capture corruption

michael_morlan wrote on 8/17/2004, 12:28 PM
I have been having a consistent problem capturing from my JVC GY-DV500 camcorder. This only happens during a batch capture and never during a manual capture. This symptoms are as follows:

30%-40% of my batch-captured clips are garbled. See the sample frame here:
http://michael-morlan.net/projects/vegas/BadFrame.jpg

The visual garbage always looks the same with large grey blocks and skewed blocks of pixels. This spatial arrangment stays the same throughout the garbled clip and amongst multiple garbled clips.

When compared on the Vegas timeline with a clean capture of the same clip, the garbled clip runs about 20% longer on the timeline with the audio playing back at a lower pitch. For instance a clean clip that runs 1:53.06 plays back, in garbled form, over 2:15.22.

This failure happens on two different machines, each with acceptable specs.

This failure happens with camera tapes that were recorded with this camera.

Another related symptom is the odd naming and replication of clip files. With each captured clip, one of the following can happen:

1. The clip captures just fine and is properly named after the name in the capture list.
2. The clip is captured, but the file named after the clip is just the first frame or so and a second clip named Clip01.avi (or some sequential number) holds the actual footage. The start time of the full Clip01.avi clip matches the batch capture in-point but the out-point doesn't.
3. The clip is captured, but there are TWO Clip01.avi and Clip02.avi (or subsequent sequential numbers) files. The first Clip is one frame and the second Clip the actual footage.

Any of these scenarios updates the batch capture list in capture program and, subsequently write those changes to the .svidcap files, completely screwing up my original timecodes. I've taken to setting all of my .svidcap files to read-only so they don't get overwritten by the actual capture process.

Any thoughts or ideas would be most welcome.

Comments

Jsnkc wrote on 8/17/2004, 12:47 PM
The capture problem has been noted many many times before. You basically need to start your capture when there is good video on the screen, if you start when there is no timecode or a slight glitch in the beginning of the tape then you end up with a bad capture. Unfortunately there is really no way to know if it is capturing bad or not untill you're done. Some people have also reccomnded capturing with other applications such as Scenealyser.
michael_morlan wrote on 8/17/2004, 3:43 PM
Thanks for the tip Jsnkc. However, I have many good tapes with clean, contiguous timecode from which I am batch capturing clips. The problem is intermittent. A clip that fails once, can be captured properly on the next try. I've tried it with a 10-second pre-roll with the same results, so it's not tape mechanism handling.

I've tried everything in the Sony Knowledge Base -- IRQ management, defragging (of course), driver updates...

I've posted a query with Sony Support. I'll pursue this further via that channel and report my findings back to this forum.

M