Audio/Video out of sync

Ptero wrote on 11/19/2005, 9:38 AM
When I was reviewing some clips I noticed that the audio is lagging behind the video by a few frames... I went back to the original captured files and it's in there too so it's not Vegas that's doing this, so it's either like that on the tape or the capture software is doing it. As it happens my project is such that it's only noticable in a handful pf places(where someone is speaking in shot, for example) so I can correct it by sliding the audio track a little to the left, but I'd like to be able to avoid it in future. Do others see this problem, and is there an easy fix?

I'm using:

Sony DCR-TRV280 camcorder
"Video Capture" application that came with the camera (part of "Picture Package") - capture is via USB as I don't have FireWire (yet)
Vegas Movie Studio+DVD Platinum 6.0

Comments

Spot|DSE wrote on 11/19/2005, 10:19 AM
This is because you are capturing USB. Get a $20.00 firewire card, all your pains will likely go away.
Ptero wrote on 11/19/2005, 7:04 PM
Thanks DSE - I was beginning to suspect this was the cause. Unfortunately all the PCI slots in my machine are occupied by cards I can't do without, so I'm trying to find a PCI expansion chassis that'll give me a couple of extra slots, then I can add FireWire - not an ideal solution but it'll have to do until I upgrade my machine.

Thanks again,

Pete
Spot|DSE wrote on 11/19/2005, 7:58 PM
There are a lot of USB/Firewire combo cards if you've got a slot that your USB is occupying.
HTH
blk_diesel wrote on 11/19/2005, 10:14 PM
I thought usb2 is faster than firewire. I capture via firewire, but I'm just asking.
Spot|DSE wrote on 11/19/2005, 10:21 PM
In theory, it is. In practice, it varies, depending on system resources and what the CPU is doing. However, Vegas is optimized for firewire, and so regardless of speed...firewire is the way to go.
Additionally, firewire is isosynchronus. In other words, all devices on the chain function at the same speed, where with USB2, bandwidth is shared.

A very creative article on Firewire vs USB2...Supports what some have been saying here about USB 2 vs Firewire for a few years on this forum.
Ptero wrote on 11/20/2005, 8:29 AM
According to the Wikipedia article about FireWire, while USB2 is theoretically faster at 480Mb/s (compared to 393Mb/s for S400 FireWire), FireWire is actually faster in practice - the article doesn't say why but my guess would be that USB has more protocol overheads, or that it's something to do with FireWire's ability to DMA data directly into the application memory space.

In any case (and to answer the earlier post) the USB/FireWire combo won't work as my USB is on-board; my system has only three PCI slots and they're all used by cards I'd rather not lose (graphics card, sound card, modem).