Noisy/grainy dvd

[skaleton]

Hello,
I have a retail dvd of a TV series from the 70s that is very noisy/grainy.
The format is PAL and the content is progressive.
I would like to convert the episodes to XVID.
I tried convolution3d ("movielq" and "vhsbq") and DeGrainMedian (limitY=2,limitUV=3,mode=1) but I found that the results were quite blurry if anything else.
Peachsmoother + VagueDenoiser and MCTemporalDenoise were suggested in other posts.
Before doing my 10th test, maybe would someone have a look at this 1 mn sample and advise me how to proceed?

[poisondeathray]

It comes down to personal preference (to what extent to denoise - some people like a bit a grain remaining, some like it super smooth)

Your clip has chroma noise (looks like color noise and rainbows), blocking, and fairly heavy grain/noise

MCTemporalDenoise works fine on that clip IMO . It has like 50 setttings, but there are presets to make it easier e.g. MCTemporalDenoise(settings="high")

You don't have waste time encoding the whole clip to get a preview. Use an editor like AvsP to preview scripts or versions of your scripts. It has multiple tabs so you can swtich quickly with the number keys between versions of scripts, for example. This way you can quickly fine tune the parameters of your filters so it matches your source

[skaleton]

Thank you poisondeathray for your reply.
I already did the tests on a small sample and you made me discover AvsPmod in another thread and that will save me more time. Actually in that thread, you provide a bunch of basic information that most people here and in Doom9 would take take for granted but that I found very useful. And I am glad to have the opportunity to thank you for it.

Anyway, back to my dvd, I see that you confirm that it is bad. You would imagine a dvd published in 2007 to be of better quality. But maybe they couldn't do better with the 1979 source.

Although it is a bit intimidating, I will give MCTemporalDenoise a try.

Regarding resolution and noise, should the resolution be adapted to the amount of noise, and in which direction? or doesn't it matter?

[poisondeathray]

Anyway, back to my dvd, I see that you confirm that it is bad. You would imagine a dvd published in 2007 to be of better quality. But maybe they couldn't do better with the 1979 source.

It's hard to say or know the "why" behind it

Although it is a bit intimidating, I will give MCTemporalDenoise a try.

It's a massive function. It's really a megafilter with about 20 different filters inside . Fortunately there are presets , but you should really use them only as a starting point . Even the one suggested above using the "high" preset setting without farther tweaks does a decent job.

Start learning to characterize and identify the artifacts that you see , e.g. what is chroma noise, what is macroblocking, what is temporal noise? etc... and that will guide you to learn about the different filter categories. You will find avisynth has a variety of filters or techniques for almost everything

Regarding resolution and noise, should the resolution be adapted to the amount of noise, and in which direction? or doesn't it matter?

Can you clarify this statement ? I don't understand what you're asking ?

By resolution do you mean frame size? You normally would set your export goals dependent on your playback target , and not let resolution dictate the noise reduction settings

[skaleton]

That was quick!
I was going to add that from what I have done so far, I am not a great fan of the super smooth.

you should really use them only as a starting point . Even the one suggested above using the "high" preset setting without farther tweaks does a decent job

OK, that makes perfect sense.

Start learning to characterize and identify the artifacts that you see , e.g. what is chroma noise, what is macroblocking, what is temporal noise?

Actually that is not the easy part to identify these artifacts. At least you help me go in the right direction.

Regarding the blocking, would you recommend a deblocking of the source (i.e. cpu=4)?

Can you clarify this statement ?

Sorry, it is how Gspot defines it. Indeed I mean the frame size, width x height. should you adapt the frame size in relation to the amount of noise? For instance, with a pal 4:3, I could do a 704 x 528. With a lot of noise, should I reduce the size? Or doesn't it matter? Or is it stupid?
Also, since the noise eats bitrate, should I increase the bitrate together with the bitrate?

Edit:

You normally would set your export goals dependent on your playback target , and not let resolution dictate the noise reduction settings

Actually I meant without any noise reduction. That was more theoretical.

I am looking at the filters. I don't quite understand

You MUST put FFTW3.DLL file from this package (not fft3dfilter.dll) to some directory in path (for example, C:\WINNT\SYSTEM32)

Can't you just put it in the plugin folder?

[poisondeathray]

I was going to add that from what I have done so far, I am not a great fan of the super smooth.

Yes, so you should customize to what you want . Some people like super smooth . But most would agree that this source is too noisy

But when I tried the DegrainMedian settings in your 1st post, I found it hardly touched the noise...there was significant noise left over - and yet you described it as "quite blurry" . I'm not sure if we are on the same page with describing things.

For noise reduction , it's important too look temporally (i.e. through a few frames) . A spatial examination of a single frame won't reveal temporal noise

Actually that is not the easy part to identify these artifacts. At least you help me go in the right direction.

You can start by looking at a few general references , some of them have pictures, and before/after comparisons . I don't know of any good ones but here are a few to start with . You can learn a lot from other user's posted examples and the filters used to deal with it. Plenty of examples here and on Doom9 forums.

http://server4.doom9.org/index.html?/capture/chroma_artefacts.html
http://www.aquilinestudios.org/avsfilters/

Deblock QED usually does a good job, but depending on your other denoising filter stack, you might not need a separate deblock filter.

Generally , the more denoising, deblocking filters you use with higher settings, the more details are eroded. (not that your source has that much to begin with)

Regarding the blocking, would you recommend a deblocking of the source (i.e. cpu=4)?

MCTD has a deblocking filter (you have specify deblock=true), but even with it off, on those default "high" settings you can see it takes care of the deblocking. If you search in the avisynth mediawiki you can find a few filters as well specific for deblocking

http://avisynth.org/mediawiki/External_filters
http://avisynth.org/mediawiki/External_filters#Deblocking

Can you clarify this statement ?

Sorry, it is how Gspot defines it. Indeed I mean the frame size, width x height. should you adapt the frame size in relation to the amount of noise? For instance, with a pal 4:3, I could do a 704 x 528. With a lot of noise, should I reduce the size? Or doesn't it matter? Or is it stupid?
Also, since the noise eats bitrate, should I increase the bitrate together with the bitrate?

You have to 1st determine what your goal is for your intended playback target. Are you going to resize with square pixels? (704x528 would suggest that), or encode anamorphic? Are you going to crop the black borders and edges ? Do you care about the slight aspect ratio error? (the black borders aren't even) . What compression ? Do you have filesize limitation or bitrate goal? Do you care about size ?

You need to answer these questions first before you proceed

Resolution is part of quality, so I wouldn't downscale unless I was forced to.

If you don't have a filesize goal, then consider quantizer or crf encoding

[jagabo]

If you're a VirtualDub fan and have a lot of time on your hands, check out Neat Video.

[poisondeathray]

I am looking at the filters. I don't quite understand

You MUST put FFTW3.DLL file from this package (not fft3dfilter.dll) to some directory in path (for example, C:\WINNT\SYSTEM32)

Can't you just put it in the plugin folder?

No, this is different than a regular avisynth plugin , but it's required for fft3dfilter, dfttest and all the filters based on those. On a windows 32-bit os, you would put that .dll in the windows\system32 folder