FFMPEG-SCALER(1) FFMPEG-SCALER(1)

# [NAME](#NAME)

ffmpeg-scaler - FFmpeg video scaling and pixel format converter

# [DESCRIPTION](#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](#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**](#scaler,)

Choose the scaling algorithm to use. Default value is **auto** for both. It accepts the following values:

[**auto**](#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)

Bilinear filter. (AKA triangle filter)

[**bicubic**](#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,)

Point sampling (AKA nearest neighbor).

[**area**](#area)

Area averaging. Equivalent to **bilinear** for upscaling.

[**gaussian**](#gaussian)

2-tap Gaussian filter approximation. The sharpness parameter can be configured by setting "param0", defaulting to 3.0.

[**sinc**](#sinc)

Unwindowed sinc filter.

[**lanczos**](#lanczos)

Lanczos resampling (sinc windowed sinc). The number of filter taps can be configured by setting "param0", defaulting to 3.

[**spline**](#spline)

Unwindowed natural bicubic spline.

[**sws\_flags**](#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**](#fast_bilinear)

Select fast bilinear scaling algorithm. (Deprecated)

[**bilinear**](#bilinear~2)

Select bilinear scaling algorithm. (Deprecated)

[**bicubic**](#bicubic~2)

Select bicubic scaling algorithm. (Deprecated)

[**experimental**](#experimental)

Select experimental scaling algorithm. (Deprecated)

[**neighbor**](#neighbor)

Select nearest neighbor rescaling algorithm. (Deprecated)

[**area**](#area~2)

Select averaging area rescaling algorithm. (Deprecated)

[**bicublin**](#bicublin)

Select bicubic scaling algorithm for the luma component, bilinear for chroma components. (Deprecated)

[**gauss**](#gauss)

Select Gaussian rescaling algorithm. (Deprecated)

[**sinc**](#sinc~2)

Select sinc rescaling algorithm. (Deprecated)

[**lanczos**](#lanczos~2)

Select Lanczos rescaling algorithm. The default width (alpha) is 3 and can be changed by setting "param0". (Deprecated)

[**spline**](#spline~2)

Select natural bicubic spline rescaling algorithm. (Deprecated)

[**print\_info**](#print_info)

Enable printing/debug logging.

[**accurate\_rnd**](#accurate_rnd)

Enable accurate rounding.

[**full\_chroma\_int**](#full_chroma_int)

Enable full chroma interpolation.

[**full\_chroma\_inp**](#full_chroma_inp)

Select full chroma input.

[**bitexact**](#bitexact)

Enable bitexact output.

[**unstable**](#unstable)

Allow the use of experimental new code. May subtly affect the output or even produce wrong results. For testing only.

[**srcw** *(API only)*](#srcw)

Set source width.

[**srch** *(API only)*](#srch)

Set source height.

[**dstw** *(API only)*](#dstw)

Set destination width.

[**dsth** *(API only)*](#dsth)

Set destination height.

[**src\_format** *(API only)*](#src_format)

Set source pixel format (must be expressed as an integer).

[**dst\_format** *(API only)*](#dst_format)

Set destination pixel format (must be expressed as an integer).

[**src\_range** *(boolean)*](#src_range)

If value is set to 1, indicates source is full range. Default value is 0, which indicates source is limited range.

[**dst\_range** *(boolean)*](#dst_range)

If value is set to 1, enable full range for destination. Default value is 0, which enables limited range.

[**gamma** *(boolean)*](#gamma)

If value is set to 1, enable gamma correct scaling. Default value is 0.

[**param0, param1**](#param0,)

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**](#sws_dither)

Set the dithering algorithm. Accepts one of the following values. Default value is **auto**.

[**auto**](#auto~2)

automatic choice

[**none**](#none)

no dithering

[**bayer**](#bayer)

bayer dither

[**ed**](#ed)

error diffusion dither

[**a\_dither**](#a_dither)

arithmetic dither, based using addition

[**x\_dither**](#x_dither)

arithmetic dither, based using xor (more random/less apparent patterning that a\_dither).

[**alphablend**](#alphablend)

Set the alpha blending to use when the input has alpha but the output does not. Default value is **none**.

[**uniform\_color**](#uniform_color)

Blend onto a uniform background color

[**checkerboard**](#checkerboard)

Blend onto a checkerboard

[**none**](#none~2)

No blending

[**sws\_backends**](#sws_backends)

Set the allowed swscale backends. This is a flags option, so multiple backends may be combined.

[**auto**](#auto~3)

Automatic selection. Equal to either **stable** or **all** depending on whether or not the **unstable** flag is set. This is the default value.

[**stable**](#stable)

All stable backends.

[**unstable**](#unstable~2)

All unstable backends.

[**all**](#all)

All available backends.

[**legacy**](#legacy)

Legacy swscale code.

[**c**](#c)

Template-based reference code.

[**memcpy**](#memcpy)

Fast path using libc "memcpy".

[**x86**](#x86)

x86 SIMD kernels.

[**aarch64**](#aarch64)

AArch64 NEON kernels.

[**spirv**](#spirv)

Vulkan SPIR-V backend.

# [SEE ALSO](#SEE_ALSO)

[**ffmpeg**(1)](/man/os/ffmpeg-9.0/ffmpeg.1), [**ffplay**(1)](/man/os/ffmpeg-9.0/ffplay.1), [**ffprobe**(1)](/man/os/ffmpeg-9.0/ffprobe.1), [**libswscale**(3)](/man/os/ffmpeg-9.0/libswscale.3)

# [AUTHORS](#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.

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Document: ffmpeg-scaler(1) from ffmpeg-9.0 9.0.2-r9 (Chainguard OS)
Source: https://github.com/FFmpeg/FFmpeg