Scene Detection: Firewire or USB?

grohaz wrote on 10/30/2005, 5:42 PM
Hi everyone,

I can succesfully capture video from my miniDV cam. It's a SONY DCR-HC85 and connected via the USB link. The capture works fine, but the scene detection does not.

When using an iMac and iMovie, scene detection works with the same camera & tape, but it is connected via the firewire port.

Hence the following question:

1) Does the scene detection only work with a firewire connection or should it work with a USB connection too?

Comments

Chienworks wrote on 10/30/2005, 6:08 PM
MiniDV scene detection with Vegas probably relies on getting the raw DV data. You need a firewire connection to get this. USB captures are notoriously troublesome and low quality.
johnmeyer wrote on 10/30/2005, 9:33 PM
To my knowledge, you cannot use USB to capture the DV video stream. This is not to say that you won't get any video; instead, what I am saying -- and what Kelly said -- is that capture via USB will be a re-sample of the video, rather than just a plain copy of the bits on your tape to your hard disk. Remember, DV "capture" is a misnomer. There is no capture, and no encoding, merely a copy, just like when you copy a file from one disk to another on your computer.
farss wrote on 10/30/2005, 11:07 PM
John et al,
you know this isn't strictly correct I've recently discovered. I don't know about the vision but VidCap can all too easily end up not giving you a bit copy of the audio recorded on the DV tape. A tape recorded at 16/48K can be captured by VidCap as 16/32K. This bug exists in every release of VidCap and has even found it's way into SDI captures.
I've had a formal trouble ticket logged with Support from months, to date the responses aren't too encouraging, they think this is a classic "how do I capture video" problem.
Bob.
johnmeyer wrote on 10/31/2005, 8:45 PM
Bob,

Have you tried Scenalyzer or some alternate capture program? I gave up on Sony capture years ago. I don't think they have any engineers left that understand how it works, and therefore I don't see any fixes, much less any enhancements, coming our way.
logiquem wrote on 11/1/2005, 10:59 AM
BTW, the last Scenalyser version can also apply optical detection *after* capture...
JackW wrote on 11/1/2005, 11:14 AM
John and Kelly:

According to the ScenalyzerLive web site --

"Due to the file-size or file-format limitation under the FAT32 file-system (Windows 98 SE, Windows ME) .avi files are limited to 2 or 4 GB, ScenalyzerLive provides a solid Workaround for this 2/4GB problem."

How does this work on drives that are formatted for NTFS? Anything I should know before purchasing?

Jack


riredale wrote on 11/1/2005, 3:49 PM
If you have NTFS, you don't need to worry about the 4GB limit. What SClive does for FAT32 drives is to immediately close off the avi when it reaches 4GB and begins a new avi. Later, you can just pull the multiple avis up to the timeline and butt them together.

I believe there is an item in the "options" menu where you tell the program to split at 4GB.
Chienworks wrote on 11/1/2005, 4:36 PM
What riredale said. :)

SONY's VidCap does the same thing with FAT32 and captures larger files intact with NTFS.
grohaz wrote on 11/6/2005, 5:05 PM
Thanks for you advice, you were right on!

I bought a Firewire card the next day and scene detection worked flawlessly!


Guy Bruner wrote on 11/7/2005, 6:19 AM
USB High Speed can be used to capture video from some camcorders (like the higher end consumer Panasonics) that support it. However, Vegas doesn't like capturing over USB because USB capture uses DirectShow filters instead of VfW filters. Usually what results is video is captured but no audio. I have not heard of scene detection not working, but I suppose that is just another artifact of incompatibility in the filters used during the process. IOW, this is a Type 1 vs. Type 2 AVI issue.