Comment by izacus
> This doesn't always work because the computed value should be an even integer; if it's not, ffmpeg will raise an error and tell you why; then you can replace the -1 with the nearest even integer (I wonder why it can't do that by itself, but apparently, it can't).
It's not about integer, but some of the sizes need to be even. You can use `-vf scale=320:-2` to ensure that.
It's hard for a number to be even without first being an integer, no? ;-)
But thanks for '-2', didn't know about that! It's the exact default option I needed! Will be using that always from now on.
https://stackoverflow.com/questions/71092347/ffmeg-option-sc...