PDA

View Full Version : AutoGK as the ultimate quality enhancer?


eirikso
26th May 2004, 22:39
When using AutoGK with a forced horizontal resolution of 1024 pixels and with a file size of 2-3 GB the final XVID file is actually looking better than the original.

This sounds strange, it is hard to believe that a recompressed movie looks better than the original. However, the original DVD was made to play back on an interlaced TV screen. The XVID file is filtered and deinterlaced for optimal playback on a computer.

As long as I haven't set up ffdshow and any advanced realtime playback filtering in my DVD software it is absolutely possible to recompress into a movie that actually looks better than the original when played back by a computer.

This leads my thoughts into something interesting:

How about making an "extreme quality" AutoGK? In addition to the very nice deinterlacing and filtering it is already doing it could add some advanced framerate-doubling and interpolation.

I have managed to make the most smooth playing video I have ever seen by using a technique from this page to interpolate my footage up to "true" 50fps:
http://www.100fps.com/

In addition to this I have managed to get amazing qualities by using ffdshow set up by a guide on this page:
http://htpcnews.com/main.php?id=ffdshowdvd_1

But, making the 50fps movie was time consuming and involved a lot of different steps. And, using ffdshow soon maxed out my CPU.

The solution could be "the ultimate AutoGK quality enhancer": Utilize the fact that XVID can give better quality at a smaller file size and make a setting that will generate high definition-looking extremely smooth 50fps video files of a regular DVD at a size that is about the same or smaller.

_eirikso

eirikso
31st May 2004, 09:21
I have experimented a little bit more with the deinterlacing that is described at www.100fps.com

I use dgmpgdec106 to make a d2v-file and use this script in AVISynth:

--------------------
loadplugin("C:\Program Files\DVD2AVI dgmpgdec106\DGDecode.dll")
mpeg2source("movie-name.d2v")
separatefields
--------------------

In VirtualDubMod I simply add the DeinterlaceSmooth-filter from Gunnar Thalin. Voila: a 50fps incredebly smooth playing movie.

Is there a possibility that it in a future release would be possible to customly add filters in VirtualDubMod and commands in the AVI-synth scripts so that I could use AutoGK to create my 50fps-files?

However, in this case I guess AutoGK would have to do a lot of things different, because the final movie is 50fps. I guess both the sound and the subtitles would need some work...

_eirikso

len0x
31st May 2004, 11:15
Not that its not fun, but creating custom frame-rates from AutoGK is not something I wanna persue due to compatibility reasons.

henryho_hk
7th June 2004, 01:34
I think it is a brilliant idea!

We have AVPC with HDTV outputs already. People are using them to drive their 3-lens projects at home. However, these real-time hardware are very expensive. AutoGK is, on the other hand, free.

Once we have HD AVI, we shall have standalone MPEG4 HD players, e.g. 720p, 1080i, 1080p output. Who needs HD WMV when we have HD AVI?

len0x
7th June 2004, 10:44
Having HD output from HD input is one thing, having HD output from DVD is totally insane idea...

eirikso
7th June 2004, 15:07
Of course, making true HD from a standard definition DVD is impossible. To get the full potential of a high resolution screen or projector you need true HD input. The closest we get today is WMV HD. At NAB in Las Vegas this year they demonstrated this several places and it looks beautiful.

However, the best equipment you can get today for playback of a standard definition DVD is actually a powerful PC with the right software.

The standard DVD has a resolution of 720x576 (PAL) or 720x480 (NTSC). By using advanced realtime filtering you can interpolate the pixels to simulate a higher resolution. If you at the same time apply advanced sharpening and other filters you can get a quality that looks far better than a simple "enlarge-the-pixels-to-fit-my-big-screen"-method. In addition to this you can apply advanced processing to compensate for the fact that 25 or 30 fps interlaced is not the best framerate either.

So, yes - making true HD from a standard DVD is both insane and impossible. However, it is possible to tweak DVD playback to give a better quality than an unprocessed standard playback would give.

Today, people do this by using ffdshow in realtime while playing back the DVD. This will only work if you have a very powerful CPU. My original thought was to find a system that could help me doing the advanced filtering while recompressing, so that I do not need that much processing power for playback.

I get excellent results today by using AutoGK, forcing the horizontal resolution to 1024 pixels and setting a file size between 2 and 3 GB.

The idea was to go even further and start experimenting with more advanced filtering, interpolation and deinterlacing.

This was meant as a suggestion. AutoGK is a very powerful tool. It is amazingly easy to install and operate considering the advanced applications and methods that are working in the background. I think I have read something about plans for support for configuration files. Maybe that would open possibilities for running AutoGK in the same user friendly way, but add that one little filter to the VirtualDub work that is done in the background...?

_eirikso

len0x
7th June 2004, 17:38
Originally posted by eirikso
The idea was to go even further and start experimenting with more advanced filtering, interpolation and deinterlacing.


This is exactly what AutoGK was not meant for...

eirikso
8th June 2004, 08:23
I understand that if I want to do advanced experimenting the best way is to do it manually in VirtualDub, AVISynth etc.

But, my plan was that YOU, the creator of AutoGK should spend huge amounts of time experimenting with the ulitmate deinterlacing and filtering solution. After a couple of months experimenting you give us one small and easy option in AutoGK called "Extreme Quality Backup".

...kidding...

I'll keep using AutoGK and really appreciate the combination of quality and ease of use. I understand that making huge amounts of settings and advanced possibilities is not the focus of that kind of tool. However, I can dream on... The ease of AutoGK _and_ the possibility to throw in a filter and some adjustments.

_eirikso