ffmpeg-scaler(1)
| FFMPEG-SCALER(1) | FFMPEG-SCALER(1) |
NAME
ffmpeg-scaler - FFmpeg video scaling and pixel format converter
DESCRIPTION
The FFmpeg rescaler provides a high-level interface to the libswscale library image conversion utilities. In particular it allows one to perform image rescaling and pixel format conversion.
SCALER OPTIONS
The video scaler supports the following named options.
Options may be set by specifying -option value in the FFmpeg tools, with a few API-only exceptions noted below. For programmatic use, they can be set explicitly in the "SwsContext" options or through the libavutil/opt.h API.
- scaler, scaler_sub
- Choose the scaling algorithm to use. Default value is auto for both. It accepts the following values:
- auto
- Aumotic choice. For scaler_sub, this means the same algorithm as scaler. For scaler, this defaults to the scaler flag selected by sws_flags.
- bilinear
- Bilinear filter. (AKA triangle filter)
- bicubic
- 2-tap cubic BC-spline (AKA Mitchell-Netravali spline). The B and C parameters can be configured by setting "param0" and "param1", defaulting to 0.0 and 0.6 respectively.
- point, neighbor
- Point sampling (AKA nearest neighbor).
- area
- Area averaging. Equivalent to bilinear for upscaling.
- gaussian
- 2-tap Gaussian filter approximation. The sharpness parameter can be configured by setting "param0", defaulting to 3.0.
- sinc
- Unwindowed sinc filter.
- lanczos
- Lanczos resampling (sinc windowed sinc). The number of filter taps can be configured by setting "param0", defaulting to 3.
- spline
- Unwindowed natural bicubic spline.
- sws_flags
- Set the scaler flags. This is also used to set the scaling algorithm,
though this usage is deprecated in favor of setting scaler. Only a
single algorithm may be selected. Default value is bicubic.
It accepts the following values:
- fast_bilinear
- Select fast bilinear scaling algorithm. (Deprecated)
- bilinear
- Select bilinear scaling algorithm. (Deprecated)
- bicubic
- Select bicubic scaling algorithm. (Deprecated)
- experimental
- Select experimental scaling algorithm. (Deprecated)
- neighbor
- Select nearest neighbor rescaling algorithm. (Deprecated)
- area
- Select averaging area rescaling algorithm. (Deprecated)
- bicublin
- Select bicubic scaling algorithm for the luma component, bilinear for chroma components. (Deprecated)
- gauss
- Select Gaussian rescaling algorithm. (Deprecated)
- sinc
- Select sinc rescaling algorithm. (Deprecated)
- lanczos
- Select Lanczos rescaling algorithm. The default width (alpha) is 3 and can be changed by setting "param0". (Deprecated)
- spline
- Select natural bicubic spline rescaling algorithm. (Deprecated)
- print_info
- Enable printing/debug logging.
- accurate_rnd
- Enable accurate rounding.
- full_chroma_int
- Enable full chroma interpolation.
- full_chroma_inp
- Select full chroma input.
- bitexact
- Enable bitexact output.
- unstable
- Allow the use of experimental new code. May subtly affect the output or even produce wrong results. For testing only.
- srcw (API only)
- Set source width.
- srch (API only)
- Set source height.
- dstw (API only)
- Set destination width.
- dsth (API only)
- Set destination height.
- src_format (API only)
- Set source pixel format (must be expressed as an integer).
- dst_format (API only)
- Set destination pixel format (must be expressed as an integer).
- src_range (boolean)
- If value is set to 1, indicates source is full range. Default value is 0, which indicates source is limited range.
- dst_range (boolean)
- If value is set to 1, enable full range for destination. Default value is 0, which enables limited range.
- gamma (boolean)
- If value is set to 1, enable gamma correct scaling. Default value is 0.
- param0, param1
- Set scaling algorithm parameters. The specified values are specific of some scaling algorithms and ignored by others. The specified values are floating point number values.
- sws_dither
- Set the dithering algorithm. Accepts one of the following values. Default value is auto.
- auto
- automatic choice
- none
- no dithering
- bayer
- bayer dither
- ed
- error diffusion dither
- a_dither
- arithmetic dither, based using addition
- x_dither
- arithmetic dither, based using xor (more random/less apparent patterning that a_dither).
- alphablend
- Set the alpha blending to use when the input has alpha but the output does not. Default value is none.
- uniform_color
- Blend onto a uniform background color
- checkerboard
- Blend onto a checkerboard
- none
- No blending
- sws_backends
- Set the allowed swscale backends. This is a flags option, so multiple backends may be combined.
- auto
- Automatic selection. Equal to either stable or all depending on whether or not the unstable flag is set. This is the default value.
- stable
- All stable backends.
- unstable
- All unstable backends.
- all
- All available backends.
- legacy
- Legacy swscale code.
- c
- Template-based reference code.
- memcpy
- Fast path using libc "memcpy".
- x86
- x86 SIMD kernels.
- aarch64
- AArch64 NEON kernels.
- spirv
- Vulkan SPIR-V backend.
SEE ALSO
ffmpeg(1), ffplay(1), ffprobe(1), libswscale(3)
AUTHORS
The FFmpeg developers.
For details about the authorship, see the Git history of the project (https://git.ffmpeg.org/ffmpeg), e.g. by typing the command git log in the FFmpeg source directory, or browsing the online repository at <https://git.ffmpeg.org/ffmpeg>.
Maintainers for the specific components are listed in the file MAINTAINERS in the source code tree.