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 Vidvox Hap video encoder.
1278 @item format @var{integer}
1279 Specifies the Hap format to encode.
1287 Default value is @option{hap}.
1289 @item chunks @var{integer}
1290 Specifies the number of chunks to split frames into, between 1 and 64. This
1291 permits multithreaded decoding of large frames, potentially at the cost of
1292 data-rate. The encoder may modify this value to divide frames evenly.
1294 Default value is @var{1}.
1296 @item compressor @var{integer}
1297 Specifies the second-stage compressor to use. If set to @option{none},
1298 @option{chunks} will be limited to 1, as chunked uncompressed frames offer no
1306 Default value is @option{snappy}.
1312 The native jpeg 2000 encoder is lossy by default, the @code{-q:v}
1313 option can be used to set the encoding quality. Lossless encoding
1314 can be selected with @code{-pred 1}.
1319 @item format @var{integer}
1320 Can be set to either @code{j2k} or @code{jp2} (the default) that
1321 makes it possible to store non-rgb pix_fmts.
1323 @item tile_width @var{integer}
1324 Sets tile width. Range is 1 to 1073741824. Default is 256.
1326 @item tile_height @var{integer}
1327 Sets tile height. Range is 1 to 1073741824. Default is 256.
1329 @item pred @var{integer}
1330 Allows setting the discrete wavelet transform (DWT) type
1332 @item dwt97int (Lossy)
1333 @item dwt53 (Lossless)
1335 Default is @code{dwt97int}
1337 @item sop @var{boolean}
1338 Enable this to add SOP marker at the start of each packet. Disabled by default.
1340 @item eph @var{boolean}
1341 Enable this to add EPH marker at the end of each packet header. Disabled by default.
1343 @item prog @var{integer}
1344 Sets the progression order to be used by the encoder.
1345 Possible values are:
1353 Set to @code{lrcp} by default.
1355 @item layer_rates @var{string}
1356 By default, when this option is not used, compression is done using the quality metric.
1357 This option allows for compression using compression ratio. The compression ratio for each
1358 level could be specified. The compression ratio of a layer @code{l} species the what ratio of
1359 total file size is contained in the first @code{l} layers.
1364 ffmpeg -i input.bmp -c:v jpeg2000 -layer_rates "100,10,1" output.j2k
1367 This would compress the image to contain 3 layers, where the data contained in the
1368 first layer would be compressed by 1000 times, compressed by 100 in the first two layers,
1369 and shall contain all data while using all 3 layers.
1375 rav1e AV1 encoder wrapper.
1377 Requires the presence of the rav1e headers and library during configuration.
1378 You need to explicitly configure the build with @code{--enable-librav1e}.
1384 Sets the maximum quantizer to use when using bitrate mode.
1387 Sets the minimum quantizer to use when using bitrate mode.
1390 Uses quantizer mode to encode at the given quantizer (0-255).
1393 Selects the speed preset (0-10) to encode with.
1396 Selects how many tiles to encode with.
1399 Selects how many rows of tiles to encode with.
1402 Selects how many columns of tiles to encode with.
1405 Set rav1e options using a list of @var{key}=@var{value} pairs separated
1406 by ":". See @command{rav1e --help} for a list of options.
1408 For example to specify librav1e encoding options with @option{-rav1e-params}:
1411 ffmpeg -i input -c:v librav1e -b:v 500K -rav1e-params speed=5:low_latency=true output.mp4
1418 libaom AV1 encoder wrapper.
1420 Requires the presence of the libaom headers and library during
1421 configuration. You need to explicitly configure the build with
1422 @code{--enable-libaom}.
1426 The wrapper supports the following standard libavcodec options:
1431 Set bitrate target in bits/second. By default this will use
1432 variable-bitrate mode. If @option{maxrate} and @option{minrate} are
1433 also set to the same value then it will use constant-bitrate mode,
1434 otherwise if @option{crf} is set as well then it will use
1435 constrained-quality mode.
1438 Set key frame placement. The GOP size sets the maximum distance between
1439 key frames; if zero the output stream will be intra-only. The minimum
1440 distance is ignored unless it is the same as the GOP size, in which case
1441 key frames will always appear at a fixed interval. Not set by default,
1442 so without this option the library has completely free choice about
1443 where to place key frames.
1446 Set minimum/maximum quantisation values. Valid range is from 0 to 63
1447 (warning: this does not match the quantiser values actually used by AV1
1448 - divide by four to map real quantiser values to this range). Defaults
1449 to min/max (no constraint).
1451 @item minrate maxrate bufsize rc_init_occupancy
1452 Set rate control buffering parameters. Not used if not set - defaults
1453 to unconstrained variable bitrate.
1456 Set the number of threads to use while encoding. This may require the
1457 @option{tiles} or @option{row-mt} options to also be set to actually
1458 use the specified number of threads fully. Defaults to the number of
1459 hardware threads supported by the host machine.
1462 Set the encoding profile. Defaults to using the profile which matches
1463 the bit depth and chroma subsampling of the input.
1467 The wrapper also has some specific options:
1472 Set the quality/encoding speed tradeoff. Valid range is from 0 to 8,
1473 higher numbers indicating greater speed and lower quality. The default
1474 value is 1, which will be slow and high quality.
1477 Enable use of alternate reference frames. Defaults to the internal
1478 default of the library.
1480 @item arnr-max-frames (@emph{frames})
1481 Set altref noise reduction max frame count. Default is -1.
1483 @item arnr-strength (@emph{strength})
1484 Set altref noise reduction filter strength. Range is -1 to 6. Default is -1.
1486 @item aq-mode (@emph{aq-mode})
1487 Set adaptive quantization mode. Possible values:
1490 @item none (@emph{0})
1493 @item variance (@emph{1})
1496 @item complexity (@emph{2})
1499 @item cyclic (@emph{3})
1503 @item tune (@emph{tune})
1504 Set the distortion metric the encoder is tuned with. Default is @code{psnr}.
1507 @item psnr (@emph{0})
1509 @item ssim (@emph{1})
1513 Set the maximum number of frames which the encoder may keep in flight
1514 at any one time for lookahead purposes. Defaults to the internal
1515 default of the library.
1517 @item error-resilience
1518 Enable error resilience features:
1521 Improve resilience against losses of whole frames.
1523 Not enabled by default.
1526 Set the quality/size tradeoff for constant-quality (no bitrate target)
1527 and constrained-quality (with maximum bitrate target) modes. Valid
1528 range is 0 to 63, higher numbers indicating lower quality and smaller
1529 output size. Only used if set; by default only the bitrate target is
1533 Set a change threshold on blocks below which they will be skipped by
1534 the encoder. Defined in arbitrary units as a nonnegative integer,
1535 defaulting to zero (no blocks are skipped).
1537 @item drop-threshold
1538 Set a threshold for dropping frames when close to rate control bounds.
1539 Defined as a percentage of the target buffer - when the rate control
1540 buffer falls below this percentage, frames will be dropped until it
1541 has refilled above the threshold. Defaults to zero (no frames are
1544 @item denoise-noise-level (@emph{level})
1545 Amount of noise to be removed for grain synthesis. Grain synthesis is disabled if
1546 this option is not set or set to 0.
1548 @item denoise-block-size (@emph{pixels})
1549 Block size used for denoising for grain synthesis. If not set, AV1 codec
1550 uses the default value of 32.
1552 @item undershoot-pct (@emph{pct})
1553 Set datarate undershoot (min) percentage of the target bitrate. Range is -1 to 100.
1556 @item overshoot-pct (@emph{pct})
1557 Set datarate overshoot (max) percentage of the target bitrate. Range is -1 to 1000.
1560 @item minsection-pct (@emph{pct})
1561 Minimum percentage variation of the GOP bitrate from the target bitrate. If minsection-pct
1562 is not set, the libaomenc wrapper computes it as follows: @code{(minrate * 100 / bitrate)}.
1563 Range is -1 to 100. Default is -1 (unset).
1565 @item maxsection-pct (@emph{pct})
1566 Maximum percentage variation of the GOP bitrate from the target bitrate. If maxsection-pct
1567 is not set, the libaomenc wrapper computes it as follows: @code{(maxrate * 100 / bitrate)}.
1568 Range is -1 to 5000. Default is -1 (unset).
1570 @item frame-parallel (@emph{boolean})
1571 Enable frame parallel decodability features. Default is true.
1574 Set the number of tiles to encode the input video with, as columns x
1575 rows. Larger numbers allow greater parallelism in both encoding and
1576 decoding, but may decrease coding efficiency. Defaults to the minimum
1577 number of tiles required by the size of the input video (this is 1x1
1578 (that is, a single tile) for sizes up to and including 4K).
1580 @item tile-columns tile-rows
1581 Set the number of tiles as log2 of the number of tile rows and columns.
1582 Provided for compatibility with libvpx/VP9.
1584 @item row-mt (Requires libaom >= 1.0.0-759-g90a15f4f2)
1585 Enable row based multi-threading. Disabled by default.
1587 @item enable-cdef (@emph{boolean})
1588 Enable Constrained Directional Enhancement Filter. The libaom-av1
1589 encoder enables CDEF by default.
1591 @item enable-restoration (@emph{boolean})
1592 Enable Loop Restoration Filter. Default is true for libaom-av1.
1594 @item enable-global-motion (@emph{boolean})
1595 Enable the use of global motion for block prediction. Default is true.
1597 @item enable-intrabc (@emph{boolean})
1598 Enable block copy mode for intra block prediction. This mode is
1599 useful for screen content. Default is true.
1601 @item enable-rect-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
1602 Enable rectangular partitions. Default is true.
1604 @item enable-1to4-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
1605 Enable 1:4/4:1 partitions. Default is true.
1607 @item enable-ab-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
1608 Enable AB shape partitions. Default is true.
1610 @item enable-angle-delta (@emph{boolean}) (Requires libaom >= v2.0.0)
1611 Enable angle delta intra prediction. Default is true.
1613 @item enable-cfl-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1614 Enable chroma predicted from luma intra prediction. Default is true.
1616 @item enable-filter-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1617 Enable filter intra predictor. Default is true.
1619 @item enable-intra-edge-filter (@emph{boolean}) (Requires libaom >= v2.0.0)
1620 Enable intra edge filter. Default is true.
1622 @item enable-smooth-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1623 Enable smooth intra prediction mode. Default is true.
1625 @item enable-paeth-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
1626 Enable paeth predictor in intra prediction. Default is true.
1628 @item enable-palette (@emph{boolean}) (Requires libaom >= v2.0.0)
1629 Enable palette prediction mode. Default is true.
1631 @item enable-flip-idtx (@emph{boolean}) (Requires libaom >= v2.0.0)
1632 Enable extended transform type, including FLIPADST_DCT, DCT_FLIPADST,
1633 FLIPADST_FLIPADST, ADST_FLIPADST, FLIPADST_ADST, IDTX, V_DCT, H_DCT,
1634 V_ADST, H_ADST, V_FLIPADST, H_FLIPADST. Default is true.
1636 @item enable-tx64 (@emph{boolean}) (Requires libaom >= v2.0.0)
1637 Enable 64-pt transform. Default is true.
1639 @item reduced-tx-type-set (@emph{boolean}) (Requires libaom >= v2.0.0)
1640 Use reduced set of transform types. Default is false.
1642 @item use-intra-dct-only (@emph{boolean}) (Requires libaom >= v2.0.0)
1643 Use DCT only for INTRA modes. Default is false.
1645 @item use-inter-dct-only (@emph{boolean}) (Requires libaom >= v2.0.0)
1646 Use DCT only for INTER modes. Default is false.
1648 @item use-intra-default-tx-only (@emph{boolean}) (Requires libaom >= v2.0.0)
1649 Use Default-transform only for INTRA modes. Default is false.
1651 @item enable-ref-frame-mvs (@emph{boolean}) (Requires libaom >= v2.0.0)
1652 Enable temporal mv prediction. Default is true.
1654 @item enable-reduced-reference-set (@emph{boolean}) (Requires libaom >= v2.0.0)
1655 Use reduced set of single and compound references. Default is false.
1657 @item enable-obmc (@emph{boolean}) (Requires libaom >= v2.0.0)
1658 Enable obmc. Default is true.
1660 @item enable-dual-filter (@emph{boolean}) (Requires libaom >= v2.0.0)
1661 Enable dual filter. Default is true.
1663 @item enable-diff-wtd-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1664 Enable difference-weighted compound. Default is true.
1666 @item enable-dist-wtd-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1667 Enable distance-weighted compound. Default is true.
1669 @item enable-onesided-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1670 Enable one sided compound. Default is true.
1672 @item enable-interinter-wedge (@emph{boolean}) (Requires libaom >= v2.0.0)
1673 Enable interinter wedge compound. Default is true.
1675 @item enable-interintra-wedge (@emph{boolean}) (Requires libaom >= v2.0.0)
1676 Enable interintra wedge compound. Default is true.
1678 @item enable-masked-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1679 Enable masked compound. Default is true.
1681 @item enable-interintra-comp (@emph{boolean}) (Requires libaom >= v2.0.0)
1682 Enable interintra compound. Default is true.
1684 @item enable-smooth-interintra (@emph{boolean}) (Requires libaom >= v2.0.0)
1685 Enable smooth interintra mode. Default is true.
1688 Set libaom options using a list of @var{key}=@var{value} pairs separated
1689 by ":". For a list of supported options, see @command{aomenc --help} under the
1690 section "AV1 Specific Options".
1692 For example to specify libaom encoding options with @option{-aom-params}:
1695 ffmpeg -i input -c:v libaom-av1 -b:v 500K -aom-params tune=psnr:enable-tpl-model=1 output.mp4
1702 SVT-AV1 encoder wrapper.
1704 Requires the presence of the SVT-AV1 headers and library during configuration.
1705 You need to explicitly configure the build with @code{--enable-libsvtav1}.
1711 Set the encoding profile.
1714 Set the operating point level.
1717 Set the operating point tier.
1720 Set the rate control mode to use.
1725 Constant quantizer: use fixed values of qindex (dependent on the frame type)
1726 throughout the stream. This mode is the default.
1729 Variable bitrate: use a target bitrate for the whole stream.
1732 Constrained variable bitrate: use a target bitrate for each GOP.
1736 Set the maximum quantizer to use when using a bitrate mode.
1739 Set the minimum quantizer to use when using a bitrate mode.
1742 Set the quantizer used in cqp rate control mode (0-63).
1745 Enable scene change detection.
1748 Set number of frames to look ahead (0-120).
1751 Set the quality-speed tradeoff, in the range 0 to 8. Higher values are
1752 faster but lower quality. Defaults to 8 (highest speed).
1755 Set log2 of the number of rows of tiles to use (0-6).
1758 Set log2 of the number of columns of tiles to use (0-4).
1764 Kvazaar H.265/HEVC encoder.
1766 Requires the presence of the libkvazaar headers and library during
1767 configuration. You need to explicitly configure the build with
1768 @option{--enable-libkvazaar}.
1775 Set target video bitrate in bit/s and enable rate control.
1777 @item kvazaar-params
1778 Set kvazaar parameters as a list of @var{name}=@var{value} pairs separated
1779 by commas (,). See kvazaar documentation for a list of options.
1783 @section libopenh264
1785 Cisco libopenh264 H.264/MPEG-4 AVC encoder wrapper.
1787 This encoder requires the presence of the libopenh264 headers and
1788 library during configuration. You need to explicitly configure the
1789 build with @code{--enable-libopenh264}. The library is detected using
1790 @command{pkg-config}.
1792 For more information about the library see
1793 @url{http://www.openh264.org}.
1797 The following FFmpeg global options affect the configurations of the
1798 libopenh264 encoder.
1802 Set the bitrate (as a number of bits per second).
1808 Set the max bitrate (as a number of bits per second).
1810 @item flags +global_header
1811 Set global header in the bitstream.
1814 Set the number of slices, used in parallelized encoding. Default value
1815 is 0. This is only used when @option{slice_mode} is set to
1819 Set slice mode. Can assume one of the following possible values:
1823 a fixed number of slices
1825 one slice per row of macroblocks
1827 automatic number of slices according to number of threads
1832 Default value is @samp{auto}.
1835 Enable loop filter, if set to 1 (automatically enabled). To disable
1839 Set profile restrictions. If set to the value of @samp{main} enable
1840 CABAC (set the @code{SEncParamExt.iEntropyCodingModeFlag} flag to 1).
1843 Set maximum NAL size in bytes.
1845 @item allow_skip_frames
1846 Allow skipping frames to hit the target bitrate if set to 1.
1851 libtheora Theora encoder wrapper.
1853 Requires the presence of the libtheora headers and library during
1854 configuration. You need to explicitly configure the build with
1855 @code{--enable-libtheora}.
1857 For more information about the libtheora project see
1858 @url{http://www.theora.org/}.
1862 The following global options are mapped to internal libtheora options
1863 which affect the quality and the bitrate of the encoded stream.
1867 Set the video bitrate in bit/s for CBR (Constant Bit Rate) mode. In
1868 case VBR (Variable Bit Rate) mode is enabled this option is ignored.
1871 Used to enable constant quality mode (VBR) encoding through the
1872 @option{qscale} flag, and to enable the @code{pass1} and @code{pass2}
1878 @item global_quality
1879 Set the global quality as an integer in lambda units.
1881 Only relevant when VBR mode is enabled with @code{flags +qscale}. The
1882 value is converted to QP units by dividing it by @code{FF_QP2LAMBDA},
1883 clipped in the [0 - 10] range, and then multiplied by 6.3 to get a
1884 value in the native libtheora range [0-63]. A higher value corresponds
1885 to a higher quality.
1888 Enable VBR mode when set to a non-negative value, and set constant
1889 quality value as a double floating point value in QP units.
1891 The value is clipped in the [0-10] range, and then multiplied by 6.3
1892 to get a value in the native libtheora range [0-63].
1894 This option is valid only using the @command{ffmpeg} command-line
1895 tool. For library interface users, use @option{global_quality}.
1898 @subsection Examples
1902 Set maximum constant quality (VBR) encoding with @command{ffmpeg}:
1904 ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
1908 Use @command{ffmpeg} to convert a CBR 1000 kbps Theora video stream:
1910 ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
1916 VP8/VP9 format supported through libvpx.
1918 Requires the presence of the libvpx headers and library during configuration.
1919 You need to explicitly configure the build with @code{--enable-libvpx}.
1923 The following options are supported by the libvpx wrapper. The
1924 @command{vpxenc}-equivalent options or values are listed in parentheses
1927 To reduce the duplication of documentation, only the private options
1928 and some others requiring special attention are documented here. For
1929 the documentation of the undocumented generic options, see
1930 @ref{codec-options,,the Codec Options chapter}.
1932 To get more documentation of the libvpx options, invoke the command
1933 @command{ffmpeg -h encoder=libvpx}, @command{ffmpeg -h encoder=libvpx-vp9} or
1934 @command{vpxenc --help}. Further information is available in the libvpx API
1939 @item b (@emph{target-bitrate})
1940 Set bitrate in bits/s. Note that FFmpeg's @option{b} option is
1941 expressed in bits/s, while @command{vpxenc}'s @option{target-bitrate} is in
1944 @item g (@emph{kf-max-dist})
1946 @item keyint_min (@emph{kf-min-dist})
1948 @item qmin (@emph{min-q})
1950 @item qmax (@emph{max-q})
1952 @item bufsize (@emph{buf-sz}, @emph{buf-optimal-sz})
1953 Set ratecontrol buffer size (in bits). Note @command{vpxenc}'s options are
1954 specified in milliseconds, the libvpx wrapper converts this value as follows:
1955 @code{buf-sz = bufsize * 1000 / bitrate},
1956 @code{buf-optimal-sz = bufsize * 1000 / bitrate * 5 / 6}.
1958 @item rc_init_occupancy (@emph{buf-initial-sz})
1959 Set number of bits which should be loaded into the rc buffer before decoding
1960 starts. Note @command{vpxenc}'s option is specified in milliseconds, the libvpx
1961 wrapper converts this value as follows:
1962 @code{rc_init_occupancy * 1000 / bitrate}.
1964 @item undershoot-pct
1965 Set datarate undershoot (min) percentage of the target bitrate.
1968 Set datarate overshoot (max) percentage of the target bitrate.
1970 @item skip_threshold (@emph{drop-frame})
1972 @item qcomp (@emph{bias-pct})
1974 @item maxrate (@emph{maxsection-pct})
1975 Set GOP max bitrate in bits/s. Note @command{vpxenc}'s option is specified as a
1976 percentage of the target bitrate, the libvpx wrapper converts this value as
1977 follows: @code{(maxrate * 100 / bitrate)}.
1979 @item minrate (@emph{minsection-pct})
1980 Set GOP min bitrate in bits/s. Note @command{vpxenc}'s option is specified as a
1981 percentage of the target bitrate, the libvpx wrapper converts this value as
1982 follows: @code{(minrate * 100 / bitrate)}.
1984 @item minrate, maxrate, b @emph{end-usage=cbr}
1985 @code{(minrate == maxrate == bitrate)}.
1987 @item crf (@emph{end-usage=cq}, @emph{cq-level})
1989 @item tune (@emph{tune})
1991 @item psnr (@emph{psnr})
1992 @item ssim (@emph{ssim})
1995 @item quality, deadline (@emph{deadline})
1998 Use best quality deadline. Poorly named and quite slow, this option should be
1999 avoided as it may give worse quality output than good.
2001 Use good quality deadline. This is a good trade-off between speed and quality
2002 when used with the @option{cpu-used} option.
2004 Use realtime quality deadline.
2007 @item speed, cpu-used (@emph{cpu-used})
2008 Set quality/speed ratio modifier. Higher values speed up the encode at the cost
2011 @item nr (@emph{noise-sensitivity})
2014 Set a change threshold on blocks below which they will be skipped by the
2017 @item slices (@emph{token-parts})
2018 Note that FFmpeg's @option{slices} option gives the total number of partitions,
2019 while @command{vpxenc}'s @option{token-parts} is given as
2020 @code{log2(partitions)}.
2022 @item max-intra-rate
2023 Set maximum I-frame bitrate as a percentage of the target bitrate. A value of 0
2026 @item force_key_frames
2027 @code{VPX_EFLAG_FORCE_KF}
2029 @item Alternate reference frame related
2032 Enable use of alternate reference frames (2-pass only).
2033 Values greater than 1 enable multi-layer alternate reference frames (VP9 only).
2034 @item arnr-maxframes
2035 Set altref noise reduction max frame count.
2037 Set altref noise reduction filter type: backward, forward, centered.
2039 Set altref noise reduction filter strength.
2040 @item rc-lookahead, lag-in-frames (@emph{lag-in-frames})
2041 Set number of frames to look ahead for frametype and ratecontrol.
2044 @item error-resilient
2045 Enable error resiliency features.
2047 @item sharpness @var{integer}
2048 Increase sharpness at the expense of lower PSNR.
2049 The valid range is [0, 7].
2052 Sets the temporal scalability configuration using a :-separated list of
2053 key=value pairs. For example, to specify temporal scalability parameters
2056 ffmpeg -i INPUT -c:v libvpx -ts-parameters ts_number_layers=3:\
2057 ts_target_bitrate=250,500,1000:ts_rate_decimator=4,2,1:\
2058 ts_periodicity=4:ts_layer_id=0,2,1,2:ts_layering_mode=3 OUTPUT
2060 Below is a brief explanation of each of the parameters, please
2061 refer to @code{struct vpx_codec_enc_cfg} in @code{vpx/vpx_encoder.h} for more
2064 @item ts_number_layers
2065 Number of temporal coding layers.
2066 @item ts_target_bitrate
2067 Target bitrate for each temporal layer (in kbps).
2068 (bitrate should be inclusive of the lower temporal layer).
2069 @item ts_rate_decimator
2070 Frame rate decimation factor for each temporal layer.
2071 @item ts_periodicity
2072 Length of the sequence defining frame temporal layer membership.
2074 Template defining the membership of frames to temporal layers.
2075 @item ts_layering_mode
2076 (optional) Selecting the temporal structure from a set of pre-defined temporal layering modes.
2077 Currently supports the following options.
2080 No temporal layering flags are provided internally,
2081 relies on flags being passed in using @code{metadata} field in @code{AVFrame}
2082 with following keys.
2085 Sets the flags passed into the encoder to indicate the referencing scheme for
2087 Refer to function @code{vpx_codec_encode} in @code{vpx/vpx_encoder.h} for more
2090 Explicitly sets the temporal id of the current frame to encode.
2093 Two temporal layers. 0-1...
2095 Three temporal layers. 0-2-1-2...; with single reference frame.
2097 Same as option "3", except there is a dependency between
2098 the two temporal layer 2 frames within the temporal period.
2102 @item VP9-specific options
2105 Enable lossless mode.
2107 Set number of tile columns to use. Note this is given as
2108 @code{log2(tile_columns)}. For example, 8 tile columns would be requested by
2109 setting the @option{tile-columns} option to 3.
2111 Set number of tile rows to use. Note this is given as @code{log2(tile_rows)}.
2112 For example, 4 tile rows would be requested by setting the @option{tile-rows}
2114 @item frame-parallel
2115 Enable frame parallel decodability features.
2117 Set adaptive quantization mode (0: off (default), 1: variance 2: complexity, 3:
2118 cyclic refresh, 4: equator360).
2119 @item colorspace @emph{color-space}
2120 Set input color space. The VP9 bitstream supports signaling the following
2123 @item @samp{rgb} @emph{sRGB}
2124 @item @samp{bt709} @emph{bt709}
2125 @item @samp{unspecified} @emph{unknown}
2126 @item @samp{bt470bg} @emph{bt601}
2127 @item @samp{smpte170m} @emph{smpte170}
2128 @item @samp{smpte240m} @emph{smpte240}
2129 @item @samp{bt2020_ncl} @emph{bt2020}
2131 @item row-mt @var{boolean}
2132 Enable row based multi-threading.
2134 Set content type: default (0), screen (1), film (2).
2135 @item corpus-complexity
2136 Corpus VBR mode is a variant of standard VBR where the complexity distribution
2137 midpoint is passed in rather than calculated for a specific clip or chunk.
2139 The valid range is [0, 10000]. 0 (default) uses standard VBR.
2140 @item enable-tpl @var{boolean}
2141 Enable temporal dependency model.
2142 @item ref-frame-config
2143 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.
2144 @*Use a :-separated list of key=value pairs.
2147 av_dict_set(&av_frame->metadata, "ref-frame-config", \
2148 "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");
2151 @item rfc_update_buffer_slot
2152 Indicates the buffer slot number to update
2153 @item rfc_update_last
2154 Indicates whether to update the LAST frame
2155 @item rfc_update_golden
2156 Indicates whether to update GOLDEN frame
2157 @item rfc_update_alt_ref
2158 Indicates whether to update ALT_REF frame
2159 @item rfc_lst_fb_idx
2160 LAST frame buffer index
2161 @item rfc_gld_fb_idx
2162 GOLDEN frame buffer index
2163 @item rfc_alt_fb_idx
2164 ALT_REF frame buffer index
2165 @item rfc_reference_last
2166 Indicates whether to reference LAST frame
2167 @item rfc_reference_golden
2168 Indicates whether to reference GOLDEN frame
2169 @item rfc_reference_alt_ref
2170 Indicates whether to reference ALT_REF frame
2171 @item rfc_reference_duration
2172 Indicates frame duration
2178 For more information about libvpx see:
2179 @url{http://www.webmproject.org/}
2183 libwebp WebP Image encoder wrapper
2185 libwebp is Google's official encoder for WebP images. It can encode in either
2186 lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
2187 frame. Lossless images are a separate codec developed by Google.
2189 @subsection Pixel Format
2191 Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
2192 to limitations of the format and libwebp. Alpha is supported for either mode.
2193 Because of API limitations, if RGB is passed in when encoding lossy or YUV is
2194 passed in for encoding lossless, the pixel format will automatically be
2195 converted using functions from libwebp. This is not ideal and is done only for
2202 @item -lossless @var{boolean}
2203 Enables/Disables use of lossless mode. Default is 0.
2205 @item -compression_level @var{integer}
2206 For lossy, this is a quality/speed tradeoff. Higher values give better quality
2207 for a given size at the cost of increased encoding time. For lossless, this is
2208 a size/speed tradeoff. Higher values give smaller size at the cost of increased
2209 encoding time. More specifically, it controls the number of extra algorithms
2210 and compression tools used, and varies the combination of these tools. This
2211 maps to the @var{method} option in libwebp. The valid range is 0 to 6.
2214 @item -qscale @var{float}
2215 For lossy encoding, this controls image quality, 0 to 100. For lossless
2216 encoding, this controls the effort and time spent at compressing more. The
2217 default value is 75. Note that for usage via libavcodec, this option is called
2218 @var{global_quality} and must be multiplied by @var{FF_QP2LAMBDA}.
2220 @item -preset @var{type}
2221 Configuration preset. This does some automatic settings based on the general
2225 Do not use a preset.
2227 Use the encoder default.
2229 Digital picture, like portrait, inner shot
2231 Outdoor photograph, with natural lighting
2233 Hand or line drawing, with high-contrast details
2235 Small-sized colorful images
2242 @section libx264, libx264rgb
2244 x264 H.264/MPEG-4 AVC encoder wrapper.
2246 This encoder requires the presence of the libx264 headers and library
2247 during configuration. You need to explicitly configure the build with
2248 @code{--enable-libx264}.
2250 libx264 supports an impressive number of features, including 8x8 and
2251 4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
2252 entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
2253 for detail retention (adaptive quantization, psy-RD, psy-trellis).
2255 Many libx264 encoder options are mapped to FFmpeg global codec
2256 options, while unique encoder options are provided through private
2257 options. Additionally the @option{x264opts} and @option{x264-params}
2258 private options allows one to pass a list of key=value tuples as accepted
2259 by the libx264 @code{x264_param_parse} function.
2261 The x264 project website is at
2262 @url{http://www.videolan.org/developers/x264.html}.
2264 The libx264rgb encoder is the same as libx264, except it accepts packed RGB
2265 pixel formats as input instead of YUV.
2267 @subsection Supported Pixel Formats
2269 x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at
2270 x264's configure time. FFmpeg only supports one bit depth in one particular
2271 build. In other words, it is not possible to build one FFmpeg with multiple
2272 versions of x264 with different bit depths.
2276 The following options are supported by the libx264 wrapper. The
2277 @command{x264}-equivalent options or values are listed in parentheses
2280 To reduce the duplication of documentation, only the private options
2281 and some others requiring special attention are documented here. For
2282 the documentation of the undocumented generic options, see
2283 @ref{codec-options,,the Codec Options chapter}.
2285 To get a more accurate and extensive documentation of the libx264
2286 options, invoke the command @command{x264 --fullhelp} or consult
2287 the libx264 documentation.
2290 @item b (@emph{bitrate})
2291 Set bitrate in bits/s. Note that FFmpeg's @option{b} option is
2292 expressed in bits/s, while @command{x264}'s @option{bitrate} is in
2295 @item bf (@emph{bframes})
2297 @item g (@emph{keyint})
2299 @item qmin (@emph{qpmin})
2300 Minimum quantizer scale.
2302 @item qmax (@emph{qpmax})
2303 Maximum quantizer scale.
2305 @item qdiff (@emph{qpstep})
2306 Maximum difference between quantizer scales.
2308 @item qblur (@emph{qblur})
2309 Quantizer curve blur
2311 @item qcomp (@emph{qcomp})
2312 Quantizer curve compression factor
2314 @item refs (@emph{ref})
2315 Number of reference frames each P-frame can use. The range is from @var{0-16}.
2317 @item sc_threshold (@emph{scenecut})
2318 Sets the threshold for the scene change detection.
2320 @item trellis (@emph{trellis})
2321 Performs Trellis quantization to increase efficiency. Enabled by default.
2323 @item nr (@emph{nr})
2325 @item me_range (@emph{merange})
2326 Maximum range of the motion search in pixels.
2328 @item me_method (@emph{me})
2329 Set motion estimation method. Possible values in the decreasing order
2333 @item dia (@emph{dia})
2334 @item epzs (@emph{dia})
2335 Diamond search with radius 1 (fastest). @samp{epzs} is an alias for
2337 @item hex (@emph{hex})
2338 Hexagonal search with radius 2.
2339 @item umh (@emph{umh})
2340 Uneven multi-hexagon search.
2341 @item esa (@emph{esa})
2343 @item tesa (@emph{tesa})
2344 Hadamard exhaustive search (slowest).
2348 Normally, when forcing a I-frame type, the encoder can select any type
2349 of I-frame. This option forces it to choose an IDR-frame.
2351 @item subq (@emph{subme})
2352 Sub-pixel motion estimation method.
2354 @item b_strategy (@emph{b-adapt})
2355 Adaptive B-frame placement decision algorithm. Use only on first-pass.
2357 @item keyint_min (@emph{min-keyint})
2361 Set entropy encoder. Possible values:
2368 Enable CAVLC and disable CABAC. It generates the same effect as
2369 @command{x264}'s @option{--no-cabac} option.
2373 Set full pixel motion estimation comparison algorithm. Possible values:
2377 Enable chroma in motion estimation.
2380 Ignore chroma in motion estimation. It generates the same effect as
2381 @command{x264}'s @option{--no-chroma-me} option.
2384 @item threads (@emph{threads})
2385 Number of encoding threads.
2388 Set multithreading technique. Possible values:
2392 Slice-based multithreading. It generates the same effect as
2393 @command{x264}'s @option{--sliced-threads} option.
2395 Frame-based multithreading.
2399 Set encoding flags. It can be used to disable closed GOP and enable
2400 open GOP by setting it to @code{-cgop}. The result is similar to
2401 the behavior of @command{x264}'s @option{--open-gop} option.
2403 @item rc_init_occupancy (@emph{vbv-init})
2405 @item preset (@emph{preset})
2406 Set the encoding preset.
2408 @item tune (@emph{tune})
2409 Set tuning of the encoding params.
2411 @item profile (@emph{profile})
2412 Set profile restrictions.
2415 Enable fast settings when encoding first pass, when set to 1. When set
2416 to 0, it has the same effect of @command{x264}'s
2417 @option{--slow-firstpass} option.
2419 @item crf (@emph{crf})
2420 Set the quality for constant quality mode.
2422 @item crf_max (@emph{crf-max})
2423 In CRF mode, prevents VBV from lowering quality beyond this point.
2425 @item qp (@emph{qp})
2426 Set constant quantization rate control method parameter.
2428 @item aq-mode (@emph{aq-mode})
2429 Set AQ method. Possible values:
2432 @item none (@emph{0})
2435 @item variance (@emph{1})
2436 Variance AQ (complexity mask).
2438 @item autovariance (@emph{2})
2439 Auto-variance AQ (experimental).
2442 @item aq-strength (@emph{aq-strength})
2443 Set AQ strength, reduce blocking and blurring in flat and textured areas.
2446 Use psychovisual optimizations when set to 1. When set to 0, it has the
2447 same effect as @command{x264}'s @option{--no-psy} option.
2449 @item psy-rd (@emph{psy-rd})
2450 Set strength of psychovisual optimization, in
2451 @var{psy-rd}:@var{psy-trellis} format.
2453 @item rc-lookahead (@emph{rc-lookahead})
2454 Set number of frames to look ahead for frametype and ratecontrol.
2457 Enable weighted prediction for B-frames when set to 1. When set to 0,
2458 it has the same effect as @command{x264}'s @option{--no-weightb} option.
2460 @item weightp (@emph{weightp})
2461 Set weighted prediction method for P-frames. Possible values:
2464 @item none (@emph{0})
2466 @item simple (@emph{1})
2467 Enable only weighted refs
2468 @item smart (@emph{2})
2469 Enable both weighted refs and duplicates
2472 @item ssim (@emph{ssim})
2473 Enable calculation and printing SSIM stats after the encoding.
2475 @item intra-refresh (@emph{intra-refresh})
2476 Enable the use of Periodic Intra Refresh instead of IDR frames when set
2479 @item avcintra-class (@emph{class})
2480 Configure the encoder to generate AVC-Intra.
2481 Valid values are 50,100 and 200
2483 @item bluray-compat (@emph{bluray-compat})
2484 Configure the encoder to be compatible with the bluray standard.
2485 It is a shorthand for setting "bluray-compat=1 force-cfr=1".
2487 @item b-bias (@emph{b-bias})
2488 Set the influence on how often B-frames are used.
2490 @item b-pyramid (@emph{b-pyramid})
2491 Set method for keeping of some B-frames as references. Possible values:
2494 @item none (@emph{none})
2496 @item strict (@emph{strict})
2497 Strictly hierarchical pyramid.
2498 @item normal (@emph{normal})
2499 Non-strict (not Blu-ray compatible).
2503 Enable the use of one reference per partition, as opposed to one
2504 reference per macroblock when set to 1. When set to 0, it has the
2505 same effect as @command{x264}'s @option{--no-mixed-refs} option.
2508 Enable adaptive spatial transform (high profile 8x8 transform)
2509 when set to 1. When set to 0, it has the same effect as
2510 @command{x264}'s @option{--no-8x8dct} option.
2513 Enable early SKIP detection on P-frames when set to 1. When set
2514 to 0, it has the same effect as @command{x264}'s
2515 @option{--no-fast-pskip} option.
2517 @item aud (@emph{aud})
2518 Enable use of access unit delimiters when set to 1.
2521 Enable use macroblock tree ratecontrol when set to 1. When set
2522 to 0, it has the same effect as @command{x264}'s
2523 @option{--no-mbtree} option.
2525 @item deblock (@emph{deblock})
2526 Set loop filter parameters, in @var{alpha}:@var{beta} form.
2528 @item cplxblur (@emph{cplxblur})
2529 Set fluctuations reduction in QP (before curve compression).
2531 @item partitions (@emph{partitions})
2532 Set partitions to consider as a comma-separated list of. Possible
2537 8x8 P-frame partition.
2539 4x4 P-frame partition.
2541 4x4 B-frame partition.
2543 8x8 I-frame partition.
2545 4x4 I-frame partition.
2546 (Enabling @samp{p4x4} requires @samp{p8x8} to be enabled. Enabling
2547 @samp{i8x8} requires adaptive spatial transform (@option{8x8dct}
2548 option) to be enabled.)
2549 @item none (@emph{none})
2550 Do not consider any partitions.
2551 @item all (@emph{all})
2552 Consider every partition.
2555 @item direct-pred (@emph{direct})
2556 Set direct MV prediction mode. Possible values:
2559 @item none (@emph{none})
2560 Disable MV prediction.
2561 @item spatial (@emph{spatial})
2562 Enable spatial predicting.
2563 @item temporal (@emph{temporal})
2564 Enable temporal predicting.
2565 @item auto (@emph{auto})
2566 Automatically decided.
2569 @item slice-max-size (@emph{slice-max-size})
2570 Set the limit of the size of each slice in bytes. If not specified
2571 but RTP payload size (@option{ps}) is specified, that is used.
2573 @item stats (@emph{stats})
2574 Set the file name for multi-pass stats.
2576 @item nal-hrd (@emph{nal-hrd})
2577 Set signal HRD information (requires @option{vbv-bufsize} to be set).
2581 @item none (@emph{none})
2582 Disable HRD information signaling.
2583 @item vbr (@emph{vbr})
2585 @item cbr (@emph{cbr})
2586 Constant bit rate (not allowed in MP4 container).
2589 @item x264opts (N.A.)
2590 Set any x264 option, see @command{x264 --fullhelp} for a list.
2592 Argument is a list of @var{key}=@var{value} couples separated by
2593 ":". In @var{filter} and @var{psy-rd} options that use ":" as a separator
2594 themselves, use "," instead. They accept it as well since long ago but this
2595 is kept undocumented for some reason.
2597 For example to specify libx264 encoding options with @command{ffmpeg}:
2599 ffmpeg -i foo.mpg -c:v libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
2602 @item a53cc @var{boolean}
2603 Import closed captions (which must be ATSC compatible format) into output.
2604 Only the mpeg2 and h264 decoders provide these. Default is 1 (on).
2606 @item x264-params (N.A.)
2607 Override the x264 configuration using a :-separated list of key=value
2610 This option is functionally the same as the @option{x264opts}, but is
2611 duplicated for compatibility with the Libav fork.
2613 For example to specify libx264 encoding options with @command{ffmpeg}:
2615 ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
2616 cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
2617 no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
2621 Encoding ffpresets for common usages are provided so they can be used with the
2622 general presets system (e.g. passing the @option{pre} option).
2626 x265 H.265/HEVC encoder wrapper.
2628 This encoder requires the presence of the libx265 headers and library
2629 during configuration. You need to explicitly configure the build with
2630 @option{--enable-libx265}.
2636 Sets target video bitrate.
2647 Number of reference frames each P-frame can use. The range is from @var{1-16}.
2650 Set the x265 preset.
2653 Set the x265 tune parameter.
2656 Set profile restrictions.
2659 Set the quality for constant quality mode.
2662 Set constant quantization rate control method parameter.
2665 Minimum quantizer scale.
2668 Maximum quantizer scale.
2671 Maximum difference between quantizer scales.
2674 Quantizer curve blur
2677 Quantizer curve compression factor
2684 Normally, when forcing a I-frame type, the encoder can select any type
2685 of I-frame. This option forces it to choose an IDR-frame.
2688 Set x265 options using a list of @var{key}=@var{value} couples separated
2689 by ":". See @command{x265 --help} for a list of options.
2691 For example to specify libx265 encoding options with @option{-x265-params}:
2694 ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
2700 xavs2 AVS2-P2/IEEE1857.4 encoder wrapper.
2702 This encoder requires the presence of the libxavs2 headers and library
2703 during configuration. You need to explicitly configure the build with
2704 @option{--enable-libxavs2}.
2706 The following standard libavcodec options are used:
2709 @option{b} / @option{bit_rate}
2711 @option{g} / @option{gop_size}
2713 @option{bf} / @option{max_b_frames}
2716 The encoder also has its own specific options:
2720 @item lcu_row_threads
2721 Set the number of parallel threads for rows from 1 to 8 (default 5).
2724 Set the xavs2 quantization parameter from 1 to 63 (default 34). This is
2725 used to set the initial qp for the first frame.
2728 Set the xavs2 quantization parameter from 1 to 63 (default 34). This is
2729 used to set the qp value under constant-QP mode.
2732 Set the max qp for rate control from 1 to 63 (default 55).
2735 Set the min qp for rate control from 1 to 63 (default 20).
2738 Set the Speed level from 0 to 9 (default 0). Higher is better but slower.
2741 Set the log level from -1 to 3 (default 0). -1: none, 0: error,
2742 1: warning, 2: info, 3: debug.
2745 Set xavs2 options using a list of @var{key}=@var{value} couples separated
2748 For example to specify libxavs2 encoding options with @option{-xavs2-params}:
2751 ffmpeg -i input -c:v libxavs2 -xavs2-params RdoqLevel=0 output.avs2
2757 Xvid MPEG-4 Part 2 encoder wrapper.
2759 This encoder requires the presence of the libxvidcore headers and library
2760 during configuration. You need to explicitly configure the build with
2761 @code{--enable-libxvid --enable-gpl}.
2763 The native @code{mpeg4} encoder supports the MPEG-4 Part 2 format, so
2764 users can encode to this format without this library.
2768 The following options are supported by the libxvid wrapper. Some of
2769 the following options are listed but are not documented, and
2770 correspond to shared codec options. See @ref{codec-options,,the Codec
2771 Options chapter} for their documentation. The other shared options
2772 which are not listed have no effect for the libxvid encoder.
2794 Set specific encoding flags. Possible values:
2799 Use four motion vector by macroblock.
2802 Enable high quality AC prediction.
2805 Only encode grayscale.
2808 Enable the use of global motion compensation (GMC).
2811 Enable quarter-pixel motion compensation.
2817 Place global headers in extradata instead of every keyframe.
2824 Set motion estimation method. Possible values in decreasing order of
2825 speed and increasing order of quality:
2829 Use no motion estimation (default).
2834 Enable advanced diamond zonal search for 16x16 blocks and half-pixel
2835 refinement for 16x16 blocks. @samp{x1} and @samp{log} are aliases for
2839 Enable all of the things described above, plus advanced diamond zonal
2840 search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
2841 estimation on chroma planes.
2844 Enable all of the things described above, plus extended 16x16 and 8x8
2849 Set macroblock decision algorithm. Possible values in the increasing
2854 Use macroblock comparing function algorithm (default).
2857 Enable rate distortion-based half pixel and quarter pixel refinement for
2861 Enable all of the things described above, plus rate distortion-based
2862 half pixel and quarter pixel refinement for 8x8 blocks, and rate
2863 distortion-based search using square pattern.
2867 Enable lumi masking adaptive quantization when set to 1. Default is 0
2871 Enable variance adaptive quantization when set to 1. Default is 0
2874 When combined with @option{lumi_aq}, the resulting quality will not
2875 be better than any of the two specified individually. In other
2876 words, the resulting quality will be the worse one of the two
2880 Set structural similarity (SSIM) displaying method. Possible values:
2884 Disable displaying of SSIM information.
2887 Output average SSIM at the end of encoding to stdout. The format of
2888 showing the average SSIM is:
2894 For users who are not familiar with C, %f means a float number, or
2895 a decimal (e.g. 0.939232).
2898 Output both per-frame SSIM data during encoding and average SSIM at
2899 the end of encoding to stdout. The format of per-frame information
2903 SSIM: avg: %1.3f min: %1.3f max: %1.3f
2906 For users who are not familiar with C, %1.3f means a float number
2907 rounded to 3 digits after the dot (e.g. 0.932).
2912 Set SSIM accuracy. Valid options are integers within the range of
2913 0-4, while 0 gives the most accurate result and 4 computes the
2918 @section MediaFoundation
2920 This provides wrappers to encoders (both audio and video) in the
2921 MediaFoundation framework. It can access both SW and HW encoders.
2922 Video encoders can take input in either of nv12 or yuv420p form
2923 (some encoders support both, some support only either - in practice,
2924 nv12 is the safer choice, especially among HW encoders).
2928 MPEG-2 video encoder.
2934 Select the mpeg2 profile to encode:
2948 Select the mpeg2 level to encode:
2957 @item seq_disp_ext @var{integer}
2958 Specifies if the encoder should write a sequence_display_extension to the
2963 Decide automatically to write it or not (this is the default) by checking if
2964 the data to be written is different from the default or unspecified values.
2972 @item video_format @var{integer}
2973 Specifies the video_format written into the sequence display extension
2974 indicating the source of the video pictures. The default is @samp{unspecified},
2975 can be @samp{component}, @samp{pal}, @samp{ntsc}, @samp{secam} or @samp{mac}.
2976 For maximum compatibility, use @samp{component}.
2977 @item a53cc @var{boolean}
2978 Import closed captions (which must be ATSC compatible format) into output.
2986 @subsection Private options
2989 @item dpi @var{integer}
2990 Set physical density of pixels, in dots per inch, unset by default
2991 @item dpm @var{integer}
2992 Set physical density of pixels, in dots per meter, unset by default
2997 Apple ProRes encoder.
2999 FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
3000 The used encoder can be chosen with the @code{-vcodec} option.
3002 @subsection Private Options for prores-ks
3005 @item profile @var{integer}
3006 Select the ProRes profile to encode
3016 @item quant_mat @var{integer}
3017 Select quantization matrix.
3026 If set to @var{auto}, the matrix matching the profile will be picked.
3027 If not set, the matrix providing the highest quality, @var{default}, will be
3030 @item bits_per_mb @var{integer}
3031 How many bits to allot for coding one macroblock. Different profiles use
3032 between 200 and 2400 bits per macroblock, the maximum is 8000.
3034 @item mbs_per_slice @var{integer}
3035 Number of macroblocks in each slice (1-8); the default value (8)
3036 should be good in almost all situations.
3038 @item vendor @var{string}
3039 Override the 4-byte vendor ID.
3040 A custom vendor ID like @var{apl0} would claim the stream was produced by
3043 @item alpha_bits @var{integer}
3044 Specify number of bits for alpha component.
3045 Possible values are @var{0}, @var{8} and @var{16}.
3046 Use @var{0} to disable alpha plane coding.
3050 @subsection Speed considerations
3052 In the default mode of operation the encoder has to honor frame constraints
3053 (i.e. not produce frames with size bigger than requested) while still making
3054 output picture as good as possible.
3055 A frame containing a lot of small details is harder to compress and the encoder
3056 would spend more time searching for appropriate quantizers for each slice.
3058 Setting a higher @option{bits_per_mb} limit will improve the speed.
3060 For the fastest encoding speed set the @option{qscale} parameter (4 is the
3061 recommended value) and do not set a size constraint.
3063 @section QSV encoders
3065 The family of Intel QuickSync Video encoders (MPEG-2, H.264, HEVC, JPEG/MJPEG and VP9)
3067 The ratecontrol method is selected as follows:
3071 When @option{global_quality} is specified, a quality-based mode is used.
3072 Specifically this means either
3075 @var{CQP} - constant quantizer scale, when the @option{qscale} codec flag is
3076 also set (the @option{-qscale} ffmpeg option).
3079 @var{LA_ICQ} - intelligent constant quality with lookahead, when the
3080 @option{look_ahead} option is also set.
3083 @var{ICQ} -- intelligent constant quality otherwise.
3087 Otherwise, a bitrate-based mode is used. For all of those, you should specify at
3088 least the desired average bitrate with the @option{b} option.
3091 @var{LA} - VBR with lookahead, when the @option{look_ahead} option is specified.
3094 @var{VCM} - video conferencing mode, when the @option{vcm} option is set.
3097 @var{CBR} - constant bitrate, when @option{maxrate} is specified and equal to
3098 the average bitrate.
3101 @var{VBR} - variable bitrate, when @option{maxrate} is specified, but is higher
3102 than the average bitrate.
3105 @var{AVBR} - average VBR mode, when @option{maxrate} is not specified. This mode
3106 is further configured by the @option{avbr_accuracy} and
3107 @option{avbr_convergence} options.
3111 Note that depending on your system, a different mode than the one you specified
3112 may be selected by the encoder. Set the verbosity level to @var{verbose} or
3113 higher to see the actual settings used by the QSV runtime.
3115 Additional libavcodec global options are mapped to MSDK options as follows:
3119 @option{g/gop_size} -> @option{GopPicSize}
3122 @option{bf/max_b_frames}+1 -> @option{GopRefDist}
3125 @option{rc_init_occupancy/rc_initial_buffer_occupancy} ->
3126 @option{InitialDelayInKB}
3129 @option{slices} -> @option{NumSlice}
3132 @option{refs} -> @option{NumRefFrame}
3135 @option{b_strategy/b_frame_strategy} -> @option{BRefType}
3138 @option{cgop/CLOSED_GOP} codec flag -> @option{GopOptFlag}
3141 For the @var{CQP} mode, the @option{i_qfactor/i_qoffset} and
3142 @option{b_qfactor/b_qoffset} set the difference between @var{QPP} and @var{QPI},
3143 and @var{QPP} and @var{QPB} respectively.
3146 Setting the @option{coder} option to the value @var{vlc} will make the H.264
3147 encoder use CAVLC instead of CABAC.
3156 @item iterative_dia_size
3157 dia size for the iterative motion estimation
3160 @section VAAPI encoders
3162 Wrappers for hardware encoders accessible via VAAPI.
3164 These encoders only accept input in VAAPI hardware surfaces. If you have input
3165 in software frames, use the @option{hwupload} filter to upload them to the GPU.
3167 The following standard libavcodec options are used:
3170 @option{g} / @option{gop_size}
3172 @option{bf} / @option{max_b_frames}
3176 If not set, this will be determined automatically from the format of the input
3177 frames and the profiles supported by the driver.
3181 @option{b} / @option{bit_rate}
3183 @option{maxrate} / @option{rc_max_rate}
3185 @option{bufsize} / @option{rc_buffer_size}
3187 @option{rc_init_occupancy} / @option{rc_initial_buffer_occupancy}
3189 @option{compression_level}
3191 Speed / quality tradeoff: higher values are faster / worse quality.
3193 @option{q} / @option{global_quality}
3195 Size / quality tradeoff: higher values are smaller / worse quality.
3201 @option{i_qfactor} / @option{i_quant_factor}
3203 @option{i_qoffset} / @option{i_quant_offset}
3205 @option{b_qfactor} / @option{b_quant_factor}
3207 @option{b_qoffset} / @option{b_quant_offset}
3212 All encoders support the following options:
3215 Some drivers/platforms offer a second encoder for some codecs intended to use
3216 less power than the default encoder; setting this option will attempt to use
3217 that encoder. Note that it may support a reduced feature set, so some other
3218 options may not be available in this mode.
3221 Set the number of normal intra frames between full-refresh (IDR) frames in
3222 open-GOP mode. The intra frames are still IRAPs, but will not include global
3223 headers and may have non-decodable leading pictures.
3226 Set the B-frame reference depth. When set to one (the default), all B-frames
3227 will refer only to P- or I-frames. When set to greater values multiple layers
3228 of B-frames will be present, frames in each layer only referring to frames in
3232 Set the rate control mode to use. A given driver may only support a subset of
3238 Choose the mode automatically based on driver support and the other options.
3239 This is the default.
3247 Intelligent constant-quality.
3249 Quality-defined variable-bitrate.
3251 Average variable bitrate.
3256 Each encoder also has its own specific options:
3260 @option{profile} sets the value of @emph{profile_idc} and the @emph{constraint_set*_flag}s.
3261 @option{level} sets the value of @emph{level_idc}.
3265 Set entropy encoder (default is @emph{cabac}). Possible values:
3278 Include access unit delimiters in the stream (not included by default).
3281 Set SEI message types to include.
3282 Some combination of the following values:
3285 Include a @emph{user_data_unregistered} message containing information about
3288 Include picture timing parameters (@emph{buffering_period} and
3289 @emph{pic_timing} messages).
3290 @item recovery_point
3291 Include recovery points where appropriate (@emph{recovery_point} messages).
3297 @option{profile} and @option{level} set the values of
3298 @emph{general_profile_idc} and @emph{general_level_idc} respectively.
3302 Include access unit delimiters in the stream (not included by default).
3305 Set @emph{general_tier_flag}. This may affect the level chosen for the stream
3306 if it is not explicitly specified.
3309 Set SEI message types to include.
3310 Some combination of the following values:
3313 Include HDR metadata if the input frames have it
3314 (@emph{mastering_display_colour_volume} and @emph{content_light_level}
3319 Set the number of tiles to encode the input video with, as columns x rows.
3320 Larger numbers allow greater parallelism in both encoding and decoding, but
3321 may decrease coding efficiency.
3326 Only baseline DCT encoding is supported. The encoder always uses the standard
3327 quantisation and huffman tables - @option{global_quality} scales the standard
3328 quantisation table (range 1-100).
3330 For YUV, 4:2:0, 4:2:2 and 4:4:4 subsampling modes are supported. RGB is also
3331 supported, and will create an RGB JPEG.
3335 Include JFIF header in each frame (not included by default).
3337 Include standard huffman tables (on by default). Turning this off will save
3338 a few hundred bytes in each output frame, but may lose compatibility with some
3339 JPEG decoders which don't fully handle MJPEG.
3343 @option{profile} and @option{level} set the value of @emph{profile_and_level_indication}.
3346 B-frames are not supported.
3348 @option{global_quality} sets the @emph{q_idx} used for non-key frames (range 0-127).
3351 @item loop_filter_level
3352 @item loop_filter_sharpness
3353 Manually set the loop filter parameters.
3357 @option{global_quality} sets the @emph{q_idx} used for P-frames (range 0-255).
3360 @item loop_filter_level
3361 @item loop_filter_sharpness
3362 Manually set the loop filter parameters.
3365 B-frames are supported, but the output stream is always in encode order rather than display
3366 order. If B-frames are enabled, it may be necessary to use the @option{vp9_raw_reorder}
3367 bitstream filter to modify the output stream to display frames in the correct order.
3369 Only normal frames are produced - the @option{vp9_superframe} bitstream filter may be
3370 required to produce a stream usable with all decoders.
3376 SMPTE VC-2 (previously BBC Dirac Pro). This codec was primarily aimed at
3377 professional broadcasting but since it supports yuv420, yuv422 and yuv444 at
3378 8 (limited range or full range), 10 or 12 bits, this makes it suitable for
3379 other tasks which require low overhead and low compression (like screen
3387 Sets target video bitrate. Usually that's around 1:6 of the uncompressed
3388 video bitrate (e.g. for 1920x1080 50fps yuv422p10 that's around 400Mbps). Higher
3389 values (close to the uncompressed bitrate) turn on lossless compression mode.
3392 Enables field coding when set (e.g. to tt - top field first) for interlaced
3393 inputs. Should increase compression with interlaced content as it splits the
3394 fields and encodes each separately.
3397 Sets the total amount of wavelet transforms to apply, between 1 and 5 (default).
3398 Lower values reduce compression and quality. Less capable decoders may not be
3399 able to handle values of @option{wavelet_depth} over 3.
3402 Sets the transform type. Currently only @var{5_3} (LeGall) and @var{9_7}
3404 are implemented, with 9_7 being the one with better compression and thus
3409 Sets the slice size for each slice. Larger values result in better compression.
3410 For compatibility with other more limited decoders use @option{slice_width} of
3411 32 and @option{slice_height} of 8.
3414 Sets the undershoot tolerance of the rate control system in percent. This is
3415 to prevent an expensive search from being run.
3418 Sets the quantization matrix preset to use by default or when @option{wavelet_depth}
3423 Uses the default quantization matrix from the specifications, extended with
3424 values for the fifth level. This provides a good balance between keeping detail
3425 and omitting artifacts.
3429 Use a completely zeroed out quantization matrix. This increases PSNR but might
3430 reduce perception. Use in bogus benchmarks.
3434 Reduces detail but attempts to preserve color at extremely low bitrates.
3439 @c man end VIDEO ENCODERS
3441 @chapter Subtitles Encoders
3442 @c man begin SUBTITLES ENCODERS
3446 This codec encodes the bitmap subtitle format that is used in DVDs.
3447 Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
3448 and they can also be used in Matroska files.
3454 Specify the global palette used by the bitmaps.
3456 The format for this option is a string containing 16 24-bits hexadecimal
3457 numbers (without 0x prefix) separated by commas, for example @code{0d00ee,
3458 ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
3459 7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b}.
3462 When set to 1, enable a work-around that makes the number of pixel rows
3463 even in all subtitles. This fixes a problem with some players that
3464 cut off the bottom row if the number is odd. The work-around just adds
3465 a fully transparent row if needed. The overhead is low, typically
3466 one byte per subtitle on average.
3468 By default, this work-around is disabled.
3471 @c man end SUBTITLES ENCODERS