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
1273 GIF image/animation encoder.
1278 @item gifflags @var{integer}
1279 Sets the flags used for GIF encoding.
1283 Enables picture offsetting.
1288 Enables transparency detection between frames.
1294 @item gifimage @var{integer}
1295 Enables encoding one full GIF image per frame, rather than an animated GIF.
1297 Default value is @option{0}.
1299 @item global_palette @var{integer}
1300 Writes a palette to the global GIF header where feasible.
1302 If disabled, every frame will always have a palette written, even if there
1303 is a global palette supplied.
1305 Default value is @option{1}.
1311 Vidvox Hap video encoder.
1316 @item format @var{integer}
1317 Specifies the Hap format to encode.
1325 Default value is @option{hap}.
1327 @item chunks @var{integer}
1328 Specifies the number of chunks to split frames into, between 1 and 64. This
1329 permits multithreaded decoding of large frames, potentially at the cost of
1330 data-rate. The encoder may modify this value to divide frames evenly.
1332 Default value is @var{1}.
1334 @item compressor @var{integer}
1335 Specifies the second-stage compressor to use. If set to @option{none},
1336 @option{chunks} will be limited to 1, as chunked uncompressed frames offer no
1344 Default value is @option{snappy}.
1350 The native jpeg 2000 encoder is lossy by default, the @code{-q:v}
1351 option can be used to set the encoding quality. Lossless encoding
1352 can be selected with @code{-pred 1}.
1357 @item format @var{integer}
1358 Can be set to either @code{j2k} or @code{jp2} (the default) that
1359 makes it possible to store non-rgb pix_fmts.
1361 @item tile_width @var{integer}
1362 Sets tile width. Range is 1 to 1073741824. Default is 256.
1364 @item tile_height @var{integer}
1365 Sets tile height. Range is 1 to 1073741824. Default is 256.
1367 @item pred @var{integer}
1368 Allows setting the discrete wavelet transform (DWT) type
1370 @item dwt97int (Lossy)
1371 @item dwt53 (Lossless)
1373 Default is @code{dwt97int}
1375 @item sop @var{boolean}
1376 Enable this to add SOP marker at the start of each packet. Disabled by default.
1378 @item eph @var{boolean}
1379 Enable this to add EPH marker at the end of each packet header. Disabled by default.
1381 @item prog @var{integer}
1382 Sets the progression order to be used by the encoder.
1383 Possible values are:
1391 Set to @code{lrcp} by default.
1393 @item layer_rates @var{string}
1394 By default, when this option is not used, compression is done using the quality metric.
1395 This option allows for compression using compression ratio. The compression ratio for each
1396 level could be specified. The compression ratio of a layer @code{l} species the what ratio of
1397 total file size is contained in the first @code{l} layers.
1402 ffmpeg -i input.bmp -c:v jpeg2000 -layer_rates "100,10,1" output.j2k
1405 This would compress the image to contain 3 layers, where the data contained in the
1406 first layer would be compressed by 1000 times, compressed by 100 in the first two layers,
1407 and shall contain all data while using all 3 layers.
1413 rav1e AV1 encoder wrapper.
1415 Requires the presence of the rav1e headers and library during configuration.
1416 You need to explicitly configure the build with @code{--enable-librav1e}.
1422 Sets the maximum quantizer to use when using bitrate mode.
1425 Sets the minimum quantizer to use when using bitrate mode.
1428 Uses quantizer mode to encode at the given quantizer (0-255).
1431 Selects the speed preset (0-10) to encode with.
1434 Selects how many tiles to encode with.
1437 Selects how many rows of tiles to encode with.
1440 Selects how many columns of tiles to encode with.
1443 Set rav1e options using a list of @var{key}=@var{value} pairs separated
1444 by ":". See @command{rav1e --help} for a list of options.
1446 For example to specify librav1e encoding options with @option{-rav1e-params}:
1449 ffmpeg -i input -c:v librav1e -b:v 500K -rav1e-params speed=5:low_latency=true output.mp4
1456 libaom AV1 encoder wrapper.
1458 Requires the presence of the libaom headers and library during
1459 configuration. You need to explicitly configure the build with
1460 @code{--enable-libaom}.
1464 The wrapper supports the following standard libavcodec options:
1469 Set bitrate target in bits/second. By default this will use
1470 variable-bitrate mode. If @option{maxrate} and @option{minrate} are
1471 also set to the same value then it will use constant-bitrate mode,
1472 otherwise if @option{crf} is set as well then it will use
1473 constrained-quality mode.
1476 Set key frame placement. The GOP size sets the maximum distance between
1477 key frames; if zero the output stream will be intra-only. The minimum
1478 distance is ignored unless it is the same as the GOP size, in which case
1479 key frames will always appear at a fixed interval. Not set by default,
1480 so without this option the library has completely free choice about
1481 where to place key frames.
1484 Set minimum/maximum quantisation values. Valid range is from 0 to 63
1485 (warning: this does not match the quantiser values actually used by AV1
1486 - divide by four to map real quantiser values to this range). Defaults
1487 to min/max (no constraint).
1489 @item minrate maxrate bufsize rc_init_occupancy
1490 Set rate control buffering parameters. Not used if not set - defaults
1491 to unconstrained variable bitrate.
1494 Set the number of threads to use while encoding. This may require the
1495 @option{tiles} or @option{row-mt} options to also be set to actually
1496 use the specified number of threads fully. Defaults to the number of
1497 hardware threads supported by the host machine.
1500 Set the encoding profile. Defaults to using the profile which matches
1501 the bit depth and chroma subsampling of the input.
1505 The wrapper also has some specific options:
1510 Set the quality/encoding speed tradeoff. Valid range is from 0 to 8,
1511 higher numbers indicating greater speed and lower quality. The default
1512 value is 1, which will be slow and high quality.
1515 Enable use of alternate reference frames. Defaults to the internal
1516 default of the library.
1518 @item arnr-max-frames (@emph{frames})
1519 Set altref noise reduction max frame count. Default is -1.
1521 @item arnr-strength (@emph{strength})
1522 Set altref noise reduction filter strength. Range is -1 to 6. Default is -1.
1524 @item aq-mode (@emph{aq-mode})
1525 Set adaptive quantization mode. Possible values:
1528 @item none (@emph{0})
1531 @item variance (@emph{1})
1534 @item complexity (@emph{2})
1537 @item cyclic (@emph{3})
1541 @item tune (@emph{tune})
1542 Set the distortion metric the encoder is tuned with. Default is @code{psnr}.
1545 @item psnr (@emph{0})
1547 @item ssim (@emph{1})
1551 Set the maximum number of frames which the encoder may keep in flight
1552 at any one time for lookahead purposes. Defaults to the internal
1553 default of the library.
1555 @item error-resilience
1556 Enable error resilience features:
1559 Improve resilience against losses of whole frames.
1561 Not enabled by default.
1564 Set the quality/size tradeoff for constant-quality (no bitrate target)
1565 and constrained-quality (with maximum bitrate target) modes. Valid
1566 range is 0 to 63, higher numbers indicating lower quality and smaller
1567 output size. Only used if set; by default only the bitrate target is
1571 Set a change threshold on blocks below which they will be skipped by
1572 the encoder. Defined in arbitrary units as a nonnegative integer,
1573 defaulting to zero (no blocks are skipped).
1575 @item drop-threshold
1576 Set a threshold for dropping frames when close to rate control bounds.
1577 Defined as a percentage of the target buffer - when the rate control
1578 buffer falls below this percentage, frames will be dropped until it
1579 has refilled above the threshold. Defaults to zero (no frames are
1582 @item denoise-noise-level (@emph{level})
1583 Amount of noise to be removed for grain synthesis. Grain synthesis is disabled if
1584 this option is not set or set to 0.
1586 @item denoise-block-size (@emph{pixels})
1587 Block size used for denoising for grain synthesis. If not set, AV1 codec
1588 uses the default value of 32.
1590 @item undershoot-pct (@emph{pct})
1591 Set datarate undershoot (min) percentage of the target bitrate. Range is -1 to 100.
1594 @item overshoot-pct (@emph{pct})
1595 Set datarate overshoot (max) percentage of the target bitrate. Range is -1 to 1000.
1598 @item minsection-pct (@emph{pct})
1599 Minimum percentage variation of the GOP bitrate from the target bitrate. If minsection-pct
1600 is not set, the libaomenc wrapper computes it as follows: @code{(minrate * 100 / bitrate)}.
1601 Range is -1 to 100. Default is -1 (unset).
1603 @item maxsection-pct (@emph{pct})
1604 Maximum percentage variation of the GOP bitrate from the target bitrate. If maxsection-pct
1605 is not set, the libaomenc wrapper computes it as follows: @code{(maxrate * 100 / bitrate)}.
1606 Range is -1 to 5000. Default is -1 (unset).
1608 @item frame-parallel (@emph{boolean})
1609 Enable frame parallel decodability features. Default is true.
1612 Set the number of tiles to encode the input video with, as columns x
1613 rows. Larger numbers allow greater parallelism in both encoding and
1614 decoding, but may decrease coding efficiency. Defaults to the minimum
1615 number of tiles required by the size of the input video (this is 1x1
1616 (that is, a single tile) for sizes up to and including 4K).
1618 @item tile-columns tile-rows
1619 Set the number of tiles as log2 of the number of tile rows and columns.
1620 Provided for compatibility with libvpx/VP9.
1622 @item row-mt (Requires libaom >= 1.0.0-759-g90a15f4f2)
1623 Enable row based multi-threading. Disabled by default.
1625 @item enable-cdef (@emph{boolean})
1626 Enable Constrained Directional Enhancement Filter. The libaom-av1
1627 encoder enables CDEF by default.
1629 @item enable-restoration (@emph{boolean})
1630 Enable Loop Restoration Filter. Default is true for libaom-av1.
1632 @item enable-global-motion (@emph{boolean})
1633 Enable the use of global motion for block prediction. Default is true.
1635 @item enable-intrabc (@emph{boolean})
1636 Enable block copy mode for intra block prediction. This mode is
1637 useful for screen content. Default is true.
1639 @item enable-rect-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
1640 Enable rectangular partitions. Default is true.
1642 @item enable-1to4-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
1643 Enable 1:4/4:1 partitions. Default is true.
1645 @item enable-ab-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
1646 Enable AB shape partitions. Default is true.
1648 @item enable-angle-delta (@emph{boolean}) (Requires libaom >= v2.0.0)
1649 Enable angle delta intra prediction. Default is true.
1651 @item enable-cfl-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1652 Enable chroma predicted from luma intra prediction. Default is true.
1654 @item enable-filter-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1655 Enable filter intra predictor. Default is true.
1657 @item enable-intra-edge-filter (@emph{boolean}) (Requires libaom >= v2.0.0)
1658 Enable intra edge filter. Default is true.
1660 @item enable-smooth-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1661 Enable smooth intra prediction mode. Default is true.
1663 @item enable-paeth-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1664 Enable paeth predictor in intra prediction. Default is true.
1666 @item enable-palette (@emph{boolean}) (Requires libaom >= v2.0.0)
1667 Enable palette prediction mode. Default is true.
1669 @item enable-flip-idtx (@emph{boolean}) (Requires libaom >= v2.0.0)
1670 Enable extended transform type, including FLIPADST_DCT, DCT_FLIPADST,
1671 FLIPADST_FLIPADST, ADST_FLIPADST, FLIPADST_ADST, IDTX, V_DCT, H_DCT,
1672 V_ADST, H_ADST, V_FLIPADST, H_FLIPADST. Default is true.
1674 @item enable-tx64 (@emph{boolean}) (Requires libaom >= v2.0.0)
1675 Enable 64-pt transform. Default is true.
1677 @item reduced-tx-type-set (@emph{boolean}) (Requires libaom >= v2.0.0)
1678 Use reduced set of transform types. Default is false.
1680 @item use-intra-dct-only (@emph{boolean}) (Requires libaom >= v2.0.0)
1681 Use DCT only for INTRA modes. Default is false.
1683 @item use-inter-dct-only (@emph{boolean}) (Requires libaom >= v2.0.0)
1684 Use DCT only for INTER modes. Default is false.
1686 @item use-intra-default-tx-only (@emph{boolean}) (Requires libaom >= v2.0.0)
1687 Use Default-transform only for INTRA modes. Default is false.
1689 @item enable-ref-frame-mvs (@emph{boolean}) (Requires libaom >= v2.0.0)
1690 Enable temporal mv prediction. Default is true.
1692 @item enable-reduced-reference-set (@emph{boolean}) (Requires libaom >= v2.0.0)
1693 Use reduced set of single and compound references. Default is false.
1695 @item enable-obmc (@emph{boolean}) (Requires libaom >= v2.0.0)
1696 Enable obmc. Default is true.
1698 @item enable-dual-filter (@emph{boolean}) (Requires libaom >= v2.0.0)
1699 Enable dual filter. Default is true.
1701 @item enable-diff-wtd-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1702 Enable difference-weighted compound. Default is true.
1704 @item enable-dist-wtd-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1705 Enable distance-weighted compound. Default is true.
1707 @item enable-onesided-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1708 Enable one sided compound. Default is true.
1710 @item enable-interinter-wedge (@emph{boolean}) (Requires libaom >= v2.0.0)
1711 Enable interinter wedge compound. Default is true.
1713 @item enable-interintra-wedge (@emph{boolean}) (Requires libaom >= v2.0.0)
1714 Enable interintra wedge compound. Default is true.
1716 @item enable-masked-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1717 Enable masked compound. Default is true.
1719 @item enable-interintra-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1720 Enable interintra compound. Default is true.
1722 @item enable-smooth-interintra (@emph{boolean}) (Requires libaom >= v2.0.0)
1723 Enable smooth interintra mode. Default is true.
1726 Set libaom options using a list of @var{key}=@var{value} pairs separated
1727 by ":". For a list of supported options, see @command{aomenc --help} under the
1728 section "AV1 Specific Options".
1730 For example to specify libaom encoding options with @option{-aom-params}:
1733 ffmpeg -i input -c:v libaom-av1 -b:v 500K -aom-params tune=psnr:enable-tpl-model=1 output.mp4
1740 SVT-AV1 encoder wrapper.
1742 Requires the presence of the SVT-AV1 headers and library during configuration.
1743 You need to explicitly configure the build with @code{--enable-libsvtav1}.
1749 Set the encoding profile.
1752 Set the operating point level.
1755 Set the operating point tier.
1758 Set the rate control mode to use.
1763 Constant quantizer: use fixed values of qindex (dependent on the frame type)
1764 throughout the stream. This mode is the default.
1767 Variable bitrate: use a target bitrate for the whole stream.
1770 Constrained variable bitrate: use a target bitrate for each GOP.
1774 Set the maximum quantizer to use when using a bitrate mode.
1777 Set the minimum quantizer to use when using a bitrate mode.
1780 Set the quantizer used in cqp rate control mode (0-63).
1783 Enable scene change detection.
1786 Set number of frames to look ahead (0-120).
1789 Set the quality-speed tradeoff, in the range 0 to 8. Higher values are
1790 faster but lower quality. Defaults to 8 (highest speed).
1793 Set log2 of the number of rows of tiles to use (0-6).
1796 Set log2 of the number of columns of tiles to use (0-4).
1802 Kvazaar H.265/HEVC encoder.
1804 Requires the presence of the libkvazaar headers and library during
1805 configuration. You need to explicitly configure the build with
1806 @option{--enable-libkvazaar}.
1813 Set target video bitrate in bit/s and enable rate control.
1815 @item kvazaar-params
1816 Set kvazaar parameters as a list of @var{name}=@var{value} pairs separated
1817 by commas (,). See kvazaar documentation for a list of options.
1821 @section libopenh264
1823 Cisco libopenh264 H.264/MPEG-4 AVC encoder wrapper.
1825 This encoder requires the presence of the libopenh264 headers and
1826 library during configuration. You need to explicitly configure the
1827 build with @code{--enable-libopenh264}. The library is detected using
1828 @command{pkg-config}.
1830 For more information about the library see
1831 @url{http://www.openh264.org}.
1835 The following FFmpeg global options affect the configurations of the
1836 libopenh264 encoder.
1840 Set the bitrate (as a number of bits per second).
1846 Set the max bitrate (as a number of bits per second).
1848 @item flags +global_header
1849 Set global header in the bitstream.
1852 Set the number of slices, used in parallelized encoding. Default value
1853 is 0. This is only used when @option{slice_mode} is set to
1857 Set slice mode. Can assume one of the following possible values:
1861 a fixed number of slices
1863 one slice per row of macroblocks
1865 automatic number of slices according to number of threads
1870 Default value is @samp{auto}.
1873 Enable loop filter, if set to 1 (automatically enabled). To disable
1877 Set profile restrictions. If set to the value of @samp{main} enable
1878 CABAC (set the @code{SEncParamExt.iEntropyCodingModeFlag} flag to 1).
1881 Set maximum NAL size in bytes.
1883 @item allow_skip_frames
1884 Allow skipping frames to hit the target bitrate if set to 1.
1889 libtheora Theora encoder wrapper.
1891 Requires the presence of the libtheora headers and library during
1892 configuration. You need to explicitly configure the build with
1893 @code{--enable-libtheora}.
1895 For more information about the libtheora project see
1896 @url{http://www.theora.org/}.
1900 The following global options are mapped to internal libtheora options
1901 which affect the quality and the bitrate of the encoded stream.
1905 Set the video bitrate in bit/s for CBR (Constant Bit Rate) mode. In
1906 case VBR (Variable Bit Rate) mode is enabled this option is ignored.
1909 Used to enable constant quality mode (VBR) encoding through the
1910 @option{qscale} flag, and to enable the @code{pass1} and @code{pass2}
1916 @item global_quality
1917 Set the global quality as an integer in lambda units.
1919 Only relevant when VBR mode is enabled with @code{flags +qscale}. The
1920 value is converted to QP units by dividing it by @code{FF_QP2LAMBDA},
1921 clipped in the [0 - 10] range, and then multiplied by 6.3 to get a
1922 value in the native libtheora range [0-63]. A higher value corresponds
1923 to a higher quality.
1926 Enable VBR mode when set to a non-negative value, and set constant
1927 quality value as a double floating point value in QP units.
1929 The value is clipped in the [0-10] range, and then multiplied by 6.3
1930 to get a value in the native libtheora range [0-63].
1932 This option is valid only using the @command{ffmpeg} command-line
1933 tool. For library interface users, use @option{global_quality}.
1936 @subsection Examples
1940 Set maximum constant quality (VBR) encoding with @command{ffmpeg}:
1942 ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
1946 Use @command{ffmpeg} to convert a CBR 1000 kbps Theora video stream:
1948 ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
1954 VP8/VP9 format supported through libvpx.
1956 Requires the presence of the libvpx headers and library during configuration.
1957 You need to explicitly configure the build with @code{--enable-libvpx}.
1961 The following options are supported by the libvpx wrapper. The
1962 @command{vpxenc}-equivalent options or values are listed in parentheses
1965 To reduce the duplication of documentation, only the private options
1966 and some others requiring special attention are documented here. For
1967 the documentation of the undocumented generic options, see
1968 @ref{codec-options,,the Codec Options chapter}.
1970 To get more documentation of the libvpx options, invoke the command
1971 @command{ffmpeg -h encoder=libvpx}, @command{ffmpeg -h encoder=libvpx-vp9} or
1972 @command{vpxenc --help}. Further information is available in the libvpx API
1977 @item b (@emph{target-bitrate})
1978 Set bitrate in bits/s. Note that FFmpeg's @option{b} option is
1979 expressed in bits/s, while @command{vpxenc}'s @option{target-bitrate} is in
1982 @item g (@emph{kf-max-dist})
1984 @item keyint_min (@emph{kf-min-dist})
1986 @item qmin (@emph{min-q})
1988 @item qmax (@emph{max-q})
1990 @item bufsize (@emph{buf-sz}, @emph{buf-optimal-sz})
1991 Set ratecontrol buffer size (in bits). Note @command{vpxenc}'s options are
1992 specified in milliseconds, the libvpx wrapper converts this value as follows:
1993 @code{buf-sz = bufsize * 1000 / bitrate},
1994 @code{buf-optimal-sz = bufsize * 1000 / bitrate * 5 / 6}.
1996 @item rc_init_occupancy (@emph{buf-initial-sz})
1997 Set number of bits which should be loaded into the rc buffer before decoding
1998 starts. Note @command{vpxenc}'s option is specified in milliseconds, the libvpx
1999 wrapper converts this value as follows:
2000 @code{rc_init_occupancy * 1000 / bitrate}.
2002 @item undershoot-pct
2003 Set datarate undershoot (min) percentage of the target bitrate.
2006 Set datarate overshoot (max) percentage of the target bitrate.
2008 @item skip_threshold (@emph{drop-frame})
2010 @item qcomp (@emph{bias-pct})
2012 @item maxrate (@emph{maxsection-pct})
2013 Set GOP max bitrate in bits/s. Note @command{vpxenc}'s option is specified as a
2014 percentage of the target bitrate, the libvpx wrapper converts this value as
2015 follows: @code{(maxrate * 100 / bitrate)}.
2017 @item minrate (@emph{minsection-pct})
2018 Set GOP min bitrate in bits/s. Note @command{vpxenc}'s option is specified as a
2019 percentage of the target bitrate, the libvpx wrapper converts this value as
2020 follows: @code{(minrate * 100 / bitrate)}.
2022 @item minrate, maxrate, b @emph{end-usage=cbr}
2023 @code{(minrate == maxrate == bitrate)}.
2025 @item crf (@emph{end-usage=cq}, @emph{cq-level})
2027 @item tune (@emph{tune})
2029 @item psnr (@emph{psnr})
2030 @item ssim (@emph{ssim})
2033 @item quality, deadline (@emph{deadline})
2036 Use best quality deadline. Poorly named and quite slow, this option should be
2037 avoided as it may give worse quality output than good.
2039 Use good quality deadline. This is a good trade-off between speed and quality
2040 when used with the @option{cpu-used} option.
2042 Use realtime quality deadline.
2045 @item speed, cpu-used (@emph{cpu-used})
2046 Set quality/speed ratio modifier. Higher values speed up the encode at the cost
2049 @item nr (@emph{noise-sensitivity})
2052 Set a change threshold on blocks below which they will be skipped by the
2055 @item slices (@emph{token-parts})
2056 Note that FFmpeg's @option{slices} option gives the total number of partitions,
2057 while @command{vpxenc}'s @option{token-parts} is given as
2058 @code{log2(partitions)}.
2060 @item max-intra-rate
2061 Set maximum I-frame bitrate as a percentage of the target bitrate. A value of 0
2064 @item force_key_frames
2065 @code{VPX_EFLAG_FORCE_KF}
2067 @item Alternate reference frame related
2070 Enable use of alternate reference frames (2-pass only).
2071 Values greater than 1 enable multi-layer alternate reference frames (VP9 only).
2072 @item arnr-maxframes
2073 Set altref noise reduction max frame count.
2075 Set altref noise reduction filter type: backward, forward, centered.
2077 Set altref noise reduction filter strength.
2078 @item rc-lookahead, lag-in-frames (@emph{lag-in-frames})
2079 Set number of frames to look ahead for frametype and ratecontrol.
2082 @item error-resilient
2083 Enable error resiliency features.
2085 @item sharpness @var{integer}
2086 Increase sharpness at the expense of lower PSNR.
2087 The valid range is [0, 7].
2090 Sets the temporal scalability configuration using a :-separated list of
2091 key=value pairs. For example, to specify temporal scalability parameters
2094 ffmpeg -i INPUT -c:v libvpx -ts-parameters ts_number_layers=3:\
2095 ts_target_bitrate=250,500,1000:ts_rate_decimator=4,2,1:\
2096 ts_periodicity=4:ts_layer_id=0,2,1,2:ts_layering_mode=3 OUTPUT
2098 Below is a brief explanation of each of the parameters, please
2099 refer to @code{struct vpx_codec_enc_cfg} in @code{vpx/vpx_encoder.h} for more
2102 @item ts_number_layers
2103 Number of temporal coding layers.
2104 @item ts_target_bitrate
2105 Target bitrate for each temporal layer (in kbps).
2106 (bitrate should be inclusive of the lower temporal layer).
2107 @item ts_rate_decimator
2108 Frame rate decimation factor for each temporal layer.
2109 @item ts_periodicity
2110 Length of the sequence defining frame temporal layer membership.
2112 Template defining the membership of frames to temporal layers.
2113 @item ts_layering_mode
2114 (optional) Selecting the temporal structure from a set of pre-defined temporal layering modes.
2115 Currently supports the following options.
2118 No temporal layering flags are provided internally,
2119 relies on flags being passed in using @code{metadata} field in @code{AVFrame}
2120 with following keys.
2123 Sets the flags passed into the encoder to indicate the referencing scheme for
2125 Refer to function @code{vpx_codec_encode} in @code{vpx/vpx_encoder.h} for more
2128 Explicitly sets the temporal id of the current frame to encode.
2131 Two temporal layers. 0-1...
2133 Three temporal layers. 0-2-1-2...; with single reference frame.
2135 Same as option "3", except there is a dependency between
2136 the two temporal layer 2 frames within the temporal period.
2140 @item VP9-specific options
2143 Enable lossless mode.
2145 Set number of tile columns to use. Note this is given as
2146 @code{log2(tile_columns)}. For example, 8 tile columns would be requested by
2147 setting the @option{tile-columns} option to 3.
2149 Set number of tile rows to use. Note this is given as @code{log2(tile_rows)}.
2150 For example, 4 tile rows would be requested by setting the @option{tile-rows}
2152 @item frame-parallel
2153 Enable frame parallel decodability features.
2155 Set adaptive quantization mode (0: off (default), 1: variance 2: complexity, 3:
2156 cyclic refresh, 4: equator360).
2157 @item colorspace @emph{color-space}
2158 Set input color space. The VP9 bitstream supports signaling the following
2161 @item @samp{rgb} @emph{sRGB}
2162 @item @samp{bt709} @emph{bt709}
2163 @item @samp{unspecified} @emph{unknown}
2164 @item @samp{bt470bg} @emph{bt601}
2165 @item @samp{smpte170m} @emph{smpte170}
2166 @item @samp{smpte240m} @emph{smpte240}
2167 @item @samp{bt2020_ncl} @emph{bt2020}
2169 @item row-mt @var{boolean}
2170 Enable row based multi-threading.
2172 Set content type: default (0), screen (1), film (2).
2173 @item corpus-complexity
2174 Corpus VBR mode is a variant of standard VBR where the complexity distribution
2175 midpoint is passed in rather than calculated for a specific clip or chunk.
2177 The valid range is [0, 10000]. 0 (default) uses standard VBR.
2178 @item enable-tpl @var{boolean}
2179 Enable temporal dependency model.
2180 @item ref-frame-config
2181 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.
2182 @*Use a :-separated list of key=value pairs.
2185 av_dict_set(&av_frame->metadata, "ref-frame-config", \
2186 "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");
2189 @item rfc_update_buffer_slot
2190 Indicates the buffer slot number to update
2191 @item rfc_update_last
2192 Indicates whether to update the LAST frame
2193 @item rfc_update_golden
2194 Indicates whether to update GOLDEN frame
2195 @item rfc_update_alt_ref
2196 Indicates whether to update ALT_REF frame
2197 @item rfc_lst_fb_idx
2198 LAST frame buffer index
2199 @item rfc_gld_fb_idx
2200 GOLDEN frame buffer index
2201 @item rfc_alt_fb_idx
2202 ALT_REF frame buffer index
2203 @item rfc_reference_last
2204 Indicates whether to reference LAST frame
2205 @item rfc_reference_golden
2206 Indicates whether to reference GOLDEN frame
2207 @item rfc_reference_alt_ref
2208 Indicates whether to reference ALT_REF frame
2209 @item rfc_reference_duration
2210 Indicates frame duration
2216 For more information about libvpx see:
2217 @url{http://www.webmproject.org/}
2221 libwebp WebP Image encoder wrapper
2223 libwebp is Google's official encoder for WebP images. It can encode in either
2224 lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
2225 frame. Lossless images are a separate codec developed by Google.
2227 @subsection Pixel Format
2229 Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
2230 to limitations of the format and libwebp. Alpha is supported for either mode.
2231 Because of API limitations, if RGB is passed in when encoding lossy or YUV is
2232 passed in for encoding lossless, the pixel format will automatically be
2233 converted using functions from libwebp. This is not ideal and is done only for
2240 @item -lossless @var{boolean}
2241 Enables/Disables use of lossless mode. Default is 0.
2243 @item -compression_level @var{integer}
2244 For lossy, this is a quality/speed tradeoff. Higher values give better quality
2245 for a given size at the cost of increased encoding time. For lossless, this is
2246 a size/speed tradeoff. Higher values give smaller size at the cost of increased
2247 encoding time. More specifically, it controls the number of extra algorithms
2248 and compression tools used, and varies the combination of these tools. This
2249 maps to the @var{method} option in libwebp. The valid range is 0 to 6.
2252 @item -qscale @var{float}
2253 For lossy encoding, this controls image quality, 0 to 100. For lossless
2254 encoding, this controls the effort and time spent at compressing more. The
2255 default value is 75. Note that for usage via libavcodec, this option is called
2256 @var{global_quality} and must be multiplied by @var{FF_QP2LAMBDA}.
2258 @item -preset @var{type}
2259 Configuration preset. This does some automatic settings based on the general
2263 Do not use a preset.
2265 Use the encoder default.
2267 Digital picture, like portrait, inner shot
2269 Outdoor photograph, with natural lighting
2271 Hand or line drawing, with high-contrast details
2273 Small-sized colorful images
2280 @section libx264, libx264rgb
2282 x264 H.264/MPEG-4 AVC encoder wrapper.
2284 This encoder requires the presence of the libx264 headers and library
2285 during configuration. You need to explicitly configure the build with
2286 @code{--enable-libx264}.
2288 libx264 supports an impressive number of features, including 8x8 and
2289 4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
2290 entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
2291 for detail retention (adaptive quantization, psy-RD, psy-trellis).
2293 Many libx264 encoder options are mapped to FFmpeg global codec
2294 options, while unique encoder options are provided through private
2295 options. Additionally the @option{x264opts} and @option{x264-params}
2296 private options allows one to pass a list of key=value tuples as accepted
2297 by the libx264 @code{x264_param_parse} function.
2299 The x264 project website is at
2300 @url{http://www.videolan.org/developers/x264.html}.
2302 The libx264rgb encoder is the same as libx264, except it accepts packed RGB
2303 pixel formats as input instead of YUV.
2305 @subsection Supported Pixel Formats
2307 x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at
2308 x264's configure time. FFmpeg only supports one bit depth in one particular
2309 build. In other words, it is not possible to build one FFmpeg with multiple
2310 versions of x264 with different bit depths.
2314 The following options are supported by the libx264 wrapper. The
2315 @command{x264}-equivalent options or values are listed in parentheses
2318 To reduce the duplication of documentation, only the private options
2319 and some others requiring special attention are documented here. For
2320 the documentation of the undocumented generic options, see
2321 @ref{codec-options,,the Codec Options chapter}.
2323 To get a more accurate and extensive documentation of the libx264
2324 options, invoke the command @command{x264 --fullhelp} or consult
2325 the libx264 documentation.
2328 @item b (@emph{bitrate})
2329 Set bitrate in bits/s. Note that FFmpeg's @option{b} option is
2330 expressed in bits/s, while @command{x264}'s @option{bitrate} is in
2333 @item bf (@emph{bframes})
2335 @item g (@emph{keyint})
2337 @item qmin (@emph{qpmin})
2338 Minimum quantizer scale.
2340 @item qmax (@emph{qpmax})
2341 Maximum quantizer scale.
2343 @item qdiff (@emph{qpstep})
2344 Maximum difference between quantizer scales.
2346 @item qblur (@emph{qblur})
2347 Quantizer curve blur
2349 @item qcomp (@emph{qcomp})
2350 Quantizer curve compression factor
2352 @item refs (@emph{ref})
2353 Number of reference frames each P-frame can use. The range is from @var{0-16}.
2355 @item sc_threshold (@emph{scenecut})
2356 Sets the threshold for the scene change detection.
2358 @item trellis (@emph{trellis})
2359 Performs Trellis quantization to increase efficiency. Enabled by default.
2361 @item nr (@emph{nr})
2363 @item me_range (@emph{merange})
2364 Maximum range of the motion search in pixels.
2366 @item me_method (@emph{me})
2367 Set motion estimation method. Possible values in the decreasing order
2371 @item dia (@emph{dia})
2372 @item epzs (@emph{dia})
2373 Diamond search with radius 1 (fastest). @samp{epzs} is an alias for
2375 @item hex (@emph{hex})
2376 Hexagonal search with radius 2.
2377 @item umh (@emph{umh})
2378 Uneven multi-hexagon search.
2379 @item esa (@emph{esa})
2381 @item tesa (@emph{tesa})
2382 Hadamard exhaustive search (slowest).
2386 Normally, when forcing a I-frame type, the encoder can select any type
2387 of I-frame. This option forces it to choose an IDR-frame.
2389 @item subq (@emph{subme})
2390 Sub-pixel motion estimation method.
2392 @item b_strategy (@emph{b-adapt})
2393 Adaptive B-frame placement decision algorithm. Use only on first-pass.
2395 @item keyint_min (@emph{min-keyint})
2399 Set entropy encoder. Possible values:
2406 Enable CAVLC and disable CABAC. It generates the same effect as
2407 @command{x264}'s @option{--no-cabac} option.
2411 Set full pixel motion estimation comparison algorithm. Possible values:
2415 Enable chroma in motion estimation.
2418 Ignore chroma in motion estimation. It generates the same effect as
2419 @command{x264}'s @option{--no-chroma-me} option.
2422 @item threads (@emph{threads})
2423 Number of encoding threads.
2426 Set multithreading technique. Possible values:
2430 Slice-based multithreading. It generates the same effect as
2431 @command{x264}'s @option{--sliced-threads} option.
2433 Frame-based multithreading.
2437 Set encoding flags. It can be used to disable closed GOP and enable
2438 open GOP by setting it to @code{-cgop}. The result is similar to
2439 the behavior of @command{x264}'s @option{--open-gop} option.
2441 @item rc_init_occupancy (@emph{vbv-init})
2443 @item preset (@emph{preset})
2444 Set the encoding preset.
2446 @item tune (@emph{tune})
2447 Set tuning of the encoding params.
2449 @item profile (@emph{profile})
2450 Set profile restrictions.
2453 Enable fast settings when encoding first pass, when set to 1. When set
2454 to 0, it has the same effect of @command{x264}'s
2455 @option{--slow-firstpass} option.
2457 @item crf (@emph{crf})
2458 Set the quality for constant quality mode.
2460 @item crf_max (@emph{crf-max})
2461 In CRF mode, prevents VBV from lowering quality beyond this point.
2463 @item qp (@emph{qp})
2464 Set constant quantization rate control method parameter.
2466 @item aq-mode (@emph{aq-mode})
2467 Set AQ method. Possible values:
2470 @item none (@emph{0})
2473 @item variance (@emph{1})
2474 Variance AQ (complexity mask).
2476 @item autovariance (@emph{2})
2477 Auto-variance AQ (experimental).
2480 @item aq-strength (@emph{aq-strength})
2481 Set AQ strength, reduce blocking and blurring in flat and textured areas.
2484 Use psychovisual optimizations when set to 1. When set to 0, it has the
2485 same effect as @command{x264}'s @option{--no-psy} option.
2487 @item psy-rd (@emph{psy-rd})
2488 Set strength of psychovisual optimization, in
2489 @var{psy-rd}:@var{psy-trellis} format.
2491 @item rc-lookahead (@emph{rc-lookahead})
2492 Set number of frames to look ahead for frametype and ratecontrol.
2495 Enable weighted prediction for B-frames when set to 1. When set to 0,
2496 it has the same effect as @command{x264}'s @option{--no-weightb} option.
2498 @item weightp (@emph{weightp})
2499 Set weighted prediction method for P-frames. Possible values:
2502 @item none (@emph{0})
2504 @item simple (@emph{1})
2505 Enable only weighted refs
2506 @item smart (@emph{2})
2507 Enable both weighted refs and duplicates
2510 @item ssim (@emph{ssim})
2511 Enable calculation and printing SSIM stats after the encoding.
2513 @item intra-refresh (@emph{intra-refresh})
2514 Enable the use of Periodic Intra Refresh instead of IDR frames when set
2517 @item avcintra-class (@emph{class})
2518 Configure the encoder to generate AVC-Intra.
2519 Valid values are 50,100 and 200
2521 @item bluray-compat (@emph{bluray-compat})
2522 Configure the encoder to be compatible with the bluray standard.
2523 It is a shorthand for setting "bluray-compat=1 force-cfr=1".
2525 @item b-bias (@emph{b-bias})
2526 Set the influence on how often B-frames are used.
2528 @item b-pyramid (@emph{b-pyramid})
2529 Set method for keeping of some B-frames as references. Possible values:
2532 @item none (@emph{none})
2534 @item strict (@emph{strict})
2535 Strictly hierarchical pyramid.
2536 @item normal (@emph{normal})
2537 Non-strict (not Blu-ray compatible).
2541 Enable the use of one reference per partition, as opposed to one
2542 reference per macroblock when set to 1. When set to 0, it has the
2543 same effect as @command{x264}'s @option{--no-mixed-refs} option.
2546 Enable adaptive spatial transform (high profile 8x8 transform)
2547 when set to 1. When set to 0, it has the same effect as
2548 @command{x264}'s @option{--no-8x8dct} option.
2551 Enable early SKIP detection on P-frames when set to 1. When set
2552 to 0, it has the same effect as @command{x264}'s
2553 @option{--no-fast-pskip} option.
2555 @item aud (@emph{aud})
2556 Enable use of access unit delimiters when set to 1.
2559 Enable use macroblock tree ratecontrol when set to 1. When set
2560 to 0, it has the same effect as @command{x264}'s
2561 @option{--no-mbtree} option.
2563 @item deblock (@emph{deblock})
2564 Set loop filter parameters, in @var{alpha}:@var{beta} form.
2566 @item cplxblur (@emph{cplxblur})
2567 Set fluctuations reduction in QP (before curve compression).
2569 @item partitions (@emph{partitions})
2570 Set partitions to consider as a comma-separated list of. Possible
2575 8x8 P-frame partition.
2577 4x4 P-frame partition.
2579 4x4 B-frame partition.
2581 8x8 I-frame partition.
2583 4x4 I-frame partition.
2584 (Enabling @samp{p4x4} requires @samp{p8x8} to be enabled. Enabling
2585 @samp{i8x8} requires adaptive spatial transform (@option{8x8dct}
2586 option) to be enabled.)
2587 @item none (@emph{none})
2588 Do not consider any partitions.
2589 @item all (@emph{all})
2590 Consider every partition.
2593 @item direct-pred (@emph{direct})
2594 Set direct MV prediction mode. Possible values:
2597 @item none (@emph{none})
2598 Disable MV prediction.
2599 @item spatial (@emph{spatial})
2600 Enable spatial predicting.
2601 @item temporal (@emph{temporal})
2602 Enable temporal predicting.
2603 @item auto (@emph{auto})
2604 Automatically decided.
2607 @item slice-max-size (@emph{slice-max-size})
2608 Set the limit of the size of each slice in bytes. If not specified
2609 but RTP payload size (@option{ps}) is specified, that is used.
2611 @item stats (@emph{stats})
2612 Set the file name for multi-pass stats.
2614 @item nal-hrd (@emph{nal-hrd})
2615 Set signal HRD information (requires @option{vbv-bufsize} to be set).
2619 @item none (@emph{none})
2620 Disable HRD information signaling.
2621 @item vbr (@emph{vbr})
2623 @item cbr (@emph{cbr})
2624 Constant bit rate (not allowed in MP4 container).
2627 @item x264opts (N.A.)
2628 Set any x264 option, see @command{x264 --fullhelp} for a list.
2630 Argument is a list of @var{key}=@var{value} couples separated by
2631 ":". In @var{filter} and @var{psy-rd} options that use ":" as a separator
2632 themselves, use "," instead. They accept it as well since long ago but this
2633 is kept undocumented for some reason.
2635 For example to specify libx264 encoding options with @command{ffmpeg}:
2637 ffmpeg -i foo.mpg -c:v libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
2640 @item a53cc @var{boolean}
2641 Import closed captions (which must be ATSC compatible format) into output.
2642 Only the mpeg2 and h264 decoders provide these. Default is 1 (on).
2644 @item x264-params (N.A.)
2645 Override the x264 configuration using a :-separated list of key=value
2648 This option is functionally the same as the @option{x264opts}, but is
2649 duplicated for compatibility with the Libav fork.
2651 For example to specify libx264 encoding options with @command{ffmpeg}:
2653 ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
2654 cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
2655 no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
2659 Encoding ffpresets for common usages are provided so they can be used with the
2660 general presets system (e.g. passing the @option{pre} option).
2664 x265 H.265/HEVC encoder wrapper.
2666 This encoder requires the presence of the libx265 headers and library
2667 during configuration. You need to explicitly configure the build with
2668 @option{--enable-libx265}.
2674 Sets target video bitrate.
2685 Number of reference frames each P-frame can use. The range is from @var{1-16}.
2688 Set the x265 preset.
2691 Set the x265 tune parameter.
2694 Set profile restrictions.
2697 Set the quality for constant quality mode.
2700 Set constant quantization rate control method parameter.
2703 Minimum quantizer scale.
2706 Maximum quantizer scale.
2709 Maximum difference between quantizer scales.
2712 Quantizer curve blur
2715 Quantizer curve compression factor
2722 Normally, when forcing a I-frame type, the encoder can select any type
2723 of I-frame. This option forces it to choose an IDR-frame.
2726 Set x265 options using a list of @var{key}=@var{value} couples separated
2727 by ":". See @command{x265 --help} for a list of options.
2729 For example to specify libx265 encoding options with @option{-x265-params}:
2732 ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
2738 xavs2 AVS2-P2/IEEE1857.4 encoder wrapper.
2740 This encoder requires the presence of the libxavs2 headers and library
2741 during configuration. You need to explicitly configure the build with
2742 @option{--enable-libxavs2}.
2744 The following standard libavcodec options are used:
2747 @option{b} / @option{bit_rate}
2749 @option{g} / @option{gop_size}
2751 @option{bf} / @option{max_b_frames}
2754 The encoder also has its own specific options:
2758 @item lcu_row_threads
2759 Set the number of parallel threads for rows from 1 to 8 (default 5).
2762 Set the xavs2 quantization parameter from 1 to 63 (default 34). This is
2763 used to set the initial qp for the first frame.
2766 Set the xavs2 quantization parameter from 1 to 63 (default 34). This is
2767 used to set the qp value under constant-QP mode.
2770 Set the max qp for rate control from 1 to 63 (default 55).
2773 Set the min qp for rate control from 1 to 63 (default 20).
2776 Set the Speed level from 0 to 9 (default 0). Higher is better but slower.
2779 Set the log level from -1 to 3 (default 0). -1: none, 0: error,
2780 1: warning, 2: info, 3: debug.
2783 Set xavs2 options using a list of @var{key}=@var{value} couples separated
2786 For example to specify libxavs2 encoding options with @option{-xavs2-params}:
2789 ffmpeg -i input -c:v libxavs2 -xavs2-params RdoqLevel=0 output.avs2
2795 Xvid MPEG-4 Part 2 encoder wrapper.
2797 This encoder requires the presence of the libxvidcore headers and library
2798 during configuration. You need to explicitly configure the build with
2799 @code{--enable-libxvid --enable-gpl}.
2801 The native @code{mpeg4} encoder supports the MPEG-4 Part 2 format, so
2802 users can encode to this format without this library.
2806 The following options are supported by the libxvid wrapper. Some of
2807 the following options are listed but are not documented, and
2808 correspond to shared codec options. See @ref{codec-options,,the Codec
2809 Options chapter} for their documentation. The other shared options
2810 which are not listed have no effect for the libxvid encoder.
2832 Set specific encoding flags. Possible values:
2837 Use four motion vector by macroblock.
2840 Enable high quality AC prediction.
2843 Only encode grayscale.
2846 Enable the use of global motion compensation (GMC).
2849 Enable quarter-pixel motion compensation.
2855 Place global headers in extradata instead of every keyframe.
2862 Set motion estimation method. Possible values in decreasing order of
2863 speed and increasing order of quality:
2867 Use no motion estimation (default).
2872 Enable advanced diamond zonal search for 16x16 blocks and half-pixel
2873 refinement for 16x16 blocks. @samp{x1} and @samp{log} are aliases for
2877 Enable all of the things described above, plus advanced diamond zonal
2878 search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
2879 estimation on chroma planes.
2882 Enable all of the things described above, plus extended 16x16 and 8x8
2887 Set macroblock decision algorithm. Possible values in the increasing
2892 Use macroblock comparing function algorithm (default).
2895 Enable rate distortion-based half pixel and quarter pixel refinement for
2899 Enable all of the things described above, plus rate distortion-based
2900 half pixel and quarter pixel refinement for 8x8 blocks, and rate
2901 distortion-based search using square pattern.
2905 Enable lumi masking adaptive quantization when set to 1. Default is 0
2909 Enable variance adaptive quantization when set to 1. Default is 0
2912 When combined with @option{lumi_aq}, the resulting quality will not
2913 be better than any of the two specified individually. In other
2914 words, the resulting quality will be the worse one of the two
2918 Set structural similarity (SSIM) displaying method. Possible values:
2922 Disable displaying of SSIM information.
2925 Output average SSIM at the end of encoding to stdout. The format of
2926 showing the average SSIM is:
2932 For users who are not familiar with C, %f means a float number, or
2933 a decimal (e.g. 0.939232).
2936 Output both per-frame SSIM data during encoding and average SSIM at
2937 the end of encoding to stdout. The format of per-frame information
2941 SSIM: avg: %1.3f min: %1.3f max: %1.3f
2944 For users who are not familiar with C, %1.3f means a float number
2945 rounded to 3 digits after the dot (e.g. 0.932).
2950 Set SSIM accuracy. Valid options are integers within the range of
2951 0-4, while 0 gives the most accurate result and 4 computes the
2956 @section MediaFoundation
2958 This provides wrappers to encoders (both audio and video) in the
2959 MediaFoundation framework. It can access both SW and HW encoders.
2960 Video encoders can take input in either of nv12 or yuv420p form
2961 (some encoders support both, some support only either - in practice,
2962 nv12 is the safer choice, especially among HW encoders).
2966 MPEG-2 video encoder.
2972 Select the mpeg2 profile to encode:
2986 Select the mpeg2 level to encode:
2995 @item seq_disp_ext @var{integer}
2996 Specifies if the encoder should write a sequence_display_extension to the
3001 Decide automatically to write it or not (this is the default) by checking if
3002 the data to be written is different from the default or unspecified values.
3010 @item video_format @var{integer}
3011 Specifies the video_format written into the sequence display extension
3012 indicating the source of the video pictures. The default is @samp{unspecified},
3013 can be @samp{component}, @samp{pal}, @samp{ntsc}, @samp{secam} or @samp{mac}.
3014 For maximum compatibility, use @samp{component}.
3015 @item a53cc @var{boolean}
3016 Import closed captions (which must be ATSC compatible format) into output.
3024 @subsection Private options
3027 @item dpi @var{integer}
3028 Set physical density of pixels, in dots per inch, unset by default
3029 @item dpm @var{integer}
3030 Set physical density of pixels, in dots per meter, unset by default
3035 Apple ProRes encoder.
3037 FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
3038 The used encoder can be chosen with the @code{-vcodec} option.
3040 @subsection Private Options for prores-ks
3043 @item profile @var{integer}
3044 Select the ProRes profile to encode
3054 @item quant_mat @var{integer}
3055 Select quantization matrix.
3064 If set to @var{auto}, the matrix matching the profile will be picked.
3065 If not set, the matrix providing the highest quality, @var{default}, will be
3068 @item bits_per_mb @var{integer}
3069 How many bits to allot for coding one macroblock. Different profiles use
3070 between 200 and 2400 bits per macroblock, the maximum is 8000.
3072 @item mbs_per_slice @var{integer}
3073 Number of macroblocks in each slice (1-8); the default value (8)
3074 should be good in almost all situations.
3076 @item vendor @var{string}
3077 Override the 4-byte vendor ID.
3078 A custom vendor ID like @var{apl0} would claim the stream was produced by
3081 @item alpha_bits @var{integer}
3082 Specify number of bits for alpha component.
3083 Possible values are @var{0}, @var{8} and @var{16}.
3084 Use @var{0} to disable alpha plane coding.
3088 @subsection Speed considerations
3090 In the default mode of operation the encoder has to honor frame constraints
3091 (i.e. not produce frames with size bigger than requested) while still making
3092 output picture as good as possible.
3093 A frame containing a lot of small details is harder to compress and the encoder
3094 would spend more time searching for appropriate quantizers for each slice.
3096 Setting a higher @option{bits_per_mb} limit will improve the speed.
3098 For the fastest encoding speed set the @option{qscale} parameter (4 is the
3099 recommended value) and do not set a size constraint.
3101 @section QSV encoders
3103 The family of Intel QuickSync Video encoders (MPEG-2, H.264, HEVC, JPEG/MJPEG and VP9)
3105 The ratecontrol method is selected as follows:
3109 When @option{global_quality} is specified, a quality-based mode is used.
3110 Specifically this means either
3113 @var{CQP} - constant quantizer scale, when the @option{qscale} codec flag is
3114 also set (the @option{-qscale} ffmpeg option).
3117 @var{LA_ICQ} - intelligent constant quality with lookahead, when the
3118 @option{look_ahead} option is also set.
3121 @var{ICQ} -- intelligent constant quality otherwise.
3125 Otherwise, a bitrate-based mode is used. For all of those, you should specify at
3126 least the desired average bitrate with the @option{b} option.
3129 @var{LA} - VBR with lookahead, when the @option{look_ahead} option is specified.
3132 @var{VCM} - video conferencing mode, when the @option{vcm} option is set.
3135 @var{CBR} - constant bitrate, when @option{maxrate} is specified and equal to
3136 the average bitrate.
3139 @var{VBR} - variable bitrate, when @option{maxrate} is specified, but is higher
3140 than the average bitrate.
3143 @var{AVBR} - average VBR mode, when @option{maxrate} is not specified. This mode
3144 is further configured by the @option{avbr_accuracy} and
3145 @option{avbr_convergence} options.
3149 Note that depending on your system, a different mode than the one you specified
3150 may be selected by the encoder. Set the verbosity level to @var{verbose} or
3151 higher to see the actual settings used by the QSV runtime.
3153 Additional libavcodec global options are mapped to MSDK options as follows:
3157 @option{g/gop_size} -> @option{GopPicSize}
3160 @option{bf/max_b_frames}+1 -> @option{GopRefDist}
3163 @option{rc_init_occupancy/rc_initial_buffer_occupancy} ->
3164 @option{InitialDelayInKB}
3167 @option{slices} -> @option{NumSlice}
3170 @option{refs} -> @option{NumRefFrame}
3173 @option{b_strategy/b_frame_strategy} -> @option{BRefType}
3176 @option{cgop/CLOSED_GOP} codec flag -> @option{GopOptFlag}
3179 For the @var{CQP} mode, the @option{i_qfactor/i_qoffset} and
3180 @option{b_qfactor/b_qoffset} set the difference between @var{QPP} and @var{QPI},
3181 and @var{QPP} and @var{QPB} respectively.
3184 Setting the @option{coder} option to the value @var{vlc} will make the H.264
3185 encoder use CAVLC instead of CABAC.
3194 @item iterative_dia_size
3195 dia size for the iterative motion estimation
3198 @section VAAPI encoders
3200 Wrappers for hardware encoders accessible via VAAPI.
3202 These encoders only accept input in VAAPI hardware surfaces. If you have input
3203 in software frames, use the @option{hwupload} filter to upload them to the GPU.
3205 The following standard libavcodec options are used:
3208 @option{g} / @option{gop_size}
3210 @option{bf} / @option{max_b_frames}
3214 If not set, this will be determined automatically from the format of the input
3215 frames and the profiles supported by the driver.
3219 @option{b} / @option{bit_rate}
3221 @option{maxrate} / @option{rc_max_rate}
3223 @option{bufsize} / @option{rc_buffer_size}
3225 @option{rc_init_occupancy} / @option{rc_initial_buffer_occupancy}
3227 @option{compression_level}
3229 Speed / quality tradeoff: higher values are faster / worse quality.
3231 @option{q} / @option{global_quality}
3233 Size / quality tradeoff: higher values are smaller / worse quality.
3239 @option{i_qfactor} / @option{i_quant_factor}
3241 @option{i_qoffset} / @option{i_quant_offset}
3243 @option{b_qfactor} / @option{b_quant_factor}
3245 @option{b_qoffset} / @option{b_quant_offset}
3250 All encoders support the following options:
3253 Some drivers/platforms offer a second encoder for some codecs intended to use
3254 less power than the default encoder; setting this option will attempt to use
3255 that encoder. Note that it may support a reduced feature set, so some other
3256 options may not be available in this mode.
3259 Set the number of normal intra frames between full-refresh (IDR) frames in
3260 open-GOP mode. The intra frames are still IRAPs, but will not include global
3261 headers and may have non-decodable leading pictures.
3264 Set the B-frame reference depth. When set to one (the default), all B-frames
3265 will refer only to P- or I-frames. When set to greater values multiple layers
3266 of B-frames will be present, frames in each layer only referring to frames in
3270 Set the rate control mode to use. A given driver may only support a subset of
3276 Choose the mode automatically based on driver support and the other options.
3277 This is the default.
3285 Intelligent constant-quality.
3287 Quality-defined variable-bitrate.
3289 Average variable bitrate.
3294 Each encoder also has its own specific options:
3298 @option{profile} sets the value of @emph{profile_idc} and the @emph{constraint_set*_flag}s.
3299 @option{level} sets the value of @emph{level_idc}.
3303 Set entropy encoder (default is @emph{cabac}). Possible values:
3316 Include access unit delimiters in the stream (not included by default).
3319 Set SEI message types to include.
3320 Some combination of the following values:
3323 Include a @emph{user_data_unregistered} message containing information about
3326 Include picture timing parameters (@emph{buffering_period} and
3327 @emph{pic_timing} messages).
3328 @item recovery_point
3329 Include recovery points where appropriate (@emph{recovery_point} messages).
3335 @option{profile} and @option{level} set the values of
3336 @emph{general_profile_idc} and @emph{general_level_idc} respectively.
3340 Include access unit delimiters in the stream (not included by default).
3343 Set @emph{general_tier_flag}. This may affect the level chosen for the stream
3344 if it is not explicitly specified.
3347 Set SEI message types to include.
3348 Some combination of the following values:
3351 Include HDR metadata if the input frames have it
3352 (@emph{mastering_display_colour_volume} and @emph{content_light_level}
3357 Set the number of tiles to encode the input video with, as columns x rows.
3358 Larger numbers allow greater parallelism in both encoding and decoding, but
3359 may decrease coding efficiency.
3364 Only baseline DCT encoding is supported. The encoder always uses the standard
3365 quantisation and huffman tables - @option{global_quality} scales the standard
3366 quantisation table (range 1-100).
3368 For YUV, 4:2:0, 4:2:2 and 4:4:4 subsampling modes are supported. RGB is also
3369 supported, and will create an RGB JPEG.
3373 Include JFIF header in each frame (not included by default).
3375 Include standard huffman tables (on by default). Turning this off will save
3376 a few hundred bytes in each output frame, but may lose compatibility with some
3377 JPEG decoders which don't fully handle MJPEG.
3381 @option{profile} and @option{level} set the value of @emph{profile_and_level_indication}.
3384 B-frames are not supported.
3386 @option{global_quality} sets the @emph{q_idx} used for non-key frames (range 0-127).
3389 @item loop_filter_level
3390 @item loop_filter_sharpness
3391 Manually set the loop filter parameters.
3395 @option{global_quality} sets the @emph{q_idx} used for P-frames (range 0-255).
3398 @item loop_filter_level
3399 @item loop_filter_sharpness
3400 Manually set the loop filter parameters.
3403 B-frames are supported, but the output stream is always in encode order rather than display
3404 order. If B-frames are enabled, it may be necessary to use the @option{vp9_raw_reorder}
3405 bitstream filter to modify the output stream to display frames in the correct order.
3407 Only normal frames are produced - the @option{vp9_superframe} bitstream filter may be
3408 required to produce a stream usable with all decoders.
3414 SMPTE VC-2 (previously BBC Dirac Pro). This codec was primarily aimed at
3415 professional broadcasting but since it supports yuv420, yuv422 and yuv444 at
3416 8 (limited range or full range), 10 or 12 bits, this makes it suitable for
3417 other tasks which require low overhead and low compression (like screen
3425 Sets target video bitrate. Usually that's around 1:6 of the uncompressed
3426 video bitrate (e.g. for 1920x1080 50fps yuv422p10 that's around 400Mbps). Higher
3427 values (close to the uncompressed bitrate) turn on lossless compression mode.
3430 Enables field coding when set (e.g. to tt - top field first) for interlaced
3431 inputs. Should increase compression with interlaced content as it splits the
3432 fields and encodes each separately.
3435 Sets the total amount of wavelet transforms to apply, between 1 and 5 (default).
3436 Lower values reduce compression and quality. Less capable decoders may not be
3437 able to handle values of @option{wavelet_depth} over 3.
3440 Sets the transform type. Currently only @var{5_3} (LeGall) and @var{9_7}
3442 are implemented, with 9_7 being the one with better compression and thus
3447 Sets the slice size for each slice. Larger values result in better compression.
3448 For compatibility with other more limited decoders use @option{slice_width} of
3449 32 and @option{slice_height} of 8.
3452 Sets the undershoot tolerance of the rate control system in percent. This is
3453 to prevent an expensive search from being run.
3456 Sets the quantization matrix preset to use by default or when @option{wavelet_depth}
3461 Uses the default quantization matrix from the specifications, extended with
3462 values for the fifth level. This provides a good balance between keeping detail
3463 and omitting artifacts.
3467 Use a completely zeroed out quantization matrix. This increases PSNR but might
3468 reduce perception. Use in bogus benchmarks.
3472 Reduces detail but attempts to preserve color at extremely low bitrates.
3477 @c man end VIDEO ENCODERS
3479 @chapter Subtitles Encoders
3480 @c man begin SUBTITLES ENCODERS
3484 This codec encodes the bitmap subtitle format that is used in DVDs.
3485 Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
3486 and they can also be used in Matroska files.
3492 Specify the global palette used by the bitmaps.
3494 The format for this option is a string containing 16 24-bits hexadecimal
3495 numbers (without 0x prefix) separated by commas, for example @code{0d00ee,
3496 ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
3497 7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b}.
3500 When set to 1, enable a work-around that makes the number of pixel rows
3501 even in all subtitles. This fixes a problem with some players that
3502 cut off the bottom row if the number is odd. The work-around just adds
3503 a fully transparent row if needed. The overhead is low, typically
3504 one byte per subtitle on average.
3506 By default, this work-around is disabled.
3509 @c man end SUBTITLES ENCODERS