QTGMC deinterlacing method

Suggest features for HandBrake.
Zardoz
Posts: 9
Joined: Mon May 14, 2012 5:00 pm

QTGMC deinterlacing method

Postby Zardoz » Mon May 14, 2012 5:31 pm

Hi,

While I absolutely love Handbrake and it's core functionality, as well as the overall performance of the yadif deinterlacer, I've been recently blown away by the QTGMC levels of quality I've seen on some of the material online. The thing with the decomb function is that it doesn't always get triggered when needed and constant "slower" yadif destroys image quality on dvd sources (which isn't too high to start with already) too much.

I'll be honest, I am a complete noob at programming and even avisynth gives me a hard time, so I cannot possibly comprehend the amount of work required for the implementation of the functionality that I am suggesting, but I believe I did see other topics proposing motion compensated deinterlacers and some of them even using commercial analogies.

I would love hear other suggestions whether arguing for or against and the rationale behind them, as my overall knowledge of the topic is fairly basic, as well as alternative approaches to quality deinterlacing the devteam's been contemplating.

Thanks.

ArturB
Posts: 6
Joined: Mon May 28, 2012 7:15 am

Re: QTGMC deinterlacing method

Postby ArturB » Sun Jun 03, 2012 7:32 pm

i tried many deinterlacers and decomb is one of the best.
use that custom parameters: 7:2:0:2:30 for fully deinterlacing.
if a video is mixed, most deinterlaced and sometimes only interlaced then that works with a better quality: 7:2:0:4:30 but may produce a little interlacing errors...
if somebody know better parameters, then poste them :)

Zardoz
Posts: 9
Joined: Mon May 14, 2012 5:00 pm

Re: QTGMC deinterlacing method

Postby Zardoz » Tue Jun 05, 2012 5:17 pm

Thanks for those suggestions, I've tried the 7:2:0:4:30 and really like the results. Could someone please break the settings down for me? Does this config use EEDI2?

mduell
Veteran User
Posts: 5010
Joined: Sat Apr 21, 2007 8:54 pm

Re: QTGMC deinterlacing method

Postby mduell » Tue Jun 05, 2012 5:35 pm

Zardoz wrote:Thanks for those suggestions, I've tried the 7:2:0:4:30 and really like the results. Could someone please break the settings down for me? Does this config use EEDI2?


https://trac.handbrake.fr/browser/trunk/libhb/decomb.c lines 13 - 75

Zardoz
Posts: 9
Joined: Mon May 14, 2012 5:00 pm

Re: QTGMC deinterlacing method

Postby Zardoz » Tue Jun 05, 2012 10:57 pm

Will I be seeing better results if I replace 7 at the front with 8 or even say 25?
-------------------------------------------------------------------------------------------
okay, mode 25 rules. Very slow, at least 6-7 times a slow as 7 but the image is very sharp, file size increases by about 3% (with the settings I use, so it may vary). Since I use -3 -3 deblock the blockiness becomes quite prominent even on the not-so-blocky DVD sources, so increasing deblocking strength might save some space as well. I believe this topic may be closed now since my original query is answered. QTGMC is probably at least as slow as mode 25 and the quality gains if any would be hard to notice (at least for DVD sources).

Zardoz
Posts: 9
Joined: Mon May 14, 2012 5:00 pm

Re: QTGMC deinterlacing method

Postby Zardoz » Sat Jun 16, 2012 11:06 am

Seems like my settling this topic's been a little premature. I've been playing with QTGMC from within the megui wrap and the "Slow" setting speed well exceeds Handbrake's mode 25 decomb. I get roughly 0,7 fps on a given video file with mode 25 and almost 5 fps with QTGMC Slow with the same file. Quality-wise it's hard to tell which one is better, but the speed boost is most welcome, QTGMC is actually usable while mode 25 not so much.

So QTGMC would still be a very welcome addition to Handbrake, especially since Handbrake's interface is so much more straightforward and easy to use.

Update. Slower QTGMC still yields me a healthy 3 fps (on my Athlon X4). And that was me not using multithreading with Avisynth, 50% faster with it :-)
---------------------------------------------------------------------------------------------------------------------------------------------------
Actually I think the "Slow" QTGMC does significantly outperform mode 25 quality-wise, I love the "retain noise" option as well, size soars with crf 18 and psycho-visual trellis 0,25 but the image quality is well beyond source (considering on-the-fly player deinterlacers). So yeah, QTGMC is a very welcome feature indeed.

Downgraded286
Posts: 10
Joined: Mon Nov 16, 2015 3:26 am

Re: QTGMC deinterlacing method

Postby Downgraded286 » Mon Nov 16, 2015 3:36 am

Found this thread with the Search function.

In trying to encode an interlaced South Park DVD I ripped, I had some serious problems. With Decomb set on "Bob", I still got some interlacing artifacts. My search eventually led me to the complicated AviSynth tool & QTGMC, however, AviSynth spits out a huge 40GB file, and drops audio, subtitles, and chapter markers. I then have to merge the video from the file AviSynth made with the audio from the origional interlaced file with MKVToolNix, which spits out another massive file. And then, Handbrake doesn't load it (it will load the file AviSynth made, and other files I made with MKVToolNix, but NOT the files I try to make in MKVToolNix consisting of the AviSynth output and the origional file it came from).

Anyways, having a QTGMC filter in Handbrake would bypass all that complicated crap and make for some real nice (and simple) deinterlacing. The quality is so much better than what Handbrake can do, at least for South Park... and animation in general as I understand.

musicvid
Veteran User
Posts: 2848
Joined: Sat Jun 27, 2009 1:19 am

Re: QTGMC deinterlacing method

Postby musicvid » Mon Nov 16, 2015 8:55 am

You've tacked on to a 3.5 year old thread that has little or nothing to do with its title.
For the last time, Handbrake does not support Avisynth filters.
QTGMC is far from the holy grail you make it out to be; it is neither "nice" nor "simple" as you fantasize.
It is a patchwork of code that is old, cumbersome, deathly slow, and complicated. It is only slightly better than Handbrake decomb, and only in some instances. In the time since this thread was written, the doom9ers have since moved on to greener pastures.

That said, show the developers your code patch in a new thread, and they will be happy to look at it.

If this is actually a disguised support request, post in the appropriate forum with logs and examples as required.

Downgraded286
Posts: 10
Joined: Mon Nov 16, 2015 3:26 am

Re: QTGMC deinterlacing method

Postby Downgraded286 » Mon Nov 16, 2015 2:47 pm

Firstly, about the old thread... I realize its age. As I said, I found the thread via the Search function as per the forum rules, rather than posing a duplicate thread. Additionally, I fail to see how it has little or nothing to do with the thread title. I'm not asking for/suggesting AviSynth support, I'm suggesting adding QTGMC support to Handbrake as the OP suggests, though I could be misunderstanding something here... at this point in time I see QTGMC as a deinterlacing method, not an AviSynth filter. It becomes an AviSynth filter if you use it with AviSynth, but if QTGMC were added to Handbrake, and you didn't have to use AviSynth to use it, it wouldn't be an AviSynth filter...

Secondly, QTGMC is a lot better than Decomb in Handbrake, at least, in my experience with South Park. With Decomb in Handbrake, image quality took a dive and the filter didn't catch all the interlacing/combing artifacts. QTGMC left the image quality alone and, in my testing thus far, got rid of all the artifacts. QTGMC isn't that slow either. I am someone who highly favors quality over encoding speed. As long as my encodes aren't running at 2FPS, I'm okay with it. For me, QTGMC ran at around 38fps, which is faster than my encoding with Handbrake the way I have it set up. My processor, by today's standards, isn't all that great, either... so it can't be that bad.

You say people on Doom9 have moved on from QTGMC. It's the best I found (it was recommended to me on VideoHelp very recently) so far... but if you know of a better method, please let me know. I agree that it is very cumbersome... the steps I had to take in order to even use QTGMC at all were far from simple.

musicvid
Veteran User
Posts: 2848
Joined: Sat Jun 27, 2009 1:19 am

Re: QTGMC deinterlacing method

Postby musicvid » Mon Nov 16, 2015 7:02 pm

Look for posts by Nick Hope on doom9 and Sonycreativesoftware if you are interested in the latest regarding QTGMC. Nick has also dedicated some webpage tutorials to the subject.

The Handbrake developers' interests in the idea are unknown at this time, so I will graciously defer your question…

Downgraded286
Posts: 10
Joined: Mon Nov 16, 2015 3:26 am

Re: QTGMC deinterlacing method

Postby Downgraded286 » Tue Nov 17, 2015 1:49 am

I see. It's a feature I would very much like to see added to Handbrake, though I appreciate your referrals.


Return to “Feature Requests”

cron