[FFmpeg-user] ffmpeg architecture question

[Mark Filipak]

Another cogent point:

Suppose I put 'datascope' before a filter that would pass the original frame (say, based on a 
color), but that the filter won't pass the 'scope' image (because it doesn't contain that color). I 
haven't tried it, but I'll bet that the 'scope' image doesn't appear at all and that the frame is 
dropped.

(Note that if I moved the 'datascope' to after the filter, it would work as expected.)

Supposing that I'm correct, and considering the prior experiments that I did conduct, the 
non-recursive nature of ffmpeg filter complexes is an important architectural feature that's not 
documented.

Understand that I'm not criticizing ffmpeg. ffmpeg works how it works and that's fine. It just 
doesn't work like an oscilloscope. It could have been designed to work like an oscilloscope, but it 
wasn't. That's okay, but it really should be documented.

Do you agree, Paul, or am I mistaken?