Bad DivX -------> Good DVD (Framerate, Blocks, Color, Resolution)

[Johnny_Deep_Down_Below]

Hello!

I have a typical DivX Movie:

-Low Resolution (~VCD Resolution)
-Bad Colors
-Framerate of 23,xyz FPS
-DivX artifacts

So, I'm looking for a GOOD way to change the framerate (NO longer or shorter Movie, etc.) and a way to correct the quality issues caused by DivX.

Any good Avisynth solution?

[scharfis_brain]

So, I'm looking for a GOOD way to change the framerate (NO longer or shorter Movie, etc.) and a way to correct the quality issues caused by DivX. Any good Avisynth solution? Ahem... No...!

changing framerate = OK
- without changing lenght causes motion-jitter
- with changing lenght causes playing faster/slower

changing resolution = OK
- but you'll amplify the artifacts of DivX

conclusion: forget it...

[Awatef]

And just as information:

23,976fps is no weird framerate as you may think, it is the so called NTSC-Film framerate. Every movie and most animes must be encoded in this framerate when ripped from an NTSC DVD.

[Johnny_Deep_Down_Below]

Well, I can't forget it.

It's not available on DVD, and of course not in PAL.

I think it has been recorded from NTSC TV (30fps) and lowered
to ~23.... fps for reducing size, is this process reversable?

How good are the results of tools like blockbuster (I don't see a problem to use them BEFORE resizing).

[scharfis_brain]

I think it has been recorded from NTSC TV (30fps) and lowered to ~23.... fps for reducing size, is this process reversable?
Please take a look at NTSC-Telecining, this will clear up many things.
(24fps Film is Telecined to 30fps-interlaced, therefore after capturing a IVTC is applied, which restores the 24fps of the Film)

[DoW]

What you are talking about is reencoding a file that has already been compressed, which will only enchance the artifacts. There is almost no way that you can clean it up except by turning on postprocessing in whatever divx your using (and even this is marginal). Truth be told, unless you can find another source that is cleaner, there is nothing that you co do about it, and are just gonna have to live with it. Also, why would you want to raise the framerate? There is a reason that people decimate to 23.976 fps aside from saving space, and that is to reverse the telecide process. The video was most likely originally 23.976, TC up to 30 for NTSC play on TVs. Lowering takes it back to it original framerate.

PS. Blockbuster only PREVENTS blocks from forming in the encoding process by adding noise, it does not remove them.

[Awatef]

You won't be able to clean it really up, but you may try SmartSmoother in VirtualDub.

Second, if you want PAL, no way to get a perfect convertion without shortening the movie (so called PAL speed up from 23,976fps to 25).
This is done with: AssumeFPS(25)
You can use tools like BeSweet or for better results the rare "Prosoniq TimeFactory" to speed up your audio.

The bad method, which won't change the duration is:
ConvertFPS(25)
This will introduce blending/ghosting in your video.

[Johnny_Deep_Down_Below]

Well, I need PAL because it should become a compatible DVD.

If I take Bitrates of about 8000 kbit/s (only 45 Minutes), there should not be new MPEG2 artifacts.

There is definately no other source, it's a TV episode, which has not been broadcasted in Germany, so no other possibility than DivX.

There are Tools like MotionPerfect, which try to expect the next image, and try to create a perfect motion.
Results are simply bad.

So I have to try your shortening, but that makes the episode 2 minutes shorter.
But how good are the results of your tool?
(Better/worse than Cooledit)

And still the last important things:

What to do against the bad colours and is there a good tutorial for Blockbuster?

[Awatef]

Prosoniq TimeFactory is the absolutely *BEST* time stretching software and the results are *PERFECT*. But AFAIK, it can't convert files longer than 45 minutes.
If it doesn't convert your file to the end, you may cut the episode in 2 (for example first part before publicity, second part after publicity)

[scharfis_brain]

@ Jhonny: just make a PAL-Speedup from 23,976 to 25 fps, you won't notice a difference. Every Film in Germany/Europe has this PAL-Speedup! Even a lot of TV-Episodes

In AVIsynth you can use this for speedup:

avisource("x:\path\yourfile.avi")
Assumefps(25)
newsamplerate=Audiorate()*25/Framerate()
AssumeSampleRate(newsamplerate)
resampleaudio(Audiorate())



Doing a motioncompensated Framerate conversion is IMHO overkill!

What to do against the bad colours and is there a good tutorial for Blockbuster?
Provide A short clip, so that we can imagine the errors.
And blockbuster CAN'T help in this situation! It only adds noise and is thought for low-bitrate encoding! You said, that you'll encode with high bitrates!

[Johnny_Deep_Down_Below]

Here, short sample clip:

http://mitglied.lycos.de/rolfmayer1/samplevid.avi

[Johnny_Deep_Down_Below]

Additional information:

File is about 5 Megs.

The first part (of the Intro) shows you the bad colors (if you know the original).
The second parts (where they kill the woman) show you lots of problems caused by DivX.

[scharfis_brain]

IMO leave it as it is!

I can't see an color problems. Execpt that the saturation at the beginning is a little low...

You can't ged rid of the DivX artifacts, because you have to smooth them out, but the smoother will also smooth the details and other things in non-blocky parts of the Video...

MacGyver in Germany is a standardsconversion (fieldblending) like Startrek-TNG, so capturing it makes no sense...

[Johnny_Deep_Down_Below]

What do you mean with "standardsconversion" ?

The episode is from American TV (ABC or so), my German DVB Rips are MUCH better (no artifacts of course, and better colour).

[sh0dan]

Not that much to do about it. Some observations:

- The worst part (at least when framestepping) is the occasional interlaced frame. It has been resized so there is no way to remove it :(

- Colors seem fairly ok - even though a bit late 70/early 80'ish. Reminds me of MacGyver. ;)

- Framerate - no need to change it - it will only make matters worse.

- DivX quality - it can only be made better by softening.

A suggested script (which produce quite soft material):

AVISource("C:\download\samplevid.avi",false)
undot()
VagueDenoiser(filter=7,threshold=0.8,method=1,nsteps=3,chroma= true)
mergeluma(unfilter(40,-60))

Undot usually doesn't hurt - it might remove a few stray pixels.

VagueDenoise is for denoising - I don't know much about the parameters, but these seem to give a nice result.

Unfilter is a bit tricky. It _sharpens_ horizonally, and it blurs quite heavily vertically. This is to make it a bit sharper, and for killing off most of the interlaced frames. If you don't care about the interlaced frames unfilter(30,30) might be better.

Regarding color - gaining red a bit seems to help en the first few scenes - I'm not sure if that helps you anything. Use "Coloryuv(cont_v=35)" to try this out.

[Johnny_Deep_Down_Below]

There is no function named "undot"

It's the same with "VagueDenoiser" and "unfilter".

Which Avisynth version do you use?

And is there any automatical way to detect all errors caused
by deinterlacing (like in frame 110) ?

[DoW]

Im sure Shodan is using 2.52, and the reason your getting
There is no function named "undot"
is because those are not included in vanilla Avisynth, they are plugins that you need to download. See Plugins and Stuff (http://www.avisynth.org/index.php?page=Section+3%3A+Filters%2C+plugins+and+colorspaces)

[sh0dan]

... or download them directly from here (http://www.avisynth.org/~warpenterprises/).

[Johnny_Deep_Down_Below]

There's no VagueDenoiser and Undot is only for Avisynth 2.5x

:( :( :(

[sh0dan]

VagueDenoise (http://forum.doom9.org/showthread.php?s=&threadid=56871) - you could just look a bit around. It's also 2.5 only.

[Johnny_Deep_Down_Below]

sh0dan, your script does not work:

VagueDenoiser(filter=7,threshold=0.8,method=1,nsteps=3,chroma= true)

It says: VagueDenoiser does not know an argument named "filter".

This is also not mentioned in VagueDenoiser documentation.

[Lefungus]

"filter" parameter is no more mentionned into the documentation, so it means it doesn't exist anymore. Look at the thread mentionned above.
And some parameters you're using are default now so you could just try

VagueDenoiser(threshold=0.8)

[Johnny_Deep_Down_Below]

What was filter good for?

[Lefungus]

"filter" was there to choose which wavelet filter was to be applied. But it's always Brislawn 10/10 now.