Scale (resize) and convert (pixel format) the input video, using accelerated CUDA kernels. Setting the output width and height works in the same way as for the scale filter.
The filter accepts the following options:
- w, h
-
Set the output video dimension expression. Default value is the input dimension.
Allows for the same expressions as the scale filter.
- interp_algo
-
Sets the algorithm used for scaling:
- nearest
-
Nearest neighbour
Used by default if input parameters match the desired output.
- bilinear
-
Bilinear
- bicubic
-
Bicubic
This is the default.
- lanczos
-
Lanczos
- format
-
Controls the output pixel format. By default, or if none is specified, the input pixel format is used.
The filter does not support converting between YUV and RGB pixel formats.
- passthrough
-
If set to 0, every frame is processed, even if no conversion is neccesary. This mode can be useful to use the filter as a buffer for a downstream frame-consumer that exhausts the limited decoder frame pool.
If set to 1, frames are passed through as-is if they match the desired output parameters. This is the default behaviour.
- param
-
Algorithm-Specific parameter.
Affects the curves of the bicubic algorithm.
- force_original_aspect_ratio, force_divisible_by
-
Work the same as the identical scale filter options.
Examples
-
Scale input to 720p, keeping aspect ratio and ensuring the output is yuv420p.
scale_cuda=-2:720:format=yuv420p
-
Upscale to 4K using nearest neighbour algorithm.
scale_cuda=4096:2160:interp_algo=nearest
-
Don’t do any conversion or scaling, but copy all input frames into newly allocated ones. This can be useful to deal with a filter and encode chain that otherwise exhausts the decoders frame pool.
scale_cuda=passthrough=0