OK we are experiencing a number of problems with a couple of MacBooks we have pertaining to Firewire External Video output, in relation to footage shot and transferred from P2 cards... But for simplicity, I will focus on one MacBook initially:
2nd Gen (unibody) MacBook
We are shooting SD material on a Panasonic 370 camera using two 16gig P2 cards. When we Log and Transfer into a Final Cut project, lay it out on a sequence, it will play fine when viewing soley off the Canvas window and monitoring off the MacBook's bult-in speakers.
However when we enable External Video to an Firewire D/A device (Canopus ADVC-1000 or a Sony DSR-20 DVCAM deck), the audio will drop out in certain portions of clips the second time playing back.
Some really strange aspects of this problem:
Applying some benign filter to the clip restores the audio. It doesn't even have to be an audio filter. I applied the Broadcast Safe filter to all clips on the timeline and audio playback through the Firewire device was restored. This implies to me that there is some kind of corruption in the DV stream within the clips?
If we import clips sourced from a DVCAM deck, these issues don't occur at all.
If we Log and Transfer the same clips from the same P2 cards by connecting the same camera to another FCP7-equipped MacBook, they behave fine.
Additionally we tried putting the P2 cards into a Panasonic 170 and connecting it to the MacBook in question for Log and Transfer. They still experienced the same strange symptoms.
In all my years I've only seen clips with this kind of 'corruption-only-through-Firewire' when they were sourced from *tapes* that had tape clogs or the like. I am at a loss as to why such corruption could happen on P2 cards... and furthermore in a manner such that only a single Mac exhibits the symptoms...
I'd be grateful for a sanity check... and any brainstorms narrowing down the source of the problem.