You've already forked FFmpeg
mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2025-08-10 06:10:52 +02:00
doc/filters: document vf_libplacebo
Signed-off-by: Niklas Haas <git@haasn.dev>
This commit is contained in:
Niklas Haas
504
doc/filters.texi
504
doc/filters.texi
@@ -14793,6 +14793,510 @@ ffmpeg -i input.mov -vf lensfun=make=Canon:model="Canon EOS 100D":lens_model="Ca
|
|||||||
|
|
||||||
@end itemize
|
@end itemize
|
||||||
|
|
||||||
|
@section libplacebo
|
||||||
|
|
||||||
|
Flexible GPU-accelerated processing filter based on libplacebo
|
||||||
|
(@url{https://code.videolan.org/videolan/libplacebo}). Note that this filter
|
||||||
|
currently only accepts Vulkan input frames.
|
||||||
|
|
||||||
|
@subsection Options
|
||||||
|
|
||||||
|
The options for this filter are divided into the following sections:
|
||||||
|
|
||||||
|
@subsubsection Output mode
|
||||||
|
These options control the overall output mode. By default, libplacebo will try
|
||||||
|
to preserve the source colorimetry and size as best as it can, but it will
|
||||||
|
apply any embedded film grain, dolby vision metadata or anamorphic SAR present
|
||||||
|
in source frames.
|
||||||
|
@table @option
|
||||||
|
@item w
|
||||||
|
@item h
|
||||||
|
Set the output video dimension expression. Default value is the input dimension.
|
||||||
|
|
||||||
|
Allows for the same expressions as the @ref{scale} filter.
|
||||||
|
|
||||||
|
@item format
|
||||||
|
Set the output format override. If unset (the default), frames will be output
|
||||||
|
in the same format as the respective input frames. Otherwise, format conversion
|
||||||
|
will be performed.
|
||||||
|
|
||||||
|
@item force_original_aspect_ratio
|
||||||
|
@item force_divisible_by
|
||||||
|
Work the same as the identical @ref{scale} filter options.
|
||||||
|
|
||||||
|
@item normalize_sar
|
||||||
|
If enabled (the default), output frames will always have a pixel aspect ratio
|
||||||
|
of 1:1. If disabled, any aspect ratio mismatches, including those from e.g.
|
||||||
|
anamorphic video sources, are forwarded to the output pixel aspect ratio.
|
||||||
|
|
||||||
|
@item pad_crop_ratio
|
||||||
|
Specifies a ratio (between @code{0.0} and @code{1.0}) between padding and
|
||||||
|
cropping when the input aspect ratio does not match the output aspect ratio and
|
||||||
|
@option{normalize_sar} is in effect. The default of @code{0.0} always pads the
|
||||||
|
content with black borders, while a value of @code{1.0} always crops off parts
|
||||||
|
of the content. Intermediate values are possible, leading to a mix of the two
|
||||||
|
approaches.
|
||||||
|
|
||||||
|
@item colorspace
|
||||||
|
@item color_primaries
|
||||||
|
@item color_trc
|
||||||
|
@item range
|
||||||
|
Configure the colorspace that output frames will be delivered in. The default
|
||||||
|
value of @code{auto} outputs frames in the same format as the input frames,
|
||||||
|
leading to no change. For any other value, conversion will be performed.
|
||||||
|
|
||||||
|
See the @ref{setparams} filter for a list of possible values.
|
||||||
|
|
||||||
|
@item apply_filmgrain
|
||||||
|
Apply film grain (e.g. AV1 or H.274) if present in source frames, and strip
|
||||||
|
it from the output. Enabled by default.
|
||||||
|
|
||||||
|
@item apply_dolbyvision
|
||||||
|
Apply Dolby Vision RPU metadata if present in source frames, and strip it from
|
||||||
|
the output. Enabled by default. Note that Dolby Vision will always output
|
||||||
|
BT.2020+PQ, overriding the usual input frame metadata. These will also be
|
||||||
|
picked as the values of @code{auto} for the respective frame output options.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@subsubsection Scaling
|
||||||
|
The options in this section control how libplacebo performs upscaling and (if
|
||||||
|
necessary) downscaling. Note that libplacebo will always internally operate on
|
||||||
|
4:4:4 content, so any sub-sampled chroma formats such as @code{yuv420p} will
|
||||||
|
necessarily be upsampled and downsampled as part of the rendering process. That
|
||||||
|
means scaling might be in effect even if the source and destination resolution
|
||||||
|
are the same.
|
||||||
|
@table @option
|
||||||
|
@item upscaler
|
||||||
|
@item downscaler
|
||||||
|
Configure the filter kernel used for upscaling and downscaling. The respective
|
||||||
|
defaults are @code{spline36} and @code{mitchell}. For a full list of possible
|
||||||
|
values, pass @code{help} to these options. The most important values are:
|
||||||
|
@table @samp
|
||||||
|
|
||||||
|
@item none
|
||||||
|
Forces the use of built-in GPU texture sampling (typically bilinear). Extremely
|
||||||
|
fast but poor quality, especially when downscaling.
|
||||||
|
|
||||||
|
@item bilinear
|
||||||
|
Bilinear interpolation. Can generally be done for free on GPUs, except when
|
||||||
|
doing so would lead to aliasing. Fast and low quality.
|
||||||
|
|
||||||
|
@item nearest
|
||||||
|
Nearest-neighbour interpolation. Sharp but highly aliasing.
|
||||||
|
|
||||||
|
@item oversample
|
||||||
|
Algorithm that looks visually similar to nearest-neighbour interpolation but
|
||||||
|
tries to preserve pixel aspect ratio. Good for pixel art, since it results in
|
||||||
|
minimal distortion of the artistic appearance.
|
||||||
|
|
||||||
|
@item lanczos
|
||||||
|
Standard sinc-sinc interpolation kernel.
|
||||||
|
|
||||||
|
@item spline36
|
||||||
|
Cubic spline approximation of lanczos. No difference in performance, but has
|
||||||
|
very slightly less ringing.
|
||||||
|
|
||||||
|
@item ewa_lanczos
|
||||||
|
Elliptically weighted average version of lanczos, based on a jinc-sinc kernel.
|
||||||
|
This is also popularly referred to as just "Jinc scaling". Slow but very high
|
||||||
|
quality.
|
||||||
|
|
||||||
|
@item gaussian
|
||||||
|
Gaussian kernel. Has certain ideal mathematical properties, but subjectively
|
||||||
|
very blurry.
|
||||||
|
|
||||||
|
@item mitchell
|
||||||
|
Cubic BC spline with parameters recommended by Mitchell and Netravali. Very
|
||||||
|
little ringing.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@item lut_entries
|
||||||
|
Configures the size of scaler LUTs, ranging from @code{1} to @code{256}. The
|
||||||
|
default of @code{0} will pick libplacebo's internal default, typically
|
||||||
|
@code{64}.
|
||||||
|
|
||||||
|
@item antiringing
|
||||||
|
Enables anti-ringing (for non-EWA filters). The value (between @code{0.0} and
|
||||||
|
@code{1.0}) configures the strength of the anti-ringing algorithm. May increase
|
||||||
|
aliasing if set too high. Disabled by default.
|
||||||
|
|
||||||
|
@item sigmoid
|
||||||
|
Enable sigmoidal compression during upscaling. Reduces ringing slightly.
|
||||||
|
Enabled by default.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@subsubsection Debanding
|
||||||
|
Libplacebo comes with a built-in debanding filter that is good at counteracting
|
||||||
|
many common sources of banding and blocking. Turning this on is highly
|
||||||
|
recommended whenever quality is desired.
|
||||||
|
@table @option
|
||||||
|
@item deband
|
||||||
|
Enable (fast) debanding algorithm. Disabled by default.
|
||||||
|
|
||||||
|
@item deband_iterations
|
||||||
|
Number of deband iterations of the debanding algorithm. Each iteration is
|
||||||
|
performed with progressively increased radius (and diminished threshold).
|
||||||
|
Recommended values are in the range @code{1} to @code{4}. Defaults to @code{1}.
|
||||||
|
|
||||||
|
@item deband_threshold
|
||||||
|
Debanding filter strength. Higher numbers lead to more aggressive debanding.
|
||||||
|
Defaults to @code{4.0}.
|
||||||
|
|
||||||
|
@item deband_radius
|
||||||
|
Debanding filter radius. A higher radius is better for slow gradients, while
|
||||||
|
a lower radius is better for steep gradients. Defaults to @code{16.0}.
|
||||||
|
|
||||||
|
@item deband_grain
|
||||||
|
Amount of extra output grain to add. Helps hide imperfections. Defaults to
|
||||||
|
@code{6.0}.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@subsubsection Color adjustment
|
||||||
|
A collection of subjective color controls. Not very rigorous, so the exact
|
||||||
|
effect will vary somewhat depending on the input primaries and colorspace.
|
||||||
|
@table @option
|
||||||
|
@item brightness
|
||||||
|
Brightness boost, between @code{-1.0} and @code{1.0}. Defaults to @code{0.0}.
|
||||||
|
|
||||||
|
@item contrast
|
||||||
|
Contrast gain, between @code{0.0} and @code{16.0}. Defaults to @code{1.0}.
|
||||||
|
|
||||||
|
@item saturation
|
||||||
|
Saturation gain, between @code{0.0} and @code{16.0}. Defaults to @code{1.0}.
|
||||||
|
|
||||||
|
@item hue
|
||||||
|
Hue shift in radians, between @code{-3.14} and @code{3.14}. Defaults to
|
||||||
|
@code{0.0}. This will rotate the UV subvector, defaulting to BT.709
|
||||||
|
coefficients for RGB inputs.
|
||||||
|
|
||||||
|
@item gamma
|
||||||
|
Gamma adjustment, between @code{0.0} and @code{16.0}. Defaults to @code{1.0}.
|
||||||
|
|
||||||
|
@item cones
|
||||||
|
Cone model to use for color blindness simulation. Accepts any combination of
|
||||||
|
@code{l}, @code{m} and @code{s}. Here are some examples:
|
||||||
|
@table @samp
|
||||||
|
@item m
|
||||||
|
Deuteranomaly / deuteranopia (affecting 3%-4% of the population)
|
||||||
|
@item l
|
||||||
|
Protanomaly / protanopia (affecting 1%-2% of the population)
|
||||||
|
@item l+m
|
||||||
|
Monochromacy (very rare)
|
||||||
|
@item l+m+s
|
||||||
|
Achromatopsy (complete loss of daytime vision, extremely rare)
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@item cone-strength
|
||||||
|
Gain factor for the cones specified by @code{cones}, between @code{0.0} and
|
||||||
|
@code{10.0}. A value of @code{1.0} results in no change to color vision. A
|
||||||
|
value of @code{0.0} (the default) simulates complete loss of those cones. Values
|
||||||
|
above @code{1.0} result in exaggerating the differences between cones, which
|
||||||
|
may help compensate for reduced color vision.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@subsubsection Peak detection
|
||||||
|
To help deal with sources that only have static HDR10 metadata (or no tagging
|
||||||
|
whatsoever), libplacebo uses its own internal frame analysis compute shader to
|
||||||
|
analyze source frames and adapt the tone mapping function in realtime. If this
|
||||||
|
is too slow, or if exactly reproducible frame-perfect results are needed, it's
|
||||||
|
recommended to turn this feature off.
|
||||||
|
@table @option
|
||||||
|
@item peak_detect
|
||||||
|
Enable HDR peak detection. Ignores static MaxCLL/MaxFALL values in favor of
|
||||||
|
dynamic detection from the input. Note that the detected values do not get
|
||||||
|
written back to the output frames, they merely guide the internal tone mapping
|
||||||
|
process. Enabled by default.
|
||||||
|
|
||||||
|
@item smoothing_period
|
||||||
|
Peak detection smoothing period, between @code{0.0} and @code{1000.0}. Higher
|
||||||
|
values result in peak detection becoming less responsive to changes in the
|
||||||
|
input. Defaults to @code{100.0}.
|
||||||
|
|
||||||
|
@item minimum_peak
|
||||||
|
Lower bound on the detected peak (relative to SDR white), between @code{0.0}
|
||||||
|
and @code{100.0}. Defaults to @code{1.0}.
|
||||||
|
|
||||||
|
@item scene_threshold_low
|
||||||
|
@item scene_threshold_high
|
||||||
|
Lower and upper thresholds for scene change detection. Expressed in a
|
||||||
|
logarithmic scale between @code{0.0} and @code{100.0}. Default to @code{5.5}
|
||||||
|
and @code{10.0}, respectively. Setting either to a negative value disables
|
||||||
|
this functionality.
|
||||||
|
|
||||||
|
@item overshoot
|
||||||
|
Peak smoothing overshoot margin, between @code{0.0} and @code{1.0}. Provides a
|
||||||
|
safety margin to prevent clipping as a result of peak smoothing. Defaults to
|
||||||
|
@code{0.05}, corresponding to a margin of 5%.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@subsubsection Tone mapping
|
||||||
|
The options in this section control how libplacebo performs tone-mapping and
|
||||||
|
gamut-mapping when dealing with mismatches between wide-gamut or HDR content.
|
||||||
|
In general, libplacebo relies on accurate source tagging and mastering display
|
||||||
|
gamut information to produce the best results.
|
||||||
|
@table @option
|
||||||
|
@item intent
|
||||||
|
Rendering intent to use when adapting between different primary color gamuts
|
||||||
|
(after tone-mapping).
|
||||||
|
@table @samp
|
||||||
|
@item perceptual
|
||||||
|
Perceptual gamut mapping. Currently equivalent to relative colorimetric.
|
||||||
|
@item relative
|
||||||
|
Relative colorimetric. This is the default.
|
||||||
|
@item absolute
|
||||||
|
Absolute colorimetric.
|
||||||
|
@item saturation
|
||||||
|
Saturation mapping. Forcibly stretches the source gamut to the target gamut.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@item gamut_mode
|
||||||
|
How to handle out-of-gamut colors that can occur as a result of colorimetric
|
||||||
|
gamut mapping.
|
||||||
|
@table @samp
|
||||||
|
@item clip
|
||||||
|
Do nothing, simply clip out-of-range colors to the RGB volume. This is the
|
||||||
|
default.
|
||||||
|
@item warn
|
||||||
|
Highlight out-of-gamut pixels (by coloring them pink).
|
||||||
|
@item darken
|
||||||
|
Linearly reduces content brightness to preserves saturated details, followed by
|
||||||
|
clipping the remaining out-of-gamut colors. As the name implies, this makes
|
||||||
|
everything darker, but provides a good balance between preserving details and
|
||||||
|
colors.
|
||||||
|
@item desaturate
|
||||||
|
Hard-desaturates out-of-gamut colors towards white, while preserving the
|
||||||
|
luminance. Has a tendency to shift colors.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@item tonemapping
|
||||||
|
Tone-mapping algorithm to use. Available values are:
|
||||||
|
@table @samp
|
||||||
|
@item auto
|
||||||
|
Automatic selection based on internal heuristics. This is the default.
|
||||||
|
@item clip
|
||||||
|
Performs no tone-mapping, just clips out-of-range colors. Retains perfect color
|
||||||
|
accuracy for in-range colors but completely destroys out-of-range information.
|
||||||
|
Does not perform any black point adaptation. Not configurable.
|
||||||
|
@item bt.2390
|
||||||
|
EETF from the ITU-R Report BT.2390, a hermite spline roll-off with linear
|
||||||
|
segment. The knee point offset is configurable. Note that this parameter
|
||||||
|
defaults to @code{1.0}, rather than the value of @code{0.5} from the ITU-R
|
||||||
|
spec.
|
||||||
|
@item bt.2446a
|
||||||
|
EETF from ITU-R Report BT.2446, method A. Designed for well-mastered HDR
|
||||||
|
sources. Can be used for both forward and inverse tone mapping. Not
|
||||||
|
configurable.
|
||||||
|
@item spline
|
||||||
|
Simple spline consisting of two polynomials, joined by a single pivot point.
|
||||||
|
The parameter gives the pivot point (in PQ space), defaulting to @code{0.30}.
|
||||||
|
Can be used for both forward and inverse tone mapping.
|
||||||
|
@item reinhard
|
||||||
|
Simple non-linear, global tone mapping algorithm. The parameter specifies the
|
||||||
|
local contrast coefficient at the display peak. Essentially, a parameter of
|
||||||
|
@code{0.5} implies that the reference white will be about half as bright as
|
||||||
|
when clipping. Defaults to @code{0.5}, which results in the simplest
|
||||||
|
formulation of this function.
|
||||||
|
@item mobius
|
||||||
|
Generalization of the reinhard tone mapping algorithm to support an additional
|
||||||
|
linear slope near black. The tone mapping parameter indicates the trade-off
|
||||||
|
between the linear section and the non-linear section. Essentially, for a given
|
||||||
|
parameter @var{x}, every color value below @var{x} will be mapped linearly,
|
||||||
|
while higher values get non-linearly tone-mapped. Values near @code{1.0} make
|
||||||
|
this curve behave like @code{clip}, while values near @code{0.0} make this
|
||||||
|
curve behave like @code{reinhard}. The default value is @code{0.3}, which
|
||||||
|
provides a good balance between colorimetric accuracy and preserving
|
||||||
|
out-of-gamut details.
|
||||||
|
@item hable
|
||||||
|
Piece-wise, filmic tone-mapping algorithm developed by John Hable for use in
|
||||||
|
Uncharted 2, inspired by a similar tone-mapping algorithm used by Kodak.
|
||||||
|
Popularized by its use in video games with HDR rendering. Preserves both dark
|
||||||
|
and bright details very well, but comes with the drawback of changing the
|
||||||
|
average brightness quite significantly. This is sort of similar to
|
||||||
|
@code{reinhard} with parameter @code{0.24}.
|
||||||
|
@item gamma
|
||||||
|
Fits a gamma (power) function to transfer between the source and target color
|
||||||
|
spaces, effectively resulting in a perceptual hard-knee joining two roughly
|
||||||
|
linear sections. This preserves details at all scales fairly accurately, but
|
||||||
|
can result in an image with a muted or dull appearance. The parameter is used
|
||||||
|
as the cutoff point, defaulting to @code{0.5}.
|
||||||
|
@item linear
|
||||||
|
Linearly stretches the input range to the output range, in PQ space. This will
|
||||||
|
preserve all details accurately, but results in a significantly different
|
||||||
|
average brightness. Can be used for inverse tone-mapping in addition to regular
|
||||||
|
tone-mapping. The parameter can be used as an additional linear gain
|
||||||
|
coefficient (defaulting to @code{1.0}).
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@item tonemapping_param
|
||||||
|
For tunable tone mapping functions, this parameter can be used to fine-tune the
|
||||||
|
curve behavior. Refer to the documentation of @code{tonemapping}. The default
|
||||||
|
value of @code{0.0} is replaced by the curve's preferred default setting.
|
||||||
|
|
||||||
|
@item tonemapping_mode
|
||||||
|
This option determines how the tone mapping function specified by
|
||||||
|
@code{tonemapping} is applied to the colors in a scene. Possible values are:
|
||||||
|
@table @samp
|
||||||
|
@item auto
|
||||||
|
Automatic selection based on internal heuristics. This is the default.
|
||||||
|
@item rgb
|
||||||
|
Apply the function per-channel in the RGB colorspace.
|
||||||
|
Per-channel tone-mapping in RGB. Guarantees no clipping and heavily desaturates
|
||||||
|
the output, but distorts the colors quite significantly. Very similar to the
|
||||||
|
"Hollywood" look and feel.
|
||||||
|
@item max
|
||||||
|
Tone-mapping is performed on the brightest component found in the signal. Good
|
||||||
|
at preserving details in highlights, but has a tendency to crush blacks.
|
||||||
|
@item hybrid
|
||||||
|
Tone-map per-channel for highlights and linearly (luma-based) for
|
||||||
|
midtones/shadows, based on a fixed gamma @code{2.4} coefficient curve.
|
||||||
|
@item luma
|
||||||
|
Tone-map linearly on the luma component (CIE Y), and adjust (desaturate) the
|
||||||
|
chromaticities to compensate using a simple constant factor. This is
|
||||||
|
essentially the mode used in ITU-R BT.2446 method A.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@item inverse_tonemapping
|
||||||
|
If enabled, this filter will also attempt stretching SDR signals to fill HDR
|
||||||
|
output color volumes. Disabled by default.
|
||||||
|
|
||||||
|
@item tonemapping_crosstalk
|
||||||
|
Extra tone-mapping crosstalk factor, between @code{0.0} and @code{0.3}. This
|
||||||
|
can help reduce issues tone-mapping certain bright spectral colors. Defaults to
|
||||||
|
@code{0.04}.
|
||||||
|
|
||||||
|
@item tonemapping_lut_size
|
||||||
|
Size of the tone-mapping LUT, between @code{2} and @code{1024}. Defaults to
|
||||||
|
@code{256}. Note that this figure is squared when combined with
|
||||||
|
@code{peak_detect}.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@subsubsection Dithering
|
||||||
|
By default, libplacebo will dither whenever necessary, which includes rendering
|
||||||
|
to any integer format below 16-bit precision. It's recommended to always leave
|
||||||
|
this on, since not doing so may result in visible banding in the output, even
|
||||||
|
if the @code{debanding} filter is enabled. If maximum performance is needed,
|
||||||
|
use @code{ordered_fixed} instead of disabling dithering.
|
||||||
|
@table @option
|
||||||
|
@item dithering
|
||||||
|
Dithering method to use. Accepts the following values:
|
||||||
|
@table @samp
|
||||||
|
@item none
|
||||||
|
Disables dithering completely. May result in visible banding.
|
||||||
|
@item blue
|
||||||
|
Dither with pseudo-blue noise. This is the default.
|
||||||
|
@item ordered
|
||||||
|
Tunable ordered dither pattern.
|
||||||
|
@item ordered_fixed
|
||||||
|
Faster ordered dither with a fixed size of @code{6}. Texture-less.
|
||||||
|
@item white
|
||||||
|
Dither with white noise. Texture-less.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@item dither_lut_size
|
||||||
|
Dither LUT size, as log base2 between @code{1} and @code{8}. Defaults to
|
||||||
|
@code{6}, corresponding to a LUT size of @code{64x64}.
|
||||||
|
|
||||||
|
@item dither_temporal
|
||||||
|
Enables temporal dithering. Disabled by default.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@subsubsection Custom shaders
|
||||||
|
libplacebo supports a number of custom shaders based on the mpv .hook GLSL
|
||||||
|
syntax. A collection of such shaders can be found here:
|
||||||
|
@url{https://github.com/mpv-player/mpv/wiki/User-Scripts#user-shaders}
|
||||||
|
|
||||||
|
A full description of the mpv shader format is beyond the scope of this
|
||||||
|
section, but a summary can be found here:
|
||||||
|
@url{https://mpv.io/manual/master/#options-glsl-shader}
|
||||||
|
@table @option
|
||||||
|
@item custom_shader_path
|
||||||
|
Specifies a path to a custom shader file to load at runtime.
|
||||||
|
|
||||||
|
@item custom_shader_bin
|
||||||
|
Specifies a complete custom shader as a raw string.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@subsubsection Debugging / performance
|
||||||
|
All of the options in this section default off. They may be of assistance when
|
||||||
|
attempting to squeeze the maximum performance at the cost of quality.
|
||||||
|
@table @option
|
||||||
|
@item skip_aa
|
||||||
|
Disable anti-aliasing when downscaling.
|
||||||
|
|
||||||
|
@item polar_cutoff
|
||||||
|
Truncate polar (EWA) scaler kernels below this absolute magnitude, between
|
||||||
|
@code{0.0} and @code{1.0}.
|
||||||
|
|
||||||
|
@item disable_linear
|
||||||
|
Disable linear light scaling.
|
||||||
|
|
||||||
|
@item disable_builtin
|
||||||
|
Disable built-in GPU sampling (forces LUT).
|
||||||
|
|
||||||
|
@item force_icc_lut
|
||||||
|
Force the use of a full ICC 3DLUT for gamut mapping.
|
||||||
|
|
||||||
|
@item disable_fbos
|
||||||
|
Forcibly disable FBOs, resulting in loss of almost all functionality, but
|
||||||
|
offering the maximum possible speed.
|
||||||
|
@end table
|
||||||
|
|
||||||
|
@subsection Commands
|
||||||
|
This filter supports almost all of the above options as @ref{commands}.
|
||||||
|
|
||||||
|
@subsection Examples
|
||||||
|
@itemize
|
||||||
|
@item
|
||||||
|
Complete example for how to initialize the Vulkan device, upload frames to the
|
||||||
|
GPU, perform filter conversion to yuv420p, and download frames back to the CPU
|
||||||
|
for output. Note that in specific cases you can get around the need to perform
|
||||||
|
format conversion by specifying the correct @code{format} filter option
|
||||||
|
corresponding to the input frames.
|
||||||
|
@example
|
||||||
|
ffmpeg -i $INPUT -init_hw_device vulkan -vf hwupload,libplacebo=format=yuv420p,hwdownload,format=yuv420p $OUTPUT
|
||||||
|
@end example
|
||||||
|
|
||||||
|
@item
|
||||||
|
Tone-map input to standard gamut BT.709 output:
|
||||||
|
@example
|
||||||
|
libplacebo=colorspace=bt709:color_primaries=bt709:color_trc=bt709:range=tv
|
||||||
|
@end example
|
||||||
|
|
||||||
|
@item
|
||||||
|
Rescale input to fit into standard 1080p, with high quality scaling:
|
||||||
|
@example
|
||||||
|
libplacebo=w=1920:h=1080:force_original_aspect_ratio=decrease:normalize_sar=true:upscaler=ewa_lanczos:downscaler=ewa_lanczos
|
||||||
|
@end example
|
||||||
|
|
||||||
|
@item
|
||||||
|
Convert input to standard sRGB JPEG:
|
||||||
|
@example
|
||||||
|
libplacebo=format=yuv420p:colorspace=bt470bg:color_primaries=bt709:color_trc=iec61966-2-1:range=pc
|
||||||
|
@end example
|
||||||
|
|
||||||
|
@item
|
||||||
|
Use higher quality debanding settings:
|
||||||
|
@example
|
||||||
|
libplacebo=deband=true:deband_iterations=3:deband_radius=8:deband_threshold=6
|
||||||
|
@end example
|
||||||
|
|
||||||
|
@item
|
||||||
|
Run this filter on the CPU, on systems with Mesa installed (and with the most
|
||||||
|
expensive options disabled):
|
||||||
|
@example
|
||||||
|
ffmpeg ... -init_hw_device vulkan:llvmpipe ... -vf libplacebo=upscaler=none:downscaler=none:peak_detect=false
|
||||||
|
@end example
|
||||||
|
|
||||||
|
@item
|
||||||
|
Suppress CPU-based AV1/H.274 film grain application in the decoder, in favor of
|
||||||
|
doing it with this filter. Note that this is only a gain if the frames are
|
||||||
|
either already on the GPU, or if you're using libplacebo for other purposes,
|
||||||
|
since otherwise the VRAM roundtrip will more than offset any expected speedup.
|
||||||
|
@example
|
||||||
|
ffmpeg -export_side_data +film_grain ... -vf libplacebo=apply_filmgrain=true
|
||||||
|
@end example
|
||||||
|
@end itemize
|
||||||
|
|
||||||
@section libvmaf
|
@section libvmaf
|
||||||
|
|
||||||
Calulate the VMAF (Video Multi-Method Assessment Fusion) score for a
|
Calulate the VMAF (Video Multi-Method Assessment Fusion) score for a
|
||||||
|
|||||||
Reference in New Issue
Block a user