Audio Dropout - inconsistent - in viewer and source

We're having some weird audio playback issues in Final Cut Pro 5.1
(the problem continues after upgrading to 5.1.2):

When playing in the timeline or source windows, the video will play
continuously but audio will at some point stop playing (though still
register on the audio meter). If we hit stop and then play again, the
audio starts up again right away. This has become more and more
frequent over the course of a couple of weeks.


Sometimes an error message will come up:

"Warning - Dropped Frames
If this occurs frequently try:
-Turning off 'Unlimited RT' [we tried this]
-Lowering your compression data rate [??]
-Closing open sequences [I work with 2 or 3 sequences open at once -
never been a problem]
-Lowering the preference for real-time audio tracks [we tried this]
-Increasing the speed of your system and/or disk drives and/or network
connection."


We also tried throwing out the .plist files in library and user preferences.

Audio is routed from G5 via firewire, through Sony DVCam deck, to Alesis mixer.

We have 1 500GB & 2 1TB GRAID drives (daisy chained), G5 Mac...

Anyone had this issue before???!

Thanks,
Melinda

The fact that the audio meters keep going suggest to me that something's wrong with your external devices -- FireWire cable, DVCam deck, mixer.

Disable external playback (APPLE-F12) and plug headphones into your computer's jack directly. Does the playback issue still occur?


www.derekmok.com

The problem is fairly unpredictable, so I will try it for a while and get back to you. Thanks!

<<<We have 1 500GB & 2 1TB GRAID drives (daisy chained), G5 Mac... >>>

I'd start there. That's way too much stuff to hang from one FireWire 400 port. The front and back connections on a G5 count as one unless you added a third party FireWire card.

What happens if you export the show to one stand-alone file on an internal drive, disconnect all the external stuff except the playback pathway, and press play?

Are any of the drives anywhere filling up? No drive the system can see should be over 90% full including the System Drive.

Also, if you are playing a complicated show with lots of effects from those large slow drives, it wouldn't surprise me you couldn't see stuff in real time. At the very least, the drives should be on their own FireWire card. Given the size of your drives, two cards. The fact that this problem is slowly getting worse also indicates filling up drives.

Koz

I completely agree - a lot to attach to the one port. Wouldn't have set it up that way myself - but I walked into this setup last week. Apparently it has been working until just before I arrived on the scene, however. (My worry would be that the firewire port isn't going to handle the activity and burn out!)

Drives - can rule out - they all have 15-25% of their space left.

I've plugged the speakers directly into the mixer (mono output from the G5) and there haven't been any drop-outs yet.

SO, could it be that the daisy chain is ok, but when one adds the firewire out to the deck, it's too much for the G5 to handle?

Melinda

<<<SO, could it be that the daisy chain is ok, but when one adds the firewire out to the deck, it's too much for the G5 to handle? >>>

Totally. The G5 is trying to maintain two complete data pathways *for each device* connected. You run out of speedy data transfer in a big hurry when you do that. Pushing a spreadsheet or photoshop picture down a system like that would work because the G5 would allocate time and space as needed. The problem is video doesn't wait. "Here, stop listening to the sound for a second while I catch up." Doesn't work like that. Tape machines and humans expect an uninterrupted show and that means a steady fast connection to everything involved with the show. FireWire is good, but it isn't that good.

<<<firewire port isn't going to handle the activity and burn out!)>>>

No. FireWire ports are designed to manage and manipulate many devices--usually devices that don't have speed requirements--successfully. In the case of the six pin FireWire connector (the big one), there is also power on the pins. Some FireWire devices use this power to avoid connecting to either batteries or the socket in the wall. Usually devices like pocket drives.

You can damage a FireWire connection. It is possible, if you get a running start from across the room, to plug the six pin connector in backwards. It's very entertaining if you do that. Either the device (drive, camera) or the Mac or both can be destroyed. The Mac System Board will burn and the FireWire connection on the camcorder will no longer be usable--effectively killing the camera.

The other thing you can do is run over an operating FireWire cable with your chair and accidentally connect two or more wires together by damaging the plastic. This will make everybody in your office glad they're not you.

Outside of physical damage and speed problems, there isn't too much else you can do to to hurt FireWire.

Koz

I would also try doing an audio mixdown. I'ts possible that doing this would relieve some of the strain on your playback and stop the dropped frames.

For more info on this, check this FAQ entry Audio spluttering or missing

Here is some more help from the FAQ. Dropped frame warnings

So, just to get to the root of it, would this problem be fixed by adding an internal firewire port, or should we just bite the bullet and get a Canopus card or something along those lines?

Thanks again for all your help!

<<<So, just to get to the root of it,>>>

Click on this and solve all my problems.

Sorry, it's not that easy. Each time you daisy chain a FireWire drive, a video system becomes slightly less stable. Every time you fail to render your audio tracks it becomes slightly less stable, and so on. You run into clear, visible troubles when the system becomes so unstable that it can't play live video. If you fix *any one* of those problems, video services will start to work again.

We like to eliminate as many instabilities as possible right up front so nobody ever says, "I have dropped frames," even if they make a mistake. We like elbow room.

Adding a FireWire card is a cheap fix and very highly recommended. Also, crank down through all those suggestions posted above and do *all that apply*. When was the last time you executed the "periodic" services? That will slow you down.

It is possible to try and edit a movie that's just so big and complicated that you can't physcially/electrically do it. In that case, we recommend doing the show in segments.

Koz

Thanks for all who replied.

I installed 2 firewire pci cards for the drives, also figured out that the assistant eds who digitized the media (before I came onto the project) had media in folders within folders within folders so I fixed that, threw out all the render files and made sure they were all on one drive (ugh), installed a Canopus box that worked for a day (we're going to replace it).... So, when the Canopus was in gear, all systems were go. I think everything I did brought the system to a slightly smoother level.

Melinda