autogk vs gk

[Broesel]

Hi everybody!
I wonder how big the difference between autogk and gk might be, regarding the quality of the output .avi
All in all they use both the same programs as besweet and virtual dub!
I'm no longer satisfied with my autogk results, but I surely would have my difficulties chosing the right bitrate, aspect ratio error and so on, if I witch sides! So do you think, I will do better setting these values by myself using gk, instead of leaving it up to autogk to take care for me of this?
Is there any way of analysing the output files, to get an objective comarison, which is better? I hate staring at my TV or Monitor, trying to make out which is sharper!
And do you know (roughly) how much space a mp3 takes, for a average movie, compared to AC3?
Thak you very much!
Broesel

[killingspree]

hi and welcome to the forum,

in short i think it is rather unlikely that you produce better files using gk instaed of autoGK off the start. autogk has been improoved a lot, so probably, if you do not like the results autogk gave you, you should probably rather go for more cds instead of another program.

that said, i have to add i'm a very happy gk user and still am of the opinion that i can produce slightly better results. but mostly i only use gknot because it lets me do dual audio stream avi files. so if you want to learn the real way how it is done, go ahead learn it, it's fun ;)

an objective comparison is always kinda controversial. there are tools that compare two ouputs for PSNR values (or alike), but honestly, the only judgment you can really trust is your own. ;)

an mp3 file, depending on the bitrate of course is rougly a third in size compared to the original ac3 file.

hth
steVe

[Broesel]

HI!
Thanks for your comment ! (More comments are most welcome)
By the way: no problem creating dual audio, using autogk: Read the guide - search for "F10" in it, and the right phrase will appear...
Broesel

[killingspree]

ouch... i got to read up on autogk ... thx for the hint ;)

one more question about your disatisfaction with autoGK: what do you not like about your autoGK encodes? perhaps we can help improve those...

[Broesel]

1.
Example: For several seconds, the head of a speaking person is shown. To the left and to the right of the head, I find pretty disturbing, large pixels of the background wall. And when the head turns, the wall seems to swim with the movement... seems to be undesiered side-effects of the encoding!?! Or is it the codec, and no program can handle this better than an other program can?

2.
For an action movie, setting the output to 4,5Gbyte (using autogk) to get a real good looking backup is useless: - autogk seems not to be able to create large output files like that. 3,5Gbyte was maximum I received, so far! But 3,5 is not a good size (I'd waste quite a bit of space on a 4,5DVD), and going for half of the 4,5Gbyte => see 1.

I was hoping to be able to solve things like that, using 3pass option (going for 2.250MB) or ordering larger output sizes! But I received already an answer on an other posting, concerning Xvid: No 3pass option possible - only with divX.
Right now, I'm trying to find out, what's best: 3pass divX or 2pass Xvid...
Thanks a lot! Hope you're with me - concerning my bad english :-))
Broesel

[killingspree]

hi again,

about 1): yes those are codec, or even sometimes source issues. xvid preserves a lot of detail and keeps the picture sharp and crisp, which some times on the other hand kind of creates bad effects on the background - like blocking and movement.

other codecs like divx rather soften the picture more, so you get less blockiness or background movement, but you will also retain less detail. i guess it will always be kind of a tradeoff - i personally prefer to keep as much detail as possible. in other words, i use xvid ;)

4.5 GB for an xvid avi (even with dual ac3) seems overkill to me. (also for divx and other codecs alike) - those codecs are simply not constructed for such high bitrates. if you really want these sizes i honestly would recommend to go for mpeg2 instead. if you use CCE for reencoding, you'll probably recieve better quality than using any mpeg4 codec.

hth
steVe

[dvd_maniac]

Or is it the codec, and no program can handle this better than an other program can?

I have been using Nero Recode for AVC H.264 mp4 files.

If you look at the codec comparison Doom9 just did, it seems to be the best codec to use. I do not know why you would use mp4 to only shrink the video a little. I shrink 2 hour action movies to around 850MB and can bearly, if at all tell the difference between the mp4 file and the dvd on my 57" Hitachi hdtv.

[Broesel]

Hello again!
Good to know these general things about the codecs!
But:
1. Nero Recode ... another program? another codec?
2. What are "AVC H.264 mp4 files" ?
Is there somewhere, I can read about the diffrences between mpeg2, mpeg4, H.264, and so on?
3. CCE ???

In case it's simplier that way:
I'd like to create 2 sorts of backups:
1. modern action movies (as matrix or lotr), dual ac3
2. everything else (as comedy-movies or. older movies)., dual mp3

For movies of 1.categorie, I thought I go for 2250Mb, for movies of the second categorie, I'd go for 1125 or 1500Mb...

Any recommandations?
Cheers guys! Thanks a thousand times!
Broesel

[jggimi]

1. Nero Recode ... another program? another codec?

Yes. Yes.

2. What are "AVC H.264 mp4 files" ?

AVC is a very recent advancement in the MPEG-4 standard.

Is there somewhere, I can read about the diffrences between mpeg2, mpeg4, H.264, and so on?

MPEG-4 can be read about in MPEG-4 Information (including AVC/H.264) (http://forum.doom9.org/showthread.php?s=&threadid=73022).

3. CCE ???

Cinema Craft Encoder, a popular series of MPEG-2 encoders from Custom Technology Corporation, ranging in price from a consumer version at around US$60, all the way to a professional encoding tool at around US$14,000. Doom9 has a forum (http://forum.doom9.org/forumdisplay.php?s=&forumid=37) for it.

Any recommandations? (sic)

dvd_maniac already suggested you review Doom9's MPEG-4 codec comparisons.

Here's the main link (http://www.doom9.org/codec-comparisons.htm).

[jggimi]

I thought I'd also take the time to describe the differences between AGK and GK, since that was your initial question.

AGK

AGK makes many decisions for you. While there are the so-called "hidden" options that allow for a little customization, for the most part it is a highly automated tool. Can output look lousy with AGK? Sure. The operator can make mistakes, such as forcing an improper fixed width, or selecting an improper output size for the content.

In your case, you might be happier if you merely selected a 1-pass quality-based encoding, and select 100% quality. Each encoding will be as large as it can possibly be for the selected width. I would recommend setting the width to "auto" to allow AGK to properly resize based on the display aspect ratio of the DVD.

GK

GK lets you make many of your own decisions; based upon compressibility tests of individual content, you may select different resolutions or different output sizes before encoding. With AGK, you cannot make these sorts of decisions with any a priori knowledge of the content's compressibility. You may see a recommendation to choose a different output size in the log, but by then it is too late.

GK allows you to use .avi input, which is something AGK cannot. With AviSynth (.avs) input one can also use any DirectShow compliant video format as input for GK, as well.

GK allows you to select all sorts of noise reduction filtration, or to edit AviSynth scripts and add your own adjustments to video content, or otherwise custom control the encoding.

GK can also be used as an AviSynth generator, for use with other encoding technologies or Non Linear Editing suites.

Summary

In the hands of a skilled operator, output from GK can certainly look better than the same output from AGK, because a human being can test and retest the content and make adjustments or add custom filtration to produce peak results.

In the hands of the novice, output from GK may look significantly worse.

[len0x]

At the moment for regular DVD-2-AVI conversion the only advantage that GK has that can make an impact on output quality (providing that AutoGK didn't misdetect the source) is:

- ability to use custom avisynth filters
- ability to use custom codec parameters (inclusing custom matrixes for XviD)

That's it. If you don't know exactly what you're looking for then AutoGK cannot be easily overtaken :)

P.S. AVI input will be on the way shortly for AutoGK as well.

[Broesel]

mhmmm. Seems like Autogk & Xvid is the better choise (the avi-input is of no interest for me, anyway)
.. on the other hand...
The codec-comparism makes me think about the nero-codecs.
That would mean another 100bucks for the stand-alone, or, the other option would be a TV-output at my PC and s.th like a water-cool-system (my PC is pretty noisy).
Uff, lord, things are starting to get complicated!
Cheers,
Broesel

[len0x]

Originally posted by Broesel
The codec-comparism makes me think about the nero-codecs.
That would mean another 100bucks for the stand-alone

That is a common mistake - AVC codec used by Nero Digital is not supported by any hardware chips yet. ASP codec wasn't even used in comprasion (it will be supported by new coming hardware though) and is inferior to XviD.

I think lots of ppl bought that trick :)

[Broesel]

https://www.siemssen-resale.de/shop/

...oder verwechsel ich da was!?

edit (by killingspree): translation: "...or did I mix something up?"

Broesel

[len0x]

I only assume you're asking what does it support? :)

There are two codecs in Nero Recode: ND ASP (sort of the same as DivX/XviD feature-wise), ND AVC (next generation of mpeg4 codecs). Player only supports ND ASP that was not used in codec shootout.

[killingspree]

@broesel: i've read through large parts of the website and although it does not explicitely say that it does only support mpeg4 asp - i'm fairly sure it is this way. everything else would probably generate a lot more press :)

anyway please refrain from writing in german here. this board's only language is english!!

thx

[Broesel]

Sorry 'bout that german phrase - wasn't written on purpos...
guess I will go for a TV-out graphic card to be able to use the latest codecs... that means I will get rid of my standalone Xoro 400pro... anyboy interested :-)
Broesel

[Taxidermista]

Originally posted by killingspree
hi again,
4.5 GB for an xvid avi (even with dual ac3) seems overkill to me. (also for divx and other codecs alike) - those codecs are simply not constructed for such high bitrates. if you really want these sizes i honestly would recommend to go for mpeg2 instead. if you use CCE for reencoding, you'll probably recieve better quality than using any mpeg4 codec.

hth
steVe

I don't think 4,5 GB are overkill if you encode an HDTV 1080i movie to a 1280x720 divx or xvid for example.

[killingspree]

Originally posted by Taxidermista
I don't think 4,5 GB are overkill if you encode an HDTV 1080i movie to a 1280x720 divx or xvid for example.

that wasn't what i was talking about... and i don't think Broesel had encoding HDTV in mind when he asked the question!

[Broesel]

All I want is to back up my DVD-movies. The quality shall still be suitable for the "next TV-generation" (LCD, Plasma or whatever). I don't want to complain in 5 years 'bout the lack of quality as I do today, concerning my VHS-videos... I'm not recording any movies that are shown on TV...
I will care about nero these days...
Broesel