Whats that buzz?

ams · Post by **ams** » Wed Apr 06, 2005 3:42 am

I am a home user wanting to put my years of analogue tape onto PC and then burn onto DVD for family and friends.
I am capturing SVHS PAL from a JVC GR-AXM30 onto my P4 PC through a composite connection. A lot of noise seems to be captured in the process. Is there a way to minimise noise capture or if not to remove once the capture process is complete?

Capture details are:

NTSC drop frame (25fps)
MPEG files
24 Bits, 720 x 576, 25fps
Upper Field First
4:3
Video data rate: Variable (Max. 8000 kbps)
Audio data rate: 224 kbps
MPEG audio layer 2, 48 KHz, Stereo

My final output is to DVD for TV purposes.

thecoalman · Post by **thecoalman** » Wed Apr 06, 2005 4:23 am

There's two things I can think of, one you have a grounding issue which is a little beyond my area of knowledge. I've just seen it posted numerous times as a cause for buzzing

-or-

your getting inteference through your RCA cables. Try some monster cables.

BrianCee · Post by **BrianCee** » Wed Apr 06, 2005 11:14 am

You also seem to have some very peculiar capture properties, if you do have NTSC then you should have 29.97 fps not 25 - you also have the frame size for PAL and since you state you are recording from a PAL VCR I assume you are in PAL area - so where did you get the NTSC bit from ????

On a wider note it really would help if people could at least put their country of domicile in their profile so that it shows in the panel to the left like mine and many of the other regular posters - saves a lot of guesswork and confusion.

ams · Post by **ams** » Wed Apr 06, 2005 2:07 pm

Apologies for the inconsistent data supplied and the lack of location information. I am using PAL format so the NTSC is incorrect.
I've also updated my profile so now it will show Sydney Australia.

Any ideas on getting rid of the noise?

thecoalman · Post by **thecoalman** » Wed Apr 06, 2005 2:33 pm

ams wrote:
Any ideas on getting rid of the noise?

If it's auido noise your referring to the two reasons I listed above are probably the most common causes. Another suggestion would be the jack your plugging the audio cable into. If you have a different jack on your comp try that one to see if it's still buzzing. Just enable the jack in your soundcard config and turn the VCR on so it's sending some audio.

Another thing you may want to try is connect it to a TV as it sits now, just switch the RCA cables to the TV....

lalkana · Post by **lalkana** » Wed Apr 06, 2005 5:27 pm

The way I am reading your post, you are referring to noise in the picture? If so, I have found that capturing VHS through my Sony D8 really does improve the picture. It also lets me capture directly to DV. You could also try running the VHS through a color stablizer and capturing that output. I think the SIMA unit is about $100. I am not aware of any post-capture process that will do much for you.

lalkana · Post by **lalkana** » Wed Apr 06, 2005 5:30 pm

The way I am reading your post, you are referring to noise in the picture? If so, I have found that capturing VHS through my Sony D8 really does improve the picture. It also lets me capture directly to DV. You could also try running the VHS through a color stablizer and capturing that output. I think the SIMA unit is about $100. I am not aware of any post-capture process that will do much for you.

DVDDoug · Post by **DVDDoug** » Wed Apr 06, 2005 9:30 pm

...PC through a composite connection.

I assume that means you have a capture card. The capture card has a composite video input and an audio input? Or, does the audio go to your sound card?

You can eliminate any possible "ground loops" by running the camcorder from batteries. This will also eliminate any power-supply hum. (You can still pick-up electro-magnetic power-line noise through the air.)

Make sure that you are using a shielded cable. Use a short cable (2 meters or less). Try a different cable... yours may be defective. Or, try putting a "hot" AC power cord near the audio cable. If the buzz gets worse, you have a bad or unshielded cable.

Make sure that you are using the computer's line input, not the mic input.

Does the camera have a volume control? Crank it up for a higher signal-to-noise ratio.

You could also try mixing-and-matching some other equipment, to try to identify the source of the problem. Do you get the buzz when you plug your VCR into your computer? Do you get the buzz when you connect the camera to your TV or stereo?

It's virtually impossible to eliminate all noise in analog audio, and the typical sound card or chipset are not as good as the typical living room stereo system.

If you can't eliminate the noise, you can try to remove it (after capturing) with a (software) audio filter. Extract the audio to a wave file (from the Video Studio SHARE tab). Then, use a wave editor such as GoldWave ($45 USD) to filter-out the noise. Then, use the fixed-up audio in your project.

THoff · Post by **THoff** » Wed Apr 06, 2005 9:55 pm

The free Audacity audio editor also has a noise removal feature.

ams · Post by **ams** » Thu Apr 07, 2005 2:54 am

Thanks everyone, lots of great tips here. I should also give you some more info.

The noise is audio noise not video. I have a HDTV card (Fusion) which has 3 connections: air antenna, Thru pass port and Video IN (composite I think).

I use the composite port and then have an composite/RCA and S-Video adapter with four plugs (Yellow, White, Red and S-Video)

I connect Yellow and White plugs to my GR-AXM30 JVC VHS camera. This is powered by mains.

I actually went to an electrical shop and asked them if there was any way I could remove the sound (you know by spending heaps of money in their shop buying more cables, but they said that no it wouldnt make any difference!) , but I tend to believe you guys, so I will go out and buy some shielded cables.

I will also try using a battery on the camera instead of mains.

from memory I think that the sound is ok connected to a TV, but I will check this out again.

ams · Post by **ams** » Thu Apr 07, 2005 2:58 am

Sorry, should also mentione that the interncal capture card has an analog audio output port which I have attached to my sound card which is a soundblaster live 24 bit.

htchien · Post by **htchien** » Thu Apr 07, 2005 3:49 am

Try capturing in 16bit audio and see what happens.

H.T.

THoff · Post by **THoff** » Thu Apr 07, 2005 4:43 am

Make sure the mixer for the SoundBlaster has online one recording source enabled, the one that you used to connect your capture device. If there is a microphone plugged into another port, that may be the source of the buzzing noise.

ams · Post by **ams** » Thu Apr 07, 2005 4:51 am

well interesting development. I connected the camcorder(battery only) using RCA cables to TV and wacked up the sound and I can hear the buzzing there too!

So then I put the tape into a VCR and the buzzing disappeared. That got me thinking that it must either be the cable or the camcorder.

phd · Post by **phd** » Thu Apr 07, 2005 11:23 am

Is it possible since you're only hooking up the yellow and white cables to your camcorder that you're picking up the hum from not using both audio inputs (red and white.) Or that you have the red wire plugged into the computer and the center post is touching a ground somewhere?

Perhaps your problem will be solved with a splitter to go from mono (camcorder) to stereo (computer.) Or make sure the red wire is not plugged into your computer since you don't have the other end plugged in anywhere else.