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-   -   KVCD: Default Quantize Matrix is best? (http://www.digitalfaq.com/archives/encode/456-kvcd-default-quantize.html)

deltaboy 06-18-2002 09:12 PM

KVCD: Default Quantize Matrix is best?
 
just to let you all know,

i did some small tests with the new kVCD template and found that using the default settings work best. i tested with this and changing the B/P picture spoilage. leaving it at 0/0 and combining with the default quantize matrix, i produced the lowest amount of black/dark macros. 0/20 and Andreas gave the worst results (IMO).

lemme know what everyone thinks and if they have any arguments to discuss.
thx.

**note: these tests were performed on the Snatch DVD and with my own tweaked settings:

CQ 78 max: 2300 min: 300
B/P picture spoilage: 0/0
GOP: 1-18-3-1-48
detect scene change
default quantize matrix
use floating point DCT

PlaiBoi 06-19-2002 12:10 AM

hmm...sounds interesting. Can you possibly upload some samples comparing the two?

deltaboy 06-19-2002 12:14 AM

id be happy to, but where? i have no space to upload, unless someone is willing to help.

PlaiBoi 06-19-2002 12:45 AM

you can just upload this yahoo briefcase i made. :)

username: kvcdx
password: samples

http://briefcase.yahoo.com

Thanx.

Rookie 06-19-2002 04:38 AM

The 'Andreas Matrix' is optimized for high compression so its obvious that the picture quality is inferiour compared to the standard Matrix. Did you compare the filesize of your different samples(cant login to the briefcase right now)? Lower the CQ to 60 or even lower and compare again, I bet the sample with the 'Andreas Matrix' will improve compared to the standard matrix . TMPGEnc will get very brutal to the frame if the choosen quantize matrix exeeds the selected max Bitrate/CQ level.

For a great collection of quantize matrixes look here:

http://www.dvd-svcd-forum.de/phorum/...t=ST;f=18;t=47



I dont know exactly what B/P picture spoilage do but when I changed B spoilage from 20 to 0 in the kvcdx2(dont really remember which and what version) template the resulting file was bigger. Anyone knows more?







Rookie

Daagar 06-19-2002 10:10 AM

As mentioned above, it is the filesize of the resulting output that is important here. If filesize was of no concern, you'd probably be better off using CCE and going to mpeg2(svcd) with some crazy high bitrate. Of course, now every movie would take 2-4 cdrs. The beauty of the KVCD template is that it allows great picture quality _in the least amount of space_. Obviously, if you are shrinking something from 9GB to a mere 800meg, something is going to be lost somewhere.

PlaiBoi 06-19-2002 03:19 PM

The briefcase is fine...he hasnt uploaded the samples yet though. Im eager to see them.

deltaboy 06-20-2002 01:39 AM

sorry dude. im very busy. however... im on it!

deltaboy 06-20-2002 02:09 AM

k PLAIBOI, they have been successfully uploaded. lemme know if they are all correct.

im using powerDVD to test all my clips. look at the black backgrounds as well as the dark head at the end. i seem to notice less activity in the picture. the moving picture does not pixelate as much. it appears to be a cleaner picture in the 0/0 default clip.

another thing to consider is that the filesize is second to 0/20 default for the smallest filesize. this leads me to believe that my choice is the best, IMO.

prove me wrong, but im am very content with this configuration setting.

hope this helps and turns some heads. gl everyone.

Rookie 06-20-2002 09:40 AM

Maybe im hitting the cake here but imho there is no best choice that applies for all ocassions. I doubt that your settings allow 120 minutes on one CD and that is what its all about here.

To say it again. The big problem with the standard matrix is that it needs an minimum ammount of bitrate that is much higher than eg. the Andreas Matrix. In 2-Pass VBR mode going under that bitrate will make TMPGEnc to 'requantize' (more like raping that frame) again until the desired bitrate is reached. in CQ mode the resulting file would, depending on the settings, bigger or blockier. Finding the right matrix for an choosen average bitrate is an longish process but like Kwag proved its well worth the effort :D

So Im sure your samples(which I cant access at work) will prove you right but I also bet that with the 1 CD kvcdx2 template and the standard matrix you will get worse results in both quality and filesize.

Rookie

Daagar 06-20-2002 11:28 AM

As well... these clips were of just the opening screens of a movie. Lots of black backgrounds and white text, without much action or movement. While your settings do appear to be good for this brief part, how do they fare over the length of an entire movie? I'd be curious what happens if you did a similar test from a high action scene, or other suitable 30sec.

Timberwolf 06-20-2002 11:58 AM

I've read it somewhere around here Kwag saying that the andreas matrix takes care of the excellent picture quality whiet his GOP arrangement takes care of the the superb compression (or is it the other way around?):).

I don't agree with the original poster because I've also tried the default settings a lot of times because the result plays without any problem with my player. Alas, the picture is not as crisp and clear and the file size is a lot bigger as compared with the kwag template. So I decided to stick with the kwag template and try to solve the sound and video skip every 4 seconds in my player ............ and I think I got it solved.

deltaboy 06-20-2002 09:05 PM

ROOKIE is right on the button. there is NO best choice that will be the same for every encode. im just out there to find a happy medium for myself. i just post to help people and open up their minds.

yes, it is also true that my settings wont allow a long movie (120min+). i just use these settings because i find more movies average around the 85min-105min mark. ive never had to drop my CQ below 72... yet!

in regards to DAGGER, i chose the beginning sequence for my tests because when it comes to playing the whole movie on my standalone, i always look closely for the first little while. by the time the movie is 15min in, i couldnt care if i was watching a DVD, kVCD, VCD, or VHS, or whatever. when youre not looking for the imediate detail, most videos look pretty much the same (unless the obvious, of course).

all i wanted to do was to express my opinion and give people some leads so they dont have to go thru the enourmously lengthy proccess i had to go thru when i was a newb. these settings are acceptable for me and im going to leave them this way, slowly tweaking them as everything and everyone get a little smarter in this field.

take care!

PlaiBoi 06-21-2002 06:00 PM

After looking over these samples. The DEFAULT did seem to look better to me, BUT it seemed to "stutter" or lag in the beginning of the clip. The andreas did not have this "stutter", and the differance in quality was barley noticeable.


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