[FFmpeg-user] How to improve result of transitions

[Michael Koch]

> However, now that I understand that for 4 seconds transition you need 4
> seconds on each video, I don't understand why you need two parameters,
> duration and offset. Why not simply define the duration, and have ffmpeg
> calculate the offset as videoDuration minus transitionDuration?

I think that's because when the transition begins FFmpeg doesn't yet 
know the length of the input stream.
It could also be a live stream with unknown length.

Michael