ffsws

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FFMPEG video rescaler

Register name used to load filter: ffsws
This filter may be automatically loaded during graph resolution.
Filters of this class can connect to each-other.

This filter rescales raw video data using FFMPEG to the specified size and pixel format.

Output size assignment

If osize is {0,0}, the output dimensions will be set to the input size, and input aspect ratio will be ignored.

If osize is {0,H} (resp. {W,0}), the output width (resp. height) will be set to respect input aspect ratio. If keepar=nosrc, input sample aspect ratio is ignored.

Aspect Ratio and Sample Aspect Ratio

When output sample aspect ratio is set, the output dimensions are divided by the output sample aspect ratio.
Example

ffsws:osize=288x240:osar=3/2

The output dimensions will be 192x240.

When aspect ratio is not kept (keepar=off):

• source is resampled to desired dimensions
• if output aspect ratio is not set, output will use source sample aspect ratio

When aspect ratio is partially kept (keepar=nosrc):

• resampling is done on the input data without taking input sample aspect ratio into account
• if output sample aspect ratio is not set (osar=0/N), source aspect ratio is forwarded to output.

When aspect ratio is fully kept (keepar=full), output aspect ratio is force to 1/1 if not set.

When sample aspect ratio is kept, the filter will:

• center the rescaled input frame on the output frame
• fill extra pixels with padclr

Algorithms options

• for bicubic, to tune the shape of the basis function, p1 tunes f(1) and p2 f´(1)
• for gauss p1 tunes the exponent and thus cutoff frequency
• for lanczos p1 tunes the width of the window function

See FFMPEG documentation (https://ffmpeg.org/documentation.html) for more details

Options

osize (v2di): osize of output video
ofmt (pfmt, default: none, minmax: none,yuv420,yvu420,yuv420_10,yuv422,yuv422_10,yuv444,yuv444_10,uyvy,vyuy,yuyv,yvyu,uyvl,vyul,yuyl,yvyl,nv12,nv21,nv1l,nv2l,yuva,yuvd,yuv444a,yuv444p,v308,yuv444ap,v408,v410,v210,grey,algr,gral,rgb4,rgb5,rgb6,rgba,argb,bgra,abgr,rgb,bgr,xrgb,rgbx,xbgr,bgrx,rgbd,rgbds,uncv): pixel format for output video. When not set, input format is used
scale (enum, default: bicubic): scaling mode (see filter help) (fastbilinear|bilinear|bicubic|X|point|area|bicublin|gauss|sinc|lanzcos|spline)

p1 (dbl, default: +I): scaling algo param1
p2 (dbl, default: +I): scaling algo param2
ofr (bool, default: false): force output full range
brightness (bool, default: 0): 16.16 fixed point brightness correction, 0 means use default
contrast (uint, default: 0): 16.16 fixed point brightness correction, 0 means use default
saturation (uint, default: 0): 16.16 fixed point brightness correction, 0 means use default
otable (sintl): the yuv2rgb coefficients describing the output yuv space, normally ff_yuv2rgb_coeffs[x], use default if not set
itable (sintl): the yuv2rgb coefficients describing the input yuv space, normally ff_yuv2rgb_coeffs[x], use default if not set
keepar (enum, default: off): keep aspect ratio

• off: ignore aspect ratio
• full: respect aspect ratio, applying input sample aspect ratio info
• nosrc: respect aspect ratio but ignore input sample aspect ratio

padclr (str, default: black): clear color when aspect ration preservation is used
osar (frac, default: 0/1): force output pixel aspect ratio