I'm going to be capturing from my MiniDV camcorder using a rather slow 1ghz Windows XP laptop while "in the field".
I understand that if I choose to capture in DV format that the capture process is a simple copy of the bits from the camcorder to the hard disk of the laptop. As a computer hardware and software guy I know that if I had designed the camera-computer protocol I would have designed in a way for the computer to at least detect that it had missed some bits during the transfer (and better yet allow it to back up and recapture those missing bits).
My question to those who know the low level details of the capture process over firewire: Does the capture program (Visual Studio) know when the capture it's just made is buggy and if so does it inform the user?
If it does then I'd feel safe reusing the video tape after a capture was done to the laptop. If not then I'll have to keep the tapes around until I get back from the field and can use a very fast desktop machine to do the capture as well.
error detection on capture??
Moderator: Ken Berry
-
THoff
UVS can display the number of dropped frames (through a checkbox in the Preferences), so you would know whether some of the data just didn't make it.
Beyond that, DV "capture" is nothing more than a digital data transfer, complete with CRC information. As such, it doesn't suffer from the same shortcomings as analog captures with quality degradation, flicker, color calibration issues etc.
One of my computers is a 1.5GHz P4M laptop, and when I capture from DV devices (such as my Panasonic PV-GS400 camcorder or a Canopus ADVC-300 A/D converter), Videostudio will occasionally drop a frame when another process performs disk I/O. The buffer (if any) that UVS uses seems to be too small to cope with anything but the shortest disruptions. As a result, I mainly capture using WinDV. It can buffer up to 99 frames in memory, its resource footprint is much smaller, and it's not a full-screen application.
Beyond that, DV "capture" is nothing more than a digital data transfer, complete with CRC information. As such, it doesn't suffer from the same shortcomings as analog captures with quality degradation, flicker, color calibration issues etc.
One of my computers is a 1.5GHz P4M laptop, and when I capture from DV devices (such as my Panasonic PV-GS400 camcorder or a Canopus ADVC-300 A/D converter), Videostudio will occasionally drop a frame when another process performs disk I/O. The buffer (if any) that UVS uses seems to be too small to cope with anything but the shortest disruptions. As a result, I mainly capture using WinDV. It can buffer up to 99 frames in memory, its resource footprint is much smaller, and it's not a full-screen application.
-
jkftiger
error detection on capture??
Thanks for the very useful information.
As I suspected I wasn't getting any frame losses on my desktop but I lost about 7 frames in 3 minutes on my laptop. I tried WinDV and it was able to do transfer on the laptop with no losses at all.
As I suspected I wasn't getting any frame losses on my desktop but I lost about 7 frames in 3 minutes on my laptop. I tried WinDV and it was able to do transfer on the laptop with no losses at all.
-
THoff
Yeah, same here.
On my desktop (where I actually do my editing) I never experience any dropped frames, but on the laptop with a pokey 4200 RPM hard drive, the system is just barely able to keep up with the constant barrage of data from the DV devices.
Without the ability to buffer a few seconds worth of data in memory, Videostudio occasionally drops the ball, whereas WinDV can handle ~4 seconds of interruptions -- it is no problem to load Internet Explorer during captures and surf the 'net, for instance. And if you have antivirus software or the Disk Indexing Service running, you are really asking for trouble on a laptop if you capture using Videostudio...
On my desktop (where I actually do my editing) I never experience any dropped frames, but on the laptop with a pokey 4200 RPM hard drive, the system is just barely able to keep up with the constant barrage of data from the DV devices.
Without the ability to buffer a few seconds worth of data in memory, Videostudio occasionally drops the ball, whereas WinDV can handle ~4 seconds of interruptions -- it is no problem to load Internet Explorer during captures and surf the 'net, for instance. And if you have antivirus software or the Disk Indexing Service running, you are really asking for trouble on a laptop if you capture using Videostudio...