Some Corrupted Frames During FireWire Capture

[dgorini]

Hello,

Sorry about my broken english, but english is not my first language.

I used to capture video on a Pentium III 666Mhz and never had any problems.

Now that I have a much faster PC which is an Athlon 2500XP, 512 MB of RAM and lots of free GBs of hard drive space(motherboard chipset is nForce) I have some currupt frames every now and then.





I would say that I get around 10 corrupt frames per hour of video and it sometimes affects the sound as well.

I have tried so far with different degrees of success:
- Increasing PCI latency of the Firewire card and decreasing the video-card latency.
- Lowering Hardware acceleration settings.
- Different softwares (Ulead, PowerDirector)
- 2 Different firewire cards and 2 different cables.

If anybody out there has experienced this problem before could please let me know if there's a solution for the problem (other than buying a new PC )

Thanks,
Daniel

[Ken Berry]

My first reaction would be to suggest you check to ensure you are capturing to DV format, and doing so, moreover, using the Type 1 Encoder (under the options cogwheel icon in the Edit screen).

If you are not capturing to DV/AVI format, then be aware that you need a fairly powerful computer to capture direct to mpeg-2 without problems like dropped frames or stops and starts and eventually problems of synchronisation between the video and audio. Capturing to DV format is very easy on the computer as it is really only transferring the contents of your video tape in the camera at the same level of quality.

But if you are already capturing DV format, then I would think your computer might not be able to handle capturing using Type 2 Encoder all that well. Again, the sort of problem you might experience would include dropped frames and stuttering or jerky audio and/or video. Type 2 requires more computer resources. That is why we normally suggest that people use Type 1 Encoder as it places less demand on the computer resources.

You also need to ensure that any background programs like screensavers, anti-virus programs and the like have been switched off while capturing as these can sometimes interfere. Capturing video uses a lot of your computer resources and you want to free up as many of those resources as possible before you start to capture.

[dgorini]

Hi Ken,

Thanks for your reply.

I will give it a try capturing as DV-type I and see what happens.

I should have mentioned that I am capturing DV format and my computer runs lean, I meanm no background processes, anti-virus or other things that might use cpu cycles.

Also, I'd like to mention that I don't get dropped frames. If I get is right at the beginning whithin the first half-second or so. Anyways, after editing (and removing the corrupted frames) and burning, the final result looks great.

Thanks,
Daniel

[THoff]

First, I would try to determine whether the problem is with the video data itself (an encoding artifact or tape problem), or the data transfer.

Start by running a cleaning tape through the camcorder in accordance with the instructions for it, just to rule out head fouling.

Then capture a section of the tape that exhibits the problem a second time (just a few seconds).

If the artifacts do NOT exist in both videos, you have an I/O problem, probably with the drivers for the Firewire bus.

If the artifacts do exist in both videos, it could be a damaged section of tape or an incorrectly encoded video. You could try the tape in another camcorder or DV deck to see if the problem goes away, but it is doubtful.

You can also try capturing the same section of tape again on your old system just to double-check.

[dgorini]

Hi THoff.

The artifacts appear at random times, its not in the same section of the tape. Sometimes what I do is to capture again an entire video segment just to get rid of 1 single corrupted frame.

What I have noticed though is that the artifacts very often show up in the same spots in the frame.

I could be wrong but it seems to me that there's too much data flowing through the data/pci bus and my motherboard is not handling it properly. It is a 2 and half years old PC, but what really I don't get is why my old PC was much better for capturing data.

BTW, my Video card is also pretty decent. Its an ATI Radeon 9600 XT... I upgraded it hopping that my previous nVidia 440 MX was the culprit...

Thanks,
Daniel

[THoff]

DV requires just 25Mbps of the 400Mbps that IEEE 1394a can provide, so there is no reason why that should cause a problem.

There were problems with some AMD-based motherboards and the VIA chipset drivers for them. The problem resulted in data corruption and/or data loss, as well as sound problems. That's why I would explore updated drivers for your nForce-based board.

[DiscCoasterPro]

THoff .. I sure can't comment on this particular problem as editing isn't my long suite. But, boy did you hit a nerve when you mentioned VIA chipsets, LOL .. OMG .. I have had a plethora of problems revolving around VIA chipsets in a variety of motherboards. When I see a motherboard with a VIA chipset, besides breaking into a cold sweat, I have the urge to beat it with a mallet.

[dgorini]

I have tested capturing as DV-Type I and I am still getting the corrupt frames every now and then.

I do suspect is something related to the nforce motherboard. I am running the latest version of BIOS, tonight I will try downloading the latest nVidia drivers for XP and give it a try. I haven't upgraded those in the last 6 months or so...

BTW : The motherboard is a Soltek SL-75FRN2-L (Golden Flame)

[dgorini]

Ok,

Found something that looks like an answer on a different forum:

Cheap FireWire card....

http://www.videohelp.com/forum/viewtopi ... ow#1082591

[DiscCoasterPro]

hmm .. did ya notice he said the "V" word with that firewire card.

ohhh.. I get the heebie geebies when I hear it.