Capture Quality Declined....

[calhoun]

I have a P4 2.66Ghz, 1GB ram, Geforce4 Ti 4200 and Play TVHD capture card(cx23881) running with XP. I've been capturing excellent quality videos(VHS) for more than 6 months now by capturing in an uncompressed format then post encoding it. My problem is that recently the quality of capture (before encoding) has degraded (very pixelated). After reinstalling drivers and software and checking for interference from all my hardware such as all other cards, power supply, cables etc, decided to reformat and reinstall Windows XP, after this failed to fix the problem I bought a new capture card (WinFast TV2000 XP Expert). With this NEW card I encounter the same low quality pixelated capture.

Could a component of my relatively new computer(ram, processor, motherboard etc) be somehow interfering with the capture process?

Thanks.

[Nelson37]

Please detail ANY repeat ANY changes to the software or hardware made between when it DID work and when it DID NOT work, even so minor as relocating the box or power cord, or installing a screen saver or new modem.

Do you notice any degradation in your incoming signal? I would be inclined to suspect this. Are you recording more commonly at different times than before? They often sneak down the bitrate late at night, or on lower-grade movies. What is your source?

[calhoun]

I had tried many different software products claiming high quality "real time" mpeg encoding and found them nowhere near the quality of my tried and tested method of capturing uncompressed huffyuv then post encoding. However any changes that these software products could possibly have made to my system should have been rectified when I reformatted and reinstalled windows XP only reinstalling the basic software that always worked for me.

The source for my captures is 2 VCR's (S-video and Composite), both present the same quality degraded source signal when I start my capture programs (VirtualDub, Virtual VCR etc..) This is before I even start capturing.. the preview is blocky. My VCR work fine when connected to TV.

While I am hesitant to claim myself an expert I do have 100's of hours capturing experience and believe this problem is not something "simple" though I would love to be proved wrong.

[Nelson37]

Perhaps I was not clear. In order to determine the solution, it is often helpful to identify the cause of the problem. Please detail ANY repeat ANY changes to the software or hardware made between when it DID work and when it DID NOT work, even so minor as relocating the box or power cord, or installing a screen saver or new modem.

At some point in time (point A), it DID work. At a second point in time, (point B), it did NOT work. Since nothing that has been done after point B solved the problem, this is irrelevant other than indicate what the solution is NOT. BTW, during re-install, are you ABSOLUTELY CERTAIN that the identical drivers, software, and updates were installed, in PRECISELY THE SAME ORDER?

Detail any and all changes that occurred between point A and point B. Something as simple as a fan or radio moved closer to the PC could be the cause. If it just suddenly stopped working, without any new software or hardware changes, then you try different sources and cables, disconnecting unnecessary accessories, etc. You mention 2 different VCR's but did not specify 2 different tapes. Are your tapes perhaps stored near a large speaker or powerful electric motor? (or were they, even briefly?) Try another source such as cable or DVD. Unplug all other electrical devices on the same circuit, and eliminate any intervening video connections. Unplug the audio connectors to test video only.

I troubleshoot PC problems for a living. The mantra is Isolate and Identify. Minimize the Variables.

[calhoun]

Thanks Nelson37,

I do not believe any software changes were made to my machine, certainly no hardware changed. I understand the mantra you spoke of and I have already looked into everything you suggested..

Hence in my first post the last paragraph I ask if it is possible for some component of my system (motherboard, processor, ram, electrolytic capacitor etc) to have failed... Isolate and Identify, but when all else fails what is left?


Frustrated..

Where you live Nelson? I'll bring my PC around.

[hwoodwar]

Calhoun:

I suggest you try a different different cables from the VCR to the capture card. With all the info you have supplied, something going bad with those cables is what I would suspect the most.

[calhoun]

Hey Hwoodwar,

I mentioned that I checked cables in my first post and just to elaborate on that point I tested 2 sets of composite cables and 3 different s-video cables...all the same..

Its gotta be a Mobo component.

Damn this is gettin to me......

[Nelson37]

Remove all unnecessary boards, disconnect any unneeded drives. Disable any built-in devices, including audio. Try a different power supply, they are cheap, easily available, relatively easy to swap, and are often a source of wierd problems. Swap RAM with another PC to test, same reasons.

Try taking the PC to a completely different location (building) to exclude electrical problems. The guy in the apartment below, or house next door, could have a new CB radio.

Assuming diagnostic software does not show a problem, and they rarely do while it still runs, the best way to "test" a MOBO is to replace it and see if the problem goes away, while making NO other changes. This would require an identical motherboard, if you have to load different drivers this introduces another variable. However, should be good enough to RMA your original board if the problem goes away.

[Popee]

Have you followed through on any of these captures and actually created a DVD or VCD, and see how it plays on a stand alone player. Perhaps there is nothing wrong with the actual capture, but just how it 'looks' when played or previewed through your PC.

Just a thought.

[calhoun]

Thanks for trying to help guys.

Nelson, Yeah mate I have already tried all that you suggest and taken my PC to my parents house to try and eliminate the possiblity of local interference from neighbours etc..

Popee, yes I have made full VCD's and compared them with the GOOD VCD's I created before this problem started. The VCD's I make now are grainy and have lots of "low bitrate" type artifacting.. whereas my earlier VCD's had no artifacting or graininess.

I guess i'll have to wait until I can afford a new MOBO, i'll cry if that doesnt fix it though