[FFmpeg-user] Order for Filters

[Carl Eugen Hoyos]

Nicholas Robbins writes:

> > But if the input is letterboxed, you should definitely crop 
> > first.
> 
> The input definitely appears to be letterboxed. Is there some 
> difference between "appearing" to be letterboxed and actually 
> being letterboxed that I should check for?

Please remember that I live in PAL country and my mother tongue 
is not English: Does "letterboxed" mean black bars either left 
and right or above and below the actual image?
If yes, what is the difference between "apparent black bars" 
and "actual black bars"?
I think we can agree that the black bars do not help fieldmatch 
but take time to process and should therefore be removed as 
early in the process as possible.

Carl Eugen