The Setup…

I capture video in HDV format, which uses compressed audio. When importing these clips into Adobe Premiere Pro CS5, the video gets “indexes” and the audio gets “conformed”. Conforming audio essentially involves decompressing it and stretching it out to 32-bit samples that are more efficient for non-linear editing. These 32-bit samples are stored in Adobe’s proprietary CFA files that are either stored with your source clips or in a subdirectory of your home directory.

As I’m using a laptop, with limited local storage, so I keep all of my projects on a network attached RAID. Over gigabit, there is more than enough throughput to scrub real-time through several layers.

The Showstopper….

When opening the project directly on the NAS, all of the clips spontaneously start re-indexing and conforming every time I click on one. When the same project is opened from the local laptop drive, this does not occur.

My NAS is actually an Ubuntu Linux server running “netatalk” to run AFP (Apple Filing Protocol) shares. I played with several combinations of options in the “AppleVolumes.default” file with no luck. Then, I changed the preference in Premiere to store the CFA files on the laptop’s drive while still keeping the project on the server. Still no luck…

The Cause…

I found that my laptop and NAS clocks were out of sync. It appears that netatalk uses the NAS clock to set the date-time stamp of files as they are created or modified. In my case, the NAS was about 90 seconds ahead of the laptop’s clock. When Adobe updated the files on the server, the date/time stamp appeared newer than the CFA file timestamp on the local disk, causing it to be flagged for re-generation in an endless loop.

The Solution…

I installed the “afp” package on the NAS with apt-get, to synchronise it with timeservers on the internet. As my laptop was already configured do to so as well, the clocks were now in sync. After opening the project once more from the server, the conforming issues were gone!

This solution may apply to Windows based Samba shares and “real” Apple servers running AFP.

I hope this post is useful to someone out there…