What Must I Do (or spend) To Get Rid Of This?

norm1153 · 26th February 2004, 11:17

Greetings:

The answer to this may be in hardware, or maybe software, but whichever, here goes, anyway:

I've captured video from a range of sources, including a few miniDV camcorders, up to but not quite the Sony VX2000.

In every single case, the resulting AVI shows a very fine layer of "snow" - for want of a better word. Interestingly, if the scene includes a horizontal pan either way, this "snow" (very, very fine particles behaving exactly like snow on analog tv receivers on unused channels) layer becomes a completely still layer of something with a sheen-like quality, that remains fixed in its position, even as the camera pans the scene. As soon as the camera stops panning, it's back to "snow."

My question: how to get rid of that.

Is there an mpeg encoder good enough to finally eliminate that?

Is it part of the MiniDV, spec, and if so, would the Pro version clear that up (and how much would I have to spend to get a camera that does the "Pro" version?

Could it be in the Capture Card/Hardware? (RT2500)

I hope my explanation of the "snow" is clear enough, or that someone with more experience than myself recognizes what I am trying to explain!

Thanks in advance for any replies!

Norm

bb · 26th February 2004, 12:53

Was it snowing when you took the video?

Seriously, I need some more information on this phenomenon. Is the "snow" really white or somehow coloured? How was the lighting? Bright or low-light? How did you capture the video (firewire or analogue, which devices)?

If the snow is in the DV material and not caused by interference in cables, you should probably use noise filters, e.g. through AviSynth. Encoders may reduce noise in pre-processing, but as their main subject is the MPEG-2 encoding, I'd rather try to clean the video before sending it to the encoder. Much has been written about denoising here, and many different filters are available.

bb

communist · 26th February 2004, 14:18

Quote:

Originally posted by norm1153

Is it part of the MiniDV, spec, and if so, would the Pro version clear that up (and how much would I have to spend to get a camera that does the "Pro" version?

You could go for DVCPRO 50 / Betacam or D9 format to get better pictures but that would be quite expensive.

If you shot in low-light its probably just the noise resulting from GAIN function on your cam / general noise due to low light.

If its on all kind of different DV-footage you shot with that particular cam then it maybe a problem with the camera.

Just run different denoiser's on it too see if you can fix it that way (since you plan to reencode anyway).

26th February 2004, 11:17	#1 \| Link
norm1153 Registered User Join Date: Feb 2004 Location: San Jose, CA Posts: 5	What Must I Do (or spend) To Get Rid Of This? Greetings: The answer to this may be in hardware, or maybe software, but whichever, here goes, anyway: I've captured video from a range of sources, including a few miniDV camcorders, up to but not quite the Sony VX2000. In every single case, the resulting AVI shows a very fine layer of "snow" - for want of a better word. Interestingly, if the scene includes a horizontal pan either way, this "snow" (very, very fine particles behaving exactly like snow on analog tv receivers on unused channels) layer becomes a completely still layer of something with a sheen-like quality, that remains fixed in its position, even as the camera pans the scene. As soon as the camera stops panning, it's back to "snow." My question: how to get rid of that. Is there an mpeg encoder good enough to finally eliminate that? Is it part of the MiniDV, spec, and if so, would the Pro version clear that up (and how much would I have to spend to get a camera that does the "Pro" version? Could it be in the Capture Card/Hardware? (RT2500) I hope my explanation of the "snow" is clear enough, or that someone with more experience than myself recognizes what I am trying to explain! Thanks in advance for any replies! Norm

26th February 2004, 12:53	#2 \| Link
bb Moderator Join Date: Oct 2001 Location: Germany Posts: 2,665	Was it snowing when you took the video? Seriously, I need some more information on this phenomenon. Is the "snow" really white or somehow coloured? How was the lighting? Bright or low-light? How did you capture the video (firewire or analogue, which devices)? If the snow is in the DV material and not caused by interference in cables, you should probably use noise filters, e.g. through AviSynth. Encoders may reduce noise in pre-processing, but as their main subject is the MPEG-2 encoding, I'd rather try to clean the video before sending it to the encoder. Much has been written about denoising here, and many different filters are available. bb