mirror of https://git.ffmpeg.org/ffmpeg.git
3297 lines
93 KiB
Plaintext
3297 lines
93 KiB
Plaintext
@chapter Encoders
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@c man begin ENCODERS
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Encoders are configured elements in FFmpeg which allow the encoding of
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multimedia streams.
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When you configure your FFmpeg build, all the supported native encoders
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are enabled by default. Encoders requiring an external library must be enabled
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manually via the corresponding @code{--enable-lib} option. You can list all
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available encoders using the configure option @code{--list-encoders}.
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You can disable all the encoders with the configure option
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@code{--disable-encoders} and selectively enable / disable single encoders
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with the options @code{--enable-encoder=@var{ENCODER}} /
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@code{--disable-encoder=@var{ENCODER}}.
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The option @code{-encoders} of the ff* tools will display the list of
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enabled encoders.
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@c man end ENCODERS
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@chapter Audio Encoders
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@c man begin AUDIO ENCODERS
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A description of some of the currently available audio encoders
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follows.
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@anchor{aacenc}
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@section aac
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Advanced Audio Coding (AAC) encoder.
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This encoder is the default AAC encoder, natively implemented into FFmpeg.
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@subsection Options
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@table @option
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@item b
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Set bit rate in bits/s. Setting this automatically activates constant bit rate
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(CBR) mode. If this option is unspecified it is set to 128kbps.
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@item q
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Set quality for variable bit rate (VBR) mode. This option is valid only using
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the @command{ffmpeg} command-line tool. For library interface users, use
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@option{global_quality}.
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@item cutoff
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Set cutoff frequency. If unspecified will allow the encoder to dynamically
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adjust the cutoff to improve clarity on low bitrates.
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@item aac_coder
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Set AAC encoder coding method. Possible values:
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@table @samp
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@item twoloop
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Two loop searching (TLS) method.
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This method first sets quantizers depending on band thresholds and then tries
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to find an optimal combination by adding or subtracting a specific value from
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all quantizers and adjusting some individual quantizer a little. Will tune
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itself based on whether @option{aac_is}, @option{aac_ms} and @option{aac_pns}
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are enabled.
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@item anmr
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Average noise to mask ratio (ANMR) trellis-based solution.
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This is an experimental coder which currently produces a lower quality, is more
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unstable and is slower than the default twoloop coder but has potential.
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Currently has no support for the @option{aac_is} or @option{aac_pns} options.
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Not currently recommended.
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@item fast
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Constant quantizer method.
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Uses a cheaper version of twoloop algorithm that doesn't try to do as many
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clever adjustments. Worse with low bitrates (less than 64kbps), but is better
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and much faster at higher bitrates.
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This is the default choice for a coder
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@end table
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@item aac_ms
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Sets mid/side coding mode. The default value of "auto" will automatically use
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M/S with bands which will benefit from such coding. Can be forced for all bands
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using the value "enable", which is mainly useful for debugging or disabled using
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"disable".
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@item aac_is
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Sets intensity stereo coding tool usage. By default, it's enabled and will
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automatically toggle IS for similar pairs of stereo bands if it's beneficial.
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Can be disabled for debugging by setting the value to "disable".
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@item aac_pns
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Uses perceptual noise substitution to replace low entropy high frequency bands
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with imperceptible white noise during the decoding process. By default, it's
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enabled, but can be disabled for debugging purposes by using "disable".
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@item aac_tns
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Enables the use of a multitap FIR filter which spans through the high frequency
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bands to hide quantization noise during the encoding process and is reverted
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by the decoder. As well as decreasing unpleasant artifacts in the high range
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this also reduces the entropy in the high bands and allows for more bits to
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be used by the mid-low bands. By default it's enabled but can be disabled for
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debugging by setting the option to "disable".
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@item aac_ltp
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Enables the use of the long term prediction extension which increases coding
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efficiency in very low bandwidth situations such as encoding of voice or
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solo piano music by extending constant harmonic peaks in bands throughout
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frames. This option is implied by profile:a aac_low and is incompatible with
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aac_pred. Use in conjunction with @option{-ar} to decrease the samplerate.
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@item aac_pred
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Enables the use of a more traditional style of prediction where the spectral
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coefficients transmitted are replaced by the difference of the current
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coefficients minus the previous "predicted" coefficients. In theory and sometimes
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in practice this can improve quality for low to mid bitrate audio.
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This option implies the aac_main profile and is incompatible with aac_ltp.
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@item profile
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Sets the encoding profile, possible values:
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@table @samp
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@item aac_low
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The default, AAC "Low-complexity" profile. Is the most compatible and produces
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decent quality.
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@item mpeg2_aac_low
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Equivalent to @code{-profile:a aac_low -aac_pns 0}. PNS was introduced with the
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MPEG4 specifications.
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@item aac_ltp
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Long term prediction profile, is enabled by and will enable the @option{aac_ltp}
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option. Introduced in MPEG4.
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@item aac_main
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Main-type prediction profile, is enabled by and will enable the @option{aac_pred}
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option. Introduced in MPEG2.
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@end table
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If this option is unspecified it is set to @samp{aac_low}.
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@end table
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@section ac3 and ac3_fixed
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AC-3 audio encoders.
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These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366, as well as
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the undocumented RealAudio 3 (a.k.a. dnet).
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The @var{ac3} encoder uses floating-point math, while the @var{ac3_fixed}
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encoder only uses fixed-point integer math. This does not mean that one is
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always faster, just that one or the other may be better suited to a
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particular system. The floating-point encoder will generally produce better
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quality audio for a given bitrate. The @var{ac3_fixed} encoder is not the
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default codec for any of the output formats, so it must be specified explicitly
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using the option @code{-acodec ac3_fixed} in order to use it.
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@subsection AC-3 Metadata
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The AC-3 metadata options are used to set parameters that describe the audio,
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but in most cases do not affect the audio encoding itself. Some of the options
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do directly affect or influence the decoding and playback of the resulting
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bitstream, while others are just for informational purposes. A few of the
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options will add bits to the output stream that could otherwise be used for
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audio data, and will thus affect the quality of the output. Those will be
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indicated accordingly with a note in the option list below.
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These parameters are described in detail in several publicly-available
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documents.
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@itemize
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@item @uref{http://www.atsc.org/cms/standards/a_52-2010.pdf,A/52:2010 - Digital Audio Compression (AC-3) (E-AC-3) Standard}
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@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}
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@item @uref{http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/18_Metadata.Guide.pdf,Dolby Metadata Guide}
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@item @uref{http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/46_DDEncodingGuidelines.pdf,Dolby Digital Professional Encoding Guidelines}
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@end itemize
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@subsubsection Metadata Control Options
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@table @option
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@item -per_frame_metadata @var{boolean}
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Allow Per-Frame Metadata. Specifies if the encoder should check for changing
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metadata for each frame.
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@table @option
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@item 0
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The metadata values set at initialization will be used for every frame in the
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stream. (default)
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@item 1
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Metadata values can be changed before encoding each frame.
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@end table
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@end table
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@subsubsection Downmix Levels
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@table @option
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@item -center_mixlev @var{level}
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Center Mix Level. The amount of gain the decoder should apply to the center
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channel when downmixing to stereo. This field will only be written to the
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bitstream if a center channel is present. The value is specified as a scale
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factor. There are 3 valid values:
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@table @option
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@item 0.707
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Apply -3dB gain
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@item 0.595
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Apply -4.5dB gain (default)
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@item 0.500
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Apply -6dB gain
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@end table
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@item -surround_mixlev @var{level}
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Surround Mix Level. The amount of gain the decoder should apply to the surround
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channel(s) when downmixing to stereo. This field will only be written to the
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bitstream if one or more surround channels are present. The value is specified
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as a scale factor. There are 3 valid values:
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@table @option
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@item 0.707
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Apply -3dB gain
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@item 0.500
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Apply -6dB gain (default)
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@item 0.000
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Silence Surround Channel(s)
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@end table
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@end table
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@subsubsection Audio Production Information
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Audio Production Information is optional information describing the mixing
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environment. Either none or both of the fields are written to the bitstream.
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@table @option
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@item -mixing_level @var{number}
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Mixing Level. Specifies peak sound pressure level (SPL) in the production
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environment when the mix was mastered. Valid values are 80 to 111, or -1 for
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unknown or not indicated. The default value is -1, but that value cannot be
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used if the Audio Production Information is written to the bitstream. Therefore,
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if the @code{room_type} option is not the default value, the @code{mixing_level}
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option must not be -1.
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@item -room_type @var{type}
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Room Type. Describes the equalization used during the final mixing session at
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the studio or on the dubbing stage. A large room is a dubbing stage with the
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industry standard X-curve equalization; a small room has flat equalization.
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This field will not be written to the bitstream if both the @code{mixing_level}
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option and the @code{room_type} option have the default values.
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@table @option
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@item 0
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@itemx notindicated
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Not Indicated (default)
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@item 1
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@itemx large
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Large Room
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@item 2
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@itemx small
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Small Room
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@end table
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@end table
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@subsubsection Other Metadata Options
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@table @option
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@item -copyright @var{boolean}
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Copyright Indicator. Specifies whether a copyright exists for this audio.
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@table @option
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@item 0
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@itemx off
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No Copyright Exists (default)
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@item 1
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@itemx on
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Copyright Exists
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@end table
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@item -dialnorm @var{value}
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Dialogue Normalization. Indicates how far the average dialogue level of the
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program is below digital 100% full scale (0 dBFS). This parameter determines a
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level shift during audio reproduction that sets the average volume of the
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dialogue to a preset level. The goal is to match volume level between program
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sources. A value of -31dB will result in no volume level change, relative to
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the source volume, during audio reproduction. Valid values are whole numbers in
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the range -31 to -1, with -31 being the default.
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@item -dsur_mode @var{mode}
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Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround
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(Pro Logic). This field will only be written to the bitstream if the audio
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stream is stereo. Using this option does @b{NOT} mean the encoder will actually
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apply Dolby Surround processing.
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@table @option
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@item 0
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@itemx notindicated
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Not Indicated (default)
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@item 1
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@itemx off
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Not Dolby Surround Encoded
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@item 2
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@itemx on
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Dolby Surround Encoded
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@end table
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@item -original @var{boolean}
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Original Bit Stream Indicator. Specifies whether this audio is from the
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original source and not a copy.
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@table @option
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@item 0
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@itemx off
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Not Original Source
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@item 1
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@itemx on
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Original Source (default)
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@end table
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@end table
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@subsection Extended Bitstream Information
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The extended bitstream options are part of the Alternate Bit Stream Syntax as
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specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts.
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If any one parameter in a group is specified, all values in that group will be
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written to the bitstream. Default values are used for those that are written
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but have not been specified. If the mixing levels are written, the decoder
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will use these values instead of the ones specified in the @code{center_mixlev}
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and @code{surround_mixlev} options if it supports the Alternate Bit Stream
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Syntax.
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@subsubsection Extended Bitstream Information - Part 1
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@table @option
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@item -dmix_mode @var{mode}
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Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt
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(Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
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@table @option
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@item 0
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@itemx notindicated
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Not Indicated (default)
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@item 1
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@itemx ltrt
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Lt/Rt Downmix Preferred
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@item 2
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@itemx loro
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Lo/Ro Downmix Preferred
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@end table
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@item -ltrt_cmixlev @var{level}
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Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the
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center channel when downmixing to stereo in Lt/Rt mode.
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@table @option
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@item 1.414
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Apply +3dB gain
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@item 1.189
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Apply +1.5dB gain
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@item 1.000
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Apply 0dB gain
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@item 0.841
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Apply -1.5dB gain
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@item 0.707
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Apply -3.0dB gain
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@item 0.595
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Apply -4.5dB gain (default)
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@item 0.500
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Apply -6.0dB gain
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@item 0.000
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Silence Center Channel
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@end table
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@item -ltrt_surmixlev @var{level}
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Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the
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surround channel(s) when downmixing to stereo in Lt/Rt mode.
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@table @option
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@item 0.841
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Apply -1.5dB gain
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@item 0.707
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Apply -3.0dB gain
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@item 0.595
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Apply -4.5dB gain
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@item 0.500
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Apply -6.0dB gain (default)
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@item 0.000
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Silence Surround Channel(s)
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@end table
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@item -loro_cmixlev @var{level}
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Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the
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center channel when downmixing to stereo in Lo/Ro mode.
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@table @option
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@item 1.414
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Apply +3dB gain
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@item 1.189
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Apply +1.5dB gain
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@item 1.000
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Apply 0dB gain
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@item 0.841
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Apply -1.5dB gain
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@item 0.707
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Apply -3.0dB gain
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@item 0.595
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Apply -4.5dB gain (default)
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@item 0.500
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Apply -6.0dB gain
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@item 0.000
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Silence Center Channel
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@end table
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@item -loro_surmixlev @var{level}
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Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the
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surround channel(s) when downmixing to stereo in Lo/Ro mode.
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@table @option
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@item 0.841
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Apply -1.5dB gain
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@item 0.707
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Apply -3.0dB gain
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@item 0.595
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Apply -4.5dB gain
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@item 0.500
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Apply -6.0dB gain (default)
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@item 0.000
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Silence Surround Channel(s)
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@end table
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@end table
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@subsubsection Extended Bitstream Information - Part 2
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@table @option
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@item -dsurex_mode @var{mode}
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Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX
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(7.1 matrixed to 5.1). Using this option does @b{NOT} mean the encoder will actually
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apply Dolby Surround EX processing.
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@table @option
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@item 0
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@itemx notindicated
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Not Indicated (default)
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@item 1
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@itemx on
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Dolby Surround EX Off
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@item 2
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@itemx off
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Dolby Surround EX On
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@end table
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@item -dheadphone_mode @var{mode}
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Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone
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encoding (multi-channel matrixed to 2.0 for use with headphones). Using this
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option does @b{NOT} mean the encoder will actually apply Dolby Headphone
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processing.
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@table @option
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@item 0
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@itemx notindicated
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Not Indicated (default)
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@item 1
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@itemx on
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Dolby Headphone Off
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@item 2
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@itemx off
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Dolby Headphone On
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@end table
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@item -ad_conv_type @var{type}
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A/D Converter Type. Indicates whether the audio has passed through HDCD A/D
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conversion.
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@table @option
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@item 0
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@itemx standard
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Standard A/D Converter (default)
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@item 1
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@itemx hdcd
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HDCD A/D Converter
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@end table
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@end table
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@subsection Other AC-3 Encoding Options
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@table @option
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@item -stereo_rematrixing @var{boolean}
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Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
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is an optional AC-3 feature that increases quality by selectively encoding
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the left/right channels as mid/side. This option is enabled by default, and it
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is highly recommended that it be left as enabled except for testing purposes.
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@item cutoff @var{frequency}
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Set lowpass cutoff frequency. If unspecified, the encoder selects a default
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determined by various other encoding parameters.
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@end table
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@subsection Floating-Point-Only AC-3 Encoding Options
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These options are only valid for the floating-point encoder and do not exist
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for the fixed-point encoder due to the corresponding features not being
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implemented in fixed-point.
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@table @option
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@item -channel_coupling @var{boolean}
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Enables/Disables use of channel coupling, which is an optional AC-3 feature
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that increases quality by combining high frequency information from multiple
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channels into a single channel. The per-channel high frequency information is
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sent with less accuracy in both the frequency and time domains. This allows
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more bits to be used for lower frequencies while preserving enough information
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to reconstruct the high frequencies. This option is enabled by default for the
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floating-point encoder and should generally be left as enabled except for
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testing purposes or to increase encoding speed.
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@table @option
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@item -1
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@itemx auto
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Selected by Encoder (default)
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@item 0
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@itemx off
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Disable Channel Coupling
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@item 1
|
|
@itemx on
|
|
Enable Channel Coupling
|
|
@end table
|
|
|
|
@item -cpl_start_band @var{number}
|
|
Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
|
|
value higher than the bandwidth is used, it will be reduced to 1 less than the
|
|
coupling end band. If @var{auto} is used, the start band will be determined by
|
|
the encoder based on the bit rate, sample rate, and channel layout. This option
|
|
has no effect if channel coupling is disabled.
|
|
@table @option
|
|
@item -1
|
|
@itemx auto
|
|
Selected by Encoder (default)
|
|
@end table
|
|
|
|
@end table
|
|
|
|
@anchor{flac}
|
|
@section flac
|
|
|
|
FLAC (Free Lossless Audio Codec) Encoder
|
|
|
|
@subsection Options
|
|
|
|
The following options are supported by FFmpeg's flac encoder.
|
|
|
|
@table @option
|
|
@item compression_level
|
|
Sets the compression level, which chooses defaults for many other options
|
|
if they are not set explicitly. Valid values are from 0 to 12, 5 is the
|
|
default.
|
|
|
|
@item frame_size
|
|
Sets the size of the frames in samples per channel.
|
|
|
|
@item lpc_coeff_precision
|
|
Sets the LPC coefficient precision, valid values are from 1 to 15, 15 is the
|
|
default.
|
|
|
|
@item lpc_type
|
|
Sets the first stage LPC algorithm
|
|
@table @samp
|
|
@item none
|
|
LPC is not used
|
|
|
|
@item fixed
|
|
fixed LPC coefficients
|
|
|
|
@item levinson
|
|
|
|
@item cholesky
|
|
@end table
|
|
|
|
@item lpc_passes
|
|
Number of passes to use for Cholesky factorization during LPC analysis
|
|
|
|
@item min_partition_order
|
|
The minimum partition order
|
|
|
|
@item max_partition_order
|
|
The maximum partition order
|
|
|
|
@item prediction_order_method
|
|
@table @samp
|
|
@item estimation
|
|
@item 2level
|
|
@item 4level
|
|
@item 8level
|
|
@item search
|
|
Bruteforce search
|
|
@item log
|
|
@end table
|
|
|
|
@item ch_mode
|
|
Channel mode
|
|
@table @samp
|
|
@item auto
|
|
The mode is chosen automatically for each frame
|
|
@item indep
|
|
Channels are independently coded
|
|
@item left_side
|
|
@item right_side
|
|
@item mid_side
|
|
@end table
|
|
|
|
@item exact_rice_parameters
|
|
Chooses if rice parameters are calculated exactly or approximately.
|
|
if set to 1 then they are chosen exactly, which slows the code down slightly and
|
|
improves compression slightly.
|
|
|
|
@item multi_dim_quant
|
|
Multi Dimensional Quantization. If set to 1 then a 2nd stage LPC algorithm is
|
|
applied after the first stage to finetune the coefficients. This is quite slow
|
|
and slightly improves compression.
|
|
|
|
@end table
|
|
|
|
@anchor{opusenc}
|
|
@section opus
|
|
|
|
Opus encoder.
|
|
|
|
This is a native FFmpeg encoder for the Opus format. Currently its in development and
|
|
only implements the CELT part of the codec. Its quality is usually worse and at best
|
|
is equal to the libopus encoder.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item b
|
|
Set bit rate in bits/s. If unspecified it uses the number of channels and the layout
|
|
to make a good guess.
|
|
|
|
@item opus_delay
|
|
Sets the maximum delay in milliseconds. Lower delays than 20ms will very quickly
|
|
decrease quality.
|
|
@end table
|
|
|
|
@anchor{libfdk-aac-enc}
|
|
@section libfdk_aac
|
|
|
|
libfdk-aac AAC (Advanced Audio Coding) encoder wrapper.
|
|
|
|
The libfdk-aac library is based on the Fraunhofer FDK AAC code from
|
|
the Android project.
|
|
|
|
Requires the presence of the libfdk-aac headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libfdk-aac}. The library is also incompatible with GPL,
|
|
so if you allow the use of GPL, you should configure with
|
|
@code{--enable-gpl --enable-nonfree --enable-libfdk-aac}.
|
|
|
|
This encoder has support for the AAC-HE profiles.
|
|
|
|
VBR encoding, enabled through the @option{vbr} or @option{flags
|
|
+qscale} options, is experimental and only works with some
|
|
combinations of parameters.
|
|
|
|
Support for encoding 7.1 audio is only available with libfdk-aac 0.1.3 or
|
|
higher.
|
|
|
|
For more information see the fdk-aac project at
|
|
@url{http://sourceforge.net/p/opencore-amr/fdk-aac/}.
|
|
|
|
@subsection Options
|
|
|
|
The following options are mapped on the shared FFmpeg codec options.
|
|
|
|
@table @option
|
|
@item b
|
|
Set bit rate in bits/s. If the bitrate is not explicitly specified, it
|
|
is automatically set to a suitable value depending on the selected
|
|
profile.
|
|
|
|
In case VBR mode is enabled the option is ignored.
|
|
|
|
@item ar
|
|
Set audio sampling rate (in Hz).
|
|
|
|
@item channels
|
|
Set the number of audio channels.
|
|
|
|
@item flags +qscale
|
|
Enable fixed quality, VBR (Variable Bit Rate) mode.
|
|
Note that VBR is implicitly enabled when the @option{vbr} value is
|
|
positive.
|
|
|
|
@item cutoff
|
|
Set cutoff frequency. If not specified (or explicitly set to 0) it
|
|
will use a value automatically computed by the library. Default value
|
|
is 0.
|
|
|
|
@item profile
|
|
Set audio profile.
|
|
|
|
The following profiles are recognized:
|
|
@table @samp
|
|
@item aac_low
|
|
Low Complexity AAC (LC)
|
|
|
|
@item aac_he
|
|
High Efficiency AAC (HE-AAC)
|
|
|
|
@item aac_he_v2
|
|
High Efficiency AAC version 2 (HE-AACv2)
|
|
|
|
@item aac_ld
|
|
Low Delay AAC (LD)
|
|
|
|
@item aac_eld
|
|
Enhanced Low Delay AAC (ELD)
|
|
@end table
|
|
|
|
If not specified it is set to @samp{aac_low}.
|
|
@end table
|
|
|
|
The following are private options of the libfdk_aac encoder.
|
|
|
|
@table @option
|
|
@item afterburner
|
|
Enable afterburner feature if set to 1, disabled if set to 0. This
|
|
improves the quality but also the required processing power.
|
|
|
|
Default value is 1.
|
|
|
|
@item eld_sbr
|
|
Enable SBR (Spectral Band Replication) for ELD if set to 1, disabled
|
|
if set to 0.
|
|
|
|
Default value is 0.
|
|
|
|
@item eld_v2
|
|
Enable ELDv2 (LD-MPS extension for ELD stereo signals) for ELDv2 if set to 1,
|
|
disabled if set to 0.
|
|
|
|
Note that option is available when fdk-aac version (AACENCODER_LIB_VL0.AACENCODER_LIB_VL1.AACENCODER_LIB_VL2) > (4.0.0).
|
|
|
|
Default value is 0.
|
|
|
|
@item signaling
|
|
Set SBR/PS signaling style.
|
|
|
|
It can assume one of the following values:
|
|
@table @samp
|
|
@item default
|
|
choose signaling implicitly (explicit hierarchical by default,
|
|
implicit if global header is disabled)
|
|
|
|
@item implicit
|
|
implicit backwards compatible signaling
|
|
|
|
@item explicit_sbr
|
|
explicit SBR, implicit PS signaling
|
|
|
|
@item explicit_hierarchical
|
|
explicit hierarchical signaling
|
|
@end table
|
|
|
|
Default value is @samp{default}.
|
|
|
|
@item latm
|
|
Output LATM/LOAS encapsulated data if set to 1, disabled if set to 0.
|
|
|
|
Default value is 0.
|
|
|
|
@item header_period
|
|
Set StreamMuxConfig and PCE repetition period (in frames) for sending
|
|
in-band configuration buffers within LATM/LOAS transport layer.
|
|
|
|
Must be a 16-bits non-negative integer.
|
|
|
|
Default value is 0.
|
|
|
|
@item vbr
|
|
Set VBR mode, from 1 to 5. 1 is lowest quality (though still pretty
|
|
good) and 5 is highest quality. A value of 0 will disable VBR, and CBR
|
|
(Constant Bit Rate) is enabled.
|
|
|
|
Currently only the @samp{aac_low} profile supports VBR encoding.
|
|
|
|
VBR modes 1-5 correspond to roughly the following average bit rates:
|
|
|
|
@table @samp
|
|
@item 1
|
|
32 kbps/channel
|
|
@item 2
|
|
40 kbps/channel
|
|
@item 3
|
|
48-56 kbps/channel
|
|
@item 4
|
|
64 kbps/channel
|
|
@item 5
|
|
about 80-96 kbps/channel
|
|
@end table
|
|
|
|
Default value is 0.
|
|
@end table
|
|
|
|
@subsection Examples
|
|
|
|
@itemize
|
|
@item
|
|
Use @command{ffmpeg} to convert an audio file to VBR AAC in an M4A (MP4)
|
|
container:
|
|
@example
|
|
ffmpeg -i input.wav -codec:a libfdk_aac -vbr 3 output.m4a
|
|
@end example
|
|
|
|
@item
|
|
Use @command{ffmpeg} to convert an audio file to CBR 64k kbps AAC, using the
|
|
High-Efficiency AAC profile:
|
|
@example
|
|
ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a
|
|
@end example
|
|
@end itemize
|
|
|
|
@anchor{libmp3lame}
|
|
@section libmp3lame
|
|
|
|
LAME (Lame Ain't an MP3 Encoder) MP3 encoder wrapper.
|
|
|
|
Requires the presence of the libmp3lame headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libmp3lame}.
|
|
|
|
See @ref{libshine} for a fixed-point MP3 encoder, although with a
|
|
lower quality.
|
|
|
|
@subsection Options
|
|
|
|
The following options are supported by the libmp3lame wrapper. The
|
|
@command{lame}-equivalent of the options are listed in parentheses.
|
|
|
|
@table @option
|
|
@item b (@emph{-b})
|
|
Set bitrate expressed in bits/s for CBR or ABR. LAME @code{bitrate} is
|
|
expressed in kilobits/s.
|
|
|
|
@item q (@emph{-V})
|
|
Set constant quality setting for VBR. This option is valid only
|
|
using the @command{ffmpeg} command-line tool. For library interface
|
|
users, use @option{global_quality}.
|
|
|
|
@item compression_level (@emph{-q})
|
|
Set algorithm quality. Valid arguments are integers in the 0-9 range,
|
|
with 0 meaning highest quality but slowest, and 9 meaning fastest
|
|
while producing the worst quality.
|
|
|
|
@item cutoff (@emph{--lowpass})
|
|
Set lowpass cutoff frequency. If unspecified, the encoder dynamically
|
|
adjusts the cutoff.
|
|
|
|
@item reservoir
|
|
Enable use of bit reservoir when set to 1. Default value is 1. LAME
|
|
has this enabled by default, but can be overridden by use
|
|
@option{--nores} option.
|
|
|
|
@item joint_stereo (@emph{-m j})
|
|
Enable the encoder to use (on a frame by frame basis) either L/R
|
|
stereo or mid/side stereo. Default value is 1.
|
|
|
|
@item abr (@emph{--abr})
|
|
Enable the encoder to use ABR when set to 1. The @command{lame}
|
|
@option{--abr} sets the target bitrate, while this options only
|
|
tells FFmpeg to use ABR still relies on @option{b} to set bitrate.
|
|
|
|
@end table
|
|
|
|
@section libopencore-amrnb
|
|
|
|
OpenCORE Adaptive Multi-Rate Narrowband encoder.
|
|
|
|
Requires the presence of the libopencore-amrnb headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libopencore-amrnb --enable-version3}.
|
|
|
|
This is a mono-only encoder. Officially it only supports 8000Hz sample rate,
|
|
but you can override it by setting @option{strict} to @samp{unofficial} or
|
|
lower.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
|
|
@item b
|
|
Set bitrate in bits per second. Only the following bitrates are supported,
|
|
otherwise libavcodec will round to the nearest valid bitrate.
|
|
|
|
@table @option
|
|
@item 4750
|
|
@item 5150
|
|
@item 5900
|
|
@item 6700
|
|
@item 7400
|
|
@item 7950
|
|
@item 10200
|
|
@item 12200
|
|
@end table
|
|
|
|
@item dtx
|
|
Allow discontinuous transmission (generate comfort noise) when set to 1. The
|
|
default value is 0 (disabled).
|
|
|
|
@end table
|
|
|
|
@section libopus
|
|
|
|
libopus Opus Interactive Audio Codec encoder wrapper.
|
|
|
|
Requires the presence of the libopus headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libopus}.
|
|
|
|
@subsection Option Mapping
|
|
|
|
Most libopus options are modelled after the @command{opusenc} utility from
|
|
opus-tools. The following is an option mapping chart describing options
|
|
supported by the libopus wrapper, and their @command{opusenc}-equivalent
|
|
in parentheses.
|
|
|
|
@table @option
|
|
|
|
@item b (@emph{bitrate})
|
|
Set the bit rate in bits/s. FFmpeg's @option{b} option is
|
|
expressed in bits/s, while @command{opusenc}'s @option{bitrate} in
|
|
kilobits/s.
|
|
|
|
@item vbr (@emph{vbr}, @emph{hard-cbr}, and @emph{cvbr})
|
|
Set VBR mode. The FFmpeg @option{vbr} option has the following
|
|
valid arguments, with the @command{opusenc} equivalent options
|
|
in parentheses:
|
|
|
|
@table @samp
|
|
@item off (@emph{hard-cbr})
|
|
Use constant bit rate encoding.
|
|
|
|
@item on (@emph{vbr})
|
|
Use variable bit rate encoding (the default).
|
|
|
|
@item constrained (@emph{cvbr})
|
|
Use constrained variable bit rate encoding.
|
|
@end table
|
|
|
|
@item compression_level (@emph{comp})
|
|
Set encoding algorithm complexity. Valid options are integers in
|
|
the 0-10 range. 0 gives the fastest encodes but lower quality, while 10
|
|
gives the highest quality but slowest encoding. The default is 10.
|
|
|
|
@item frame_duration (@emph{framesize})
|
|
Set maximum frame size, or duration of a frame in milliseconds. The
|
|
argument must be exactly the following: 2.5, 5, 10, 20, 40, 60. Smaller
|
|
frame sizes achieve lower latency but less quality at a given bitrate.
|
|
Sizes greater than 20ms are only interesting at fairly low bitrates.
|
|
The default is 20ms.
|
|
|
|
@item packet_loss (@emph{expect-loss})
|
|
Set expected packet loss percentage. The default is 0.
|
|
|
|
@item application (N.A.)
|
|
Set intended application type. Valid options are listed below:
|
|
|
|
@table @samp
|
|
@item voip
|
|
Favor improved speech intelligibility.
|
|
@item audio
|
|
Favor faithfulness to the input (the default).
|
|
@item lowdelay
|
|
Restrict to only the lowest delay modes.
|
|
@end table
|
|
|
|
@item cutoff (N.A.)
|
|
Set cutoff bandwidth in Hz. The argument must be exactly one of the
|
|
following: 4000, 6000, 8000, 12000, or 20000, corresponding to
|
|
narrowband, mediumband, wideband, super wideband, and fullband
|
|
respectively. The default is 0 (cutoff disabled).
|
|
|
|
@item mapping_family (@emph{mapping_family})
|
|
Set channel mapping family to be used by the encoder. The default value of -1
|
|
uses mapping family 0 for mono and stereo inputs, and mapping family 1
|
|
otherwise. The default also disables the surround masking and LFE bandwidth
|
|
optimzations in libopus, and requires that the input contains 8 channels or
|
|
fewer.
|
|
|
|
Other values include 0 for mono and stereo, 1 for surround sound with masking
|
|
and LFE bandwidth optimizations, and 255 for independent streams with an
|
|
unspecified channel layout.
|
|
|
|
@item apply_phase_inv (N.A.) (requires libopus >= 1.2)
|
|
If set to 0, disables the use of phase inversion for intensity stereo,
|
|
improving the quality of mono downmixes, but slightly reducing normal stereo
|
|
quality. The default is 1 (phase inversion enabled).
|
|
|
|
@end table
|
|
|
|
@anchor{libshine}
|
|
@section libshine
|
|
|
|
Shine Fixed-Point MP3 encoder wrapper.
|
|
|
|
Shine is a fixed-point MP3 encoder. It has a far better performance on
|
|
platforms without an FPU, e.g. armel CPUs, and some phones and tablets.
|
|
However, as it is more targeted on performance than quality, it is not on par
|
|
with LAME and other production-grade encoders quality-wise. Also, according to
|
|
the project's homepage, this encoder may not be free of bugs as the code was
|
|
written a long time ago and the project was dead for at least 5 years.
|
|
|
|
This encoder only supports stereo and mono input. This is also CBR-only.
|
|
|
|
The original project (last updated in early 2007) is at
|
|
@url{http://sourceforge.net/projects/libshine-fxp/}. We only support the
|
|
updated fork by the Savonet/Liquidsoap project at @url{https://github.com/savonet/shine}.
|
|
|
|
Requires the presence of the libshine headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libshine}.
|
|
|
|
See also @ref{libmp3lame}.
|
|
|
|
@subsection Options
|
|
|
|
The following options are supported by the libshine wrapper. The
|
|
@command{shineenc}-equivalent of the options are listed in parentheses.
|
|
|
|
@table @option
|
|
@item b (@emph{-b})
|
|
Set bitrate expressed in bits/s for CBR. @command{shineenc} @option{-b} option
|
|
is expressed in kilobits/s.
|
|
|
|
@end table
|
|
|
|
@section libtwolame
|
|
|
|
TwoLAME MP2 encoder wrapper.
|
|
|
|
Requires the presence of the libtwolame headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libtwolame}.
|
|
|
|
@subsection Options
|
|
|
|
The following options are supported by the libtwolame wrapper. The
|
|
@command{twolame}-equivalent options follow the FFmpeg ones and are in
|
|
parentheses.
|
|
|
|
@table @option
|
|
@item b (@emph{-b})
|
|
Set bitrate expressed in bits/s for CBR. @command{twolame} @option{b}
|
|
option is expressed in kilobits/s. Default value is 128k.
|
|
|
|
@item q (@emph{-V})
|
|
Set quality for experimental VBR support. Maximum value range is
|
|
from -50 to 50, useful range is from -10 to 10. The higher the
|
|
value, the better the quality. This option is valid only using the
|
|
@command{ffmpeg} command-line tool. For library interface users,
|
|
use @option{global_quality}.
|
|
|
|
@item mode (@emph{--mode})
|
|
Set the mode of the resulting audio. Possible values:
|
|
|
|
@table @samp
|
|
@item auto
|
|
Choose mode automatically based on the input. This is the default.
|
|
@item stereo
|
|
Stereo
|
|
@item joint_stereo
|
|
Joint stereo
|
|
@item dual_channel
|
|
Dual channel
|
|
@item mono
|
|
Mono
|
|
@end table
|
|
|
|
@item psymodel (@emph{--psyc-mode})
|
|
Set psychoacoustic model to use in encoding. The argument must be
|
|
an integer between -1 and 4, inclusive. The higher the value, the
|
|
better the quality. The default value is 3.
|
|
|
|
@item energy_levels (@emph{--energy})
|
|
Enable energy levels extensions when set to 1. The default value is
|
|
0 (disabled).
|
|
|
|
@item error_protection (@emph{--protect})
|
|
Enable CRC error protection when set to 1. The default value is 0
|
|
(disabled).
|
|
|
|
@item copyright (@emph{--copyright})
|
|
Set MPEG audio copyright flag when set to 1. The default value is 0
|
|
(disabled).
|
|
|
|
@item original (@emph{--original})
|
|
Set MPEG audio original flag when set to 1. The default value is 0
|
|
(disabled).
|
|
|
|
@end table
|
|
|
|
@section libvo-amrwbenc
|
|
|
|
VisualOn Adaptive Multi-Rate Wideband encoder.
|
|
|
|
Requires the presence of the libvo-amrwbenc headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libvo-amrwbenc --enable-version3}.
|
|
|
|
This is a mono-only encoder. Officially it only supports 16000Hz sample
|
|
rate, but you can override it by setting @option{strict} to
|
|
@samp{unofficial} or lower.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
|
|
@item b
|
|
Set bitrate in bits/s. Only the following bitrates are supported, otherwise
|
|
libavcodec will round to the nearest valid bitrate.
|
|
|
|
@table @samp
|
|
@item 6600
|
|
@item 8850
|
|
@item 12650
|
|
@item 14250
|
|
@item 15850
|
|
@item 18250
|
|
@item 19850
|
|
@item 23050
|
|
@item 23850
|
|
@end table
|
|
|
|
@item dtx
|
|
Allow discontinuous transmission (generate comfort noise) when set to 1. The
|
|
default value is 0 (disabled).
|
|
|
|
@end table
|
|
|
|
@section libvorbis
|
|
|
|
libvorbis encoder wrapper.
|
|
|
|
Requires the presence of the libvorbisenc headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libvorbis}.
|
|
|
|
@subsection Options
|
|
|
|
The following options are supported by the libvorbis wrapper. The
|
|
@command{oggenc}-equivalent of the options are listed in parentheses.
|
|
|
|
To get a more accurate and extensive documentation of the libvorbis
|
|
options, consult the libvorbisenc's and @command{oggenc}'s documentations.
|
|
See @url{http://xiph.org/vorbis/},
|
|
@url{http://wiki.xiph.org/Vorbis-tools}, and oggenc(1).
|
|
|
|
@table @option
|
|
@item b (@emph{-b})
|
|
Set bitrate expressed in bits/s for ABR. @command{oggenc} @option{-b} is
|
|
expressed in kilobits/s.
|
|
|
|
@item q (@emph{-q})
|
|
Set constant quality setting for VBR. The value should be a float
|
|
number in the range of -1.0 to 10.0. The higher the value, the better
|
|
the quality. The default value is @samp{3.0}.
|
|
|
|
This option is valid only using the @command{ffmpeg} command-line tool.
|
|
For library interface users, use @option{global_quality}.
|
|
|
|
@item cutoff (@emph{--advanced-encode-option lowpass_frequency=N})
|
|
Set cutoff bandwidth in Hz, a value of 0 disables cutoff. @command{oggenc}'s
|
|
related option is expressed in kHz. The default value is @samp{0} (cutoff
|
|
disabled).
|
|
|
|
@item minrate (@emph{-m})
|
|
Set minimum bitrate expressed in bits/s. @command{oggenc} @option{-m} is
|
|
expressed in kilobits/s.
|
|
|
|
@item maxrate (@emph{-M})
|
|
Set maximum bitrate expressed in bits/s. @command{oggenc} @option{-M} is
|
|
expressed in kilobits/s. This only has effect on ABR mode.
|
|
|
|
@item iblock (@emph{--advanced-encode-option impulse_noisetune=N})
|
|
Set noise floor bias for impulse blocks. The value is a float number from
|
|
-15.0 to 0.0. A negative bias instructs the encoder to pay special attention
|
|
to the crispness of transients in the encoded audio. The tradeoff for better
|
|
transient response is a higher bitrate.
|
|
|
|
@end table
|
|
|
|
@anchor{libwavpack}
|
|
@section libwavpack
|
|
|
|
A wrapper providing WavPack encoding through libwavpack.
|
|
|
|
Only lossless mode using 32-bit integer samples is supported currently.
|
|
|
|
Requires the presence of the libwavpack headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libwavpack}.
|
|
|
|
Note that a libavcodec-native encoder for the WavPack codec exists so users can
|
|
encode audios with this codec without using this encoder. See @ref{wavpackenc}.
|
|
|
|
@subsection Options
|
|
|
|
@command{wavpack} command line utility's corresponding options are listed in
|
|
parentheses, if any.
|
|
|
|
@table @option
|
|
@item frame_size (@emph{--blocksize})
|
|
Default is 32768.
|
|
|
|
@item compression_level
|
|
Set speed vs. compression tradeoff. Acceptable arguments are listed below:
|
|
|
|
@table @samp
|
|
@item 0 (@emph{-f})
|
|
Fast mode.
|
|
|
|
@item 1
|
|
Normal (default) settings.
|
|
|
|
@item 2 (@emph{-h})
|
|
High quality.
|
|
|
|
@item 3 (@emph{-hh})
|
|
Very high quality.
|
|
|
|
@item 4-8 (@emph{-hh -x}@var{EXTRAPROC})
|
|
Same as @samp{3}, but with extra processing enabled.
|
|
|
|
@samp{4} is the same as @option{-x2} and @samp{8} is the same as @option{-x6}.
|
|
|
|
@end table
|
|
@end table
|
|
|
|
@anchor{mjpegenc}
|
|
@section mjpeg
|
|
|
|
Motion JPEG encoder.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item huffman
|
|
Set the huffman encoding strategy. Possible values:
|
|
|
|
@table @samp
|
|
@item default
|
|
Use the default huffman tables. This is the default strategy.
|
|
|
|
@item optimal
|
|
Compute and use optimal huffman tables.
|
|
|
|
@end table
|
|
@end table
|
|
|
|
@anchor{wavpackenc}
|
|
@section wavpack
|
|
|
|
WavPack lossless audio encoder.
|
|
|
|
This is a libavcodec-native WavPack encoder. There is also an encoder based on
|
|
libwavpack, but there is virtually no reason to use that encoder.
|
|
|
|
See also @ref{libwavpack}.
|
|
|
|
@subsection Options
|
|
|
|
The equivalent options for @command{wavpack} command line utility are listed in
|
|
parentheses.
|
|
|
|
@subsubsection Shared options
|
|
|
|
The following shared options are effective for this encoder. Only special notes
|
|
about this particular encoder will be documented here. For the general meaning
|
|
of the options, see @ref{codec-options,,the Codec Options chapter}.
|
|
|
|
@table @option
|
|
@item frame_size (@emph{--blocksize})
|
|
For this encoder, the range for this option is between 128 and 131072. Default
|
|
is automatically decided based on sample rate and number of channel.
|
|
|
|
For the complete formula of calculating default, see
|
|
@file{libavcodec/wavpackenc.c}.
|
|
|
|
@item compression_level (@emph{-f}, @emph{-h}, @emph{-hh}, and @emph{-x})
|
|
This option's syntax is consistent with @ref{libwavpack}'s.
|
|
@end table
|
|
|
|
@subsubsection Private options
|
|
|
|
@table @option
|
|
@item joint_stereo (@emph{-j})
|
|
Set whether to enable joint stereo. Valid values are:
|
|
|
|
@table @samp
|
|
@item on (@emph{1})
|
|
Force mid/side audio encoding.
|
|
@item off (@emph{0})
|
|
Force left/right audio encoding.
|
|
@item auto
|
|
Let the encoder decide automatically.
|
|
@end table
|
|
|
|
@item optimize_mono
|
|
Set whether to enable optimization for mono. This option is only effective for
|
|
non-mono streams. Available values:
|
|
|
|
@table @samp
|
|
@item on
|
|
enabled
|
|
@item off
|
|
disabled
|
|
@end table
|
|
|
|
@end table
|
|
|
|
@c man end AUDIO ENCODERS
|
|
|
|
@chapter Video Encoders
|
|
@c man begin VIDEO ENCODERS
|
|
|
|
A description of some of the currently available video encoders
|
|
follows.
|
|
|
|
@section Hap
|
|
|
|
Vidvox Hap video encoder.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item format @var{integer}
|
|
Specifies the Hap format to encode.
|
|
|
|
@table @option
|
|
@item hap
|
|
@item hap_alpha
|
|
@item hap_q
|
|
@end table
|
|
|
|
Default value is @option{hap}.
|
|
|
|
@item chunks @var{integer}
|
|
Specifies the number of chunks to split frames into, between 1 and 64. This
|
|
permits multithreaded decoding of large frames, potentially at the cost of
|
|
data-rate. The encoder may modify this value to divide frames evenly.
|
|
|
|
Default value is @var{1}.
|
|
|
|
@item compressor @var{integer}
|
|
Specifies the second-stage compressor to use. If set to @option{none},
|
|
@option{chunks} will be limited to 1, as chunked uncompressed frames offer no
|
|
benefit.
|
|
|
|
@table @option
|
|
@item none
|
|
@item snappy
|
|
@end table
|
|
|
|
Default value is @option{snappy}.
|
|
|
|
@end table
|
|
|
|
@section jpeg2000
|
|
|
|
The native jpeg 2000 encoder is lossy by default, the @code{-q:v}
|
|
option can be used to set the encoding quality. Lossless encoding
|
|
can be selected with @code{-pred 1}.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item format
|
|
Can be set to either @code{j2k} or @code{jp2} (the default) that
|
|
makes it possible to store non-rgb pix_fmts.
|
|
|
|
@end table
|
|
|
|
@section librav1e
|
|
|
|
rav1e AV1 encoder wrapper.
|
|
|
|
Requires the presence of the rav1e headers and library during configuration.
|
|
You need to explicitly configure the build with @code{--enable-librav1e}.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item qmax
|
|
Sets the maximum quantizer to use when using bitrate mode.
|
|
|
|
@item qmin
|
|
Sets the minimum quantizer to use when using bitrate mode.
|
|
|
|
@item qp
|
|
Uses quantizer mode to encode at the given quantizer (0-255).
|
|
|
|
@item speed
|
|
Selects the speed preset (0-10) to encode with.
|
|
|
|
@item tiles
|
|
Selects how many tiles to encode with.
|
|
|
|
@item tile-rows
|
|
Selects how many rows of tiles to encode with.
|
|
|
|
@item tile-columns
|
|
Selects how many columns of tiles to encode with.
|
|
|
|
@item rav1e-params
|
|
Set rav1e options using a list of @var{key}=@var{value} pairs separated
|
|
by ":". See @command{rav1e --help} for a list of options.
|
|
|
|
For example to specify librav1e encoding options with @option{-rav1e-params}:
|
|
|
|
@example
|
|
ffmpeg -i input -c:v librav1e -b:v 500K -rav1e-params speed=5:low_latency=true output.mp4
|
|
@end example
|
|
|
|
@end table
|
|
|
|
@section libaom-av1
|
|
|
|
libaom AV1 encoder wrapper.
|
|
|
|
Requires the presence of the libaom headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libaom}.
|
|
|
|
@subsection Options
|
|
|
|
The wrapper supports the following standard libavcodec options:
|
|
|
|
@table @option
|
|
|
|
@item b
|
|
Set bitrate target in bits/second. By default this will use
|
|
variable-bitrate mode. If @option{maxrate} and @option{minrate} are
|
|
also set to the same value then it will use constant-bitrate mode,
|
|
otherwise if @option{crf} is set as well then it will use
|
|
constrained-quality mode.
|
|
|
|
@item g keyint_min
|
|
Set key frame placement. The GOP size sets the maximum distance between
|
|
key frames; if zero the output stream will be intra-only. The minimum
|
|
distance is ignored unless it is the same as the GOP size, in which case
|
|
key frames will always appear at a fixed interval. Not set by default,
|
|
so without this option the library has completely free choice about
|
|
where to place key frames.
|
|
|
|
@item qmin qmax
|
|
Set minimum/maximum quantisation values. Valid range is from 0 to 63
|
|
(warning: this does not match the quantiser values actually used by AV1
|
|
- divide by four to map real quantiser values to this range). Defaults
|
|
to min/max (no constraint).
|
|
|
|
@item minrate maxrate bufsize rc_init_occupancy
|
|
Set rate control buffering parameters. Not used if not set - defaults
|
|
to unconstrained variable bitrate.
|
|
|
|
@item threads
|
|
Set the number of threads to use while encoding. This may require the
|
|
@option{tiles} or @option{row-mt} options to also be set to actually
|
|
use the specified number of threads fully. Defaults to the number of
|
|
hardware threads supported by the host machine.
|
|
|
|
@item profile
|
|
Set the encoding profile. Defaults to using the profile which matches
|
|
the bit depth and chroma subsampling of the input.
|
|
|
|
@end table
|
|
|
|
The wrapper also has some specific options:
|
|
|
|
@table @option
|
|
|
|
@item cpu-used
|
|
Set the quality/encoding speed tradeoff. Valid range is from 0 to 8,
|
|
higher numbers indicating greater speed and lower quality. The default
|
|
value is 1, which will be slow and high quality.
|
|
|
|
@item auto-alt-ref
|
|
Enable use of alternate reference frames. Defaults to the internal
|
|
default of the library.
|
|
|
|
@item arnr-max-frames (@emph{frames})
|
|
Set altref noise reduction max frame count. Default is -1.
|
|
|
|
@item arnr-strength (@emph{strength})
|
|
Set altref noise reduction filter strength. Range is -1 to 6. Default is -1.
|
|
|
|
@item aq-mode (@emph{aq-mode})
|
|
Set adaptive quantization mode. Possible values:
|
|
|
|
@table @samp
|
|
@item none (@emph{0})
|
|
Disabled.
|
|
|
|
@item variance (@emph{1})
|
|
Variance-based.
|
|
|
|
@item complexity (@emph{2})
|
|
Complexity-based.
|
|
|
|
@item cyclic (@emph{3})
|
|
Cyclic refresh.
|
|
@end table
|
|
|
|
@item tune (@emph{tune})
|
|
Set the distortion metric the encoder is tuned with. Default is @code{psnr}.
|
|
|
|
@table @samp
|
|
@item psnr (@emph{0})
|
|
|
|
@item ssim (@emph{1})
|
|
@end table
|
|
|
|
@item lag-in-frames
|
|
Set the maximum number of frames which the encoder may keep in flight
|
|
at any one time for lookahead purposes. Defaults to the internal
|
|
default of the library.
|
|
|
|
@item error-resilience
|
|
Enable error resilience features:
|
|
@table @option
|
|
@item default
|
|
Improve resilience against losses of whole frames.
|
|
@end table
|
|
Not enabled by default.
|
|
|
|
@item crf
|
|
Set the quality/size tradeoff for constant-quality (no bitrate target)
|
|
and constrained-quality (with maximum bitrate target) modes. Valid
|
|
range is 0 to 63, higher numbers indicating lower quality and smaller
|
|
output size. Only used if set; by default only the bitrate target is
|
|
used.
|
|
|
|
@item static-thresh
|
|
Set a change threshold on blocks below which they will be skipped by
|
|
the encoder. Defined in arbitrary units as a nonnegative integer,
|
|
defaulting to zero (no blocks are skipped).
|
|
|
|
@item drop-threshold
|
|
Set a threshold for dropping frames when close to rate control bounds.
|
|
Defined as a percentage of the target buffer - when the rate control
|
|
buffer falls below this percentage, frames will be dropped until it
|
|
has refilled above the threshold. Defaults to zero (no frames are
|
|
dropped).
|
|
|
|
@item denoise-noise-level (@emph{level})
|
|
Amount of noise to be removed for grain synthesis. Grain synthesis is disabled if
|
|
this option is not set or set to 0.
|
|
|
|
@item denoise-block-size (@emph{pixels})
|
|
Block size used for denoising for grain synthesis. If not set, AV1 codec
|
|
uses the default value of 32.
|
|
|
|
@item undershoot-pct (@emph{pct})
|
|
Set datarate undershoot (min) percentage of the target bitrate. Range is -1 to 100.
|
|
Default is -1.
|
|
|
|
@item overshoot-pct (@emph{pct})
|
|
Set datarate overshoot (max) percentage of the target bitrate. Range is -1 to 1000.
|
|
Default is -1.
|
|
|
|
@item minsection-pct (@emph{pct})
|
|
Minimum percentage variation of the GOP bitrate from the target bitrate. If minsection-pct
|
|
is not set, the libaomenc wrapper computes it as follows: @code{(minrate * 100 / bitrate)}.
|
|
Range is -1 to 100. Default is -1 (unset).
|
|
|
|
@item maxsection-pct (@emph{pct})
|
|
Maximum percentage variation of the GOP bitrate from the target bitrate. If maxsection-pct
|
|
is not set, the libaomenc wrapper computes it as follows: @code{(maxrate * 100 / bitrate)}.
|
|
Range is -1 to 5000. Default is -1 (unset).
|
|
|
|
@item frame-parallel (@emph{boolean})
|
|
Enable frame parallel decodability features. Default is true.
|
|
|
|
@item tiles
|
|
Set the number of tiles to encode the input video with, as columns x
|
|
rows. Larger numbers allow greater parallelism in both encoding and
|
|
decoding, but may decrease coding efficiency. Defaults to the minimum
|
|
number of tiles required by the size of the input video (this is 1x1
|
|
(that is, a single tile) for sizes up to and including 4K).
|
|
|
|
@item tile-columns tile-rows
|
|
Set the number of tiles as log2 of the number of tile rows and columns.
|
|
Provided for compatibility with libvpx/VP9.
|
|
|
|
@item row-mt (Requires libaom >= 1.0.0-759-g90a15f4f2)
|
|
Enable row based multi-threading. Disabled by default.
|
|
|
|
@item enable-cdef (@emph{boolean})
|
|
Enable Constrained Directional Enhancement Filter. The libaom-av1
|
|
encoder enables CDEF by default.
|
|
|
|
@item enable-restoration (@emph{boolean})
|
|
Enable Loop Restoration Filter. Default is true for libaom-av1.
|
|
|
|
@item enable-global-motion (@emph{boolean})
|
|
Enable the use of global motion for block prediction. Default is true.
|
|
|
|
@item enable-intrabc (@emph{boolean})
|
|
Enable block copy mode for intra block prediction. This mode is
|
|
useful for screen content. Default is true.
|
|
|
|
@item enable-rect-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
|
|
Enable rectangular partitions. Default is true.
|
|
|
|
@item enable-1to4-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
|
|
Enable 1:4/4:1 partitions. Default is true.
|
|
|
|
@item enable-ab-partitions (@emph{boolean}) (Requires libaom >= v2.0.0)
|
|
Enable AB shape partitions. Default is true.
|
|
|
|
@item enable-angle-delta (@emph{boolean}) (Requires libaom >= v2.0.0)
|
|
Enable angle delta intra prediction. Default is true.
|
|
|
|
@item enable-cfl-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
|
|
Enable chroma predicted from luma intra prediction. Default is true.
|
|
|
|
@item enable-filter-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
|
|
Enable filter intra predictor. Default is true.
|
|
|
|
@item enable-intra-edge-filter (@emph{boolean}) (Requires libaom >= v2.0.0)
|
|
Enable intra edge filter. Default is true.
|
|
|
|
@item enable-smooth-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
|
|
Enable smooth intra prediction mode. Default is true.
|
|
|
|
@item enable-paeth-intra (@emph{boolean}) (Requires libaom >= v2.0.0)
|
|
Enable paeth predictor in intra prediction. Default is true.
|
|
|
|
@item enable-palette (@emph{boolean}) (Requires libaom >= v2.0.0)
|
|
Enable palette prediction mode. Default is true.
|
|
|
|
@end table
|
|
|
|
@section libkvazaar
|
|
|
|
Kvazaar H.265/HEVC encoder.
|
|
|
|
Requires the presence of the libkvazaar headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@option{--enable-libkvazaar}.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
|
|
@item b
|
|
Set target video bitrate in bit/s and enable rate control.
|
|
|
|
@item kvazaar-params
|
|
Set kvazaar parameters as a list of @var{name}=@var{value} pairs separated
|
|
by commas (,). See kvazaar documentation for a list of options.
|
|
|
|
@end table
|
|
|
|
@section libopenh264
|
|
|
|
Cisco libopenh264 H.264/MPEG-4 AVC encoder wrapper.
|
|
|
|
This encoder requires the presence of the libopenh264 headers and
|
|
library during configuration. You need to explicitly configure the
|
|
build with @code{--enable-libopenh264}. The library is detected using
|
|
@command{pkg-config}.
|
|
|
|
For more information about the library see
|
|
@url{http://www.openh264.org}.
|
|
|
|
@subsection Options
|
|
|
|
The following FFmpeg global options affect the configurations of the
|
|
libopenh264 encoder.
|
|
|
|
@table @option
|
|
@item b
|
|
Set the bitrate (as a number of bits per second).
|
|
|
|
@item g
|
|
Set the GOP size.
|
|
|
|
@item maxrate
|
|
Set the max bitrate (as a number of bits per second).
|
|
|
|
@item flags +global_header
|
|
Set global header in the bitstream.
|
|
|
|
@item slices
|
|
Set the number of slices, used in parallelized encoding. Default value
|
|
is 0. This is only used when @option{slice_mode} is set to
|
|
@samp{fixed}.
|
|
|
|
@item slice_mode
|
|
Set slice mode. Can assume one of the following possible values:
|
|
|
|
@table @samp
|
|
@item fixed
|
|
a fixed number of slices
|
|
@item rowmb
|
|
one slice per row of macroblocks
|
|
@item auto
|
|
automatic number of slices according to number of threads
|
|
@item dyn
|
|
dynamic slicing
|
|
@end table
|
|
|
|
Default value is @samp{auto}.
|
|
|
|
@item loopfilter
|
|
Enable loop filter, if set to 1 (automatically enabled). To disable
|
|
set a value of 0.
|
|
|
|
@item profile
|
|
Set profile restrictions. If set to the value of @samp{main} enable
|
|
CABAC (set the @code{SEncParamExt.iEntropyCodingModeFlag} flag to 1).
|
|
|
|
@item max_nal_size
|
|
Set maximum NAL size in bytes.
|
|
|
|
@item allow_skip_frames
|
|
Allow skipping frames to hit the target bitrate if set to 1.
|
|
@end table
|
|
|
|
@section libtheora
|
|
|
|
libtheora Theora encoder wrapper.
|
|
|
|
Requires the presence of the libtheora headers and library during
|
|
configuration. You need to explicitly configure the build with
|
|
@code{--enable-libtheora}.
|
|
|
|
For more information about the libtheora project see
|
|
@url{http://www.theora.org/}.
|
|
|
|
@subsection Options
|
|
|
|
The following global options are mapped to internal libtheora options
|
|
which affect the quality and the bitrate of the encoded stream.
|
|
|
|
@table @option
|
|
@item b
|
|
Set the video bitrate in bit/s for CBR (Constant Bit Rate) mode. In
|
|
case VBR (Variable Bit Rate) mode is enabled this option is ignored.
|
|
|
|
@item flags
|
|
Used to enable constant quality mode (VBR) encoding through the
|
|
@option{qscale} flag, and to enable the @code{pass1} and @code{pass2}
|
|
modes.
|
|
|
|
@item g
|
|
Set the GOP size.
|
|
|
|
@item global_quality
|
|
Set the global quality as an integer in lambda units.
|
|
|
|
Only relevant when VBR mode is enabled with @code{flags +qscale}. The
|
|
value is converted to QP units by dividing it by @code{FF_QP2LAMBDA},
|
|
clipped in the [0 - 10] range, and then multiplied by 6.3 to get a
|
|
value in the native libtheora range [0-63]. A higher value corresponds
|
|
to a higher quality.
|
|
|
|
@item q
|
|
Enable VBR mode when set to a non-negative value, and set constant
|
|
quality value as a double floating point value in QP units.
|
|
|
|
The value is clipped in the [0-10] range, and then multiplied by 6.3
|
|
to get a value in the native libtheora range [0-63].
|
|
|
|
This option is valid only using the @command{ffmpeg} command-line
|
|
tool. For library interface users, use @option{global_quality}.
|
|
@end table
|
|
|
|
@subsection Examples
|
|
|
|
@itemize
|
|
@item
|
|
Set maximum constant quality (VBR) encoding with @command{ffmpeg}:
|
|
@example
|
|
ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
|
|
@end example
|
|
|
|
@item
|
|
Use @command{ffmpeg} to convert a CBR 1000 kbps Theora video stream:
|
|
@example
|
|
ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
|
|
@end example
|
|
@end itemize
|
|
|
|
@section libvpx
|
|
|
|
VP8/VP9 format supported through libvpx.
|
|
|
|
Requires the presence of the libvpx headers and library during configuration.
|
|
You need to explicitly configure the build with @code{--enable-libvpx}.
|
|
|
|
@subsection Options
|
|
|
|
The following options are supported by the libvpx wrapper. The
|
|
@command{vpxenc}-equivalent options or values are listed in parentheses
|
|
for easy migration.
|
|
|
|
To reduce the duplication of documentation, only the private options
|
|
and some others requiring special attention are documented here. For
|
|
the documentation of the undocumented generic options, see
|
|
@ref{codec-options,,the Codec Options chapter}.
|
|
|
|
To get more documentation of the libvpx options, invoke the command
|
|
@command{ffmpeg -h encoder=libvpx}, @command{ffmpeg -h encoder=libvpx-vp9} or
|
|
@command{vpxenc --help}. Further information is available in the libvpx API
|
|
documentation.
|
|
|
|
@table @option
|
|
|
|
@item b (@emph{target-bitrate})
|
|
Set bitrate in bits/s. Note that FFmpeg's @option{b} option is
|
|
expressed in bits/s, while @command{vpxenc}'s @option{target-bitrate} is in
|
|
kilobits/s.
|
|
|
|
@item g (@emph{kf-max-dist})
|
|
|
|
@item keyint_min (@emph{kf-min-dist})
|
|
|
|
@item qmin (@emph{min-q})
|
|
|
|
@item qmax (@emph{max-q})
|
|
|
|
@item bufsize (@emph{buf-sz}, @emph{buf-optimal-sz})
|
|
Set ratecontrol buffer size (in bits). Note @command{vpxenc}'s options are
|
|
specified in milliseconds, the libvpx wrapper converts this value as follows:
|
|
@code{buf-sz = bufsize * 1000 / bitrate},
|
|
@code{buf-optimal-sz = bufsize * 1000 / bitrate * 5 / 6}.
|
|
|
|
@item rc_init_occupancy (@emph{buf-initial-sz})
|
|
Set number of bits which should be loaded into the rc buffer before decoding
|
|
starts. Note @command{vpxenc}'s option is specified in milliseconds, the libvpx
|
|
wrapper converts this value as follows:
|
|
@code{rc_init_occupancy * 1000 / bitrate}.
|
|
|
|
@item undershoot-pct
|
|
Set datarate undershoot (min) percentage of the target bitrate.
|
|
|
|
@item overshoot-pct
|
|
Set datarate overshoot (max) percentage of the target bitrate.
|
|
|
|
@item skip_threshold (@emph{drop-frame})
|
|
|
|
@item qcomp (@emph{bias-pct})
|
|
|
|
@item maxrate (@emph{maxsection-pct})
|
|
Set GOP max bitrate in bits/s. Note @command{vpxenc}'s option is specified as a
|
|
percentage of the target bitrate, the libvpx wrapper converts this value as
|
|
follows: @code{(maxrate * 100 / bitrate)}.
|
|
|
|
@item minrate (@emph{minsection-pct})
|
|
Set GOP min bitrate in bits/s. Note @command{vpxenc}'s option is specified as a
|
|
percentage of the target bitrate, the libvpx wrapper converts this value as
|
|
follows: @code{(minrate * 100 / bitrate)}.
|
|
|
|
@item minrate, maxrate, b @emph{end-usage=cbr}
|
|
@code{(minrate == maxrate == bitrate)}.
|
|
|
|
@item crf (@emph{end-usage=cq}, @emph{cq-level})
|
|
|
|
@item tune (@emph{tune})
|
|
@table @samp
|
|
@item psnr (@emph{psnr})
|
|
@item ssim (@emph{ssim})
|
|
@end table
|
|
|
|
@item quality, deadline (@emph{deadline})
|
|
@table @samp
|
|
@item best
|
|
Use best quality deadline. Poorly named and quite slow, this option should be
|
|
avoided as it may give worse quality output than good.
|
|
@item good
|
|
Use good quality deadline. This is a good trade-off between speed and quality
|
|
when used with the @option{cpu-used} option.
|
|
@item realtime
|
|
Use realtime quality deadline.
|
|
@end table
|
|
|
|
@item speed, cpu-used (@emph{cpu-used})
|
|
Set quality/speed ratio modifier. Higher values speed up the encode at the cost
|
|
of quality.
|
|
|
|
@item nr (@emph{noise-sensitivity})
|
|
|
|
@item static-thresh
|
|
Set a change threshold on blocks below which they will be skipped by the
|
|
encoder.
|
|
|
|
@item slices (@emph{token-parts})
|
|
Note that FFmpeg's @option{slices} option gives the total number of partitions,
|
|
while @command{vpxenc}'s @option{token-parts} is given as
|
|
@code{log2(partitions)}.
|
|
|
|
@item max-intra-rate
|
|
Set maximum I-frame bitrate as a percentage of the target bitrate. A value of 0
|
|
means unlimited.
|
|
|
|
@item force_key_frames
|
|
@code{VPX_EFLAG_FORCE_KF}
|
|
|
|
@item Alternate reference frame related
|
|
@table @option
|
|
@item auto-alt-ref
|
|
Enable use of alternate reference frames (2-pass only).
|
|
Values greater than 1 enable multi-layer alternate reference frames (VP9 only).
|
|
@item arnr-maxframes
|
|
Set altref noise reduction max frame count.
|
|
@item arnr-type
|
|
Set altref noise reduction filter type: backward, forward, centered.
|
|
@item arnr-strength
|
|
Set altref noise reduction filter strength.
|
|
@item rc-lookahead, lag-in-frames (@emph{lag-in-frames})
|
|
Set number of frames to look ahead for frametype and ratecontrol.
|
|
@end table
|
|
|
|
@item error-resilient
|
|
Enable error resiliency features.
|
|
|
|
@item sharpness @var{integer}
|
|
Increase sharpness at the expense of lower PSNR.
|
|
The valid range is [0, 7].
|
|
|
|
@item ts-parameters
|
|
Sets the temporal scalability configuration using a :-separated list of
|
|
key=value pairs. For example, to specify temporal scalability parameters
|
|
with @code{ffmpeg}:
|
|
@example
|
|
ffmpeg -i INPUT -c:v libvpx -ts-parameters ts_number_layers=3:\
|
|
ts_target_bitrate=250,500,1000:ts_rate_decimator=4,2,1:\
|
|
ts_periodicity=4:ts_layer_id=0,2,1,2:ts_layering_mode=3 OUTPUT
|
|
@end example
|
|
Below is a brief explanation of each of the parameters, please
|
|
refer to @code{struct vpx_codec_enc_cfg} in @code{vpx/vpx_encoder.h} for more
|
|
details.
|
|
@table @option
|
|
@item ts_number_layers
|
|
Number of temporal coding layers.
|
|
@item ts_target_bitrate
|
|
Target bitrate for each temporal layer (in kbps).
|
|
(bitrate should be inclusive of the lower temporal layer).
|
|
@item ts_rate_decimator
|
|
Frame rate decimation factor for each temporal layer.
|
|
@item ts_periodicity
|
|
Length of the sequence defining frame temporal layer membership.
|
|
@item ts_layer_id
|
|
Template defining the membership of frames to temporal layers.
|
|
@item ts_layering_mode
|
|
(optional) Selecting the temporal structure from a set of pre-defined temporal layering modes.
|
|
Currently supports the following options.
|
|
@table @option
|
|
@item 0
|
|
No temporal layering flags are provided internally,
|
|
relies on flags being passed in using @code{metadata} field in @code{AVFrame}
|
|
with following keys.
|
|
@table @option
|
|
@item vp8-flags
|
|
Sets the flags passed into the encoder to indicate the referencing scheme for
|
|
the current frame.
|
|
Refer to function @code{vpx_codec_encode} in @code{vpx/vpx_encoder.h} for more
|
|
details.
|
|
@item temporal_id
|
|
Explicitly sets the temporal id of the current frame to encode.
|
|
@end table
|
|
@item 2
|
|
Two temporal layers. 0-1...
|
|
@item 3
|
|
Three temporal layers. 0-2-1-2...; with single reference frame.
|
|
@item 4
|
|
Same as option "3", except there is a dependency between
|
|
the two temporal layer 2 frames within the temporal period.
|
|
@end table
|
|
@end table
|
|
|
|
@item VP9-specific options
|
|
@table @option
|
|
@item lossless
|
|
Enable lossless mode.
|
|
@item tile-columns
|
|
Set number of tile columns to use. Note this is given as
|
|
@code{log2(tile_columns)}. For example, 8 tile columns would be requested by
|
|
setting the @option{tile-columns} option to 3.
|
|
@item tile-rows
|
|
Set number of tile rows to use. Note this is given as @code{log2(tile_rows)}.
|
|
For example, 4 tile rows would be requested by setting the @option{tile-rows}
|
|
option to 2.
|
|
@item frame-parallel
|
|
Enable frame parallel decodability features.
|
|
@item aq-mode
|
|
Set adaptive quantization mode (0: off (default), 1: variance 2: complexity, 3:
|
|
cyclic refresh, 4: equator360).
|
|
@item colorspace @emph{color-space}
|
|
Set input color space. The VP9 bitstream supports signaling the following
|
|
colorspaces:
|
|
@table @option
|
|
@item @samp{rgb} @emph{sRGB}
|
|
@item @samp{bt709} @emph{bt709}
|
|
@item @samp{unspecified} @emph{unknown}
|
|
@item @samp{bt470bg} @emph{bt601}
|
|
@item @samp{smpte170m} @emph{smpte170}
|
|
@item @samp{smpte240m} @emph{smpte240}
|
|
@item @samp{bt2020_ncl} @emph{bt2020}
|
|
@end table
|
|
@item row-mt @var{boolean}
|
|
Enable row based multi-threading.
|
|
@item tune-content
|
|
Set content type: default (0), screen (1), film (2).
|
|
@item corpus-complexity
|
|
Corpus VBR mode is a variant of standard VBR where the complexity distribution
|
|
midpoint is passed in rather than calculated for a specific clip or chunk.
|
|
|
|
The valid range is [0, 10000]. 0 (default) uses standard VBR.
|
|
@item enable-tpl @var{boolean}
|
|
Enable temporal dependency model.
|
|
@end table
|
|
|
|
@end table
|
|
|
|
For more information about libvpx see:
|
|
@url{http://www.webmproject.org/}
|
|
|
|
@section libwebp
|
|
|
|
libwebp WebP Image encoder wrapper
|
|
|
|
libwebp is Google's official encoder for WebP images. It can encode in either
|
|
lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
|
|
frame. Lossless images are a separate codec developed by Google.
|
|
|
|
@subsection Pixel Format
|
|
|
|
Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
|
|
to limitations of the format and libwebp. Alpha is supported for either mode.
|
|
Because of API limitations, if RGB is passed in when encoding lossy or YUV is
|
|
passed in for encoding lossless, the pixel format will automatically be
|
|
converted using functions from libwebp. This is not ideal and is done only for
|
|
convenience.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
|
|
@item -lossless @var{boolean}
|
|
Enables/Disables use of lossless mode. Default is 0.
|
|
|
|
@item -compression_level @var{integer}
|
|
For lossy, this is a quality/speed tradeoff. Higher values give better quality
|
|
for a given size at the cost of increased encoding time. For lossless, this is
|
|
a size/speed tradeoff. Higher values give smaller size at the cost of increased
|
|
encoding time. More specifically, it controls the number of extra algorithms
|
|
and compression tools used, and varies the combination of these tools. This
|
|
maps to the @var{method} option in libwebp. The valid range is 0 to 6.
|
|
Default is 4.
|
|
|
|
@item -qscale @var{float}
|
|
For lossy encoding, this controls image quality, 0 to 100. For lossless
|
|
encoding, this controls the effort and time spent at compressing more. The
|
|
default value is 75. Note that for usage via libavcodec, this option is called
|
|
@var{global_quality} and must be multiplied by @var{FF_QP2LAMBDA}.
|
|
|
|
@item -preset @var{type}
|
|
Configuration preset. This does some automatic settings based on the general
|
|
type of the image.
|
|
@table @option
|
|
@item none
|
|
Do not use a preset.
|
|
@item default
|
|
Use the encoder default.
|
|
@item picture
|
|
Digital picture, like portrait, inner shot
|
|
@item photo
|
|
Outdoor photograph, with natural lighting
|
|
@item drawing
|
|
Hand or line drawing, with high-contrast details
|
|
@item icon
|
|
Small-sized colorful images
|
|
@item text
|
|
Text-like
|
|
@end table
|
|
|
|
@end table
|
|
|
|
@section libx264, libx264rgb
|
|
|
|
x264 H.264/MPEG-4 AVC encoder wrapper.
|
|
|
|
This encoder requires the presence of the libx264 headers and library
|
|
during configuration. You need to explicitly configure the build with
|
|
@code{--enable-libx264}.
|
|
|
|
libx264 supports an impressive number of features, including 8x8 and
|
|
4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
|
|
entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
|
|
for detail retention (adaptive quantization, psy-RD, psy-trellis).
|
|
|
|
Many libx264 encoder options are mapped to FFmpeg global codec
|
|
options, while unique encoder options are provided through private
|
|
options. Additionally the @option{x264opts} and @option{x264-params}
|
|
private options allows one to pass a list of key=value tuples as accepted
|
|
by the libx264 @code{x264_param_parse} function.
|
|
|
|
The x264 project website is at
|
|
@url{http://www.videolan.org/developers/x264.html}.
|
|
|
|
The libx264rgb encoder is the same as libx264, except it accepts packed RGB
|
|
pixel formats as input instead of YUV.
|
|
|
|
@subsection Supported Pixel Formats
|
|
|
|
x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at
|
|
x264's configure time. FFmpeg only supports one bit depth in one particular
|
|
build. In other words, it is not possible to build one FFmpeg with multiple
|
|
versions of x264 with different bit depths.
|
|
|
|
@subsection Options
|
|
|
|
The following options are supported by the libx264 wrapper. The
|
|
@command{x264}-equivalent options or values are listed in parentheses
|
|
for easy migration.
|
|
|
|
To reduce the duplication of documentation, only the private options
|
|
and some others requiring special attention are documented here. For
|
|
the documentation of the undocumented generic options, see
|
|
@ref{codec-options,,the Codec Options chapter}.
|
|
|
|
To get a more accurate and extensive documentation of the libx264
|
|
options, invoke the command @command{x264 --fullhelp} or consult
|
|
the libx264 documentation.
|
|
|
|
@table @option
|
|
@item b (@emph{bitrate})
|
|
Set bitrate in bits/s. Note that FFmpeg's @option{b} option is
|
|
expressed in bits/s, while @command{x264}'s @option{bitrate} is in
|
|
kilobits/s.
|
|
|
|
@item bf (@emph{bframes})
|
|
|
|
@item g (@emph{keyint})
|
|
|
|
@item qmin (@emph{qpmin})
|
|
Minimum quantizer scale.
|
|
|
|
@item qmax (@emph{qpmax})
|
|
Maximum quantizer scale.
|
|
|
|
@item qdiff (@emph{qpstep})
|
|
Maximum difference between quantizer scales.
|
|
|
|
@item qblur (@emph{qblur})
|
|
Quantizer curve blur
|
|
|
|
@item qcomp (@emph{qcomp})
|
|
Quantizer curve compression factor
|
|
|
|
@item refs (@emph{ref})
|
|
Number of reference frames each P-frame can use. The range is from @var{0-16}.
|
|
|
|
@item sc_threshold (@emph{scenecut})
|
|
Sets the threshold for the scene change detection.
|
|
|
|
@item trellis (@emph{trellis})
|
|
Performs Trellis quantization to increase efficiency. Enabled by default.
|
|
|
|
@item nr (@emph{nr})
|
|
|
|
@item me_range (@emph{merange})
|
|
Maximum range of the motion search in pixels.
|
|
|
|
@item me_method (@emph{me})
|
|
Set motion estimation method. Possible values in the decreasing order
|
|
of speed:
|
|
|
|
@table @samp
|
|
@item dia (@emph{dia})
|
|
@item epzs (@emph{dia})
|
|
Diamond search with radius 1 (fastest). @samp{epzs} is an alias for
|
|
@samp{dia}.
|
|
@item hex (@emph{hex})
|
|
Hexagonal search with radius 2.
|
|
@item umh (@emph{umh})
|
|
Uneven multi-hexagon search.
|
|
@item esa (@emph{esa})
|
|
Exhaustive search.
|
|
@item tesa (@emph{tesa})
|
|
Hadamard exhaustive search (slowest).
|
|
@end table
|
|
|
|
@item forced-idr
|
|
Normally, when forcing a I-frame type, the encoder can select any type
|
|
of I-frame. This option forces it to choose an IDR-frame.
|
|
|
|
@item subq (@emph{subme})
|
|
Sub-pixel motion estimation method.
|
|
|
|
@item b_strategy (@emph{b-adapt})
|
|
Adaptive B-frame placement decision algorithm. Use only on first-pass.
|
|
|
|
@item keyint_min (@emph{min-keyint})
|
|
Minimum GOP size.
|
|
|
|
@item coder
|
|
Set entropy encoder. Possible values:
|
|
|
|
@table @samp
|
|
@item ac
|
|
Enable CABAC.
|
|
|
|
@item vlc
|
|
Enable CAVLC and disable CABAC. It generates the same effect as
|
|
@command{x264}'s @option{--no-cabac} option.
|
|
@end table
|
|
|
|
@item cmp
|
|
Set full pixel motion estimation comparison algorithm. Possible values:
|
|
|
|
@table @samp
|
|
@item chroma
|
|
Enable chroma in motion estimation.
|
|
|
|
@item sad
|
|
Ignore chroma in motion estimation. It generates the same effect as
|
|
@command{x264}'s @option{--no-chroma-me} option.
|
|
@end table
|
|
|
|
@item threads (@emph{threads})
|
|
Number of encoding threads.
|
|
|
|
@item thread_type
|
|
Set multithreading technique. Possible values:
|
|
|
|
@table @samp
|
|
@item slice
|
|
Slice-based multithreading. It generates the same effect as
|
|
@command{x264}'s @option{--sliced-threads} option.
|
|
@item frame
|
|
Frame-based multithreading.
|
|
@end table
|
|
|
|
@item flags
|
|
Set encoding flags. It can be used to disable closed GOP and enable
|
|
open GOP by setting it to @code{-cgop}. The result is similar to
|
|
the behavior of @command{x264}'s @option{--open-gop} option.
|
|
|
|
@item rc_init_occupancy (@emph{vbv-init})
|
|
|
|
@item preset (@emph{preset})
|
|
Set the encoding preset.
|
|
|
|
@item tune (@emph{tune})
|
|
Set tuning of the encoding params.
|
|
|
|
@item profile (@emph{profile})
|
|
Set profile restrictions.
|
|
|
|
@item fastfirstpass
|
|
Enable fast settings when encoding first pass, when set to 1. When set
|
|
to 0, it has the same effect of @command{x264}'s
|
|
@option{--slow-firstpass} option.
|
|
|
|
@item crf (@emph{crf})
|
|
Set the quality for constant quality mode.
|
|
|
|
@item crf_max (@emph{crf-max})
|
|
In CRF mode, prevents VBV from lowering quality beyond this point.
|
|
|
|
@item qp (@emph{qp})
|
|
Set constant quantization rate control method parameter.
|
|
|
|
@item aq-mode (@emph{aq-mode})
|
|
Set AQ method. Possible values:
|
|
|
|
@table @samp
|
|
@item none (@emph{0})
|
|
Disabled.
|
|
|
|
@item variance (@emph{1})
|
|
Variance AQ (complexity mask).
|
|
|
|
@item autovariance (@emph{2})
|
|
Auto-variance AQ (experimental).
|
|
@end table
|
|
|
|
@item aq-strength (@emph{aq-strength})
|
|
Set AQ strength, reduce blocking and blurring in flat and textured areas.
|
|
|
|
@item psy
|
|
Use psychovisual optimizations when set to 1. When set to 0, it has the
|
|
same effect as @command{x264}'s @option{--no-psy} option.
|
|
|
|
@item psy-rd (@emph{psy-rd})
|
|
Set strength of psychovisual optimization, in
|
|
@var{psy-rd}:@var{psy-trellis} format.
|
|
|
|
@item rc-lookahead (@emph{rc-lookahead})
|
|
Set number of frames to look ahead for frametype and ratecontrol.
|
|
|
|
@item weightb
|
|
Enable weighted prediction for B-frames when set to 1. When set to 0,
|
|
it has the same effect as @command{x264}'s @option{--no-weightb} option.
|
|
|
|
@item weightp (@emph{weightp})
|
|
Set weighted prediction method for P-frames. Possible values:
|
|
|
|
@table @samp
|
|
@item none (@emph{0})
|
|
Disabled
|
|
@item simple (@emph{1})
|
|
Enable only weighted refs
|
|
@item smart (@emph{2})
|
|
Enable both weighted refs and duplicates
|
|
@end table
|
|
|
|
@item ssim (@emph{ssim})
|
|
Enable calculation and printing SSIM stats after the encoding.
|
|
|
|
@item intra-refresh (@emph{intra-refresh})
|
|
Enable the use of Periodic Intra Refresh instead of IDR frames when set
|
|
to 1.
|
|
|
|
@item avcintra-class (@emph{class})
|
|
Configure the encoder to generate AVC-Intra.
|
|
Valid values are 50,100 and 200
|
|
|
|
@item bluray-compat (@emph{bluray-compat})
|
|
Configure the encoder to be compatible with the bluray standard.
|
|
It is a shorthand for setting "bluray-compat=1 force-cfr=1".
|
|
|
|
@item b-bias (@emph{b-bias})
|
|
Set the influence on how often B-frames are used.
|
|
|
|
@item b-pyramid (@emph{b-pyramid})
|
|
Set method for keeping of some B-frames as references. Possible values:
|
|
|
|
@table @samp
|
|
@item none (@emph{none})
|
|
Disabled.
|
|
@item strict (@emph{strict})
|
|
Strictly hierarchical pyramid.
|
|
@item normal (@emph{normal})
|
|
Non-strict (not Blu-ray compatible).
|
|
@end table
|
|
|
|
@item mixed-refs
|
|
Enable the use of one reference per partition, as opposed to one
|
|
reference per macroblock when set to 1. When set to 0, it has the
|
|
same effect as @command{x264}'s @option{--no-mixed-refs} option.
|
|
|
|
@item 8x8dct
|
|
Enable adaptive spatial transform (high profile 8x8 transform)
|
|
when set to 1. When set to 0, it has the same effect as
|
|
@command{x264}'s @option{--no-8x8dct} option.
|
|
|
|
@item fast-pskip
|
|
Enable early SKIP detection on P-frames when set to 1. When set
|
|
to 0, it has the same effect as @command{x264}'s
|
|
@option{--no-fast-pskip} option.
|
|
|
|
@item aud (@emph{aud})
|
|
Enable use of access unit delimiters when set to 1.
|
|
|
|
@item mbtree
|
|
Enable use macroblock tree ratecontrol when set to 1. When set
|
|
to 0, it has the same effect as @command{x264}'s
|
|
@option{--no-mbtree} option.
|
|
|
|
@item deblock (@emph{deblock})
|
|
Set loop filter parameters, in @var{alpha}:@var{beta} form.
|
|
|
|
@item cplxblur (@emph{cplxblur})
|
|
Set fluctuations reduction in QP (before curve compression).
|
|
|
|
@item partitions (@emph{partitions})
|
|
Set partitions to consider as a comma-separated list of. Possible
|
|
values in the list:
|
|
|
|
@table @samp
|
|
@item p8x8
|
|
8x8 P-frame partition.
|
|
@item p4x4
|
|
4x4 P-frame partition.
|
|
@item b8x8
|
|
4x4 B-frame partition.
|
|
@item i8x8
|
|
8x8 I-frame partition.
|
|
@item i4x4
|
|
4x4 I-frame partition.
|
|
(Enabling @samp{p4x4} requires @samp{p8x8} to be enabled. Enabling
|
|
@samp{i8x8} requires adaptive spatial transform (@option{8x8dct}
|
|
option) to be enabled.)
|
|
@item none (@emph{none})
|
|
Do not consider any partitions.
|
|
@item all (@emph{all})
|
|
Consider every partition.
|
|
@end table
|
|
|
|
@item direct-pred (@emph{direct})
|
|
Set direct MV prediction mode. Possible values:
|
|
|
|
@table @samp
|
|
@item none (@emph{none})
|
|
Disable MV prediction.
|
|
@item spatial (@emph{spatial})
|
|
Enable spatial predicting.
|
|
@item temporal (@emph{temporal})
|
|
Enable temporal predicting.
|
|
@item auto (@emph{auto})
|
|
Automatically decided.
|
|
@end table
|
|
|
|
@item slice-max-size (@emph{slice-max-size})
|
|
Set the limit of the size of each slice in bytes. If not specified
|
|
but RTP payload size (@option{ps}) is specified, that is used.
|
|
|
|
@item stats (@emph{stats})
|
|
Set the file name for multi-pass stats.
|
|
|
|
@item nal-hrd (@emph{nal-hrd})
|
|
Set signal HRD information (requires @option{vbv-bufsize} to be set).
|
|
Possible values:
|
|
|
|
@table @samp
|
|
@item none (@emph{none})
|
|
Disable HRD information signaling.
|
|
@item vbr (@emph{vbr})
|
|
Variable bit rate.
|
|
@item cbr (@emph{cbr})
|
|
Constant bit rate (not allowed in MP4 container).
|
|
@end table
|
|
|
|
@item x264opts (N.A.)
|
|
Set any x264 option, see @command{x264 --fullhelp} for a list.
|
|
|
|
Argument is a list of @var{key}=@var{value} couples separated by
|
|
":". In @var{filter} and @var{psy-rd} options that use ":" as a separator
|
|
themselves, use "," instead. They accept it as well since long ago but this
|
|
is kept undocumented for some reason.
|
|
|
|
For example to specify libx264 encoding options with @command{ffmpeg}:
|
|
@example
|
|
ffmpeg -i foo.mpg -c:v libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
|
|
@end example
|
|
|
|
@item a53cc @var{boolean}
|
|
Import closed captions (which must be ATSC compatible format) into output.
|
|
Only the mpeg2 and h264 decoders provide these. Default is 1 (on).
|
|
|
|
@item x264-params (N.A.)
|
|
Override the x264 configuration using a :-separated list of key=value
|
|
parameters.
|
|
|
|
This option is functionally the same as the @option{x264opts}, but is
|
|
duplicated for compatibility with the Libav fork.
|
|
|
|
For example to specify libx264 encoding options with @command{ffmpeg}:
|
|
@example
|
|
ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
|
|
cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
|
|
no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
|
|
@end example
|
|
@end table
|
|
|
|
Encoding ffpresets for common usages are provided so they can be used with the
|
|
general presets system (e.g. passing the @option{pre} option).
|
|
|
|
@section libx265
|
|
|
|
x265 H.265/HEVC encoder wrapper.
|
|
|
|
This encoder requires the presence of the libx265 headers and library
|
|
during configuration. You need to explicitly configure the build with
|
|
@option{--enable-libx265}.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item b
|
|
Sets target video bitrate.
|
|
|
|
@item bf
|
|
|
|
@item g
|
|
Set the GOP size.
|
|
|
|
@item keyint_min
|
|
Minimum GOP size.
|
|
|
|
@item refs
|
|
Number of reference frames each P-frame can use. The range is from @var{1-16}.
|
|
|
|
@item preset
|
|
Set the x265 preset.
|
|
|
|
@item tune
|
|
Set the x265 tune parameter.
|
|
|
|
@item profile
|
|
Set profile restrictions.
|
|
|
|
@item crf
|
|
Set the quality for constant quality mode.
|
|
|
|
@item qp
|
|
Set constant quantization rate control method parameter.
|
|
|
|
@item qmin
|
|
Minimum quantizer scale.
|
|
|
|
@item qmax
|
|
Maximum quantizer scale.
|
|
|
|
@item qdiff
|
|
Maximum difference between quantizer scales.
|
|
|
|
@item qblur
|
|
Quantizer curve blur
|
|
|
|
@item qcomp
|
|
Quantizer curve compression factor
|
|
|
|
@item i_qfactor
|
|
|
|
@item b_qfactor
|
|
|
|
@item forced-idr
|
|
Normally, when forcing a I-frame type, the encoder can select any type
|
|
of I-frame. This option forces it to choose an IDR-frame.
|
|
|
|
@item x265-params
|
|
Set x265 options using a list of @var{key}=@var{value} couples separated
|
|
by ":". See @command{x265 --help} for a list of options.
|
|
|
|
For example to specify libx265 encoding options with @option{-x265-params}:
|
|
|
|
@example
|
|
ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
|
|
@end example
|
|
@end table
|
|
|
|
@section libxavs2
|
|
|
|
xavs2 AVS2-P2/IEEE1857.4 encoder wrapper.
|
|
|
|
This encoder requires the presence of the libxavs2 headers and library
|
|
during configuration. You need to explicitly configure the build with
|
|
@option{--enable-libxavs2}.
|
|
|
|
The following standard libavcodec options are used:
|
|
@itemize
|
|
@item
|
|
@option{b} / @option{bit_rate}
|
|
@item
|
|
@option{g} / @option{gop_size}
|
|
@item
|
|
@option{bf} / @option{max_b_frames}
|
|
@end itemize
|
|
|
|
The encoder also has its own specific options:
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item lcu_row_threads
|
|
Set the number of parallel threads for rows from 1 to 8 (default 5).
|
|
|
|
@item initial_qp
|
|
Set the xavs2 quantization parameter from 1 to 63 (default 34). This is
|
|
used to set the initial qp for the first frame.
|
|
|
|
@item qp
|
|
Set the xavs2 quantization parameter from 1 to 63 (default 34). This is
|
|
used to set the qp value under constant-QP mode.
|
|
|
|
@item max_qp
|
|
Set the max qp for rate control from 1 to 63 (default 55).
|
|
|
|
@item min_qp
|
|
Set the min qp for rate control from 1 to 63 (default 20).
|
|
|
|
@item speed_level
|
|
Set the Speed level from 0 to 9 (default 0). Higher is better but slower.
|
|
|
|
@item log_level
|
|
Set the log level from -1 to 3 (default 0). -1: none, 0: error,
|
|
1: warning, 2: info, 3: debug.
|
|
|
|
@item xavs2-params
|
|
Set xavs2 options using a list of @var{key}=@var{value} couples separated
|
|
by ":".
|
|
|
|
For example to specify libxavs2 encoding options with @option{-xavs2-params}:
|
|
|
|
@example
|
|
ffmpeg -i input -c:v libxavs2 -xavs2-params RdoqLevel=0 output.avs2
|
|
@end example
|
|
@end table
|
|
|
|
@section libxvid
|
|
|
|
Xvid MPEG-4 Part 2 encoder wrapper.
|
|
|
|
This encoder requires the presence of the libxvidcore headers and library
|
|
during configuration. You need to explicitly configure the build with
|
|
@code{--enable-libxvid --enable-gpl}.
|
|
|
|
The native @code{mpeg4} encoder supports the MPEG-4 Part 2 format, so
|
|
users can encode to this format without this library.
|
|
|
|
@subsection Options
|
|
|
|
The following options are supported by the libxvid wrapper. Some of
|
|
the following options are listed but are not documented, and
|
|
correspond to shared codec options. See @ref{codec-options,,the Codec
|
|
Options chapter} for their documentation. The other shared options
|
|
which are not listed have no effect for the libxvid encoder.
|
|
|
|
@table @option
|
|
@item b
|
|
|
|
@item g
|
|
|
|
@item qmin
|
|
|
|
@item qmax
|
|
|
|
@item mpeg_quant
|
|
|
|
@item threads
|
|
|
|
@item bf
|
|
|
|
@item b_qfactor
|
|
|
|
@item b_qoffset
|
|
|
|
@item flags
|
|
Set specific encoding flags. Possible values:
|
|
|
|
@table @samp
|
|
|
|
@item mv4
|
|
Use four motion vector by macroblock.
|
|
|
|
@item aic
|
|
Enable high quality AC prediction.
|
|
|
|
@item gray
|
|
Only encode grayscale.
|
|
|
|
@item gmc
|
|
Enable the use of global motion compensation (GMC).
|
|
|
|
@item qpel
|
|
Enable quarter-pixel motion compensation.
|
|
|
|
@item cgop
|
|
Enable closed GOP.
|
|
|
|
@item global_header
|
|
Place global headers in extradata instead of every keyframe.
|
|
|
|
@end table
|
|
|
|
@item trellis
|
|
|
|
@item me_method
|
|
Set motion estimation method. Possible values in decreasing order of
|
|
speed and increasing order of quality:
|
|
|
|
@table @samp
|
|
@item zero
|
|
Use no motion estimation (default).
|
|
|
|
@item phods
|
|
@item x1
|
|
@item log
|
|
Enable advanced diamond zonal search for 16x16 blocks and half-pixel
|
|
refinement for 16x16 blocks. @samp{x1} and @samp{log} are aliases for
|
|
@samp{phods}.
|
|
|
|
@item epzs
|
|
Enable all of the things described above, plus advanced diamond zonal
|
|
search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
|
|
estimation on chroma planes.
|
|
|
|
@item full
|
|
Enable all of the things described above, plus extended 16x16 and 8x8
|
|
blocks search.
|
|
@end table
|
|
|
|
@item mbd
|
|
Set macroblock decision algorithm. Possible values in the increasing
|
|
order of quality:
|
|
|
|
@table @samp
|
|
@item simple
|
|
Use macroblock comparing function algorithm (default).
|
|
|
|
@item bits
|
|
Enable rate distortion-based half pixel and quarter pixel refinement for
|
|
16x16 blocks.
|
|
|
|
@item rd
|
|
Enable all of the things described above, plus rate distortion-based
|
|
half pixel and quarter pixel refinement for 8x8 blocks, and rate
|
|
distortion-based search using square pattern.
|
|
@end table
|
|
|
|
@item lumi_aq
|
|
Enable lumi masking adaptive quantization when set to 1. Default is 0
|
|
(disabled).
|
|
|
|
@item variance_aq
|
|
Enable variance adaptive quantization when set to 1. Default is 0
|
|
(disabled).
|
|
|
|
When combined with @option{lumi_aq}, the resulting quality will not
|
|
be better than any of the two specified individually. In other
|
|
words, the resulting quality will be the worse one of the two
|
|
effects.
|
|
|
|
@item ssim
|
|
Set structural similarity (SSIM) displaying method. Possible values:
|
|
|
|
@table @samp
|
|
@item off
|
|
Disable displaying of SSIM information.
|
|
|
|
@item avg
|
|
Output average SSIM at the end of encoding to stdout. The format of
|
|
showing the average SSIM is:
|
|
|
|
@example
|
|
Average SSIM: %f
|
|
@end example
|
|
|
|
For users who are not familiar with C, %f means a float number, or
|
|
a decimal (e.g. 0.939232).
|
|
|
|
@item frame
|
|
Output both per-frame SSIM data during encoding and average SSIM at
|
|
the end of encoding to stdout. The format of per-frame information
|
|
is:
|
|
|
|
@example
|
|
SSIM: avg: %1.3f min: %1.3f max: %1.3f
|
|
@end example
|
|
|
|
For users who are not familiar with C, %1.3f means a float number
|
|
rounded to 3 digits after the dot (e.g. 0.932).
|
|
|
|
@end table
|
|
|
|
@item ssim_acc
|
|
Set SSIM accuracy. Valid options are integers within the range of
|
|
0-4, while 0 gives the most accurate result and 4 computes the
|
|
fastest.
|
|
|
|
@end table
|
|
|
|
@section MediaFoundation
|
|
|
|
This provides wrappers to encoders (both audio and video) in the
|
|
MediaFoundation framework. It can access both SW and HW encoders.
|
|
Video encoders can take input in either of nv12 or yuv420p form
|
|
(some encoders support both, some support only either - in practice,
|
|
nv12 is the safer choice, especially among HW encoders).
|
|
|
|
@section mpeg2
|
|
|
|
MPEG-2 video encoder.
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item profile
|
|
Select the mpeg2 profile to encode:
|
|
|
|
@table @samp
|
|
@item 422
|
|
@item high
|
|
@item ss
|
|
Spatially Scalable
|
|
@item snr
|
|
SNR Scalable
|
|
@item main
|
|
@item simple
|
|
@end table
|
|
|
|
@item seq_disp_ext @var{integer}
|
|
Specifies if the encoder should write a sequence_display_extension to the
|
|
output.
|
|
@table @option
|
|
@item -1
|
|
@itemx auto
|
|
Decide automatically to write it or not (this is the default) by checking if
|
|
the data to be written is different from the default or unspecified values.
|
|
@item 0
|
|
@itemx never
|
|
Never write it.
|
|
@item 1
|
|
@itemx always
|
|
Always write it.
|
|
@end table
|
|
@item video_format @var{integer}
|
|
Specifies the video_format written into the sequence display extension
|
|
indicating the source of the video pictures. The default is @samp{unspecified},
|
|
can be @samp{component}, @samp{pal}, @samp{ntsc}, @samp{secam} or @samp{mac}.
|
|
For maximum compatibility, use @samp{component}.
|
|
@item a53cc @var{boolean}
|
|
Import closed captions (which must be ATSC compatible format) into output.
|
|
Default is 1 (on).
|
|
@end table
|
|
|
|
@section png
|
|
|
|
PNG image encoder.
|
|
|
|
@subsection Private options
|
|
|
|
@table @option
|
|
@item dpi @var{integer}
|
|
Set physical density of pixels, in dots per inch, unset by default
|
|
@item dpm @var{integer}
|
|
Set physical density of pixels, in dots per meter, unset by default
|
|
@end table
|
|
|
|
@section ProRes
|
|
|
|
Apple ProRes encoder.
|
|
|
|
FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
|
|
The used encoder can be chosen with the @code{-vcodec} option.
|
|
|
|
@subsection Private Options for prores-ks
|
|
|
|
@table @option
|
|
@item profile @var{integer}
|
|
Select the ProRes profile to encode
|
|
@table @samp
|
|
@item proxy
|
|
@item lt
|
|
@item standard
|
|
@item hq
|
|
@item 4444
|
|
@item 4444xq
|
|
@end table
|
|
|
|
@item quant_mat @var{integer}
|
|
Select quantization matrix.
|
|
@table @samp
|
|
@item auto
|
|
@item default
|
|
@item proxy
|
|
@item lt
|
|
@item standard
|
|
@item hq
|
|
@end table
|
|
If set to @var{auto}, the matrix matching the profile will be picked.
|
|
If not set, the matrix providing the highest quality, @var{default}, will be
|
|
picked.
|
|
|
|
@item bits_per_mb @var{integer}
|
|
How many bits to allot for coding one macroblock. Different profiles use
|
|
between 200 and 2400 bits per macroblock, the maximum is 8000.
|
|
|
|
@item mbs_per_slice @var{integer}
|
|
Number of macroblocks in each slice (1-8); the default value (8)
|
|
should be good in almost all situations.
|
|
|
|
@item vendor @var{string}
|
|
Override the 4-byte vendor ID.
|
|
A custom vendor ID like @var{apl0} would claim the stream was produced by
|
|
the Apple encoder.
|
|
|
|
@item alpha_bits @var{integer}
|
|
Specify number of bits for alpha component.
|
|
Possible values are @var{0}, @var{8} and @var{16}.
|
|
Use @var{0} to disable alpha plane coding.
|
|
|
|
@end table
|
|
|
|
@subsection Speed considerations
|
|
|
|
In the default mode of operation the encoder has to honor frame constraints
|
|
(i.e. not produce frames with size bigger than requested) while still making
|
|
output picture as good as possible.
|
|
A frame containing a lot of small details is harder to compress and the encoder
|
|
would spend more time searching for appropriate quantizers for each slice.
|
|
|
|
Setting a higher @option{bits_per_mb} limit will improve the speed.
|
|
|
|
For the fastest encoding speed set the @option{qscale} parameter (4 is the
|
|
recommended value) and do not set a size constraint.
|
|
|
|
@section QSV encoders
|
|
|
|
The family of Intel QuickSync Video encoders (MPEG-2, H.264, HEVC, JPEG/MJPEG and VP9)
|
|
|
|
The ratecontrol method is selected as follows:
|
|
|
|
@itemize @bullet
|
|
@item
|
|
When @option{global_quality} is specified, a quality-based mode is used.
|
|
Specifically this means either
|
|
@itemize @minus
|
|
@item
|
|
@var{CQP} - constant quantizer scale, when the @option{qscale} codec flag is
|
|
also set (the @option{-qscale} ffmpeg option).
|
|
|
|
@item
|
|
@var{LA_ICQ} - intelligent constant quality with lookahead, when the
|
|
@option{look_ahead} option is also set.
|
|
|
|
@item
|
|
@var{ICQ} -- intelligent constant quality otherwise.
|
|
@end itemize
|
|
|
|
@item
|
|
Otherwise, a bitrate-based mode is used. For all of those, you should specify at
|
|
least the desired average bitrate with the @option{b} option.
|
|
@itemize @minus
|
|
@item
|
|
@var{LA} - VBR with lookahead, when the @option{look_ahead} option is specified.
|
|
|
|
@item
|
|
@var{VCM} - video conferencing mode, when the @option{vcm} option is set.
|
|
|
|
@item
|
|
@var{CBR} - constant bitrate, when @option{maxrate} is specified and equal to
|
|
the average bitrate.
|
|
|
|
@item
|
|
@var{VBR} - variable bitrate, when @option{maxrate} is specified, but is higher
|
|
than the average bitrate.
|
|
|
|
@item
|
|
@var{AVBR} - average VBR mode, when @option{maxrate} is not specified. This mode
|
|
is further configured by the @option{avbr_accuracy} and
|
|
@option{avbr_convergence} options.
|
|
@end itemize
|
|
@end itemize
|
|
|
|
Note that depending on your system, a different mode than the one you specified
|
|
may be selected by the encoder. Set the verbosity level to @var{verbose} or
|
|
higher to see the actual settings used by the QSV runtime.
|
|
|
|
Additional libavcodec global options are mapped to MSDK options as follows:
|
|
|
|
@itemize
|
|
@item
|
|
@option{g/gop_size} -> @option{GopPicSize}
|
|
|
|
@item
|
|
@option{bf/max_b_frames}+1 -> @option{GopRefDist}
|
|
|
|
@item
|
|
@option{rc_init_occupancy/rc_initial_buffer_occupancy} ->
|
|
@option{InitialDelayInKB}
|
|
|
|
@item
|
|
@option{slices} -> @option{NumSlice}
|
|
|
|
@item
|
|
@option{refs} -> @option{NumRefFrame}
|
|
|
|
@item
|
|
@option{b_strategy/b_frame_strategy} -> @option{BRefType}
|
|
|
|
@item
|
|
@option{cgop/CLOSED_GOP} codec flag -> @option{GopOptFlag}
|
|
|
|
@item
|
|
For the @var{CQP} mode, the @option{i_qfactor/i_qoffset} and
|
|
@option{b_qfactor/b_qoffset} set the difference between @var{QPP} and @var{QPI},
|
|
and @var{QPP} and @var{QPB} respectively.
|
|
|
|
@item
|
|
Setting the @option{coder} option to the value @var{vlc} will make the H.264
|
|
encoder use CAVLC instead of CABAC.
|
|
|
|
@end itemize
|
|
|
|
@section snow
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
@item iterative_dia_size
|
|
dia size for the iterative motion estimation
|
|
@end table
|
|
|
|
@section VAAPI encoders
|
|
|
|
Wrappers for hardware encoders accessible via VAAPI.
|
|
|
|
These encoders only accept input in VAAPI hardware surfaces. If you have input
|
|
in software frames, use the @option{hwupload} filter to upload them to the GPU.
|
|
|
|
The following standard libavcodec options are used:
|
|
@itemize
|
|
@item
|
|
@option{g} / @option{gop_size}
|
|
@item
|
|
@option{bf} / @option{max_b_frames}
|
|
@item
|
|
@option{profile}
|
|
|
|
If not set, this will be determined automatically from the format of the input
|
|
frames and the profiles supported by the driver.
|
|
@item
|
|
@option{level}
|
|
@item
|
|
@option{b} / @option{bit_rate}
|
|
@item
|
|
@option{maxrate} / @option{rc_max_rate}
|
|
@item
|
|
@option{bufsize} / @option{rc_buffer_size}
|
|
@item
|
|
@option{rc_init_occupancy} / @option{rc_initial_buffer_occupancy}
|
|
@item
|
|
@option{compression_level}
|
|
|
|
Speed / quality tradeoff: higher values are faster / worse quality.
|
|
@item
|
|
@option{q} / @option{global_quality}
|
|
|
|
Size / quality tradeoff: higher values are smaller / worse quality.
|
|
@item
|
|
@option{qmin}
|
|
@item
|
|
@option{qmax}
|
|
@item
|
|
@option{i_qfactor} / @option{i_quant_factor}
|
|
@item
|
|
@option{i_qoffset} / @option{i_quant_offset}
|
|
@item
|
|
@option{b_qfactor} / @option{b_quant_factor}
|
|
@item
|
|
@option{b_qoffset} / @option{b_quant_offset}
|
|
@item
|
|
@option{slices}
|
|
@end itemize
|
|
|
|
All encoders support the following options:
|
|
@table @option
|
|
@item low_power
|
|
Some drivers/platforms offer a second encoder for some codecs intended to use
|
|
less power than the default encoder; setting this option will attempt to use
|
|
that encoder. Note that it may support a reduced feature set, so some other
|
|
options may not be available in this mode.
|
|
|
|
@item idr_interval
|
|
Set the number of normal intra frames between full-refresh (IDR) frames in
|
|
open-GOP mode. The intra frames are still IRAPs, but will not include global
|
|
headers and may have non-decodable leading pictures.
|
|
|
|
@item b_depth
|
|
Set the B-frame reference depth. When set to one (the default), all B-frames
|
|
will refer only to P- or I-frames. When set to greater values multiple layers
|
|
of B-frames will be present, frames in each layer only referring to frames in
|
|
higher layers.
|
|
|
|
@item rc_mode
|
|
Set the rate control mode to use. A given driver may only support a subset of
|
|
modes.
|
|
|
|
Possible modes:
|
|
@table @option
|
|
@item auto
|
|
Choose the mode automatically based on driver support and the other options.
|
|
This is the default.
|
|
@item CQP
|
|
Constant-quality.
|
|
@item CBR
|
|
Constant-bitrate.
|
|
@item VBR
|
|
Variable-bitrate.
|
|
@item ICQ
|
|
Intelligent constant-quality.
|
|
@item QVBR
|
|
Quality-defined variable-bitrate.
|
|
@item AVBR
|
|
Average variable bitrate.
|
|
@end table
|
|
|
|
@end table
|
|
|
|
Each encoder also has its own specific options:
|
|
@table @option
|
|
|
|
@item h264_vaapi
|
|
@option{profile} sets the value of @emph{profile_idc} and the @emph{constraint_set*_flag}s.
|
|
@option{level} sets the value of @emph{level_idc}.
|
|
|
|
@table @option
|
|
@item coder
|
|
Set entropy encoder (default is @emph{cabac}). Possible values:
|
|
|
|
@table @samp
|
|
@item ac
|
|
@item cabac
|
|
Use CABAC.
|
|
|
|
@item vlc
|
|
@item cavlc
|
|
Use CAVLC.
|
|
@end table
|
|
|
|
@item aud
|
|
Include access unit delimiters in the stream (not included by default).
|
|
|
|
@item sei
|
|
Set SEI message types to include.
|
|
Some combination of the following values:
|
|
@table @samp
|
|
@item identifier
|
|
Include a @emph{user_data_unregistered} message containing information about
|
|
the encoder.
|
|
@item timing
|
|
Include picture timing parameters (@emph{buffering_period} and
|
|
@emph{pic_timing} messages).
|
|
@item recovery_point
|
|
Include recovery points where appropriate (@emph{recovery_point} messages).
|
|
@end table
|
|
|
|
@end table
|
|
|
|
@item hevc_vaapi
|
|
@option{profile} and @option{level} set the values of
|
|
@emph{general_profile_idc} and @emph{general_level_idc} respectively.
|
|
|
|
@table @option
|
|
@item aud
|
|
Include access unit delimiters in the stream (not included by default).
|
|
|
|
@item tier
|
|
Set @emph{general_tier_flag}. This may affect the level chosen for the stream
|
|
if it is not explicitly specified.
|
|
|
|
@item sei
|
|
Set SEI message types to include.
|
|
Some combination of the following values:
|
|
@table @samp
|
|
@item hdr
|
|
Include HDR metadata if the input frames have it
|
|
(@emph{mastering_display_colour_volume} and @emph{content_light_level}
|
|
messages).
|
|
@end table
|
|
|
|
@end table
|
|
|
|
@item mjpeg_vaapi
|
|
Only baseline DCT encoding is supported. The encoder always uses the standard
|
|
quantisation and huffman tables - @option{global_quality} scales the standard
|
|
quantisation table (range 1-100).
|
|
|
|
For YUV, 4:2:0, 4:2:2 and 4:4:4 subsampling modes are supported. RGB is also
|
|
supported, and will create an RGB JPEG.
|
|
|
|
@table @option
|
|
@item jfif
|
|
Include JFIF header in each frame (not included by default).
|
|
@item huffman
|
|
Include standard huffman tables (on by default). Turning this off will save
|
|
a few hundred bytes in each output frame, but may lose compatibility with some
|
|
JPEG decoders which don't fully handle MJPEG.
|
|
@end table
|
|
|
|
@item mpeg2_vaapi
|
|
@option{profile} and @option{level} set the value of @emph{profile_and_level_indication}.
|
|
|
|
@item vp8_vaapi
|
|
B-frames are not supported.
|
|
|
|
@option{global_quality} sets the @emph{q_idx} used for non-key frames (range 0-127).
|
|
|
|
@table @option
|
|
@item loop_filter_level
|
|
@item loop_filter_sharpness
|
|
Manually set the loop filter parameters.
|
|
@end table
|
|
|
|
@item vp9_vaapi
|
|
@option{global_quality} sets the @emph{q_idx} used for P-frames (range 0-255).
|
|
|
|
@table @option
|
|
@item loop_filter_level
|
|
@item loop_filter_sharpness
|
|
Manually set the loop filter parameters.
|
|
@end table
|
|
|
|
B-frames are supported, but the output stream is always in encode order rather than display
|
|
order. If B-frames are enabled, it may be necessary to use the @option{vp9_raw_reorder}
|
|
bitstream filter to modify the output stream to display frames in the correct order.
|
|
|
|
Only normal frames are produced - the @option{vp9_superframe} bitstream filter may be
|
|
required to produce a stream usable with all decoders.
|
|
|
|
@end table
|
|
|
|
@section vc2
|
|
|
|
SMPTE VC-2 (previously BBC Dirac Pro). This codec was primarily aimed at
|
|
professional broadcasting but since it supports yuv420, yuv422 and yuv444 at
|
|
8 (limited range or full range), 10 or 12 bits, this makes it suitable for
|
|
other tasks which require low overhead and low compression (like screen
|
|
recording).
|
|
|
|
@subsection Options
|
|
|
|
@table @option
|
|
|
|
@item b
|
|
Sets target video bitrate. Usually that's around 1:6 of the uncompressed
|
|
video bitrate (e.g. for 1920x1080 50fps yuv422p10 that's around 400Mbps). Higher
|
|
values (close to the uncompressed bitrate) turn on lossless compression mode.
|
|
|
|
@item field_order
|
|
Enables field coding when set (e.g. to tt - top field first) for interlaced
|
|
inputs. Should increase compression with interlaced content as it splits the
|
|
fields and encodes each separately.
|
|
|
|
@item wavelet_depth
|
|
Sets the total amount of wavelet transforms to apply, between 1 and 5 (default).
|
|
Lower values reduce compression and quality. Less capable decoders may not be
|
|
able to handle values of @option{wavelet_depth} over 3.
|
|
|
|
@item wavelet_type
|
|
Sets the transform type. Currently only @var{5_3} (LeGall) and @var{9_7}
|
|
(Deslauriers-Dubuc)
|
|
are implemented, with 9_7 being the one with better compression and thus
|
|
is the default.
|
|
|
|
@item slice_width
|
|
@item slice_height
|
|
Sets the slice size for each slice. Larger values result in better compression.
|
|
For compatibility with other more limited decoders use @option{slice_width} of
|
|
32 and @option{slice_height} of 8.
|
|
|
|
@item tolerance
|
|
Sets the undershoot tolerance of the rate control system in percent. This is
|
|
to prevent an expensive search from being run.
|
|
|
|
@item qm
|
|
Sets the quantization matrix preset to use by default or when @option{wavelet_depth}
|
|
is set to 5
|
|
@itemize @minus
|
|
@item
|
|
@var{default}
|
|
Uses the default quantization matrix from the specifications, extended with
|
|
values for the fifth level. This provides a good balance between keeping detail
|
|
and omitting artifacts.
|
|
|
|
@item
|
|
@var{flat}
|
|
Use a completely zeroed out quantization matrix. This increases PSNR but might
|
|
reduce perception. Use in bogus benchmarks.
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@item
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@var{color}
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Reduces detail but attempts to preserve color at extremely low bitrates.
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|
@end itemize
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@end table
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@c man end VIDEO ENCODERS
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@chapter Subtitles Encoders
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@c man begin SUBTITLES ENCODERS
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@section dvdsub
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|
This codec encodes the bitmap subtitle format that is used in DVDs.
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|
Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
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|
and they can also be used in Matroska files.
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|
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@subsection Options
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|
|
@table @option
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|
@item palette
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|
Specify the global palette used by the bitmaps.
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|
|
|
The format for this option is a string containing 16 24-bits hexadecimal
|
|
numbers (without 0x prefix) separated by commas, for example @code{0d00ee,
|
|
ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
|
|
7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b}.
|
|
|
|
@item even_rows_fix
|
|
When set to 1, enable a work-around that makes the number of pixel rows
|
|
even in all subtitles. This fixes a problem with some players that
|
|
cut off the bottom row if the number is odd. The work-around just adds
|
|
a fully transparent row if needed. The overhead is low, typically
|
|
one byte per subtitle on average.
|
|
|
|
By default, this work-around is disabled.
|
|
@end table
|
|
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@c man end SUBTITLES ENCODERS
|