Pro Tools HD 11 NTSC 23.976fps to Film 24fps sync problems

[SZE]

Hi

We have a 23.976 mix session that we need to convert/speed change to 24fps. No mix file or stems are available, so we have to do this change using the original full mix session with all original tracks, automation, etc.

A new 24fps session is created and the tracks are imported from the 23.976 session using the relevant 0.1% SRC pull up option.

We have done this exact same process in the past in Pro Tools HD 10 without problems, but upon doing it in Pro Tools HD 11 are encountering various issues:


1. After conversion, Pro Tools has inserted an additional 3.5 seconds at the start of the session

2. All audio and automation breakpoints, etc. appear to have been converted and speed changed correctly, although some clips play back in sync, some clips do not

3. Just to complicate things a little more, no 24fps master video is available, so we are playing back the 23.976 video at 24fps via the Avid video engine. There is a possibility that the subsequent sync problems are related to this, although having done the exact same thing in Pro Tools HD 10 where it worked correctly, it is a mystery


Any tips or pointers very welcome! Thanks

[Kasper]

Any reason you can't work in the original 23.976 session, print stems, then pull-up your "stem" session?

Lot less to worry about ..... no?

If you don't have a 24 FPS master to check sync, I wouldn't do it. (or at least tell your client you can't guarantee sync)
Also, throw in a head and tail pop for good measure.

Have you checked the clips in the orig session to see if they were ever in-sync, and are all original files the same sample rate?

kasper