Why are my video clips shorter than my audio clips?

travel_addict wrote on 6/13/2002, 1:35 PM

When I digitize some footage into my computor with scene detection on I notice when I select all the clips from the pool and put them to the timeline, some of the clips (maybe %50)have shorter video sections than their connected audio. It's any where from 2 to 4 frames shorter than its audio.

What is up with that.
Paul

Comments

Ron Lucas wrote on 6/13/2002, 2:13 PM
I get the same thing too. I've mentioned this here before, but I can't remember if SoFo said this was a confirmed problem or not. I use a Canon XL1s camera and an Adaptec 1394 card with Windows XP Professional. Another symptom I have when the video is shorter than the audio is the very end of the audio slows down and sounds like the devil or something similar.

Ron
Chienworks wrote on 6/13/2002, 4:04 PM
Part of this is due to the fact that video and audio come in "chunks" of different sizes. When a clip is captured, the actual length of the clip might not be a whole multiple of either of these sizes. There might be a little of either audio or video left over that doesn't line up with the other perfectly. The solution is to shoot long (and start early, for that matter), and trim the extra. This is a good thing to do anyway, regardless of the current problem.
SonyEPM wrote on 6/13/2002, 4:09 PM
travel addict: what camera are you using?
Frenchy wrote on 6/13/2002, 4:17 PM
SonicEPM:

Last night I noticed the same thing (2-5 frame difference in length) as travel_addict in some of my captured clips, while reviewing the properties in the VidCap Explorer. I'm using a 1999 vintage Sony TRV310 Digital8. PC system: Dell P3-600 running W98SE; 384 MB RAM; System Drive:30GB 7200 rpm; Media Drive: 40GB 7200 rpm IBM (50% +/- full); capturing via firewire through Dell-supplied OHCI-compliant generic 1394 card.

Thanks

Frenchy
travel_addict wrote on 6/13/2002, 4:50 PM
Using a Sony TRV320 with 98SE, ADS pyro.
In regards to Chienworks post about trimming, this is not practical. I captured a whole wedding, and wanted to throw all the clips on the timeline and tweak where needed. I didn't want to trim every clip. Maybe I should recapture with scene detection off. ?

Paul
HPV wrote on 6/13/2002, 6:17 PM
Maybe I should recapture with scene detection off. ?
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Yes, use the S key to split as needed. My Sony TR7000 digital8 does the same thing.
Vegas will also render too much audio. The fix for me on this is to set "interleave" to every frame. Default is every .250 sec. It's under "custom" in the render panel. You'll want to type in a name like "frame interleave DV" and save it as a preset (floppy disk icon).

Craig H.
travel_addict wrote on 6/13/2002, 11:31 PM
Are you Pal or NTSC, I'm NTSC.
If you're PAL would your setting not apply to me???
Paul
HPV wrote on 6/14/2002, 10:15 AM
NTSC I asked if I would have any problems with the "every frame" interleave setting, but I didn't get an answer.
BTW, the extra audio on capture is only a few samples on my system. I've never seen a full frame.

Craig H.