The hstack feature works great, but it pads the videos. That is, it puts black space between them. I use a command like this:
ffmpeg -i 1.mp4 -i 2.mp4 -filter_complex "hstack" out.mp4
How do I remove the black space separating the component videos?
Perhaps related, how do I control the size of the output video? If I could change the width of the output video, I imagine that would make the padding go away. But I couldn't find a way to combine the
scale= parameter with hstack.