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3844 lines
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3844 lines
108 KiB
@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. This is the default 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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@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 @var{ac3_fixed} encoder is not the default codec for |
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any of the output formats, so it must be specified explicitly using the option |
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@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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|
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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 |
|
is an optional AC-3 feature that increases quality by selectively encoding |
|
the left/right channels as mid/side. This option is enabled by default, and it |
|
is highly recommended that it be left as enabled except for testing purposes. |
|
|
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@item cutoff @var{frequency} |
|
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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|
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@end table |
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|
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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 |
|
for the fixed-point encoder due to the corresponding features not being |
|
implemented in fixed-point. |
|
|
|
@table @option |
|
|
|
@item -channel_coupling @var{boolean} |
|
Enables/Disables use of channel coupling, which is an optional AC-3 feature |
|
that increases quality by combining high frequency information from multiple |
|
channels into a single channel. The per-channel high frequency information is |
|
sent with less accuracy in both the frequency and time domains. This allows |
|
more bits to be used for lower frequencies while preserving enough information |
|
to reconstruct the high frequencies. This option is enabled by default for the |
|
floating-point encoder and should generally be left as enabled except for |
|
testing purposes or to increase encoding speed. |
|
@table @option |
|
@item -1 |
|
@itemx auto |
|
Selected by Encoder (default) |
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@item 0 |
|
@itemx off |
|
Disable Channel Coupling |
|
@item 1 |
|
@itemx on |
|
Enable Channel Coupling |
|
@end table |
|
|
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@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 |
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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. |
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@table @option |
|
@item -1 |
|
@itemx auto |
|
Selected by Encoder (default) |
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@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. |
|
|
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@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 |
|
|
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@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 fec (@emph{n/a}) |
|
Enable inband forward error correction. @option{packet_loss} must be non-zero |
|
to take advantage - frequency of FEC 'side-data' is proportional to expected packet loss. |
|
Default is disabled. |
|
|
|
@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{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. |
|
|
|
@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}) |
|
@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 a64_multi, a64_multi5 |
|
|
|
A64 / Commodore 64 multicolor charset encoder. @code{a64_multi5} is extended with 5th color (colram). |
|
|
|
@section GIF |
|
|
|
GIF image/animation encoder. |
|
|
|
@subsection Options |
|
|
|
@table @option |
|
@item gifflags @var{integer} |
|
Sets the flags used for GIF encoding. |
|
|
|
@table @option |
|
@item offsetting |
|
Enables picture offsetting. |
|
|
|
Default is enabled. |
|
|
|
@item transdiff |
|
Enables transparency detection between frames. |
|
|
|
Default is enabled. |
|
|
|
@end table |
|
|
|
@item gifimage @var{integer} |
|
Enables encoding one full GIF image per frame, rather than an animated GIF. |
|
|
|
Default value is @option{0}. |
|
|
|
@item global_palette @var{integer} |
|
Writes a palette to the global GIF header where feasible. |
|
|
|
If disabled, every frame will always have a palette written, even if there |
|
is a global palette supplied. |
|
|
|
Default value is @option{1}. |
|
|
|
@end table |
|
|
|
@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 @var{integer} |
|
Can be set to either @code{j2k} or @code{jp2} (the default) that |
|
makes it possible to store non-rgb pix_fmts. |
|
|
|
@item tile_width @var{integer} |
|
Sets tile width. Range is 1 to 1073741824. Default is 256. |
|
|
|
@item tile_height @var{integer} |
|
Sets tile height. Range is 1 to 1073741824. Default is 256. |
|
|
|
@item pred @var{integer} |
|
Allows setting the discrete wavelet transform (DWT) type |
|
@table @option |
|
@item dwt97int (Lossy) |
|
@item dwt53 (Lossless) |
|
@end table |
|
Default is @code{dwt97int} |
|
|
|
@item sop @var{boolean} |
|
Enable this to add SOP marker at the start of each packet. Disabled by default. |
|
|
|
@item eph @var{boolean} |
|
Enable this to add EPH marker at the end of each packet header. Disabled by default. |
|
|
|
@item prog @var{integer} |
|
Sets the progression order to be used by the encoder. |
|
Possible values are: |
|
@table @option |
|
@item lrcp |
|
@item rlcp |
|
@item rpcl |
|
@item pcrl |
|
@item cprl |
|
@end table |
|
Set to @code{lrcp} by default. |
|
|
|
@item layer_rates @var{string} |
|
By default, when this option is not used, compression is done using the quality metric. |
|
This option allows for compression using compression ratio. The compression ratio for each |
|
level could be specified. The compression ratio of a layer @code{l} species the what ratio of |
|
total file size is contained in the first @code{l} layers. |
|
|
|
Example usage: |
|
|
|
@example |
|
ffmpeg -i input.bmp -c:v jpeg2000 -layer_rates "100,10,1" output.j2k |
|
@end example |
|
|
|
This would compress the image to contain 3 layers, where the data contained in the |
|
first layer would be compressed by 1000 times, compressed by 100 in the first two layers, |
|
and shall contain all data while using all 3 layers. |
|
|
|
@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. |
|
|
|
@item enable-flip-idtx (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable extended transform type, including FLIPADST_DCT, DCT_FLIPADST, |
|
FLIPADST_FLIPADST, ADST_FLIPADST, FLIPADST_ADST, IDTX, V_DCT, H_DCT, |
|
V_ADST, H_ADST, V_FLIPADST, H_FLIPADST. Default is true. |
|
|
|
@item enable-tx64 (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable 64-pt transform. Default is true. |
|
|
|
@item reduced-tx-type-set (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Use reduced set of transform types. Default is false. |
|
|
|
@item use-intra-dct-only (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Use DCT only for INTRA modes. Default is false. |
|
|
|
@item use-inter-dct-only (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Use DCT only for INTER modes. Default is false. |
|
|
|
@item use-intra-default-tx-only (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Use Default-transform only for INTRA modes. Default is false. |
|
|
|
@item enable-ref-frame-mvs (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable temporal mv prediction. Default is true. |
|
|
|
@item enable-reduced-reference-set (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Use reduced set of single and compound references. Default is false. |
|
|
|
@item enable-obmc (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable obmc. Default is true. |
|
|
|
@item enable-dual-filter (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable dual filter. Default is true. |
|
|
|
@item enable-diff-wtd-comp (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable difference-weighted compound. Default is true. |
|
|
|
@item enable-dist-wtd-comp (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable distance-weighted compound. Default is true. |
|
|
|
@item enable-onesided-comp (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable one sided compound. Default is true. |
|
|
|
@item enable-interinter-wedge (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable interinter wedge compound. Default is true. |
|
|
|
@item enable-interintra-wedge (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable interintra wedge compound. Default is true. |
|
|
|
@item enable-masked-comp (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable masked compound. Default is true. |
|
|
|
@item enable-interintra-comp (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable interintra compound. Default is true. |
|
|
|
@item enable-smooth-interintra (@emph{boolean}) (Requires libaom >= v2.0.0) |
|
Enable smooth interintra mode. Default is true. |
|
|
|
@item aom-params |
|
Set libaom options using a list of @var{key}=@var{value} pairs separated |
|
by ":". For a list of supported options, see @command{aomenc --help} under the |
|
section "AV1 Specific Options". |
|
|
|
For example to specify libaom encoding options with @option{-aom-params}: |
|
|
|
@example |
|
ffmpeg -i input -c:v libaom-av1 -b:v 500K -aom-params tune=psnr:enable-tpl-model=1 output.mp4 |
|
@end example |
|
|
|
@end table |
|
|
|
@section libsvtav1 |
|
|
|
SVT-AV1 encoder wrapper. |
|
|
|
Requires the presence of the SVT-AV1 headers and library during configuration. |
|
You need to explicitly configure the build with @code{--enable-libsvtav1}. |
|
|
|
@subsection Options |
|
|
|
@table @option |
|
@item profile |
|
Set the encoding profile. |
|
@table @samp |
|
@item main |
|
@item high |
|
@item professional |
|
@end table |
|
|
|
@item level |
|
Set the operating point level. For example: '4.0' |
|
|
|
@item hielevel |
|
Set the Hierarchical prediction levels. |
|
@table @samp |
|
@item 3level |
|
@item 4level |
|
This is the default. |
|
@end table |
|
|
|
@item tier |
|
Set the operating point tier. |
|
@table @samp |
|
@item main |
|
This is the default. |
|
@item high |
|
@end table |
|
|
|
@item qmax |
|
Set the maximum quantizer to use when using a bitrate mode. |
|
|
|
@item qmin |
|
Set the minimum quantizer to use when using a bitrate mode. |
|
|
|
@item crf |
|
Constant rate factor value used in crf rate control mode (0-63). |
|
|
|
@item qp |
|
Set the quantizer used in cqp rate control mode (0-63). |
|
|
|
@item sc_detection |
|
Enable scene change detection. |
|
|
|
@item la_depth |
|
Set number of frames to look ahead (0-120). |
|
|
|
@item preset |
|
Set the quality-speed tradeoff, in the range 0 to 13. Higher values are |
|
faster but lower quality. |
|
|
|
@item tile_rows |
|
Set log2 of the number of rows of tiles to use (0-6). |
|
|
|
@item tile_columns |
|
Set log2 of the number of columns of tiles to use (0-4). |
|
|
|
@item svtav1-params |
|
Set SVT-AV1 options using a list of @var{key}=@var{value} pairs separated |
|
by ":". See the SVT-AV1 encoder user guide for a list of accepted parameters. |
|
|
|
@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. |
|
@item ref-frame-config |
|
Using per-frame metadata, set members of the structure @code{vpx_svc_ref_frame_config_t} in @code{vpx/vp8cx.h} to fine-control referencing schemes and frame buffer management. |
|
@*Use a :-separated list of key=value pairs. |
|
For example, |
|
@example |
|
av_dict_set(&av_frame->metadata, "ref-frame-config", \ |
|
"rfc_update_buffer_slot=7:rfc_lst_fb_idx=0:rfc_gld_fb_idx=1:rfc_alt_fb_idx=2:rfc_reference_last=0:rfc_reference_golden=0:rfc_reference_alt_ref=0"); |
|
@end example |
|
@table @option |
|
@item rfc_update_buffer_slot |
|
Indicates the buffer slot number to update |
|
@item rfc_update_last |
|
Indicates whether to update the LAST frame |
|
@item rfc_update_golden |
|
Indicates whether to update GOLDEN frame |
|
@item rfc_update_alt_ref |
|
Indicates whether to update ALT_REF frame |
|
@item rfc_lst_fb_idx |
|
LAST frame buffer index |
|
@item rfc_gld_fb_idx |
|
GOLDEN frame buffer index |
|
@item rfc_alt_fb_idx |
|
ALT_REF frame buffer index |
|
@item rfc_reference_last |
|
Indicates whether to reference LAST frame |
|
@item rfc_reference_golden |
|
Indicates whether to reference GOLDEN frame |
|
@item rfc_reference_alt_ref |
|
Indicates whether to reference ALT_REF frame |
|
@item rfc_reference_duration |
|
Indicates frame duration |
|
@end table |
|
@end table |
|
|
|
@end table |
|
|
|
For more information about libvpx see: |
|
@url{http://www.webmproject.org/} |
|
|
|
@section libwebp |
|
|
|
libwebp WebP Image encoder wrapper |
|
|
|
libwebp is Google's official encoder for WebP images. It can encode in either |
|
lossy or lossless mode. Lossy images are essentially a wrapper around a VP8 |
|
frame. Lossless images are a separate codec developed by Google. |
|
|
|
@subsection Pixel Format |
|
|
|
Currently, libwebp only supports YUV420 for lossy and RGB for lossless due |
|
to limitations of the format and libwebp. Alpha is supported for either mode. |
|
Because of API limitations, if RGB is passed in when encoding lossy or YUV is |
|
passed in for encoding lossless, the pixel format will automatically be |
|
converted using functions from libwebp. This is not ideal and is done only for |
|
convenience. |
|
|
|
@subsection Options |
|
|
|
@table @option |
|
|
|
@item -lossless @var{boolean} |
|
Enables/Disables use of lossless mode. Default is 0. |
|
|
|
@item -compression_level @var{integer} |
|
For lossy, this is a quality/speed tradeoff. Higher values give better quality |
|
for a given size at the cost of increased encoding time. For lossless, this is |
|
a size/speed tradeoff. Higher values give smaller size at the cost of increased |
|
encoding time. More specifically, it controls the number of extra algorithms |
|
and compression tools used, and varies the combination of these tools. This |
|
maps to the @var{method} option in libwebp. The valid range is 0 to 6. |
|
Default is 4. |
|
|
|
@item -quality @var{float} |
|
For lossy encoding, this controls image quality. For lossless encoding, this |
|
controls the effort and time spent in compression. |
|
Range is 0 to 100. Default is 75. |
|
|
|
@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. |
|
|
|
@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 udu_sei @var{boolean} |
|
Import user data unregistered SEI if available into output. Default is 0 (off). |
|
|
|
@item x264-params (N.A.) |
|
Override the x264 configuration using a :-separated list of key=value |
|
parameters. |
|
|
|
This option is functionally the same as the @option{x264opts}, but is |
|
duplicated for compatibility with the Libav fork. |
|
|
|
For example to specify libx264 encoding options with @command{ffmpeg}: |
|
@example |
|
ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\ |
|
cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\ |
|
no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT |
|
@end example |
|
@end table |
|
|
|
Encoding ffpresets for common usages are provided so they can be used with the |
|
general presets system (e.g. passing the @option{pre} option). |
|
|
|
@section libx265 |
|
|
|
x265 H.265/HEVC encoder wrapper. |
|
|
|
This encoder requires the presence of the libx265 headers and library |
|
during configuration. You need to explicitly configure the build with |
|
@option{--enable-libx265}. |
|
|
|
@subsection Options |
|
|
|
@table @option |
|
@item 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 udu_sei @var{boolean} |
|
Import user data unregistered SEI if available into output. Default is 0 (off). |
|
|
|
@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 level |
|
Select the mpeg2 level to encode: |
|
|
|
@table @samp |
|
@item high |
|
@item high1440 |
|
@item main |
|
@item low |
|
@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) |
|
|
|
@subsection Ratecontrol Method |
|
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. For the ICQ modes, global |
|
quality range is 1 to 51, with 1 being the best quality. |
|
@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. |
|
|
|
@subsection Global Options -> MSDK Options |
|
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 |
|
|
|
@subsection Common Options |
|
Following options are used by all qsv encoders. |
|
|
|
@table @option |
|
@item @var{async_depth} |
|
Specifies how many asynchronous operations an application performs |
|
before the application explicitly synchronizes the result. If zero, |
|
the value is not specified. |
|
|
|
@item @var{avbr_accuracy} |
|
Accuracy of the AVBR ratecontrol (unit of tenth of percent). |
|
|
|
@item @var{avbr_convergence} |
|
Convergence of the AVBR ratecontrol (unit of 100 frames) |
|
|
|
The parameters @var{avbr_accuracy} and @var{avbr_convergence} are for the |
|
average variable bitrate control (AVBR) algorithm. |
|
The algorithm focuses on overall encoding quality while meeting the specified |
|
bitrate, @var{target_bitrate}, within the accuracy range @var{avbr_accuracy}, |
|
after a @var{avbr_Convergence} period. This method does not follow HRD and the |
|
instant bitrate is not capped or padded. |
|
|
|
@item @var{preset} |
|
This option itemizes a range of choices from veryfast (best speed) to veryslow |
|
(best quality). |
|
@table @samp |
|
@item veryfast |
|
@item faster |
|
@item fast |
|
@item medium |
|
@item slow |
|
@item slower |
|
@item veryslow |
|
@end table |
|
|
|
@item @var{forced_idr} |
|
Forcing I frames as IDR frames. |
|
|
|
@item @var{low_power} |
|
For encoders set this flag to ON to reduce power consumption and GPU usage. |
|
@end table |
|
|
|
@subsection H264 options |
|
These options are used by h264_qsv |
|
|
|
@table @option |
|
@item @var{extbrc} |
|
Extended bitrate control. |
|
|
|
@item @var{recovery_point_sei} |
|
Set this flag to insert the recovery point SEI message at the beginning of every |
|
intra refresh cycle. |
|
|
|
@item @var{rdo} |
|
Enable rate distortion optimization. |
|
|
|
@item @var{max_frame_size} |
|
Maximum encoded frame size in bytes. |
|
|
|
@item @var{max_slice_size} |
|
Maximum encoded slice size in bytes. |
|
|
|
@item @var{bitrate_limit} |
|
Toggle bitrate limitations. |
|
Modifies bitrate to be in the range imposed by the QSV encoder. Setting this |
|
flag off may lead to violation of HRD conformance. Mind that specifying bitrate |
|
below the QSV encoder range might significantly affect quality. If on this |
|
option takes effect in non CQP modes: if bitrate is not in the range imposed |
|
by the QSV encoder, it will be changed to be in the range. |
|
|
|
@item @var{mbbrc} |
|
Setting this flag enables macroblock level bitrate control that generally |
|
improves subjective visual quality. Enabling this flag may have negative impact |
|
on performance and objective visual quality metric. |
|
|
|
@item @var{adaptive_i} |
|
This flag controls insertion of I frames by the QSV encoder. Turn ON this flag |
|
to allow changing of frame type from P and B to I. |
|
|
|
@item @var{adaptive_b} |
|
This flag controls changing of frame type from B to P. |
|
|
|
@item @var{p_strategy} |
|
Enable P-pyramid: 0-default 1-simple 2-pyramid(bf need to be set to 0). |
|
|
|
@item @var{b_strategy} |
|
This option controls usage of B frames as reference. |
|
|
|
@item @var{dblk_idc} |
|
This option disable deblocking. It has value in range 0~2. |
|
|
|
@item @var{cavlc} |
|
If set, CAVLC is used; if unset, CABAC is used for encoding. |
|
|
|
@item @var{vcm} |
|
Video conferencing mode, please see ratecontrol method. |
|
|
|
@item @var{idr_interval} |
|
Distance (in I-frames) between IDR frames. |
|
|
|
@item @var{pic_timing_sei} |
|
Insert picture timing SEI with pic_struct_syntax element. |
|
|
|
@item @var{single_sei_nal_unit} |
|
Put all the SEI messages into one NALU. |
|
|
|
@item @var{max_dec_frame_buffering} |
|
Maximum number of frames buffered in the DPB. |
|
|
|
@item @var{look_ahead} |
|
Use VBR algorithm with look ahead. |
|
|
|
@item @var{look_ahead_depth} |
|
Depth of look ahead in number frames. |
|
|
|
@item @var{look_ahead_downsampling} |
|
Downscaling factor for the frames saved for the lookahead analysis. |
|
@table @samp |
|
@item unknown |
|
@item auto |
|
@item off |
|
@item 2x |
|
@item 4x |
|
@end table |
|
|
|
@item @var{int_ref_type} |
|
Specifies intra refresh type. The major goal of intra refresh is improvement of |
|
error resilience without significant impact on encoded bitstream size caused by |
|
I frames. The SDK encoder achieves this by encoding part of each frame in |
|
refresh cycle using intra MBs. @var{none} means no refresh. @var{vertical} means |
|
vertical refresh, by column of MBs. To enable intra refresh, B frame should be |
|
set to 0. |
|
|
|
@item @var{int_ref_cycle_size} |
|
Specifies number of pictures within refresh cycle starting from 2. 0 and 1 are |
|
invalid values. |
|
|
|
@item @var{int_ref_qp_delta} |
|
Specifies QP difference for inserted intra MBs. This is signed value in |
|
[-51, 51] range if target encoding bit-depth for luma samples is 8 and this |
|
range is [-63, 63] for 10 bit-depth or [-75, 75] for 12 bit-depth respectively. |
|
|
|
@item @var{int_ref_cycle_dist} |
|
Distance between the beginnings of the intra-refresh cycles in frames. |
|
|
|
@item @var{profile} |
|
@table @samp |
|
@item unknown |
|
@item baseline |
|
@item main |
|
@item high |
|
@end table |
|
|
|
@item @var{a53cc} |
|
Use A53 Closed Captions (if available). |
|
|
|
@item @var{aud} |
|
Insert the Access Unit Delimiter NAL. |
|
|
|
@item @var{mfmode} |
|
Multi-Frame Mode. |
|
@table @samp |
|
@item off |
|
@item auto |
|
@end table |
|
|
|
@item @var{repeat_pps} |
|
Repeat pps for every frame. |
|
@end table |
|
|
|
@subsection HEVC Options |
|
These options are used by hevc_qsv |
|
|
|
@table @option |
|
@item @var{extbrc} |
|
Extended bitrate control. |
|
|
|
@item @var{recovery_point_sei} |
|
Set this flag to insert the recovery point SEI message at the beginning of every |
|
intra refresh cycle. |
|
|
|
@item @var{rdo} |
|
Enable rate distortion optimization. |
|
|
|
@item @var{max_frame_size} |
|
Maximum encoded frame size in bytes. |
|
|
|
@item @var{max_slice_size} |
|
Maximum encoded slice size in bytes. |
|
|
|
@item @var{mbbrc} |
|
Setting this flag enables macroblock level bitrate control that generally |
|
improves subjective visual quality. Enabling this flag may have negative impact |
|
on performance and objective visual quality metric. |
|
|
|
@item @var{p_strategy} |
|
Enable P-pyramid: 0-default 1-simple 2-pyramid(bf need to be set to 0). |
|
|
|
@item @var{b_strategy} |
|
This option controls usage of B frames as reference. |
|
|
|
@item @var{dblk_idc} |
|
This option disable deblocking. It has value in range 0~2. |
|
|
|
@item @var{idr_interval} |
|
Distance (in I-frames) between IDR frames. |
|
@table @samp |
|
@item begin_only |
|
Output an IDR-frame only at the beginning of the stream. |
|
@end table |
|
|
|
@item @var{load_plugin} |
|
A user plugin to load in an internal session. |
|
@table @samp |
|
@item none |
|
@item hevc_sw |
|
@item hevc_hw |
|
@end table |
|
|
|
@item @var{load_plugins} |
|
A :-separate list of hexadecimal plugin UIDs to load in |
|
an internal session. |
|
|
|
@item @var{look_ahead_depth} |
|
Depth of look ahead in number frames, available when extbrc option is enabled. |
|
|
|
@item @var{profile} |
|
Set the encoding profile (scc requires libmfx >= 1.32). |
|
|
|
@table @samp |
|
@item unknown |
|
@item main |
|
@item main10 |
|
@item mainsp |
|
@item rext |
|
@item scc |
|
@end table |
|
|
|
@item @var{gpb} |
|
1: GPB (generalized P/B frame) |
|
|
|
0: regular P frame. |
|
|
|
@item @var{tile_cols} |
|
Number of columns for tiled encoding. |
|
|
|
@item @var{tile_rows} |
|
Number of rows for tiled encoding. |
|
|
|
@item @var{aud} |
|
Insert the Access Unit Delimiter NAL. |
|
|
|
@item @var{pic_timing_sei} |
|
Insert picture timing SEI with pic_struct_syntax element. |
|
|
|
@item @var{transform_skip} |
|
Turn this option ON to enable transformskip. It is supported on platform equal |
|
or newer than ICL. |
|
|
|
@item @var{int_ref_type} |
|
Specifies intra refresh type. The major goal of intra refresh is improvement of |
|
error resilience without significant impact on encoded bitstream size caused by |
|
I frames. The SDK encoder achieves this by encoding part of each frame in |
|
refresh cycle using intra MBs. @var{none} means no refresh. @var{vertical} means |
|
vertical refresh, by column of MBs. To enable intra refresh, B frame should be |
|
set to 0. |
|
|
|
@item @var{int_ref_cycle_size} |
|
Specifies number of pictures within refresh cycle starting from 2. 0 and 1 are |
|
invalid values. |
|
|
|
@item @var{int_ref_qp_delta} |
|
Specifies QP difference for inserted intra MBs. This is signed value in |
|
[-51, 51] range if target encoding bit-depth for luma samples is 8 and this |
|
range is [-63, 63] for 10 bit-depth or [-75, 75] for 12 bit-depth respectively. |
|
|
|
@item @var{int_ref_cycle_dist} |
|
Distance between the beginnings of the intra-refresh cycles in frames. |
|
@end table |
|
|
|
@subsection MPEG2 Options |
|
These options are used by mpeg2_qsv |
|
@table @option |
|
@item @var{profile} |
|
@table @samp |
|
@item unknown |
|
@item simple |
|
@item main |
|
@item high |
|
@end table |
|
@end table |
|
|
|
@subsection VP9 Options |
|
These options are used by vp9_qsv |
|
@table @option |
|
@item @var{profile} |
|
@table @samp |
|
@item unknown |
|
@item profile0 |
|
@item profile1 |
|
@item profile2 |
|
@item profile3 |
|
@end table |
|
|
|
@item @var{tile_cols} |
|
Number of columns for tiled encoding (requires libmfx >= 1.29). |
|
|
|
@item @var{tile_rows} |
|
Number of rows for tiled encoding (requires libmfx >= 1.29). |
|
@end table |
|
|
|
@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 async_depth |
|
Maximum processing parallelism. Increase this to improve single channel |
|
performance. This option doesn't work if driver doesn't implement vaSyncBuffer |
|
function. Please make sure there are enough hw_frames allocated if a large |
|
number of async_depth is used. |
|
|
|
@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 |
|
|
|
@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. |
|
|
|
@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. |
|
|
|
@item |
|
@var{color} |
|
Reduces detail but attempts to preserve color at extremely low bitrates. |
|
@end itemize |
|
|
|
@end table |
|
|
|
@c man end VIDEO ENCODERS |
|
|
|
@chapter Subtitles Encoders |
|
@c man begin SUBTITLES ENCODERS |
|
|
|
@section dvdsub |
|
|
|
This codec encodes the bitmap subtitle format that is used in DVDs. |
|
Typically they are stored in VOBSUB file pairs (*.idx + *.sub), |
|
and they can also be used in Matroska files. |
|
|
|
@subsection Options |
|
|
|
@table @option |
|
@item palette |
|
Specify the global palette used by the bitmaps. |
|
|
|
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 |
|
|
|
@c man end SUBTITLES ENCODERS
|
|
|