Fixing Faint Ripple Lines From Cable on an MPEG

[shadowkaos]

Hey Guys,

I am in the middle of making a set from raw caps using a hauppage wintv-150 cap card but the channel I am capping on seems to have very faint ripple lines. I have converted these episodes to avi as well as putting the raw cap mpg to dvd and on the avi you cannot see them but on the mpg you can. Here is a sample of the mpeg http://www.megaupload.com/?d=HNL2NTDD If anyone knows how to fix it please let me know... aside from the ripples I would also like some feedback on the quality out of 10 since this is the first set I am making.

Thanks in advanced

[lordsmurf]

I have a few observations for you:

1. I can tell this is a Hauppauge PVR-150 being used. The 150 model card has a different capture/encoder chipset from the better 250 and 350 cards. It makes your video brighter than it should be. The luma is shot, and your colors are a bit neon-like and the whites are overly white. Detail is lost from this. I've seen worse, so you might be okay. The MPEG bitrate looks fine, there is no compression noise that I can tell.

2. Those ripples are an interference of some kind. It can be outside or inside your home. If it only appears on that one channel, it's probably an issue at the cable company. If it appears on multiple channels, it's probably something to do with your line strength being harmed, either with bad wires, bad connectors or crappy splitters. If it appears on all channels, it's likely an electrical feedback issue within your home. You can correct this, but only with cartoons. You'd process the captured file with a high temporal filter. On live-action, it would not work, as it would make everything look plastic and degraded. You may want to try putting the computer on a UPS from APC, instead of a surge protector. Those run about $40-45 for the mid-grade ones.

Your "AVI" is what format? AVI is just a container. Did you convert to XVID, maybe? On those, it was really filtering it, plus I would imagine you did some de-interlacing and down-resolution too, which somewhat hides the error (but they still exist!).

You might try some various VirtualDub filtering methods, before converting back to a new MPEG, but I don't really know what filter to try. You'd want to use a light amount of temporal-type filtering, mixed with an even lighter amount of in-frame type filtering.

The best solution is to remove the interference that causes this, rather than putting a band-aid on the video captures (filtering it, extra work). This means swapping out various wires, testing wires and connections, and maybe replacing some wires and splitters. The less splitting, the better. I suggest using higher-bandwidth RG6 type coaxial cable too, not RG59.

[shadowkaos]

Well the interference only appears on that channel. I do have a WinTV PVR-150. The avi is XviD and i encoded it using avisynth and virtualdub. So the only way I could fix my brightness problem is to buy a 250 or 350 or is there anyway to fix it with the 150?

[lordsmurf]

Some of the 150 units look better on composite inputs, rather than using coaxial inputs. But yes I'm afraid the only way to fix the brightness issue is to buy a 250 or 350 model. Hauppauge had a big flaw in those 150 units, and they're discontinued from what I've read recently. The early ones had audio problems too, not just video problems. That card was a mess from day one.

Check your wiring and maybe tell the cable company to drop by and test your signal strength. Weak signals (caused from wires, splitters, etc) first appear on weaker channels. Sometimes, it's a problem at the cable company itself, and it broadcasts crappy to start with. If this is a local station, it's very likely. The must-carry stations are often abused in this manner.

[shadowkaos]

Yeah, the channel is a local one. Ok thanks for your help I'll try that and save up some money for a 250/350.