[Tess] Great Teacher Onizuka - GTO [DVD 720x480 AVC AC3]

Isn't Urotsuki's encode better?

It depends one thing I really disliked about Urotsuki's encode was it looked like the colors were washed out and I preferred the brighter colors that the Discotek DVD had. This release was also denoised with waifu2x which removed a massive amount of both noise and blocking artifacts that were on the DVD and are also still present in Urotsuki's release. So if you're like me and hate video noise in older anime this encode is much better and does look much cleaner and at a 1/3 the file size of Urotsuki. You can also consult the included screenshot comparison in the description to see which you prefer.

is it actually supposed to be 30 fps though?

Urotsuki is way better judging by the screenshots. Your encode seems to wipe away a lot of the detail. In the first shot alone, you've lost pretty much all of the lines for the ceiling.

You've also encoded it into the wrong framerate.

The loss of detail is actually caused by the source. The brighter colors on the Discotek DVD wipes away a handful of background lines. You can notice it in the source screenshots as well. I personally don't see it as that big of a problem. As for the DVD being 30fps IVTC was initially used but this ended up creating a large number of combing artifacts I found QTGMC deinterlacing produced better results.

Grain better than DeGrain

The loss of detail is actually caused by the source. The brighter colors on the Discotek DVD wipes away a handful of background lines.

Except the lines I was referring to are still in the source screenshot. So it's only your encode that removed it.

I apologize upon re-reviewing I do notice what you're talking about unfortunately small detail loss like that just comes with denoising. I tired to retain the most amount of quality by using waifu2x to denoise. Personally I don't find the removal of a handful of background lines all that detrimental to watchability or even overall quality. Of course I understand denoising isn't everyone's preference but I personally prefer it over noisy video.

As for the DVD being 30fps IVTC was initially used but this ended up creating a large number of combing artifacts I found QTGMC deinterlacing produced better results.

IVTC is composed of two steps: deinterlacing and decimating. you don't have to do them at the same time. you can definitely use QTGMC for deinterlacting then decimate afterwards with another filter. there's no reason to leave it at 30 fps.

herkz, can you direct me to some guides for correctly encoding an interlaced 29.97 fps BD to 23.976 fps?

tfm.tdecimate(mode=1) or the vapoursynth equivalent

you only need to do weird stuff for old DVDs like this show

Thanks man. The Fafner JP BD is killing me.

Oddly enough I have tried decimating this video using core.vivtc.VDecimate(cycle=5, chroma=False) in vapoursynth and this ends up introducing a lot of judder I've included the clips below of the two outputs
deint+decimated: https://anonfile.com/C8a1W5Aan4/ivtc_mp4
deinterlaced: https://anonfile.com/I1a7W2A3n4/deint_mp4
I'm unsure if it has to do with the decimate filter I'm using or the source, either way this is my first time dealing with a DVD so any feedback or advice is more than appreciated. I did try using IVTC when first starting this project but couldn't find anyway to remedy this judder. I spent hours reading through vapoursynth documentation and couldn't find any type of solution I'm assuming it's the source and that's why I left it at 30 but I could be wrong and probably am.

i'd probably have to see the raw DVD to see what exactly went wrong there, but it definitely looks like it's supposed to be 24 fps based on the pans in the first two scenes.

also there's a lot of ghosting and other issues. looks like quite a fucked up source.

Interestingly enough upon comparing the framerates of various releases I've found most of them are at 30fps, Reaktor's release is at a variable 29.970, Crunchyroll is at 29.970 constant, Urotsuki's release is the most interesting using a variable 24.188 framerate at least according to mediainfo whereas ffmpeg reports a variable 29.970. Judging by the other encodes I think this may have to do with the source and it doesn't surprise me as you said the source is pretty fucked up. I had access to both the PAL and NTSC versions of the DVD set and both seem to exhibit the same issues while decimating and both suffer ghosting issues. This show in particular hasn't been an easy one to encode mainly because the source was so poor.

read some stuff on AB, looks like the source is garbage and the officialsubs suck too (with no fansubs available)

shame such a great show is left in such a poor state thanks to the outdated techniques for bringing anime to the west back then

i assume japanese DVDs aren't available online? if they even exist

I tried to source the JP DVDs to see if the quality was any better and unfortunately couldn't source them anywhere and yes the source is absolute garbage. I tired my best to clean up a large portion of it using waifu2x to denoise. The end result cleaned up a lot of lines and a big portion of rainbowing on edges.
This had a large impact on more convoluted scenes and you can see the difference very clearly in the fifth screenshot. Waifu2x also cleaned up most of these weird checkboard artifacts present in some frames, you can see them in the sixth screenshot on the right-hand inside edge of the picture frame. Waifu2x cleaned most of these up to a pretty much unnoticeable level. Unfortunately waifu2x had the side effect of removing some background lines, however, in most frames I think it still looks better than the source DVD. Plus it's not really all that noticeable without direct comparison to another source and during playback I doubt anyone could notice it.
I also completely agree it's a shame such a great show is condemned to such an awful DVD. The subs are passable I suppose they give you the gist of what's going on but they're filled with questionable translations. I can only imagine what other more advanced translation errors the subs have, as I don't even speak Japanese.
I've tried my best to clean up the source as much as physically possible but until this show gets a remaster or re-release this is about as much as I can do. The framerate of this DVD is also fucked I've been digging into more encodes on rutracker and virtually every single one is at 30fps.

Update pertaining to the framerate issues I have found an encode that does use 24fps. Yurasyk's release on rutracker is set at a constant 24fps however exhibits the exact same judder I noted when attempting to IVTC my source based on this I'm led to assume the judder is just something inherent to the source and not something on my end. Based on this I ultimately believe leaving the video deinterlaced at 30fps seems to be the best option at least with this particular DVD.

There's a proper encode by TOJIO who really fixed almost all source problems: https://rutracker.org/forum/viewtopic.php?t=5432274
It's still WIP and not updated since the last January though so episodes 41-43 are missing and some eps may need a fix or two.
The author will work on it next January.

thanks for this awesome research and hard work, looking forward to v2 or whatever TOJIO's doing

No grain...

Bad encode.

No grain wipes details. You should already know.