Random audio dropouts

Chapplemap wrote on 9/30/2003, 5:34 PM

Hello everyone. Thank you in advance for any help you can provide.

Before I continue, here are my system specs:

8IK1100 - gigabyte mobo
p4 3.0ghz
800mhz FSB
1gig of DDR ram
MEGARAID 150-2 - with 2 160GB seagate serial ATA HDs.
7200RPM 60GB seagate system drive
ATI RADEON 9000 atlantis pro
Pyro 1394 DV card

Deck: Canon GL1 or Panasonic DVX100 (PQ tapes only)

NLE: Vegas 4.0d and Premiere Pro

If I forgot to list anything please let me know.

On to the problem (please ignore my literally horrible spelling):

I am in the process of editing a documentary and I captured three tapes flawlessly (or so I think), when I began to notice random electronic noises and audio dropouts during preview. I thought it was just firewire buggin' out, but when I checked the captured files, they had the dropouts.

I tried using different tapes. All of them had dropouts. I tried using a different deck. Still dropouts. I listened to the footage via headphones, NO DROPOUTS. Also, the dropouts are completely random. Sometimes they'll pop-up, sometimes they won't. But obviously I can't have this, nor allow this to continue. I am a month away from beginning a big job and I need my system working flawlessly.

I tried re-formatting, changing 1394 cards, changing bios settings. Disabling all non-essential functions. I tried updating my bios. Changing firewire cables. Everything.

My old computer never had this problem. This is so bizarre.

Can anyone provide any advice on how to continue? I feel I am shooting in the dark trying to fix this.

I'm also interested in the bus flow of how DV gets into the computer. Perhaps someone can shed light on where the screwup is most likely occuring.

Thank you once again.

BTW I am getting this in premiere as well. (I love vegas much more!!)

- Alex

Comments

GaryStebbins wrote on 9/30/2003, 10:32 PM

I have had audio dropouts from Vegas, also. Other applications don't exhibit the problem. I posted a number of months ago about this problem, but didn't get any resolution.

Gary

craftech wrote on 10/1/2003, 6:30 PM

Neither did I on the Video forum.

John

fishtank wrote on 10/1/2003, 9:53 PM

I just saw a post in another forum where a guy had audio clicks and dropouts on his system. The cause ended up being his SATA drive - switching to a parallel drive solved the problems. Also, raid controllers can be PCI bus hogs. I realize you are tranferring to this controller, but your 1394 card needs access to the bus when capturing and may not be getting the *attention* it needs. There could be other issues such as IRQ sharing and chipset problems. It would probably be easiest to just try a regular ole PATA drive on your secondary IDE port and see if your problems go away.

I experimented with RAID some time ago and decided it was not worth the trouble as I was getting more than enough transfer rate with a single fast drive. I believe that most of us have no real need for RAID given that there are fast drives such as the WD800JB with 8MB cache etc.

filmy wrote on 10/2/2003, 2:47 PM

Assuming the captured file is ok -

I tend to get more audio drops in VV than in Premiere. For example - I can drop an MP3 file onto the Premiere timeline and it plays back out from the timeline flawlessy via the 1394 conntection. In VV you can not playback out via 1394 without doing a PTT. So 1> Drops outs happen on playback 2> They happen on a PTT. They happen most with the MP3 files but do happen with "native" DV as well. For the most part rendering solves the issue.

I don't know if it is related but I would get wierd video stutter t certian spots during a PTT in 24p mode (2-3 pulldown). This happened at the same spots in the same sections. I tried everyhintg - defraged, moved the files to another Hard drive, re rendered. Same thing always in the same spot. *However* - the actual file was fine. Playbe back flawlessly in Premiere, WinDV and from the VV Capture mod - but from the VV timeline - nope. The official SoFo response was that I should render all files as 24p (2-3) and use the capture mod to output to tape. While on the timeline and doing a PTT VV trys to do the pull down in real time and I guess it depends on the actual shot...in other words if the shot has little movement in it it can do the pull down fatser than if the shot has a lot of action in it. it doesn't really make sense to me, but the bottom line was outputting from the capture mod worked better than a PTT from the timeline.

So perhaps this is an audio issue as well.

Now I did get a bit confused. You say there is drop out but you say when you listen with headphones there are no drop outs. Is this from the hard drive or from the camera orginal? Obvious deduction is if it is fine n the camera orginal but not on the hard drive than it is something capture related. If it is fine on both the tape and the hard drive than it is something either software related or audio card related. Now if it is fine on everything *except* firewire output than check what I said above. Try WinDV (it is free) and see if you get dropouts. Try the capture mod in VV and see if there are dropouts. I can not speak for Premiere Pro as I am still using Premiere 6.5.