ADVC300 or Mike Crash DNR

LarryP wrote on 11/15/2005, 8:25 PM
I captured a VHS tape the other day using a consumer DV camera and cleaned it up with Mike Crash’s Dynamic Noise Reduction filter and the result was pretty good, certainly better than the original VHS tape.

My question is has anyone compared Mike Crash’s DNR filter to an ADVC300? The DNR filter isn’t a TBC but when you think about it averaging over a number of frames would seem to have a similar effect.

Larry

Comments

Spot|DSE wrote on 11/15/2005, 8:32 PM
Mike's is better, IMO. ADVC has some great features, and does a good job, but it's not great for this compared to what Mike's can do.
goshep wrote on 11/15/2005, 8:49 PM
Never mind...I found it.....gonna give it a whirl....
farss wrote on 11/15/2005, 9:48 PM
They're two somehwat different approaches that should be used to solve different problems.
TBCs don't reduce noise, they get the frames and / or lines of video timed correctly, without them you can get line tearing, or frames rolling around the frame.
Noise reduction comes in two flavours, simple low pass filtering or dynamic noise reduction. Low pass filtering is easy enough to simulate in Vegas with GB, DNR is a bit trickier as it looks at the chnage in value of pixels between frames to try to guess what is noise and what isn't. It does however introduce some degree of blur on movement. Mikes filter does much the same but leaves the edges alone, quite amazing to see it work on very noisy video, I'm amazed at how well the edge detection isn't fooled by all the noise.
There's other problems that you can run into with VHS such as chroma smear due to the video being recorded at way too higher level. Combine that with very bad flagging due to damaged tape and things can look really bad.
However for fairly static video such as titles the Motion Blur in Vegas can do an amazing job of cleaning things up. I;ve even cleaned up a talking head using this, rendered it out with as much MB as Vegas would give me and then masked out the lips and eyes on the head which fortunately didn't move much!

Thing to keep very much in mind in my opinion is this. Recovered VHS may look very good, until you feed it into a mpeg-2 encoder and then it can get really ugly if there's too much noise. Look long and hard at the noise, what I've seen happen is the noise get frozen for the duration of the GOP as the encoder runs out of bandwidth. I've even seen this impact noisy DV, it's not unique to VHS. Encoding at the highest bitrate possible helps no end of course, problem is those damn 4 hour VHS tapes recorded in LP and the client wants them on one DVD!

Bob.
kenr44 wrote on 11/16/2005, 4:54 AM
Where do I find Mike's link?
kenr44 wrote on 11/16/2005, 5:00 AM
Sry I found it.