Noise in LD capture with AIW 128Pro?

[tedkunich]

I've been trying to capture my SW Trilogy from LD. After all the trials and tribulations of getting a relatively frame-drop free capture, analog capture of all 6 audio channels (to reconstruct the 5.1 sound track), I noticed that there is a significant amount of noise, actually a moire pattern in the captured video that makes it unwatchable in my mind - it looks even worse after MPG2 compression. I am capturing in VDub, 720x480 30fps, Svideo direct from my LD player. Is this a common problem with this card or do I have something wrong with my setup or capture card? I'm using the Monster cable Svideo cable I use with my A/V system to connect the LD to the AIW's A/V port - I know this cable is good. Is there a grounding or shielding trick that I should know about?

Thanks
Ted

[menace]

what capture program did you use? What settings? Any time I had a shielding issue it came from my cables running too close to power cables i.e. sitting on them--although your monster cables should be shielded from that...

Out of curiosity how did you get all 6 audio channels? was that the "encode each time with a different audio signal" trick? how did that work out for you.

I am in the process of doing what you are doing and am using composite cables into an ATI VIVO through virtualvcr--very clean captures and it supports the ATI without any wrappers.

[wwaag]

Ted,

Do you get the same moire noise patterns when you simply "watch" the LD or is only with the captured video?

Some of my LDs are simply "unwatchable" as you say. I have a Pioneer CLD-702--10 years old now. I found that playback on the "B" side was always better than the A side. You would still get these noise patterns on some discs but not as bad. The video noise was one thing that really turned me off on LD technolgoy.

I also have the SW trilogy and actually, they look pretty good--it was one of the better transfers. These noise patterns are usually most pronounced in "light" scenes and occur most often toward the end of the disk.

If yours look OK on the monitor, then I suspect it must be in your capture card. If you also get these patterns when simply watching the LD, then it's probably your player.

wwaag

[flaninacupboard]

this problem can be easily fixed with ten minutes and a screwdriver. i wish i still had the samples, but when i first got my second hand pioneer cld 2950 it was defintely unwatchable. the picture was worse than on a 18 year old philips laservision player with a gas-tube laser and analogue only sound circuitry. it -really- sucked. i took the thing apart and found a few pots. the three important ones were focus gain, tracking gain and tilt offset. you want to set tracking and focus as high as you can before the transport becomes noisy, but the tilt offset is more work. play a bad disc, find a really bad scene. change the tilt offset quite a bit (note where it started!) and try again. it will be better or worse. continue with this trial and error until your picture is perfect. now it will only be a matter of time before you find at least one disc which won't play to the end, when this happens, simply move the offset back slightly and try again, until it will play everything and looks good. lot of effort, but it paid off. i also find a difference between A and B replay. A is generally better, but B seems to have better tracking (important if you're watching a CAV disc with lots of freeze cues, my side A will skip forward a frame or two on it's on, side B doesn't look as good but is rock steady.) so it's all swings and roundabouts.

[tedkunich]

Thanks guys, but the problem is NOT in the LD player - I have a relatively new (2 yr old) Pioneer DVL-919 LD/DVD combi unit - the picture quality of the unit is phenominal... you would be hard pressed to decern any difference between LD or DVD. The noise is only visible when viewed through my capture hardware...

When I get home tonight, I'll look into any grounding issues (hell, should be able to figure that out, I am an EE ) I'm just wondering if it was a common problem with the AIW cards to get noise at higher bit rates....


Thanks

T

[flaninacupboard]

if you want better quality captures, i wouldn't suggest using the AIW anyway, it gets a lot of bad press here. a better choice is something like the canopus ADVC-50, at around $250. i got one a few weeks ago, it makes a bigger difference than you might imagine.

[tedkunich]

what capture program did you use? What settings?

Out of curiosity how did you get all 6 audio channels? was that the "encode each time with a different audio signal" trick? how did that work out for you.

menace,

I'm using VirtualDub to capture 720x480 huf encode, 29.9706 fps. I plan on post processing with AVISYNTH and TMPGenc later.

I'm capturing the audio out of the 5.1 preamp output of my reciever - granted it is an analog capture, but I still think it will be better than a stereo or pro-logic audio track. The six audio channels will be synced and merged into one multichannel WAV then encoded with BeSweet to a 5.1 AC3 audio track. The only problem is that the util that I have that splices the multiwave file craps out with the larger file sizes... (I know it chokes on a 1.5G stereo file) I need to look at the source (not mine but in the GNU public domain) and see if there is a work around... I have comfirmed that this process can be done on a small file and works rather well.....

(If any brave souls would be willing to tackle the software task, let me know - I don't have the link here but it is a utility that is part of Edinburgh speech tools library... I believe it is called ch_wave. It is a unix app that will work on a PC with the Cygwin environment.)

[wwaag]

Ted,

Glad it's not your LD player. Agree with flaninacupboard about AIW--it doesn't have the best track record for participants on this forum.

I use the ADVC-100 for DV capture and have never had a problem. Just finished the widescreen version of Raiders of the Lost Ark. Switching back and forth from the Receiver, the resulting DVD was virtually indistinguishable from the LD. I've also done 2 of the 3 Star Wars discs thus far with the same results. Never a dropped frame. Works great. Would recommend it highly. Also, if you look at the capture card ratings, it's the highest. Spend a few bucks, quid, whatever--you'll be happy.

wwaag

[tedkunich]

Just an update - turns out that the S-Video connector on the ATI and/or my LD player is piss poor when it comes to ground - I used one of my monstercable RCA patchcords to connect the composite video out of the LD player to the ATI input cable (while still capturing from the S-video port) and found the picture quality to improve dramatically!! I'm back in business. Thanks for all the help!

FYI, I looked into the Canopus products, and if I were to be doing more than just these three movies (SW trilogy), then I would go that route, but as this is a one-time deal, the justification for the $ expenditure just was not there.


T