How rigid is Force Film?

[GrofLuigi]

Lately I found myself asking myself (can I write that?) why don't I ever use force film in DGIndex. Apart from the notes on 90+ % film, I couldn't find any clear information what happens if the pulldown pattern is disturbed - i.e. how does DGIndex react to dropped frames or any other disturbances. What if the pattern is shifted on one (or more) places? I guess it adapts itself, but how much? Then why telecide exists?

Too many questions, I guess, maybe answered somewhere, but I hope they bring some discussion...

GL

[Guest]

There are two types of pulldown: hard and soft. Soft means that the fields are not actually repeated in the source stream, but are repeated by setting a flag called the RFF flag. Hard means that the fields are actually repeated in the stream and there is no RFF flagging.

If you have soft pulldown, then Force Film is used. FF just ignores all RFF flags. This performs a perfect IVTC that is totally insensitive to any patterns in the stream.

If you have hard pulldown, then FF won't work. You have to use Telecide(), which tries to guess the right way to remove the pulldown, based on patterns it sees.

I couldn't find any clear information what happens if the pulldown pattern is disturbed - i.e. how does DGIndex react to dropped frames or any other disturbances. What if the pattern is shifted on one (or more) places? I guess it adapts itself, but how much? For FF, the pattern is irrelevant because FF works by just ignoring RFF flags.

Then why telecide exists? To handle hard telecined (and hybrid) pulldown.

soft telecine -> use FF
hard telecine -> use Telecide()

[GrofLuigi]

Thanks neuron2 for the explanation!
Just 1 more thing is unclear to me (you don't have to answer if you don't have time):
If you have soft pulldown, then Force Film is used. FF just ignores all RFF flags. This performs a perfect IVTC that is totally insensitive to any patterns in the stream.
So that means that the original fields in the stream can never be out of order? Cause I've read in this forum about streams with weird flags... You of all the people surely would know about that (With all the b0rked streams people send you...) ;)

Thanks again and carry on!

GL

[Guest]

So that means that the original fields in the stream can never be out of order? Of course they can. I'm talking about normal non-pathological soft 3:2 pulldown. For pathological video, FF may not function perfectly, and the field matchers may not as well.

Cause I've read in this forum about streams with weird flags... Weird flags? I prefer a more rigorous mode of discourse.

Try FF when you have a high film % from DGIndex. If the results are good, go with it. If not, try a field matcher.