Audio Hell!

D

dvxpimp

Member
O.K. comrades, I am in absolute hell on a 55 minute mini-feature right now and I would LOVE some help!

The dealio... The entire movie was captured in 24p Advanced and edited as such. All good. But, now that I am done and exporting as a regular quicktime file, all kinds of goofy audio drop out, drift and all out loss of audio is happening. It's intermittent as well.

At times the audio lines up, other times it does not. I can roll through a section and it plays with no audio in the same spot. I open it up in the viewer and the audio is there and will play. Back to the timeline, bam! Gone!

When it's wacked in the final output and I return to the timeline to check out the problem, surprise! It's now wacked there as well!

I have trashed prefs, (making sure all settings are proper as far as I know), re-saved on different drives, copied into new time lines in a new project. You name it. I have also captured separate audio and video files and placed them back in the timeline. I have captured audio as .aiff files and places that in the timeline. Still, drop outs!

I am done with this film and this is the one gosh darn thing preventing me from really being done.

Save my hair! I'm pulling pretty hard and it's going to get worse! Help or lithium!!!

Set-Up: G-5 Dually, 1-Gig Ram, 2- 120 GB (800) firewiredrives and 1 200 GB (400) firewiredrive. Final Cut Pro HD (I should be flyin'!)
 
Re: Audio Hell!

I mean outputting to Quicktime for a DVD, tape, whatever.

I did take some iMovie advice and it seems to be helping somehow, by using "Core" audio rather than "Firewire Audio." Odd, but seems to be helping. iMovie and FCP do have quite a b few similarities.

I think maybe the bus gets overwhelmed with too much firewire info. Possible?
 
Re: Audio Hell!

That is something good to try. I would suggest closing FCP and then disconnecting your camera and then opening FCP and exporting your quicktime file. I know that when I was working on my Powerbook a while back and had 2 firewire drives and my camera connected it was just too much.

Otherwise i'm not sure what's going on.

Good luck.
 
Re: Audio Hell!

[quote author=dvxpimp link=board=FCP;num=1083722273;start=0#2 date=05/05/04 at 15:21:53]I mean outputting to Quicktime for a DVD, tape, whatever.

...

I think maybe the bus gets overwhelmed with too much firewire info. Possible?[/quote]

I don't think it is possible... since exporting to Quicktime is NOT a realtime process... the machine can take as long as it wants to retrieve all the data it needs from the various sources. So if you do indeed have this problem on exported material, it doesn't make sense that any bus/time/resource limitations would be the problem (of course, anything's possible... I just wouldn't suspect that unless everything else were ruled out).

Can you specify:

What are your timeline settings (29.97fps, 30 fps, 23.98 fps, etc)?

What were your capture settings (rate, pulldown, etc)?

What is the format and of your audio (how many tracks, what format originally, what sample rate/size), and where did it come from?
 
Re: Audio Hell!

Just thought of something. Have you made sure to mixdown your audio before exporting. I don't know why this would be a problem if you are exporting to a quicktime file, but it's worth a try.
 
Re: Audio Hell!

Thanks for all the responses!

Yes, the culprit did indeed seem to be firewire. Using the "Core" audio setting seems to have fixed it. At least for now. I do have a finished product.

On a side note:
I imported and did everything in 24pAdvanced. I then exported using a Quicktime reference movie. (I had to use the DVX 2 frame offset tool BTW during editing). I have now used Cleaner to encode and after about 10 or 12 tests, I finally figured out the best way. I can post the process if anyone is interested.

Again, thanks for the help. For now, all is well. We'll see...
 
Re: Audio Hell!

Since you took the time to ask, I felt I did need to reply with the info. You seem to be quite a Guru on here and I appreciate the advice greatly.

>What are your timeline settings (29.97fps, 30 fps, 23.98 fps, etc)?<

23.98

What were your capture settings (rate, pulldown, etc)?
23.98 Advanced Pulldown

What is the format and of your audio (how many tracks, what format originally, what sample rate/size), and where did it come from?

Audio is mainly the audio from the DVX being quicktime, I suppose. I did do sweeting in Pro Tools and imported back into FCP as .aiff files making sure all playback was synched.
 
Re: Audio Hell!

[quote author=dvxpimp link=board=FCP;num=1083722273;start=0#6 date=05/06/04 at 13:37:42]Thanks for all the responses!

I then exported using a Quicktime reference movie. [/quote]

Good, I'm glad it's worked out! For the record, though, the use of a reference movie might have been the problem. A reference movie forces Quicktime to fetch video elements - different clips, rendered bits, audio bits - from many differnt locations as it plays; which may indeed be putting stress on your firewire bus (and more likely, devices) during playback. By saving it as self-contained, you force the non-real-time mixdown to a single file that can be read sequentially (i.e., most efficiently) from one place. In my previous comments, assume "Quicktime self-contained" everytime I said QuickTime, because you don't necessarily get the benefits from reference movies. Reference movies also rely on QuickTime to achieve and maintain sync in realtime during playback; self-contained movies produce locked audio and video....
 
Re: Audio Hell!

>self-contained movies produce locked audio and video<

That's true, but doesn't it also add compression this way?
 
Re: Audio Hell!

No; FCP (and most NLE's) are smart enough to compress only when necessary, and just copy material intact when possible. Changing audio/video sync (and replacing audio with other audio, etc), does not require recompression of image or audio. DV audio is uncompressed, so multiple generation compression is not a factor, though multi-generation effects processing, etc., can be.
 
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