OMF trouble from FCP

[John E. Walker]

I am looking into taking on post audio for an indie short I actually boomed on.  Picture lock won't be for another two weeks, but I took it upon myself to go meet with the picture editor to get a sense of her workflow.  Mainly, I wanted to see what kinds of trouble might be up the road (regions not named accordingly, for example).  Her timeline looked good.  I hadn't ever seen audio and video clips merged before though, which gives them a new name for one thing.  Every single clip had the word "Merged" in its name, like "10-6 Merged" for scene 10, take 6.  Usually I see audio and video clips linked.  She also unwittingly created a 16 bit sequence, not even noticing that our audio was 24 bit.  Anyway, I asked if I could take an OMF export to test out which she was totally cool with, but it didn't work.  A dialog popped up reading something like "Over 2 GB not supported."  I understand that OMF files cannot exceed 2GB, but this was only a 19 minute timeline, with 4 tracks of 48/16 audio.  We tried 2 minute handles, 30 second handles, and even no handles.  It's a mystery to me.  I have exported OMF from a project 30 minutes long with 10 mono tracks before.  Anyone know what's going on?

[bcopenhagen]

No answers for you about the OMF.  Make sure you're using OMF 2.0.

Pity about the 16-bit sequence.  You should insist on a 24-bit version, so she learns to respect the decisions and work of the whole team involved in making the film, down to the audio bit-depth that was used by the production sound mixer.  Not to mention preserving the superior noise floor characteristics and increased processing flexibility that 24-bit provides.

Back to your original question....what I can tell you for sure is that you'll find a lot more info on other, more post-specific forums.

Try these.

http://www.2-popforums.com/forums/

http://forums.creativecow.net/forums.php

http://www.gearslutz.com/board/post-production-forum/

Good luck,

Brian

PS - it's very good that you're testing out the technical side now.  The effectiveness of the audio delivery can make or break how much effort your job will be...

[Philip Perkins]

I am looking into taking on post audio for an indie short I actually boomed on.  Picture lock won't be for another two weeks, but I took it upon myself to go meet with the picture editor to get a sense of her workflow.  Mainly, I wanted to see what kinds of trouble might be up the road (regions not named accordingly, for example).  Her timeline looked good.  I hadn't ever seen audio and video clips merged before though, which gives them a new name for one thing.  Every single clip had the word "Merged" in its name, like "10-6 Merged" for scene 10, take 6.  Usually I see audio and video clips linked.  She also unwittingly created a 16 bit sequence, not even noticing that our audio was 24 bit.  Anyway, I asked if I could take an OMF export to test out which she was totally cool withbut it didn't work.  A dialog popped up reading something like "Over 2 GB not supported."  I understand that OMF files cannot exceed 2GB, but this was only a 19 minute timeline, with 4 tracks of 48/16 audio.  We tried 2 minute handles, 30 second handles, and even no handles.  It's a mystery to me.  I have exported OMF from a project 30 minutes long with 10 mono tracks before.  Anyone know what's going on?

In what app did this dialog pop up?  FCP?  The over-2GB thing must mean that the handles are not being properly spec'ed somehow. It may be that FCP is trying to export the merged video+audio clips--are you specing audio only for the OMF?  Try having the editor make a new sequence and bring in only the audio from the master sequence (and set it to 24 bit), and export from that.  If original material was imported into FCP via a file transfer then the audio is on her drives at 24 bit.  If they diged from tape at 16 bit you my be hosed on that account.  I generally always run FCP OMFs thru AVTransfer in order to "regularize" them so that DAWs have no trouble with them.

Philip Perkins

[John E. Walker]

Oh that's interesting.  I hadn't heard of AVTransfer.  I saw that the audio files FCP is referencing are 24 bit.  I suspect that her 16 bit sequence must render audio in order to playback.  So, it may be as simple as changing the bit depth in the sequence settings dialog.  The audio started out as 24 bit BWF files from a 744T and have made their way to an external hard drive sitting on her Mac.  I didn't see a place to specify audio only in the OMF.  I'm pretty sure the route her cursor took was File > Export Audio as OMF, to which a dialog box popped up.  I'll look at it again when she's available. 

[Philip Perkins]

Well good--you'll get yr 24 bit audio anyhow.

Philip Perkins

[John E. Walker]

Switching computers resolved the OMF export problem!  Funny.

Also, I got my 24 bit very easily by changing the sequence settings in FCP.  I compared a region of the OMF to its original production audio file counterpart in PT, and they sound the same.  The drawn waveforms are absolutely identical at maximum zoom, as well.  That's good news, as I won't be tediously syncing all the original files to the OMF; I can just use the OMF.