iw/2 for half the input video width, or ih-100 to subtract 100 pixels from the input video height).
In terms of performance, dont expect much parity between them in terms of performance both will run on the GPU either way. FFmpeg gets the original input video width ( iw) and height ( ih) values automatically, so you can perform mathematical operations using those values (e.g. I've already tried Lanczos and Spline (they were mentioned as "the best ones when scaling down" in my second link) and the first thing that surprised me was nearly no encoding time difference when compared to default method but the only differences in the output file I could notice were the more smooth gradients. The choice on the filter (s) you can use depend on how you build FFmpeg: Use the proprietary CUDA SDK and youll get scalenpp and scalecuda, or stick to an LLVM build without the CUDA SDK and youll still get scalecuda. Cropping and scaling videos with FFmpeg is a fairly straightforward process. I think the most popular "not default" filter is Lanczos. So the first step is to shorten the original video. while preserving the aspect ratio (most wanted) to a width of 960.
FFMPEG SCALE UP MP4
Once, you have installed ffmpeg, you can resize: a mp4 video.
I can imagine that selecting the proper filter can be crucial when scaling the video up but what about scaling it down? ffmpeg permits to set the dimension of a video to -1 in order to preserve aspect ratio.
This adds the overlay, but it stretches it to the same aspect ratio of the video which is what Im trying to avoid: ffmpeg -y -i video.mov -i watermark.png -filtercomplex 'scale-1:1280:flagsbicubic,overlay (mainw-overlayw)/2. So far I've mostly used the default scale filter method to scale the x264 video resolution down, for example -vf scale=720:576 but I've noticed that some people often use -vf scale=720:576:flags=name (or -vf scale=720x576:flags=name) where name is the name of the filter. Im trying to scale a video, and then apply an overlay keeping the aspect ration of the same.
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