Question for Frame Rate/Codec Wizards! :-)

[Oliver Peters]

[Franz Bieberkopf] “How is the architecture best described then, if not frame-based?”

By frame-based, I mean that each and every frame is separately accounted for. QT and MXF (I think) look at the header and calculate from the first frame based on duration of the clip. So they are clip-based and not frame-based. This is why you cannot lop off the beginning and end of a media file when you consolidate. You have to make a shorter copy.

Quantel, Assimilate and Autodesk use a frame-based media architecture, since their internal workings are based on image sequences. Quantel calls this “Frame Magic”, I believe. It allows you to shorten a media file simply by eliminating the unwanted head and tail frames without making a copy. I believe the old Leitch/DPS Velocity used a similar approach with their Virtual File System. This applies to their own internal media formats, though. I’m not sure if it applies to “soft-imported” compressed codecs, like when they directly access a QT media file.

[Franz Bieberkopf] “Is AV Foundation any different in this respect?”

I don’t know.

– Oliver

Oliver Peters Post Production Services, LLC
Orlando, FL
http://www.oliverpeters.com

[Keith Koby]

Did you try QT Edit or good old fashioned cinema tools to conform the frame rate without transcoding? That might work..