# phpman > man > ffmpeg-scaler(1)

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## 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.

       **sws**___**flags**
           Set the scaler flags. This is also used to set the scaling algorithm. Only a single
           algorithm should be selected. Default value is **bicubic**.

           It accepts the following values:

           **fast**___**bilinear**
               Select fast bilinear scaling algorithm.

           **bilinear**
               Select bilinear scaling algorithm.

           **bicubic**
               Select bicubic scaling algorithm.

           **experimental**
               Select experimental scaling algorithm.

           **neighbor**
               Select nearest neighbor rescaling algorithm.

           **area**
               Select averaging area rescaling algorithm.

           **bicublin**
               Select bicubic scaling algorithm for the luma component, bilinear for chroma
               components.

           **gauss**
               Select Gaussian rescaling algorithm.

           **sinc**
               Select sinc rescaling algorithm.

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

           **spline**
               Select natural bicubic spline rescaling algorithm.

           **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.

       **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.

### 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

## SEE ALSO
       [**ffmpeg**(1)](https://www.chedong.com/phpMan.php/man/ffmpeg/1/markdown), [**ffplay**(1)](https://www.chedong.com/phpMan.php/man/ffplay/1/markdown), [**ffprobe**(1)](https://www.chedong.com/phpMan.php/man/ffprobe/1/markdown), [**libswscale**(3)](https://www.chedong.com/phpMan.php/man/libswscale/3/markdown)

## AUTHORS
       The FFmpeg developers.

       For details about the authorship, see the Git history of the project
       (git://source.ffmpeg.org/ffmpeg), e.g. by typing the command **git** **log** in the FFmpeg source
       directory, or browsing the online repository at <**<http://source.ffmpeg.org>**>.

       Maintainers for the specific components are listed in the file _MAINTAINERS_ in the source code
       tree.



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