--- name: "ffmpeg-scaler" section: "1" platform: "linux" package: "ffmpeg" version: "2:9.0.2-2" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/ffmpeg-scaler" --- # ffmpeg-scaler(1) FFmpeg video scaling and pixel format converter ## 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)](/ffmpeg/1.md), [**ffplay**(1)](/ffplay/1.md), [**ffprobe**(1)](/ffprobe/1.md), [**libswscale**(3)](/libswscale/3.md) ## 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.