Willen wrote:The only thing that gets me is that the programs are broadcast at 29.97 fps (actually 59.94 fields per second, interlaced). Why not keep it all at 29.97 fps OR do IVTC and release at 23.976 fps instead of doing 119.88 fps VFR?
I would assume it's to preserve the motion of the 29.97 segments alongside having an IVTC-ish effect on the 23.976 segments. Sort of along the same rationale that if possible, don't simply deinterlace or field-match something - do an IVTC instead, except if one does that on footage that's supposed to be 29.97 the motion can potentially get sacrificed. Like I'd mentioned though, considering how null frames are treated by video decoding software, it would only be necessary to insert them into non-29.97fps segments to make everything 29.97.
I guess what gets me more is why wonky 120fps AVIs are even made anymore when newer containers can properly handle VFR content. From the little bit that I read about how 120fps AVIs are made, it's more trouble to do that than to just concatenate 23.976 and 29.97 video streams together into an MKV or MP4 (I've never actually done that with MP4, though, I've just heard that it can handle VFR also).