MVDegrain

[Chengbin]

What is the difference between MVDegrain 1 2 and 3? Which one should I use if I want maximum quality for low bitrate videos (500-800Kbps), and time is NOT an issue.

[onesloth]

http://avisynth.org.ru/mvtools/mvtools.html

[Chengbin]

Thank you

So MVDegrain 2 is a stronger denoiser. I heard that sometimes a strong denoiser might also remove details. Would that happen with MVDegrain 2?

Bottom line, if I want better quality, and don't care about time, I should go with MVDegrain 2?

[onesloth]

The whole point of MVDegrain is the motion compensated degraining. The mocomp is used to only filter out the noise and keep real detail. MVDegrain2 works pretty well but, if you really don't care about time, try MVDegrain3 instead. The decision is up to your eyes. You may find that using MVDegrain3 removes so much noise that you can see all the compression artifacts in the original source. MVD3 just compares more surrounding frames to determine what is noise in a single frame. So it shouldn't really kill much real detail, just *percieved* detail (from the noise).

There's also MDegrain from MVTools2 (http://avisynth.org.ru/mvtools/mvtools2.html). MVTools2 supposedly works better with the MT mod for avisynth. I know you said time is not a factor, but if you're using MDegrain3, and you have a multi-core proc., you'll be much happier if you can run it multi-threaded.

[Sagekilla]

Theoretically, using more motion vectors gives more accurate denoising. That's assuming you get perfect motion vectors every time. In practice, you usually get -really- good approximations so you might lose a bit of detail. It's not much though, since the MC'd noise removal of MVDegrain1-3 is very good.

Like onesloth said, you might think that there's some loss in detail but most of the time it's just noise being removed. If you look at it frame by frame (flick between source/denoised) and look closely, the denoised one "looks" like it's less detailed. But, when you're watching the video you won't notice this.

Bottom line though? Using more motion vectors is slower (obviously) but can give -extremely- good denoising without smearing. Plus, the bitrate reduction when you're using the source vs MVDegrain3 is well worth the time spent (for me anyway) ;)

[Chengbin]

Thanks. Unforunately AutoMKV doesn't support MT Avisynth. It is hyper slow (7fps). The weird side effect of this is that I can use any insanely slow x264 setting and not have a fps hit (they just use more of my CPU). I'll start using MVDegrain 3 now. I wish I had enough RAM, otherwise I can use some sane settings and run 2 encodes at the same time.

[onesloth]

Thanks. Unforunately AutoMKV doesn't support MT Avisynth.

No prob.

I've never used AutoMKV, but if it produces an AVS file that you can manually edit, and uses Avisynth 2.5.7, there's shouldn't be any reason you can't use MT Avisynth. There's a code example in the MVTools2 docs that you shows you how to use the MT() function with MDegrain2.

[Sagekilla]

@Chengbin: You being able to use any x264 settings without the fps decreasing means you're bottlenecked by avisynth. I wouldn't call 7 fps slow either. That's quite fast.

[Chengbin]

@Chengbin: You being able to use any x264 settings without the fps decreasing means you're bottlenecked by avisynth. I wouldn't call 7 fps slow either. That's quite fast.

I know. But until buzzqw decides to make AutoMKV compatible with MT Avisynth, I have no choice but to be bottlenecked.

7fps is 1080 to 480 encoding, not 1080 encoding. I only get 1fps with 1080 encoding with MVDegrain 1 on.

EDIT: Never mind, it is not 7fps. It is 5.5fps after using MVDegrain 3.

[Sagekilla]

It's very easy to make your avisynth "MT capable." Just replace the avisynth.dll in your system32 directory with the MT enabled one, and add SetMTMode() or MT() (whichever flavor you use) to your script.

[Chengbin]

Unforunately I think AutoMKV automatically creates the script, and it can't be changed.

[poisondeathray]

Unforunately I think AutoMKV automatically creates the script, and it can't be changed.

You could use another GUI, e.g. MeGUI will allow you to edit the .avs script

[Sagekilla]

Or better: Put in a feature request for an avs editor for AutoMKV ;)

[BigDid]

Unforunately I think AutoMKV automatically creates the script, and it can't be changed.
Hi,

Not exactly true. There was a modified base.avs on the wiki for avisynth and MT rev 2.57..
http://automkv.a.wiki-site.com/index.php/Advanced_Multi-threading

Now, there is also a MT-avisynth dll for 2.58; use at your own risk...
http://forum.doom9.org/showthread.php?t=144852

Did

[Chengbin]

You could use another GUI, e.g. MeGUI will allow you to edit the .avs script

I know, but MeGUI is such a pain to use.

[videoFred]

What is the difference between MVDegrain 1 2 and 3?

The number of frames used for analysis and averaging.
Please correct me if I am wrong. :eek:

Fred.

[Adub]

Nope Fred, you are correct.

[Chengbin]

Thanks a lot guys.

The quality gain is pretty significant. Not only the PQ is better (less noise), but at reduced sizes. I used to encode my TV shows (Prison Break is what I'm encoding now) to 250MB (700Kbps) files, now I'm using 200MB (530Kbps), and the quality is better. Not that I can notice it on a 5'' screen, but if I look closely, I can. This is coming from when I used 500MB per episode, now I'm using 1/3 of the bitrate, and it looks better.