内容表

1 描述

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.

2 Scaler 选项

视频缩放器支持下列命名选项。

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

3 另请参阅

ffmpeg , ffplay , ffprobe , libswscale

4 作者

FFmpeg 开发者。

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.