Denoise is essential for DVDs?

General questions or discussion about HandBrake, Video and/or audio transcoding, trends etc.
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gentleben
Posts: 24
Joined: Sun Feb 07, 2021 12:21 pm

Denoise is essential for DVDs?

Post by gentleben »

So when using any preset with DVDs, I wondered why most of them (if not all) came out all fuzzy with dots all over the screen (sometimes flickering dots). For a while, I thought it was a problem with HandBrake but then I noticed that the fuzzy image is visible in the original MKV files too (ripped using MakeMKV).

I couldn't understand it because my ancient AVI files (encoded many years ago using very old codecs such as 3IVX 4.5 and encoders such as FlaskMPEG) did not have this fuzzy image and actually looked better than HandBrake's MP4 files.

After some research, I discovered that the fuzzy image is actually noise so I did a test with HandBrake's Denoise filter enabled (set to nlmeans Light with no tuning) and the noise went away on all the movies I tried.

What surprised me is that this noise issue appears to be a problem for almost all DVDs (if not all) so this would imply that Denoise is mandatory for encoding DVDs. Since the noise is present in the original MKV files from MakeMKV, I guess HandBrake is fixing an issue with the original DVD which seems really strange to me and I wonder why the DVDs were mastered with so much noise. Perhaps because it's part of the movie and can't be fixed without remastering, I guess.

The thing is, I've not really seen many reports of complaints about DVD noise so my questions are (a) is Denoise really mandatory for DVDs as it seems to be and (b) I want to apply denoise without affecting the picture quality - 'ultra-light' denoise didn't seem to help but 'light' denoise seems to fix the problem. Would 'light' affect the picture quality?

I still find it strange that if I rip a DVD with MakeMKV (pretty much any DVD it seems), the amount of noise makes for a bad viewing experience and encoding from MP2 to MP4 with denoise filter applied actually cleans up the image and fixes the problem. I find that strange because people always say that if you want the best picture quality, rip with MakeMKV and watch the MKV files. But because of the noise issue, MP4 files encoded with HandBrake and denoise applied actually appear to be better quality than the original MKV files.
Woodstock
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Re: Denoise is essential for DVDs?

Post by Woodstock »

I have not had to use denoise for DVDs that had a good transfer from the original film.

Home made DVDs or films where the noise is used as an effect (or no clean transfer is available)... Those are a different animal. My copy of The African Queen, for example, has a lot of film grain, lint, and even the occasional film tear in the transfer. It isn't one of the "Lovingly Restored and Color Corrected (tm)" films.
mduell
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Re: Denoise is essential for DVDs?

Post by mduell »

Sometimes it's an intentional look, sometimes it was just the limitations of the film recording (or later transfer).

If you like the original look, use the film encoder tune.

If you don't like it, use the nlmeans filter.
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