pretty
772 good) and 5 is highest quality. A value of 0 will disable VBR, and CBR
773 (Constant Bit Rate) is enabled.
775 Currently only the @samp{aac_low} profile supports VBR encoding.
777 VBR modes 1-5 correspond to roughly the following average bit rates:
789 about 80-96 kbps/channel
799 Use @command{ffmpeg} to convert an audio file to VBR AAC in an M4A (MP4)
802 ffmpeg -i input.wav -codec:a libfdk_aac -vbr 3 output.m4a
806 Use @command{ffmpeg} to convert an audio file to CBR 64k kbps AAC, using the
807 High-Efficiency AAC profile:
809 ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a
816 LAME (Lame Ain't an MP3 Encoder) MP3 encoder wrapper.
818 Requires the presence of the libmp3lame headers and library during
819 configuration. You need to explicitly configure the build with
820 @code{--enable-libmp3lame}.
822 See @ref{libshine} for a fixed-point MP3 encoder, although with a
827 The following options are supported by the libmp3lame wrapper. The
828 @command{lame}-equivalent of the options are listed in parentheses.
832 Set bitrate expressed in bits/s for CBR or ABR. LAME @code{bitrate} is
833 expressed in kilobits/s.
836 Set constant quality setting for VBR. This option is valid only
837 using the @command{ffmpeg} command-line tool. For library interface
838 users, use @option{global_quality}.
840 @item compression_level (@emph{-q})
841 Set algorithm quality. Valid arguments are integers in the 0-9 range,
842 with 0 meaning highest quality but slowest, and 9 meaning fastest
843 while producing the worst quality.
845 @item cutoff (@emph{--lowpass})
846 Set lowpass cutoff frequency. If unspecified, the encoder dynamically
850 Enable use of bit reservoir when set to 1. Default value is 1. LAME
851 has this enabled by default, but can be overridden by use
852 @option{--nores} option.
854 @item joint_stereo (@emph{-m j})
855 Enable the encoder to use (on a frame by frame basis) either L/R
856 stereo or mid/side stereo. Default value is 1.
858 @item abr (@emph{--abr})
859 Enable the encoder to use ABR when set to 1. The @command{lame}
860 @option{--abr} sets the target bitrate, while this options only
861 tells FFmpeg to use ABR still relies on @option{b} to set bitrate.
865 @section libopencore-amrnb
867 OpenCORE Adaptive Multi-Rate Narrowband encoder.
869 Requires the presence of the libopencore-amrnb headers and library during
870 configuration. You need to explicitly configure the build with
871 @code{--enable-libopencore-amrnb --enable-version3}.
873 This is a mono-only encoder. Officially it only supports 8000Hz sample rate,
874 but you can override it by setting @option{strict} to @samp{unofficial} or
882 Set bitrate in bits per second. Only the following bitrates are supported,
883 otherwise libavcodec will round to the nearest valid bitrate.
897 Allow discontinuous transmission (generate comfort noise) when set to 1. The
898 default value is 0 (disabled).
904 libopus Opus Interactive Audio Codec encoder wrapper.
906 Requires the presence of the libopus headers and library during
907 configuration. You need to explicitly configure the build with
908 @code{--enable-libopus}.
910 @subsection Option Mapping
912 Most libopus options are modelled after the @command{opusenc} utility from
913 opus-tools. The following is an option mapping chart describing options
914 supported by the libopus wrapper, and their @command{opusenc}-equivalent
919 @item b (@emph{bitrate})
920 Set the bit rate in bits/s. FFmpeg's @option{b} option is
921 expressed in bits/s, while @command{opusenc}'s @option{bitrate} in
924 @item vbr (@emph{vbr}, @emph{hard-cbr}, and @emph{cvbr})
925 Set VBR mode. The FFmpeg @option{vbr} option has the following
926 valid arguments, with the @command{opusenc} equivalent options
930 @item off (@emph{hard-cbr})
931 Use constant bit rate encoding.
933 @item on (@emph{vbr})
934 Use variable bit rate encoding (the default).
936 @item constrained (@emph{cvbr})
937 Use constrained variable bit rate encoding.
940 @item compression_level (@emph{comp})
941 Set encoding algorithm complexity. Valid options are integers in
942 the 0-10 range. 0 gives the fastest encodes but lower quality, while 10
943 gives the highest quality but slowest encoding. The default is 10.
945 @item frame_duration (@emph{framesize})
946 Set maximum frame size, or duration of a frame in milliseconds. The
947 argument must be exactly the following: 2.5, 5, 10, 20, 40, 60. Smaller
948 frame sizes achieve lower latency but less quality at a given bitrate.
949 Sizes greater than 20ms are only interesting at fairly low bitrates.
952 @item packet_loss (@emph{expect-loss})
953 Set expected packet loss percentage. The default is 0.
955 @item fec (@emph{n/a})
956 Enable inband forward error correction. @option{packet_loss} must be non-zero
957 to take advantage - frequency of FEC 'side-data' is proportional to expected packet loss.
960 @item application (N.A.)
961 Set intended application type. Valid options are listed below:
965 Favor improved speech intelligibility.
967 Favor faithfulness to the input (the default).
969 Restrict to only the lowest delay modes.
973 Set cutoff bandwidth in Hz. The argument must be exactly one of the
974 following: 4000, 6000, 8000, 12000, or 20000, corresponding to
975 narrowband, mediumband, wideband, super wideband, and fullband
976 respectively. The default is 0 (cutoff disabled).
978 @item mapping_family (@emph{mapping_family})
979 Set channel mapping family to be used by the encoder. The default value of -1
980 uses mapping family 0 for mono and stereo inputs, and mapping family 1
981 otherwise. The default also disables the surround masking and LFE bandwidth
982 optimzations in libopus, and requires that the input contains 8 channels or
985 Other values include 0 for mono and stereo, 1 for surround sound with masking
986 and LFE bandwidth optimizations, and 255 for independent streams with an
987 unspecified channel layout.
989 @item apply_phase_inv (N.A.) (requires libopus >= 1.2)
990 If set to 0, disables the use of phase inversion for intensity stereo,
991 improving the quality of mono downmixes, but slightly reducing normal stereo
992 quality. The default is 1 (phase inversion enabled).
999 Shine Fixed-Point MP3 encoder wrapper.
1001 Shine is a fixed-point MP3 encoder. It has a far better performance on
1002 platforms without an FPU, e.g. armel CPUs, and some phones and tablets.
1003 However, as it is more targeted on performance than quality, it is not on par
1004 with LAME and other production-grade encoders quality-wise. Also, according to
1005 the project's homepage, this encoder may not be free of bugs as the code was
1006 written a long time ago and the project was dead for at least 5 years.
1008 This encoder only supports stereo and mono input. This is also CBR-only.
1010 The original project (last updated in early 2007) is at
1011 @url{http://sourceforge.net/projects/libshine-fxp/}. We only support the
1012 updated fork by the Savonet/Liquidsoap project at @url{https://github.com/savonet/shine}.
1014 Requires the presence of the libshine headers and library during
1015 configuration. You need to explicitly configure the build with
1016 @code{--enable-libshine}.
1018 See also @ref{libmp3lame}.
1022 The following options are supported by the libshine wrapper. The
1023 @command{shineenc}-equivalent of the options are listed in parentheses.
1027 Set bitrate expressed in bits/s for CBR. @command{shineenc} @option{-b} option
1028 is expressed in kilobits/s.
1034 TwoLAME MP2 encoder wrapper.
1036 Requires the presence of the libtwolame headers and library during
1037 configuration. You need to explicitly configure the build with
1038 @code{--enable-libtwolame}.
1042 The following options are supported by the libtwolame wrapper. The
1043 @command{twolame}-equivalent options follow the FFmpeg ones and are in
1048 Set bitrate expressed in bits/s for CBR. @command{twolame} @option{b}
1049 option is expressed in kilobits/s. Default value is 128k.
1052 Set quality for experimental VBR support. Maximum value range is
1053 from -50 to 50, useful range is from -10 to 10. The higher the
1054 value, the better the quality. This option is valid only using the
1055 @command{ffmpeg} command-line tool. For library interface users,
1056 use @option{global_quality}.
1058 @item mode (@emph{--mode})
1059 Set the mode of the resulting audio. Possible values:
1063 Choose mode automatically based on the input. This is the default.
1074 @item psymodel (@emph{--psyc-mode})
1075 Set psychoacoustic model to use in encoding. The argument must be
1076 an integer between -1 and 4, inclusive. The higher the value, the
1077 better the quality. The default value is 3.
1079 @item energy_levels (@emph{--energy})
1080 Enable energy levels extensions when set to 1. The default value is
1083 @item error_protection (@emph{--protect})
1084 Enable CRC error protection when set to 1. The default value is 0
1087 @item copyright (@emph{--copyright})
1088 Set MPEG audio copyright flag when set to 1. The default value is 0
1091 @item original (@emph{--original})
1092 Set MPEG audio original flag when set to 1. The default value is 0
1097 @section libvo-amrwbenc
1099 VisualOn Adaptive Multi-Rate Wideband encoder.
1101 Requires the presence of the libvo-amrwbenc headers and library during
1102 configuration. You need to explicitly configure the build with
1103 @code{--enable-libvo-amrwbenc --enable-version3}.
1105 This is a mono-only encoder. Officially it only supports 16000Hz sample
1106 rate, but you can override it by setting @option{strict} to
1107 @samp{unofficial} or lower.
1114 Set bitrate in bits/s. Only the following bitrates are supported, otherwise
1115 libavcodec will round to the nearest valid bitrate.
1130 Allow discontinuous transmission (generate comfort noise) when set to 1. The
1131 default value is 0 (disabled).
1137 libvorbis encoder wrapper.
1139 Requires the presence of the libvorbisenc headers and library during
1140 configuration. You need to explicitly configure the build with
1141 @code{--enable-libvorbis}.
1145 The following options are supported by the libvorbis wrapper. The
1146 @command{oggenc}-equivalent of the options are listed in parentheses.
1148 To get a more accurate and extensive documentation of the libvorbis
1149 options, consult the libvorbisenc's and @command{oggenc}'s documentations.
1150 See @url{http://xiph.org/vorbis/},
1151 @url{http://wiki.xiph.org/Vorbis-tools}, and oggenc(1).
1155 Set bitrate expressed in bits/s for ABR. @command{oggenc} @option{-b} is
1156 expressed in kilobits/s.
1159 Set constant quality setting for VBR. The value should be a float
1160 number in the range of -1.0 to 10.0. The higher the value, the better
1161 the quality. The default value is @samp{3.0}.
1163 This option is valid only using the @command{ffmpeg} command-line tool.
1164 For library interface users, use @option{global_quality}.
1166 @item cutoff (@emph{--advanced-encode-option lowpass_frequency=N})
1167 Set cutoff bandwidth in Hz, a value of 0 disables cutoff. @command{oggenc}'s
1168 related option is expressed in kHz. The default value is @samp{0} (cutoff
1171 @item minrate (@emph{-m})
1172 Set minimum bitrate expressed in bits/s. @command{oggenc} @option{-m} is
1173 expressed in kilobits/s.
1175 @item maxrate (@emph{-M})
1176 Set maximum bitrate expressed in bits/s. @command{oggenc} @option{-M} is
1177 expressed in kilobits/s. This only has effect on ABR mode.
1179 @item iblock (@emph{--advanced-encode-option impulse_noisetune=N})
1180 Set noise floor bias for impulse blocks. The value is a float number from
1181 -15.0 to 0.0. A negative bias instructs the encoder to pay special attention
1182 to the crispness of transients in the encoded audio. The tradeoff for better
1183 transient response is a higher bitrate.
1190 Motion JPEG encoder.
1196 Set the huffman encoding strategy. Possible values:
1200 Use the default huffman tables. This is the default strategy.
1203 Compute and use optimal huffman tables.
1211 WavPack lossless audio encoder.
1215 The equivalent options for @command{wavpack} command line utility are listed in
1218 @subsubsection Shared options
1220 The following shared options are effective for this encoder. Only special notes
1221 about this particular encoder will be documented here. For the general meaning
1222 of the options, see @ref{codec-options,,the Codec Options chapter}.
1225 @item frame_size (@emph{--blocksize})
1226 For this encoder, the range for this option is between 128 and 131072. Default
1227 is automatically decided based on sample rate and number of channel.
1229 For the complete formula of calculating default, see
1230 @file{libavcodec/wavpackenc.c}.
1232 @item compression_level (@emph{-f}, @emph{-h}, @emph{-hh}, and @emph{-x})
1235 @subsubsection Private options
1238 @item joint_stereo (@emph{-j})
1239 Set whether to enable joint stereo. Valid values are:
1243 Force mid/side audio encoding.
1244 @item off (@emph{0})
1245 Force left/right audio encoding.
1247 Let the encoder decide automatically.
1251 Set whether to enable optimization for mono. This option is only effective for
1252 non-mono streams. Available values:
1263 @c man end AUDIO ENCODERS
1265 @chapter Video Encoders
1266 @c man begin VIDEO ENCODERS
1268 A description of some of the currently available video encoders
1271 @section a64_multi, a64_multi5
1273 A64 / Commodore 64 multicolor charset encoder. @code{a64_multi5} is extended with 5th color (colram).
1277 GIF image/animation encoder.
1282 @item gifflags @var{integer}
1283 Sets the flags used for GIF encoding.
1287 Enables picture offsetting.
1292 Enables transparency detection between frames.
1298 @item gifimage @var{integer}
1299 Enables encoding one full GIF image per frame, rather than an animated GIF.
1301 Default value is @option{0}.
1303 @item global_palette @var{integer}
1304 Writes a palette to the global GIF header where feasible.
1306 If disabled, every frame will always have a palette written, even if there
1307 is a global palette supplied.
1309 Default value is @option{1}.
1315 Vidvox Hap video encoder.
1320 @item format @var{integer}
1321 Specifies the Hap format to encode.
1329 Default value is @option{hap}.
1331 @item chunks @var{integer}
1332 Specifies the number of chunks to split frames into, between 1 and 64. This
1333 permits multithreaded decoding of large frames, potentially at the cost of
1334 data-rate. The encoder may modify this value to divide frames evenly.
1336 Default value is @var{1}.
1338 @item compressor @var{integer}
1339 Specifies the second-stage compressor to use. If set to @option{none},
1340 @option{chunks} will be limited to 1, as chunked uncompressed frames offer no
1348 Default value is @option{snappy}.
1354 The native jpeg 2000 encoder is lossy by default, the @code{-q:v}
1355 option can be used to set the encoding quality. Lossless encoding
1356 can be selected with @code{-pred 1}.
1361 @item format @var{integer}
1362 Can be set to either @code{j2k} or @code{jp2} (the default) that
1363 makes it possible to store non-rgb pix_fmts.
1365 @item tile_width @var{integer}
1366 Sets tile width. Range is 1 to 1073741824. Default is 256.
1368 @item tile_height @var{integer}
1369 Sets tile height. Range is 1 to 1073741824. Default is 256.
1371 @item pred @var{integer}
1372 Allows setting the discrete wavelet transform (DWT) type
1374 @item dwt97int (Lossy)
1375 @item dwt53 (Lossless)
1377 Default is @code{dwt97int}
1379 @item sop @var{boolean}
1380 Enable this to add SOP marker at the start of each packet. Disabled by default.
1382 @item eph @var{boolean}
1383 Enable this to add EPH marker at the end of each packet header. Disabled by default.
1385 @item prog @var{integer}
1386 Sets the progression order to be used by the encoder.
1387 Possible values are:
1395 Set to @code{lrcp} by default.
1397 @item layer_rates @var{string}
1398 By default, when this option is not used, compression is done using the quality metric.
1399 This option allows for compression using compression ratio. The compression ratio for each
1400 level could be specified. The compression ratio of a layer @code{l} species the what ratio of
1401 total file size is contained in the first @code{l} layers.
1406 ffmpeg -i input.bmp -c:v jpeg2000 -layer_rates "100,10,1" output.j2k
1409 This would compress the image to contain 3 layers, where the data contained in the
1410 first layer would be compressed by 1000 times, compressed by 100 in the first two layers,
1411 and shall contain all data while using all 3 layers.
1417 rav1e AV1 encoder wrapper.
1419 Requires the presence of the rav1e headers and library during configuration.
1420 You need to explicitly configure the build with @code{--enable-librav1e}.
1426 Sets the maximum quantizer to use when using bitrate mode.
1429 Sets the minimum quantizer to use when using bitrate mode.
1432 Uses quantizer mode to encode at the given quantizer (0-255).
1435 Selects the speed preset (0-10) to encode with.
1438 Selects how many tiles to encode with.
1441 Selects how many rows of tiles to encode with.
1444 Selects how many columns of tiles to encode with.
1447 Set rav1e options using a list of @var{key}=@var{value} pairs separated
1448 by ":". See @command{rav1e --help} for a list of options.
1450 For example to specify librav1e encoding options with @option{-rav1e-params}:
1453 ffmpeg -i input -c:v librav1e -b:v 500K -rav1e-params speed=5:low_latency=true output.mp4
1460 libaom AV1 encoder wrapper.
1462 Requires the presence of the libaom headers and library during
1463 configuration. You need to explicitly configure the build with
1464 @code{--enable-libaom}.
1468 The wrapper supports the following standard libavcodec options:
1473 Set bitrate target in bits/second. By default this will use
1474 variable-bitrate mode. If @option{maxrate} and @option{minrate} are
1475 also set to the same value then it will use constant-bitrate mode,
1476 otherwise if @option{crf} is set as well then it will use
1477 constrained-quality mode.
1480 Set key frame placement. The GOP size sets the maximum distance between
1481 key frames; if zero the output stream will be intra-only. The minimum
1482 distance is ignored unless it is the same as the GOP size, in which case
1483 key frames will always appear at a fixed interval. Not set by default,
1484 so without this option the library has completely free choice about
1485 where to place key frames.
1488 Set minimum/maximum quantisation values. Valid range is from 0 to 63
1489 (warning: this does not match the quantiser values actually used by AV1
1490 - divide by four to map real quantiser values to this range). Defaults
1491 to min/max (no constraint).
1493 @item minrate maxrate bufsize rc_init_occupancy
1494 Set rate control buffering parameters. Not used if not set - defaults
1495 to unconstrained variable bitrate.
1498 Set the number of threads to use while encoding. This may require the
1499 @option{tiles} or @option{row-mt} options to also be set to actually
1500 use the specified number of threads fully. Defaults to the number of
1501 hardware threads supported by the host machine.
1504 Set the encoding profile. Defaults to using the profile which matches
1505 the bit depth and chroma subsampling of the input.
1509 The wrapper also has some specific options:
1514 Set the quality/encoding speed tradeoff. Valid range is from 0 to 8,
1515 higher numbers indicating greater speed and lower quality. The default
1516 value is 1, which will be slow and high quality.
1519 Enable use of alternate reference frames. Defaults to the internal
1520 default of the library.
1522 @item arnr-max-frames (@emph{frames})
1523 Set altref noise reduction max frame count. Default is -1.
1525 @item arnr-strength (@emph{strength})
1526 Set altref noise reduction filter strength. Range is -1 to 6. Default is -1.
1528 @item aq-mode (@emph{aq-mode})
1529 Set adaptive quantization mode. Possible values:
1532 @item none (@emph{0})
1535 @item variance (@emph{1})
1538 @item complexity (@emph{2})
1541 @item cyclic (@emph{3})
1545 @item tune (@emph{tune})
1546 Set the distortion metric the encoder is tuned with. Default is @code{psnr}.
1549 @item psnr (@emph{0})
1551 @item ssim (@emph{1})
1555 Set the maximum number of frames which the encoder may keep in flight
1556 at any one time for lookahead purposes. Defaults to the internal
1557 default of the library.
1559 @item error-resilience
1560 Enable error resilience features:
1563 Improve resilience against losses of whole frames.
1565 Not enabled by default.
1568 Set the quality/size tradeoff for constant-quality (no bitrate target)
1569 and constrained-quality (with maximum bitrate target) modes. Valid
1570 range is 0 to 63, higher numbers indicating lower quality and smaller
1571 output size. Only used if set; by default only the bitrate target is
1575 Set a change threshold on blocks below which they will be skipped by
1576 the encoder. Defined in arbitrary units as a nonnegative integer,
1577 defaulting to zero (no blocks are skipped).
1579 @item drop-threshold
1580 Set a threshold for dropping frames when close to rate control bounds.
1581 Defined as a percentage of the target buffer - when the rate control
1582 buffer falls below this percentage, frames will be dropped until it
1583 has refilled above the threshold. Defaults to zero (no frames are
1586 @item denoise-noise-level (@emph{level})
1587 Amount of noise to be removed for grain synthesis. Grain synthesis is disabled if
1588 this option is not set or set to 0.
1590 @item denoise-block-size (@emph{pixels})
1591 Block size used for denoising for grain synthesis. If not set, AV1 codec
1592 uses the default value of 32.
1594 @item undershoot-pct (@emph{pct})
1595 Set datarate undershoot (min) percentage of the target bitrate. Range is -1 to 100.
1598 @item overshoot-pct (@emph{pct})
1599 Set datarate overshoot (max) percentage of the target bitrate. Range is -1 to 1000.
1602 @item minsection-pct (@emph{pct})
1603 Minimum percentage variation of the GOP bitrate from the target bitrate. If minsection-pct
1604 is not set, the libaomenc wrapper computes it as follows: @code{(minrate * 100 / bitrate)}.
1605 Range is -1 to 100. Default is -1 (unset).
1607 @item maxsection-pct (@emph{pct})
1608 Maximum percentage variation of the GOP bitrate from the target bitrate. If maxsection-pct
1609 is not set, the libaomenc wrapper computes it as follows: @code{(maxrate * 100 / bitrate)}.
1610 Range is -1 to 5000. Default is -1 (unset).
1612 @item frame-parallel (@emph{boolean})
1613 Enable frame parallel decodability features. Default is true.
1616 Set the number of tiles to encode the input video with, as columns x
1617 rows. Larger numbers allow greater parallelism in both encoding and
1618 decoding, but may decrease coding efficiency. Defaults to the minimum
1619 number of tiles required by the size of the input video (this is 1x1
1620 (that is, a single tile) for sizes up to and including 4K).
1622 @item tile-columns tile-rows
1623 Set the number of tiles as log2 of the number of tile rows and columns.
1624 Provided for compatibility with libvpx/VP9.
1626 @item row-mt (Requires libaom >= 1.0.0-759-g90a15f4f2)
1627 Enable row based multi-threading. Disabled by default.
1629 @item enable-cdef (@emph{boolean})
1630 Enable Constrained Directional Enhancement Filter. The libaom-av1
1631 encoder enables CDEF by default.
1633 @item enable-restoration (@emph{boolean})
1634 Enable Loop Restoration Filter. Default is true for libaom-av1.
1636 @item enable-global-motion (@emph{boolean})
1637 Enable the use of global motion for block prediction. Default is true.
1639 @item enable-intrabc (@emph{boolean})
1640 Enable block copy mode for intra block prediction. This mode is
1641 useful for screen content. Default is true.
1643 @item enable-rect-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
1644 Enable rectangular partitions. Default is true.
1646 @item enable-1to4-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
1647 Enable 1:4/4:1 partitions. Default is true.
1649 @item enable-ab-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
1650 Enable AB shape partitions. Default is true.
1652 @item enable-angle-delta (@emph{boolean}) (Requires libaom >= v2.0.0)
1653 Enable angle delta intra prediction. Default is true.
1655 @item enable-cfl-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1656 Enable chroma predicted from luma intra prediction. Default is true.
1658 @item enable-filter-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1659 Enable filter intra predictor. Default is true.
1661 @item enable-intra-edge-filter (@emph{boolean}) (Requires libaom >= v2.0.0)
1662 Enable intra edge filter. Default is true.
1664 @item enable-smooth-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1665 Enable smooth intra prediction mode. Default is true.
1667 @item enable-paeth-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1668 Enable paeth predictor in intra prediction. Default is true.
1670 @item enable-palette (@emph{boolean}) (Requires libaom >= v2.0.0)
1671 Enable palette prediction mode. Default is true.
1673 @item enable-flip-idtx (@emph{boolean}) (Requires libaom >= v2.0.0)
1674 Enable extended transform type, including FLIPADST_DCT, DCT_FLIPADST,
1675 FLIPADST_FLIPADST, ADST_FLIPADST, FLIPADST_ADST, IDTX, V_DCT, H_DCT,
1676 V_ADST, H_ADST, V_FLIPADST, H_FLIPADST. Default is true.
1678 @item enable-tx64 (@emph{boolean}) (Requires libaom >= v2.0.0)
1679 Enable 64-pt transform. Default is true.
1681 @item reduced-tx-type-set (@emph{boolean}) (Requires libaom >= v2.0.0)
1682 Use reduced set of transform types. Default is false.
1684 @item use-intra-dct-only (@emph{boolean}) (Requires libaom >= v2.0.0)
1685 Use DCT only for INTRA modes. Default is false.
1687 @item use-inter-dct-only (@emph{boolean}) (Requires libaom >= v2.0.0)
1688 Use DCT only for INTER modes. Default is false.
1690 @item use-intra-default-tx-only (@emph{boolean}) (Requires libaom >= v2.0.0)
1691 Use Default-transform only for INTRA modes. Default is false.
1693 @item enable-ref-frame-mvs (@emph{boolean}) (Requires libaom >= v2.0.0)
1694 Enable temporal mv prediction. Default is true.
1696 @item enable-reduced-reference-set (@emph{boolean}) (Requires libaom >= v2.0.0)
1697 Use reduced set of single and compound references. Default is false.
1699 @item enable-obmc (@emph{boolean}) (Requires libaom >= v2.0.0)
1700 Enable obmc. Default is true.
1702 @item enable-dual-filter (@emph{boolean}) (Requires libaom >= v2.0.0)
1703 Enable dual filter. Default is true.
1705 @item enable-diff-wtd-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1706 Enable difference-weighted compound. Default is true.
1708 @item enable-dist-wtd-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1709 Enable distance-weighted compound. Default is true.
1711 @item enable-onesided-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1712 Enable one sided compound. Default is true.
1714 @item enable-interinter-wedge (@emph{boolean}) (Requires libaom >= v2.0.0)
1715 Enable interinter wedge compound. Default is true.
1717 @item enable-interintra-wedge (@emph{boolean}) (Requires libaom >= v2.0.0)
1718 Enable interintra wedge compound. Default is true.
1720 @item enable-masked-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1721 Enable masked compound. Default is true.
1723 @item enable-interintra-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1724 Enable interintra compound. Default is true.
1726 @item enable-smooth-interintra (@emph{boolean}) (Requires libaom >= v2.0.0)
1727 Enable smooth interintra mode. Default is true.
1730 Set libaom options using a list of @var{key}=@var{value} pairs separated
1731 by ":". For a list of supported options, see @command{aomenc --help} under the
1732 section "AV1 Specific Options".
1734 For example to specify libaom encoding options with @option{-aom-params}:
1737 ffmpeg -i input -c:v libaom-av1 -b:v 500K -aom-params tune=psnr:enable-tpl-model=1 output.mp4
1744 SVT-AV1 encoder wrapper.
1746 Requires the presence of the SVT-AV1 headers and library during configuration.
1747 You need to explicitly configure the build with @code{--enable-libsvtav1}.
1753 Set the encoding profile.
1756 Set the operating point level.
1759 Set the operating point tier.
1762 Set the rate control mode to use.
1767 Constant quantizer: use fixed values of qindex (dependent on the frame type)
1768 throughout the stream. This mode is the default.
1771 Variable bitrate: use a target bitrate for the whole stream.
1774 Constrained variable bitrate: use a target bitrate for each GOP.
1778 Set the maximum quantizer to use when using a bitrate mode.
1781 Set the minimum quantizer to use when using a bitrate mode.
1784 Set the quantizer used in cqp rate control mode (0-63).
1787 Enable scene change detection.
1790 Set number of frames to look ahead (0-120).
1793 Set the quality-speed tradeoff, in the range 0 to 8. Higher values are
1794 faster but lower quality. Defaults to 8 (highest speed).
1797 Set log2 of the number of rows of tiles to use (0-6).
1800 Set log2 of the number of columns of tiles to use (0-4).
1806 Kvazaar H.265/HEVC encoder.
1808 Requires the presence of the libkvazaar headers and library during
1809 configuration. You need to explicitly configure the build with
1810 @option{--enable-libkvazaar}.
1817 Set target video bitrate in bit/s and enable rate control.
1819 @item kvazaar-params
1820 Set kvazaar parameters as a list of @var{name}=@var{value} pairs separated
1821 by commas (,). See kvazaar documentation for a list of options.
1825 @section libopenh264
1827 Cisco libopenh264 H.264/MPEG-4 AVC encoder wrapper.
1829 This encoder requires the presence of the libopenh264 headers and
1830 library during configuration. You need to explicitly configure the
1831 build with @code{--enable-libopenh264}. The library is detected using
1832 @command{pkg-config}.
1834 For more information about the library see
1835 @url{http://www.openh264.org}.
1839 The following FFmpeg global options affect the configurations of the
1840 libopenh264 encoder.
1844 Set the bitrate (as a number of bits per second).
1850 Set the max bitrate (as a number of bits per second).
1852 @item flags +global_header
1853 Set global header in the bitstream.
1856 Set the number of slices, used in parallelized encoding. Default value
1857 is 0. This is only used when @option{slice_mode} is set to
1861 Set slice mode. Can assume one of the following possible values:
1865 a fixed number of slices
1867 one slice per row of macroblocks
1869 automatic number of slices according to number of threads
1874 Default value is @samp{auto}.
1877 Enable loop filter, if set to 1 (automatically enabled). To disable
1881 Set profile restrictions. If set to the value of @samp{main} enable
1882 CABAC (set the @code{SEncParamExt.iEntropyCodingModeFlag} flag to 1).
1885 Set maximum NAL size in bytes.
1887 @item allow_skip_frames
1888 Allow skipping frames to hit the target bitrate if set to 1.
1893 libtheora Theora encoder wrapper.
1895 Requires the presence of the libtheora headers and library during
1896 configuration. You need to explicitly configure the build with
1897 @code{--enable-libtheora}.
1899 For more information about the libtheora project see
1900 @url{http://www.theora.org/}.
1904 The following global options are mapped to internal libtheora options
1905 which affect the quality and the bitrate of the encoded stream.
1909 Set the video bitrate in bit/s for CBR (Constant Bit Rate) mode. In
1910 case VBR (Variable Bit Rate) mode is enabled this option is ignored.
1913 Used to enable constant quality mode (VBR) encoding through the
1914 @option{qscale} flag, and to enable the @code{pass1} and @code{pass2}
1920 @item global_quality
1921 Set the global quality as an integer in lambda units.
1923 Only relevant when VBR mode is enabled with @code{flags +qscale}. The
1924 value is converted to QP units by dividing it by @code{FF_QP2LAMBDA},
1925 clipped in the [0 - 10] range, and then multiplied by 6.3 to get a
1926 value in the native libtheora range [0-63]. A higher value corresponds
1927 to a higher quality.
1930 Enable VBR mode when set to a non-negative value, and set constant
1931 quality value as a double floating point value in QP units.
1933 The value is clipped in the [0-10] range, and then multiplied by 6.3
1934 to get a value in the native libtheora range [0-63].
1936 This option is valid only using the @command{ffmpeg} command-line
1937 tool. For library interface users, use @option{global_quality}.
1940 @subsection Examples
1944 Set maximum constant quality (VBR) encoding with @command{ffmpeg}:
1946 ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
1950 Use @command{ffmpeg} to convert a CBR 1000 kbps Theora video stream:
1952 ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
1958 VP8/VP9 format supported through libvpx.
1960 Requires the presence of the libvpx headers and library during configuration.
1961 You need to explicitly configure the build with @code{--enable-libvpx}.
1965 The following options are supported by the libvpx wrapper. The
1966 @command{vpxenc}-equivalent options or values are listed in parentheses
1969 To reduce the duplication of documentation, only the private options
1970 and some others requiring special attention are documented here. For
1971 the documentation of the undocumented generic options, see
1972 @ref{codec-options,,the Codec Options chapter}.
1974 To get more documentation of the libvpx options, invoke the command
1975 @command{ffmpeg -h encoder=libvpx}, @command{ffmpeg -h encoder=libvpx-vp9} or
1976 @command{vpxenc --help}. Further information is available in the libvpx API
1981 @item b (@emph{target-bitrate})
1982 Set bitrate in bits/s. Note that FFmpeg's @option{b} option is
1983 expressed in bits/s, while @command{vpxenc}'s @option{target-bitrate} is in
1986 @item g (@emph{kf-max-dist})
1988 @item keyint_min (@emph{kf-min-dist})
1990 @item qmin (@emph{min-q})
1992 @item qmax (@emph{max-q})
1994 @item bufsize (@emph{buf-sz}, @emph{buf-optimal-sz})
1995 Set ratecontrol buffer size (in bits). Note @command{vpxenc}'s options are
1996 specified in milliseconds, the libvpx wrapper converts this value as follows:
1997 @code{buf-sz = bufsize * 1000 / bitrate},
1998 @code{buf-optimal-sz = bufsize * 1000 / bitrate * 5 / 6}.
2000 @item rc_init_occupancy (@emph{buf-initial-sz})
2001 Set number of bits which should be loaded into the rc buffer before decoding
2002 starts. Note @command{vpxenc}'s option is specified in milliseconds, the libvpx
2003 wrapper converts this value as follows:
2004 @code{rc_init_occupancy * 1000 / bitrate}.
2006 @item undershoot-pct
2007 Set datarate undershoot (min) percentage of the target bitrate.
2010 Set datarate overshoot (max) percentage of the target bitrate.
2012 @item skip_threshold (@emph{drop-frame})
2014 @item qcomp (@emph{bias-pct})
2016 @item maxrate (@emph{maxsection-pct})
2017 Set GOP max bitrate in bits/s. Note @command{vpxenc}'s option is specified as a
2018 percentage of the target bitrate, the libvpx wrapper converts this value as
2019 follows: @code{(maxrate * 100 / bitrate)}.
2021 @item minrate (@emph{minsection-pct})
2022 Set GOP min bitrate in bits/s. Note @command{vpxenc}'s option is specified as a
2023 percentage of the target bitrate, the libvpx wrapper converts this value as
2024 follows: @code{(minrate * 100 / bitrate)}.
2026 @item minrate, maxrate, b @emph{end-usage=cbr}
2027 @code{(minrate == maxrate == bitrate)}.
2029 @item crf (@emph{end-usage=cq}, @emph{cq-level})
2031 @item tune (@emph{tune})
2033 @item psnr (@emph{psnr})
2034 @item ssim (@emph{ssim})
2037 @item quality, deadline (@emph{deadline})
2040 Use best quality deadline. Poorly named and quite slow, this option should be
2041 avoided as it may give worse quality output than good.
2043 Use good quality deadline. This is a good trade-off between speed and quality
2044 when used with the @option{cpu-used} option.
2046 Use realtime quality deadline.
2049 @item speed, cpu-used (@emph{cpu-used})
2050 Set quality/speed ratio modifier. Higher values speed up the encode at the cost
2053 @item nr (@emph{noise-sensitivity})
2056 Set a change threshold on blocks below which they will be skipped by the
2059 @item slices (@emph{token-parts})
2060 Note that FFmpeg's @option{slices} option gives the total number of partitions,
2061 while @command{vpxenc}'s @option{token-parts} is given as
2062 @code{log2(partitions)}.
2064 @item max-intra-rate
2065 Set maximum I-frame bitrate as a percentage of the target bitrate. A value of 0
2068 @item force_key_frames
2069 @code{VPX_EFLAG_FORCE_KF}
2071 @item Alternate reference frame related
2074 Enable use of alternate reference frames (2-pass only).
2075 Values greater than 1 enable multi-layer alternate reference frames (VP9 only).
2076 @item arnr-maxframes
2077 Set altref noise reduction max frame count.
2079 Set altref noise reduction filter type: backward, forward, centered.
2081 Set altref noise reduction filter strength.
2082 @item rc-lookahead, lag-in-frames (@emph{lag-in-frames})
2083 Set number of frames to look ahead for frametype and ratecontrol.
2086 @item error-resilient
2087 Enable error resiliency features.
2089 @item sharpness @var{integer}
2090 Increase sharpness at the expense of lower PSNR.
2091 The valid range is [0, 7].
2094 Sets the temporal scalability configuration using a :-separated list of
2095 key=value pairs. For example, to specify temporal scalability parameters
2098 ffmpeg -i INPUT -c:v libvpx -ts-parameters ts_number_layers=3:\
2099 ts_target_bitrate=250,500,1000:ts_rate_decimator=4,2,1:\
2100 ts_periodicity=4:ts_layer_id=0,2,1,2:ts_layering_mode=3 OUTPUT
2102 Below is a brief explanation of each of the parameters, please
2103 refer to @code{struct vpx_codec_enc_cfg} in @code{vpx/vpx_encoder.h} for more
2106 @item ts_number_layers
2107 Number of temporal coding layers.
2108 @item ts_target_bitrate
2109 Target bitrate for each temporal layer (in kbps).
2110 (bitrate should be inclusive of the lower temporal layer).
2111 @item ts_rate_decimator
2112 Frame rate decimation factor for each temporal layer.
2113 @item ts_periodicity
2114 Length of the sequence defining frame temporal layer membership.
2116 Template defining the membership of frames to temporal layers.
2117 @item ts_layering_mode
2118 (optional) Selecting the temporal structure from a set of pre-defined temporal layering modes.
2119 Currently supports the following options.
2122 No temporal layering flags are provided internally,
2123 relies on flags being passed in using @code{metadata} field in @code{AVFrame}
2124 with following keys.
2127 Sets the flags passed into the encoder to indicate the referencing scheme for
2129 Refer to function @code{vpx_codec_encode} in @code{vpx/vpx_encoder.h} for more
2132 Explicitly sets the temporal id of the current frame to encode.
2135 Two temporal layers. 0-1...
2137 Three temporal layers. 0-2-1-2...; with single reference frame.
2139 Same as option "3", except there is a dependency between
2140 the two temporal layer 2 frames within the temporal period.
2144 @item VP9-specific options
2147 Enable lossless mode.
2149 Set number of tile columns to use. Note this is given as
2150 @code{log2(tile_columns)}. For example, 8 tile columns would be requested by
2151 setting the @option{tile-columns} option to 3.
2153 Set number of tile rows to use. Note this is given as @code{log2(tile_rows)}.
2154 For example, 4 tile rows would be requested by setting the @option{tile-rows}
2156 @item frame-parallel
2157 Enable frame parallel decodability features.
2159 Set adaptive quantization mode (0: off (default), 1: variance 2: complexity, 3:
2160 cyclic refresh, 4: equator360).
2161 @item colorspace @emph{color-space}
2162 Set input color space. The VP9 bitstream supports signaling the following
2165 @item @samp{rgb} @emph{sRGB}
2166 @item @samp{bt709} @emph{bt709}
2167 @item @samp{unspecified} @emph{unknown}
2168 @item @samp{bt470bg} @emph{bt601}
2169 @item @samp{smpte170m} @emph{smpte170}
2170 @item @samp{smpte240m} @emph{smpte240}
2171 @item @samp{bt2020_ncl} @emph{bt2020}
2173 @item row-mt @var{boolean}
2174 Enable row based multi-threading.
2176 Set content type: default (0), screen (1), film (2).
2177 @item corpus-complexity
2178 Corpus VBR mode is a variant of standard VBR where the complexity distribution
2179 midpoint is passed in rather than calculated for a specific clip or chunk.
2181 The valid range is [0, 10000]. 0 (default) uses standard VBR.
2182 @item enable-tpl @var{boolean}
2183 Enable temporal dependency model.
2184 @item ref-frame-config
2185 Using per-frame metadata, set members of the structure @code{vpx_svc_ref_frame_config_t} in @code{vpx/vp8cx.h} to fine-control referencing schemes and frame buffer management.
2186 @*Use a :-separated list of key=value pairs.
2189 av_dict_set(&av_frame->metadata, "ref-frame-config", \
2190 "rfc_update_buffer_slot=7:rfc_lst_fb_idx=0:rfc_gld_fb_idx=1:rfc_alt_fb_idx=2:rfc_reference_last=0:rfc_reference_golden=0:rfc_reference_alt_ref=0");
2193 @item rfc_update_buffer_slot
2194 Indicates the buffer slot number to update
2195 @item rfc_update_last
2196 Indicates whether to update the LAST frame
2197 @item rfc_update_golden
2198 Indicates whether to update GOLDEN frame
2199 @item rfc_update_alt_ref
2200 Indicates whether to update ALT_REF frame
2201 @item rfc_lst_fb_idx
2202 LAST frame buffer index
2203 @item rfc_gld_fb_idx
2204 GOLDEN frame buffer index
2205 @item rfc_alt_fb_idx
2206 ALT_REF frame buffer index
2207 @item rfc_reference_last
2208 Indicates whether to reference LAST frame
2209 @item rfc_reference_golden
2210 Indicates whether to reference GOLDEN frame
2211 @item rfc_reference_alt_ref
2212 Indicates whether to reference ALT_REF frame
2213 @item rfc_reference_duration
2214 Indicates frame duration
2220 For more information about libvpx see:
2221 @url{http://www.webmproject.org/}
2225 libwebp WebP Image encoder wrapper
2227 libwebp is Google's official encoder for WebP images. It can encode in either
2228 lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
2229 frame. Lossless images are a separate codec developed by Google.
2231 @subsection Pixel Format
2233 Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
2234 to limitations of the format and libwebp. Alpha is supported for either mode.
2235 Because of API limitations, if RGB is passed in when encoding lossy or YUV is
2236 passed in for encoding lossless, the pixel format will automatically be
2237 converted using functions from libwebp. This is not ideal and is done only for
2244 @item -lossless @var{boolean}
2245 Enables/Disables use of lossless mode. Default is 0.
2247 @item -compression_level @var{integer}
2248 For lossy, this is a quality/speed tradeoff. Higher values give better quality
2249 for a given size at the cost of increased encoding time. For lossless, this is
2250 a size/speed tradeoff. Higher values give smaller size at the cost of increased
2251 encoding time. More specifically, it controls the number of extra algorithms
2252 and compression tools used, and varies the combination of these tools. This
2253 maps to the @var{method} option in libwebp. The valid range is 0 to 6.
2256 @item -qscale @var{float}
2257 For lossy encoding, this controls image quality, 0 to 100. For lossless
2258 encoding, this controls the effort and time spent at compressing more. The
2259 default value is 75. Note that for usage via libavcodec, this option is called
2260 @var{global_quality} and must be multiplied by @var{FF_QP2LAMBDA}.
2262 @item -preset @var{type}
2263 Configuration preset. This does some automatic settings based on the general
2267 Do not use a preset.
2269 Use the encoder default.
2271 Digital picture, like portrait, inner shot
2273 Outdoor photograph, with natural lighting
2275 Hand or line drawing, with high-contrast details
2277 Small-sized colorful images
2284 @section libx264, libx264rgb
2286 x264 H.264/MPEG-4 AVC encoder wrapper.
2288 This encoder requires the presence of the libx264 headers and library
2289 during configuration. You need to explicitly configure the build with
2290 @code{--enable-libx264}.
2292 libx264 supports an impressive number of features, including 8x8 and
2293 4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
2294 entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
2295 for detail retention (adaptive quantization, psy-RD, psy-trellis).
2297 Many libx264 encoder options are mapped to FFmpeg global codec
2298 options, while unique encoder options are provided through private
2299 options. Additionally the @option{x264opts} and @option{x264-params}
2300 private options allows one to pass a list of key=value tuples as accepted
2301 by the libx264 @code{x264_param_parse} function.
2303 The x264 project website is at
2304 @url{http://www.videolan.org/developers/x264.html}.
2306 The libx264rgb encoder is the same as libx264, except it accepts packed RGB
2307 pixel formats as input instead of YUV.
2309 @subsection Supported Pixel Formats
2311 x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at
2312 x264's configure time.
2316 The following options are supported by the libx264 wrapper. The
2317 @command{x264}-equivalent options or values are listed in parentheses
2320 To reduce the duplication of documentation, only the private options
2321 and some others requiring special attention are documented here. For
2322 the documentation of the undocumented generic options, see
2323 @ref{codec-options,,the Codec Options chapter}.
2325 To get a more accurate and extensive documentation of the libx264
2326 options, invoke the command @command{x264 --fullhelp} or consult
2327 the libx264 documentation.
2330 @item b (@emph{bitrate})
2331 Set bitrate in bits/s. Note that FFmpeg's @option{b} option is
2332 expressed in bits/s, while @command{x264}'s @option{bitrate} is in
2335 @item bf (@emph{bframes})
2337 @item g (@emph{keyint})
2339 @item qmin (@emph{qpmin})
2340 Minimum quantizer scale.
2342 @item qmax (@emph{qpmax})
2343 Maximum quantizer scale.
2345 @item qdiff (@emph{qpstep})
2346 Maximum difference between quantizer scales.
2348 @item qblur (@emph{qblur})
2349 Quantizer curve blur
2351 @item qcomp (@emph{qcomp})
2352 Quantizer curve compression factor
2354 @item refs (@emph{ref})
2355 Number of reference frames each P-frame can use. The range is from @var{0-16}.
2357 @item sc_threshold (@emph{scenecut})
2358 Sets the threshold for the scene change detection.
2360 @item trellis (@emph{trellis})
2361 Performs Trellis quantization to increase efficiency. Enabled by default.
2363 @item nr (@emph{nr})
2365 @item me_range (@emph{merange})
2366 Maximum range of the motion search in pixels.
2368 @item me_method (@emph{me})
2369 Set motion estimation method. Possible values in the decreasing order
2373 @item dia (@emph{dia})
2374 @item epzs (@emph{dia})
2375 Diamond search with radius 1 (fastest). @samp{epzs} is an alias for
2377 @item hex (@emph{hex})
2378 Hexagonal search with radius 2.
2379 @item umh (@emph{umh})
2380 Uneven multi-hexagon search.
2381 @item esa (@emph{esa})
2383 @item tesa (@emph{tesa})
2384 Hadamard exhaustive search (slowest).
2388 Normally, when forcing a I-frame type, the encoder can select any type
2389 of I-frame. This option forces it to choose an IDR-frame.
2391 @item subq (@emph{subme})
2392 Sub-pixel motion estimation method.
2394 @item b_strategy (@emph{b-adapt})
2395 Adaptive B-frame placement decision algorithm. Use only on first-pass.
2397 @item keyint_min (@emph{min-keyint})
2401 Set entropy encoder. Possible values:
2408 Enable CAVLC and disable CABAC. It generates the same effect as
2409 @command{x264}'s @option{--no-cabac} option.
2413 Set full pixel motion estimation comparison algorithm. Possible values:
2417 Enable chroma in motion estimation.
2420 Ignore chroma in motion estimation. It generates the same effect as
2421 @command{x264}'s @option{--no-chroma-me} option.
2424 @item threads (@emph{threads})
2425 Number of encoding threads.
2428 Set multithreading technique. Possible values:
2432 Slice-based multithreading. It generates the same effect as
2433 @command{x264}'s @option{--sliced-threads} option.
2435 Frame-based multithreading.
2439 Set encoding flags. It can be used to disable closed GOP and enable
2440 open GOP by setting it to @code{-cgop}. The result is similar to
2441 the behavior of @command{x264}'s @option{--open-gop} option.
2443 @item rc_init_occupancy (@emph{vbv-init})
2445 @item preset (@emph{preset})
2446 Set the encoding preset.
2448 @item tune (@emph{tune})
2449 Set tuning of the encoding params.
2451 @item profile (@emph{profile})
2452 Set profile restrictions.
2455 Enable fast settings when encoding first pass, when set to 1. When set
2456 to 0, it has the same effect of @command{x264}'s
2457 @option{--slow-firstpass} option.
2459 @item crf (@emph{crf})
2460 Set the quality for constant quality mode.
2462 @item crf_max (@emph{crf-max})
2463 In CRF mode, prevents VBV from lowering quality beyond this point.
2465 @item qp (@emph{qp})
2466 Set constant quantization rate control method parameter.
2468 @item aq-mode (@emph{aq-mode})
2469 Set AQ method. Possible values:
2472 @item none (@emph{0})
2475 @item variance (@emph{1})
2476 Variance AQ (complexity mask).
2478 @item autovariance (@emph{2})
2479 Auto-variance AQ (experimental).
2482 @item aq-strength (@emph{aq-strength})
2483 Set AQ strength, reduce blocking and blurring in flat and textured areas.
2486 Use psychovisual optimizations when set to 1. When set to 0, it has the
2487 same effect as @command{x264}'s @option{--no-psy} option.
2489 @item psy-rd (@emph{psy-rd})
2490 Set strength of psychovisual optimization, in
2491 @var{psy-rd}:@var{psy-trellis} format.
2493 @item rc-lookahead (@emph{rc-lookahead})
2494 Set number of frames to look ahead for frametype and ratecontrol.
2497 Enable weighted prediction for B-frames when set to 1. When set to 0,
2498 it has the same effect as @command{x264}'s @option{--no-weightb} option.
2500 @item weightp (@emph{weightp})
2501 Set weighted prediction method for P-frames. Possible values:
2504 @item none (@emph{0})
2506 @item simple (@emph{1})
2507 Enable only weighted refs
2508 @item smart (@emph{2})
2509 Enable both weighted refs and duplicates
2512 @item ssim (@emph{ssim})
2513 Enable calculation and printing SSIM stats after the encoding.
2515 @item intra-refresh (@emph{intra-refresh})
2516 Enable the use of Periodic Intra Refresh instead of IDR frames when set
2519 @item avcintra-class (@emph{class})
2520 Configure the encoder to generate AVC-Intra.
2521 Valid values are 50,100 and 200
2523 @item bluray-compat (@emph{bluray-compat})
2524 Configure the encoder to be compatible with the bluray standard.
2525 It is a shorthand for setting "bluray-compat=1 force-cfr=1".
2527 @item b-bias (@emph{b-bias})
2528 Set the influence on how often B-frames are used.
2530 @item b-pyramid (@emph{b-pyramid})
2531 Set method for keeping of some B-frames as references. Possible values:
2534 @item none (@emph{none})
2536 @item strict (@emph{strict})
2537 Strictly hierarchical pyramid.
2538 @item normal (@emph{normal})
2539 Non-strict (not Blu-ray compatible).
2543 Enable the use of one reference per partition, as opposed to one
2544 reference per macroblock when set to 1. When set to 0, it has the
2545 same effect as @command{x264}'s @option{--no-mixed-refs} option.
2548 Enable adaptive spatial transform (high profile 8x8 transform)
2549 when set to 1. When set to 0, it has the same effect as
2550 @command{x264}'s @option{--no-8x8dct} option.
2553 Enable early SKIP detection on P-frames when set to 1. When set
2554 to 0, it has the same effect as @command{x264}'s
2555 @option{--no-fast-pskip} option.
2557 @item aud (@emph{aud})
2558 Enable use of access unit delimiters when set to 1.
2561 Enable use macroblock tree ratecontrol when set to 1. When set
2562 to 0, it has the same effect as @command{x264}'s
2563 @option{--no-mbtree} option.
2565 @item deblock (@emph{deblock})
2566 Set loop filter parameters, in @var{alpha}:@var{beta} form.
2568 @item cplxblur (@emph{cplxblur})
2569 Set fluctuations reduction in QP (before curve compression).
2571 @item partitions (@emph{partitions})
2572 Set partitions to consider as a comma-separated list of. Possible
2577 8x8 P-frame partition.
2579 4x4 P-frame partition.
2581 4x4 B-frame partition.
2583 8x8 I-frame partition.
2585 4x4 I-frame partition.
2586 (Enabling @samp{p4x4} requires @samp{p8x8} to be enabled. Enabling
2587 @samp{i8x8} requires adaptive spatial transform (@option{8x8dct}
2588 option) to be enabled.)
2589 @item none (@emph{none})
2590 Do not consider any partitions.
2591 @item all (@emph{all})
2592 Consider every partition.
2595 @item direct-pred (@emph{direct})
2596 Set direct MV prediction mode. Possible values:
2599 @item none (@emph{none})
2600 Disable MV prediction.
2601 @item spatial (@emph{spatial})
2602 Enable spatial predicting.
2603 @item temporal (@emph{temporal})
2604 Enable temporal predicting.
2605 @item auto (@emph{auto})
2606 Automatically decided.
2609 @item slice-max-size (@emph{slice-max-size})
2610 Set the limit of the size of each slice in bytes. If not specified
2611 but RTP payload size (@option{ps}) is specified, that is used.
2613 @item stats (@emph{stats})
2614 Set the file name for multi-pass stats.
2616 @item nal-hrd (@emph{nal-hrd})
2617 Set signal HRD information (requires @option{vbv-bufsize} to be set).
2621 @item none (@emph{none})
2622 Disable HRD information signaling.
2623 @item vbr (@emph{vbr})
2625 @item cbr (@emph{cbr})
2626 Constant bit rate (not allowed in MP4 container).
2629 @item x264opts (N.A.)
2630 Set any x264 option, see @command{x264 --fullhelp} for a list.
2632 Argument is a list of @var{key}=@var{value} couples separated by
2633 ":". In @var{filter} and @var{psy-rd} options that use ":" as a separator
2634 themselves, use "," instead. They accept it as well since long ago but this
2635 is kept undocumented for some reason.
2637 For example to specify libx264 encoding options with @command{ffmpeg}:
2639 ffmpeg -i foo.mpg -c:v libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
2642 @item a53cc @var{boolean}
2643 Import closed captions (which must be ATSC compatible format) into output.
2644 Only the mpeg2 and h264 decoders provide these. Default is 1 (on).
2646 @item x264-params (N.A.)
2647 Override the x264 configuration using a :-separated list of key=value
2650 This option is functionally the same as the @option{x264opts}, but is
2651 duplicated for compatibility with the Libav fork.
2653 For example to specify libx264 encoding options with @command{ffmpeg}:
2655 ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
2656 cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
2657 no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
2661 Encoding ffpresets for common usages are provided so they can be used with the
2662 general presets system (e.g. passing the @option{pre} option).
2666 x265 H.265/HEVC encoder wrapper.
2668 This encoder requires the presence of the libx265 headers and library
2669 during configuration. You need to explicitly configure the build with
2670 @option{--enable-libx265}.
2676 Sets target video bitrate.
2687 Number of reference frames each P-frame can use. The range is from @var{1-16}.
2690 Set the x265 preset.
2693 Set the x265 tune parameter.
2696 Set profile restrictions.
2699 Set the quality for constant quality mode.
2702 Set constant quantization rate control method parameter.
2705 Minimum quantizer scale.
2708 Maximum quantizer scale.
2711 Maximum difference between quantizer scales.
2714 Quantizer curve blur
2717 Quantizer curve compression factor
2724 Normally, when forcing a I-frame type, the encoder can select any type
2725 of I-frame. This option forces it to choose an IDR-frame.
2728 Set x265 options using a list of @var{key}=@var{value} couples separated
2729 by ":". See @command{x265 --help} for a list of options.
2731 For example to specify libx265 encoding options with @option{-x265-params}:
2734 ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
2740 xavs2 AVS2-P2/IEEE1857.4 encoder wrapper.
2742 This encoder requires the presence of the libxavs2 headers and library
2743 during configuration. You need to explicitly configure the build with
2744 @option{--enable-libxavs2}.
2746 The following standard libavcodec options are used:
2749 @option{b} / @option{bit_rate}
2751 @option{g} / @option{gop_size}
2753 @option{bf} / @option{max_b_frames}
2756 The encoder also has its own specific options:
2760 @item lcu_row_threads
2761 Set the number of parallel threads for rows from 1 to 8 (default 5).
2764 Set the xavs2 quantization parameter from 1 to 63 (default 34). This is
2765 used to set the initial qp for the first frame.
2768 Set the xavs2 quantization parameter from 1 to 63 (default 34). This is
2769 used to set the qp value under constant-QP mode.
2772 Set the max qp for rate control from 1 to 63 (default 55).
2775 Set the min qp for rate control from 1 to 63 (default 20).
2778 Set the Speed level from 0 to 9 (default 0). Higher is better but slower.
2781 Set the log level from -1 to 3 (default 0). -1: none, 0: error,
2782 1: warning, 2: info, 3: debug.
2785 Set xavs2 options using a list of @var{key}=@var{value} couples separated
2788 For example to specify libxavs2 encoding options with @option{-xavs2-params}:
2791 ffmpeg -i input -c:v libxavs2 -xavs2-params RdoqLevel=0 output.avs2
2797 Xvid MPEG-4 Part 2 encoder wrapper.
2799 This encoder requires the presence of the libxvidcore headers and library
2800 during configuration. You need to explicitly configure the build with
2801 @code{--enable-libxvid --enable-gpl}.
2803 The native @code{mpeg4} encoder supports the MPEG-4 Part 2 format, so
2804 users can encode to this format without this library.
2808 The following options are supported by the libxvid wrapper. Some of
2809 the following options are listed but are not documented, and
2810 correspond to shared codec options. See @ref{codec-options,,the Codec
2811 Options chapter} for their documentation. The other shared options
2812 which are not listed have no effect for the libxvid encoder.
2834 Set specific encoding flags. Possible values:
2839 Use four motion vector by macroblock.
2842 Enable high quality AC prediction.
2845 Only encode grayscale.
2848 Enable the use of global motion compensation (GMC).
2851 Enable quarter-pixel motion compensation.
2857 Place global headers in extradata instead of every keyframe.
2864 Set motion estimation method. Possible values in decreasing order of
2865 speed and increasing order of quality:
2869 Use no motion estimation (default).
2874 Enable advanced diamond zonal search for 16x16 blocks and half-pixel
2875 refinement for 16x16 blocks. @samp{x1} and @samp{log} are aliases for
2879 Enable all of the things described above, plus advanced diamond zonal
2880 search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
2881 estimation on chroma planes.
2884 Enable all of the things described above, plus extended 16x16 and 8x8
2889 Set macroblock decision algorithm. Possible values in the increasing
2894 Use macroblock comparing function algorithm (default).
2897 Enable rate distortion-based half pixel and quarter pixel refinement for
2901 Enable all of the things described above, plus rate distortion-based
2902 half pixel and quarter pixel refinement for 8x8 blocks, and rate
2903 distortion-based search using square pattern.
2907 Enable lumi masking adaptive quantization when set to 1. Default is 0
2911 Enable variance adaptive quantization when set to 1. Default is 0
2914 When combined with @option{lumi_aq}, the resulting quality will not
2915 be better than any of the two specified individually. In other
2916 words, the resulting quality will be the worse one of the two
2920 Set structural similarity (SSIM) displaying method. Possible values:
2924 Disable displaying of SSIM information.
2927 Output average SSIM at the end of encoding to stdout. The format of
2928 showing the average SSIM is:
2934 For users who are not familiar with C, %f means a float number, or
2935 a decimal (e.g. 0.939232).
2938 Output both per-frame SSIM data during encoding and average SSIM at
2939 the end of encoding to stdout. The format of per-frame information
2943 SSIM: avg: %1.3f min: %1.3f max: %1.3f
2946 For users who are not familiar with C, %1.3f means a float number
2947 rounded to 3 digits after the dot (e.g. 0.932).
2952 Set SSIM accuracy. Valid options are integers within the range of
2953 0-4, while 0 gives the most accurate result and 4 computes the
2958 @section MediaFoundation
2960 This provides wrappers to encoders (both audio and video) in the
2961 MediaFoundation framework. It can access both SW and HW encoders.
2962 Video encoders can take input in either of nv12 or yuv420p form
2963 (some encoders support both, some support only either - in practice,
2964 nv12 is the safer choice, especially among HW encoders).
2968 MPEG-2 video encoder.
2974 Select the mpeg2 profile to encode:
2988 Select the mpeg2 level to encode:
2997 @item seq_disp_ext @var{integer}
2998 Specifies if the encoder should write a sequence_display_extension to the
3003 Decide automatically to write it or not (this is the default) by checking if
3004 the data to be written is different from the default or unspecified values.
3012 @item video_format @var{integer}
3013 Specifies the video_format written into the sequence display extension
3014 indicating the source of the video pictures. The default is @samp{unspecified},
3015 can be @samp{component}, @samp{pal}, @samp{ntsc}, @samp{secam} or @samp{mac}.
3016 For maximum compatibility, use @samp{component}.
3017 @item a53cc @var{boolean}
3018 Import closed captions (which must be ATSC compatible format) into output.
3026 @subsection Private options
3029 @item dpi @var{integer}
3030 Set physical density of pixels, in dots per inch, unset by default
3031 @item dpm @var{integer}
3032 Set physical density of pixels, in dots per meter, unset by default
3037 Apple ProRes encoder.
3039 FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
3040 The used encoder can be chosen with the @code{-vcodec} option.
3042 @subsection Private Options for prores-ks
3045 @item profile @var{integer}
3046 Select the ProRes profile to encode
3056 @item quant_mat @var{integer}
3057 Select quantization matrix.
3066 If set to @var{auto}, the matrix matching the profile will be picked.
3067 If not set, the matrix providing the highest quality, @var{default}, will be
3070 @item bits_per_mb @var{integer}
3071 How many bits to allot for coding one macroblock. Different profiles use
3072 between 200 and 2400 bits per macroblock, the maximum is 8000.
3074 @item mbs_per_slice @var{integer}
3075 Number of macroblocks in each slice (1-8); the default value (8)
3076 should be good in almost all situations.
3078 @item vendor @var{string}
3079 Override the 4-byte vendor ID.
3080 A custom vendor ID like @var{apl0} would claim the stream was produced by
3083 @item alpha_bits @var{integer}
3084 Specify number of bits for alpha component.
3085 Possible values are @var{0}, @var{8} and @var{16}.
3086 Use @var{0} to disable alpha plane coding.
3090 @subsection Speed considerations
3092 In the default mode of operation the encoder has to honor frame constraints
3093 (i.e. not produce frames with size bigger than requested) while still making
3094 output picture as good as possible.
3095 A frame containing a lot of small details is harder to compress and the encoder
3096 would spend more time searching for appropriate quantizers for each slice.
3098 Setting a higher @option{bits_per_mb} limit will improve the speed.
3100 For the fastest encoding speed set the @option{qscale} parameter (4 is the
3101 recommended value) and do not set a size constraint.
3103 @section QSV encoders
3105 The family of Intel QuickSync Video encoders (MPEG-2, H.264, HEVC, JPEG/MJPEG and VP9)
3107 The ratecontrol method is selected as follows:
3111 When @option{global_quality} is specified, a quality-based mode is used.
3112 Specifically this means either
3115 @var{CQP} - constant quantizer scale, when the @option{qscale} codec flag is
3116 also set (the @option{-qscale} ffmpeg option).
3119 @var{LA_ICQ} - intelligent constant quality with lookahead, when the
3120 @option{look_ahead} option is also set.
3123 @var{ICQ} -- intelligent constant quality otherwise.
3127 Otherwise, a bitrate-based mode is used. For all of those, you should specify at
3128 least the desired average bitrate with the @option{b} option.
3131 @var{LA} - VBR with lookahead, when the @option{look_ahead} option is specified.
3134 @var{VCM} - video conferencing mode, when the @option{vcm} option is set.
3137 @var{CBR} - constant bitrate, when @option{maxrate} is specified and equal to
3138 the average bitrate.
3141 @var{VBR} - variable bitrate, when @option{maxrate} is specified, but is higher
3142 than the average bitrate.
3145 @var{AVBR} - average VBR mode, when @option{maxrate} is not specified. This mode
3146 is further configured by the @option{avbr_accuracy} and
3147 @option{avbr_convergence} options.
3151 Note that depending on your system, a different mode than the one you specified
3152 may be selected by the encoder. Set the verbosity level to @var{verbose} or
3153 higher to see the actual settings used by the QSV runtime.
3155 Additional libavcodec global options are mapped to MSDK options as follows:
3159 @option{g/gop_size} -> @option{GopPicSize}
3162 @option{bf/max_b_frames}+1 -> @option{GopRefDist}
3165 @option{rc_init_occupancy/rc_initial_buffer_occupancy} ->
3166 @option{InitialDelayInKB}
3169 @option{slices} -> @option{NumSlice}
3172 @option{refs} -> @option{NumRefFrame}
3175 @option{b_strategy/b_frame_strategy} -> @option{BRefType}
3178 @option{cgop/CLOSED_GOP} codec flag -> @option{GopOptFlag}
3181 For the @var{CQP} mode, the @option{i_qfactor/i_qoffset} and
3182 @option{b_qfactor/b_qoffset} set the difference between @var{QPP} and @var{QPI},
3183 and @var{QPP} and @var{QPB} respectively.
3186 Setting the @option{coder} option to the value @var{vlc} will make the H.264
3187 encoder use CAVLC instead of CABAC.
3196 @item iterative_dia_size
3197 dia size for the iterative motion estimation
3200 @section VAAPI encoders
3202 Wrappers for hardware encoders accessible via VAAPI.
3204 These encoders only accept input in VAAPI hardware surfaces. If you have input
3205 in software frames, use the @option{hwupload} filter to upload them to the GPU.
3207 The following standard libavcodec options are used:
3210 @option{g} / @option{gop_size}
3212 @option{bf} / @option{max_b_frames}
3216 If not set, this will be determined automatically from the format of the input
3217 frames and the profiles supported by the driver.
3221 @option{b} / @option{bit_rate}
3223 @option{maxrate} / @option{rc_max_rate}
3225 @option{bufsize} / @option{rc_buffer_size}
3227 @option{rc_init_occupancy} / @option{rc_initial_buffer_occupancy}
3229 @option{compression_level}
3231 Speed / quality tradeoff: higher values are faster / worse quality.
3233 @option{q} / @option{global_quality}
3235 Size / quality tradeoff: higher values are smaller / worse quality.
3241 @option{i_qfactor} / @option{i_quant_factor}
3243 @option{i_qoffset} / @option{i_quant_offset}
3245 @option{b_qfactor} / @option{b_quant_factor}
3247 @option{b_qoffset} / @option{b_quant_offset}
3252 All encoders support the following options:
3255 Some drivers/platforms offer a second encoder for some codecs intended to use
3256 less power than the default encoder; setting this option will attempt to use
3257 that encoder. Note that it may support a reduced feature set, so some other
3258 options may not be available in this mode.
3261 Set the number of normal intra frames between full-refresh (IDR) frames in
3262 open-GOP mode. The intra frames are still IRAPs, but will not include global
3263 headers and may have non-decodable leading pictures.
3266 Set the B-frame reference depth. When set to one (the default), all B-frames
3267 will refer only to P- or I-frames. When set to greater values multiple layers
3268 of B-frames will be present, frames in each layer only referring to frames in
3272 Set the rate control mode to use. A given driver may only support a subset of
3278 Choose the mode automatically based on driver support and the other options.
3279 This is the default.
3287 Intelligent constant-quality.
3289 Quality-defined variable-bitrate.
3291 Average variable bitrate.
3296 Each encoder also has its own specific options:
3300 @option{profile} sets the value of @emph{profile_idc} and the @emph{constraint_set*_flag}s.
3301 @option{level} sets the value of @emph{level_idc}.
3305 Set entropy encoder (default is @emph{cabac}). Possible values:
3318 Include access unit delimiters in the stream (not included by default).
3321 Set SEI message types to include.
3322 Some combination of the following values:
3325 Include a @emph{user_data_unregistered} message containing information about
3328 Include picture timing parameters (@emph{buffering_period} and
3329 @emph{pic_timing} messages).
3330 @item recovery_point
3331 Include recovery points where appropriate (@emph{recovery_point} messages).
3337 @option{profile} and @option{level} set the values of
3338 @emph{general_profile_idc} and @emph{general_level_idc} respectively.
3342 Include access unit delimiters in the stream (not included by default).
3345 Set @emph{general_tier_flag}. This may affect the level chosen for the stream
3346 if it is not explicitly specified.
3349 Set SEI message types to include.
3350 Some combination of the following values:
3353 Include HDR metadata if the input frames have it
3354 (@emph{mastering_display_colour_volume} and @emph{content_light_level}
3359 Set the number of tiles to encode the input video with, as columns x rows.
3360 Larger numbers allow greater parallelism in both encoding and decoding, but
3361 may decrease coding efficiency.
3366 Only baseline DCT encoding is supported. The encoder always uses the standard
3367 quantisation and huffman tables - @option{global_quality} scales the standard
3368 quantisation table (range 1-100).
3370 For YUV, 4:2:0, 4:2:2 and 4:4:4 subsampling modes are supported. RGB is also
3371 supported, and will create an RGB JPEG.
3375 Include JFIF header in each frame (not included by default).
3377 Include standard huffman tables (on by default). Turning this off will save
3378 a few hundred bytes in each output frame, but may lose compatibility with some
3379 JPEG decoders which don't fully handle MJPEG.
3383 @option{profile} and @option{level} set the value of @emph{profile_and_level_indication}.
3386 B-frames are not supported.
3388 @option{global_quality} sets the @emph{q_idx} used for non-key frames (range 0-127).
3391 @item loop_filter_level
3392 @item loop_filter_sharpness
3393 Manually set the loop filter parameters.
3397 @option{global_quality} sets the @emph{q_idx} used for P-frames (range 0-255).
3400 @item loop_filter_level
3401 @item loop_filter_sharpness
3402 Manually set the loop filter parameters.
3405 B-frames are supported, but the output stream is always in encode order rather than display
3406 order. If B-frames are enabled, it may be necessary to use the @option{vp9_raw_reorder}
3407 bitstream filter to modify the output stream to display frames in the correct order.
3409 Only normal frames are produced - the @option{vp9_superframe} bitstream filter may be
3410 required to produce a stream usable with all decoders.
3416 SMPTE VC-2 (previously BBC Dirac Pro). This codec was primarily aimed at
3417 professional broadcasting but since it supports yuv420, yuv422 and yuv444 at
3418 8 (limited range or full range), 10 or 12 bits, this makes it suitable for
3419 other tasks which require low overhead and low compression (like screen
3427 Sets target video bitrate. Usually that's around 1:6 of the uncompressed
3428 video bitrate (e.g. for 1920x1080 50fps yuv422p10 that's around 400Mbps). Higher
3429 values (close to the uncompressed bitrate) turn on lossless compression mode.
3432 Enables field coding when set (e.g. to tt - top field first) for interlaced
3433 inputs. Should increase compression with interlaced content as it splits the
3434 fields and encodes each separately.
3437 Sets the total amount of wavelet transforms to apply, between 1 and 5 (default).
3438 Lower values reduce compression and quality. Less capable decoders may not be
3439 able to handle values of @option{wavelet_depth} over 3.
3442 Sets the transform type. Currently only @var{5_3} (LeGall) and @var{9_7}
3444 are implemented, with 9_7 being the one with better compression and thus
3449 Sets the slice size for each slice. Larger values result in better compression.
3450 For compatibility with other more limited decoders use @option{slice_width} of
3451 32 and @option{slice_height} of 8.
3454 Sets the undershoot tolerance of the rate control system in percent. This is
3455 to prevent an expensive search from being run.
3458 Sets the quantization matrix preset to use by default or when @option{wavelet_depth}
3463 Uses the default quantization matrix from the specifications, extended with
3464 values for the fifth level. This provides a good balance between keeping detail
3465 and omitting artifacts.
3469 Use a completely zeroed out quantization matrix. This increases PSNR but might
3470 reduce perception. Use in bogus benchmarks.
3474 Reduces detail but attempts to preserve color at extremely low bitrates.
3479 @c man end VIDEO ENCODERS
3481 @chapter Subtitles Encoders
3482 @c man begin SUBTITLES ENCODERS
3486 This codec encodes the bitmap subtitle format that is used in DVDs.
3487 Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
3488 and they can also be used in Matroska files.
3494 Specify the global palette used by the bitmaps.
3496 The format for this option is a string containing 16 24-bits hexadecimal
3497 numbers (without 0x prefix) separated by commas, for example @code{0d00ee,
3498 ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
3499 7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b}.
3502 When set to 1, enable a work-around that makes the number of pixel rows
3503 even in all subtitles. This fixes a problem with some players that
3504 cut off the bottom row if the number is odd. The work-around just adds
3505 a fully transparent row if needed. The overhead is low, typically
3506 one byte per subtitle on average.
3508 By default, this work-around is disabled.
3511 @c man end SUBTITLES ENCODERS