Humming sound in captured video and I need help fast

blakice wrote on 7/13/2003, 4:22 AM
Im trying to capture from my Tivo to my computer to edit and burn to DVD. Im outputting from my tivo VIA Composite to my Sony PC110 camcorder then im outputting from my camcorder via firewire. Somewhere along the line the humming is comming in. I turned down the bass on the computer and i can still hear it somewhat. I dont know what it can be should i get get another capture card with Coaxial on it? Sony's cables are proprietary and cost an arm and leg. Now i know its not from the camcorder via firewire because i can capture from my camera via firewire without any humming.

Comments

cef wrote on 7/13/2003, 4:35 AM
hi there. your humming problem may be caused by ground loops. since you said you are recording from Tivo, i assume that the whole show was already recorded in it, thus not needing the actual cable from the cable box. try unhooking/disconnecting it from the outside cable, i meant the cable carrying the signal into your tivo. if the hum is still present, then also try to connect the tivo to your capture card directly, bypassing the tv. hope it helps
blakice wrote on 7/13/2003, 4:42 AM
after further investigation i believe it is the cable i ran a composite cable to my tv from the tivo and i dont hear any humming on the tv, so now i guess i need a capture card with composite inputs, i found this one on CompUsa's website http://www.compusa.com/products/product_info.asp?product_code=296679&pfp=BROWSE will that work with Vegas, if not that one can someone recommend one that is around the same price, i would prefer to have it all in the computer but outside would be fine as long as it captures at 720x480 so i can make a dvd out of it, maybe even be USB2 or Firewire so i dont have any dropped frames, thanks guys this forum is great
mikkie wrote on 7/13/2003, 10:51 AM
A ground loop can be difficult to find and cure -> one of the most common causes is the actual cabling bringing the cable signal into your house/apt. etc... What happens basically is that the cable starts out grounded, but by the time it reaches your TV, Set top box etc., there can be a voltage difference - the cable really isn't grounded anymore - & this can be heard in the audio.

Assuming you have cable TV hooked up to your set-top box, tivo etc., disconnecting the cable is more of a test, to determine if that's where the prob. is coming from, although some folks simply disconnect whenever captureing. Hooking a composite cable up to your TV is not really a good test, the prob. can be occuring downstream, with your camera, PC etc., even though the cause is back where the cable first hooks up to your TV setup.

If possible, use svhs/svideo type cabling for your video, and higher quality composite (RCA) cabling for your audio signal, keeping these lines as short as possible.

If you disconnect the source of your original video signal, the coax cable from your sat. decoder or supplying the cable tv signal or whatever, and see if the noise is present. If it isn't, check out Jay Rose's website dplay.com for info on how to cure this, or perhaps just disconnect the coax when you capture.

If the hum is still there, check out anything plugged into your wall outlets on the same circuit as your camera, PC etc... Stuff like dimmer switches for lights and such are infamous for causing prob. - unplug, disconnect what you can.

The card you pointed out is pretty entry level... You're not going to improve on what you see on your TV from the original signal, but to preserve that quality you're going to want to look higher up the food chain. Many like to use the setup you're trying now, using your camera to convert from analog to digital - you can buy a convertor card or box that does the same thing, or if you want to try capturing analog, might check out the ATI AIW 8500 DV that compUSA has on sale this week (discontinued card but a good price). Also, not well versed in tivo stuff at all -> is there a way to transfer digitally?... might want to check that out if you haven't already.
blakice wrote on 7/13/2003, 12:48 PM
thanks for the suggestions. but they did not work, i tried unplugging the signal from my satellite and plugging the tivo into a different surge protector, i really think its the cable but i cant tell until i get an analog capture device, i already have firewire and the 8500 looked like a great idea but it only comes in AGP for i already have an AGP card thats higher end, so i guess now i have to get a break out box and test it out, can you recommend one, as for digitally extracting its a long tast where i would have to learn linux
mikkie wrote on 7/13/2003, 1:06 PM
Well, what you might do is pick up the box CompUSA also has on sale, and if it doesn't cure the problem, take it back to the store for a refund. It's the MovieBox, comes in USB2 or DV, goes for $170 after rebate.

I've seen some decent reports, but I've read some complaints on this box stopping capture if it loses signal from a vhs tape, so it might not be the best one out there - but it will tell you if it's the solution you need, and you can take it back. Most folks in this forum like the Canopus hardware, which is in my area at least a mail order only, making any return a problem.