[FFmpeg-user] Reversing PAL->NTSC telecining.

[Nicholas Robbins]

Hello,


I posted some time ago about some input that I thought was telecined, and I was having trouble with my filters. I've now had some more time to look at a similar sample, and this is what I've figured out. The video contains a pattern of 3 progressive and 3 interlaced frames. If we think of fields it is something like this:

ZA AA BB CC CD DE EF 

Where Z is from the previous batch of 5 original frames and F is from the next. This turns 5 frames into 6. Hence it was used to convert from PAL (~25fps) to NTSC (~30fps.) How do I undo this? Would some combination of fieldmatch & decimate do this? What about the pullup filter?

Thanks in advance.

-Nick