Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion.

Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 

Go Back   Doom9's Forum > Video Encoding > MPEG-2 Encoding

Reply
 
Thread Tools Search this Thread Display Modes
Old 7th May 2004, 17:51   #1  |  Link
DDogg
Retired, but still around
 
DDogg's Avatar
 
Join Date: Oct 2001
Location: Lone Star
Posts: 3,058
Some test results - Effects of matrices on filesize

The results of some tests on how different matrices effect filesize. Method used is Q28 OPV encode Min 300/Max 9000
creating a 1% sample using 'SelectRangeEvery(1200,12)' in a standard script using Mpeg2dec3DG.dll. Encoder used was
CCE 2.67.00.27 set for 16:9 with progressive settings. "D-ABR" is predicted bitrate for full encode derived from
the filesize of the 1% sample. I believe these results to be accurate within a range of +/- 2.5%.

Code:
                                                 Sample        D-ABR 
Source 23.976 Frames = 138,965                  FileSize       (Kbps)  Deviation From CCE
                                                 (bytes)               Standard Matrix
       
ISpy_Sample_6of9-24_Matrix.mpv			38,429,376	5304	+ 47.05%
ISpy_Sample_Mpeg_Std_Matrix.mpv			30,605,780	4224	+ 17.11%
ISpy_Sample_CCE_Std_Matrix.mpv			26,133,200	3607	   0.00%
ISpy_Sample_Notch_Matrix.mpv			24,118,552	3329	-  7.71%
ISpy_Sample_PackedDvd_Matrix.mpv		23,446,300	3236	- 10.28%
ISpy_Sample_Bach1_Matrix.mpv			23,371,776	3226	- 10.57%
ISpy_Sample_Jawor_1CD_LowBR.mpv	                22,394,472	3091	- 14.31%
		                                                             	     Same Matrix - Size reduction of Filtered vs. Non-Filtered
ISpy_Sample_6of9-24_Matrix_filter.mpv		29,430,004	4062	+ 12.62%   - 23.42%
ISpy_Sample_Mpeg_Std_Matrix_filter.mpv		23,229,660	3206	- 11.11%   - 24.10%
ISpy_Sample_CCE_Std_Matrix_filter.mpv		20,351,492	2809	- 22.12%   - 22.12%
ISpy_Sample_Notch_Matrix_filter.mpv		19,381,892	2675	- 25.83%   - 19.64%
ISpy_Sample_PackedDvd_Matrix_Filter.mpv		18,695,840	2581	- 28.46%   - 20.26%
ISpy_Sample_Bach1_Matrix_filter.mpv		18,657,748	2575	- 28.61%   - 20.17%
ISpy_Sample_Jawor_1CD_LowBR_Filter.mpv		17,957,524	2479	- 31.28%   - 19.81%
Note1: The 6of9 matrix is intended for use with XviD, so results when used with CCE MPEG2 may not reflect
its proper usage. I provided it as a few people had expressed a wish to try it with MPEG2.
Note2: "Filter" refers to a simple 'Undot().Deen()' combination.
Note3: I found the Jawor_1CD matrix in the XviD forum. Thread.

Last edited by DDogg; 8th May 2004 at 06:04.
DDogg is offline   Reply With Quote
Old 7th May 2004, 22:29   #2  |  Link
Teegedeck
Moderator, Ex(viD)-Mascot
 
Teegedeck's Avatar
 
Join Date: Oct 2001
Posts: 2,564
Hi,

interestingly, the HVS-best-picture matrix (talked about in that very same Javor-1CD-matrix thread) seems to be the best choice for strong compression although it most probably wouldn't score high in your test.

For quite a long time, now, I haven't tried any new matrices for low bitrates - your test makes me want to test the Bach and Javor matrices at last. Thanks!
__________________
It's a man's life in Doom9's 52nd MPEG division.
"The cat sat on the mat."
ATM I'm thoroughly enjoying the Banshee - a fantastic music player/ripper for Linux. Give it a whirl!

Last edited by Teegedeck; 7th May 2004 at 23:25.
Teegedeck is offline   Reply With Quote
Old 8th May 2004, 02:18   #3  |  Link
DDogg
Retired, but still around
 
DDogg's Avatar
 
Join Date: Oct 2001
Location: Lone Star
Posts: 3,058
T, I was thinking of you when I added the 6of9 I'll do the HVS-best-picture matrix, and maybe a few more and add the results because I'm still set up. Point me to what you would like to see.

/Add: Looks like I can't use the HVS-best-picture matrix because it has a value of 129 which CCE will not accept.

Last edited by DDogg; 8th May 2004 at 02:32.
DDogg is offline   Reply With Quote
Old 8th May 2004, 09:37   #4  |  Link
Boulder
Pig on the wing
 
Boulder's Avatar
 
Join Date: Mar 2002
Location: Hollola, Finland
Posts: 4,287
DDogg,

did you do any visual comparisons? I'd be interested in hearing your opinion as matrices are not discussed that often
__________________
And if the band you're in starts playing different tunes
I'll see you on the dark side of the Moon...
Boulder is offline   Reply With Quote
Old 10th May 2004, 04:13   #5  |  Link
DDogg
Retired, but still around
 
DDogg's Avatar
 
Join Date: Oct 2001
Location: Lone Star
Posts: 3,058
Boulder, nothing really fancy. Just scanning through the samples and looking for boogers. Since OPV varies bitrate to allow a more constant quality, video quality is not quite the issue that it is with specified bitrate based encodes. Still, some of the more severe matrices can do some nasty things. Surprisingly, since it returns one of the lowest bitrates, Jawor seems pretty good. I know your eye is better than mine. If you get time could you compare Jawor to Bach to Standard?
DDogg is offline   Reply With Quote
Old 10th May 2004, 17:46   #6  |  Link
Boulder
Pig on the wing
 
Boulder's Avatar
 
Join Date: Mar 2002
Location: Hollola, Finland
Posts: 4,287
Quote:
Originally posted by DDogg
If you get time could you compare Jawor to Bach to Standard?
Hrr..responsibility

Sure thing, I'm not exactly sure when I'll have the time but probably the next weekend. I do mostly low-bitrate MPEG-2 encodes (avg bitrate ~1500-2500kbps) so it'll be interesting to see how it comes out.

The matrix has to be modified a bit as three values are over 99 but that shouldn't really change anything. I don't know how MPEG-4's quants differ from MPEG-2's, I thought that a value of 99 would zero the corresponding frequency completely
__________________
And if the band you're in starts playing different tunes
I'll see you on the dark side of the Moon...
Boulder is offline   Reply With Quote
Old 10th May 2004, 21:54   #7  |  Link
DDogg
Retired, but still around
 
DDogg's Avatar
 
Join Date: Oct 2001
Location: Lone Star
Posts: 3,058
Quote:
I thought that a value of 99 would zero the corresponding frequency completely
Heck, don't get me to lying (Texan for, "I don't have a clue"). I just pasted the Jawor thing in at the last moment.
DDogg is offline   Reply With Quote
Old 11th May 2004, 07:24   #8  |  Link
Boulder
Pig on the wing
 
Boulder's Avatar
 
Join Date: Mar 2002
Location: Hollola, Finland
Posts: 4,287
Actually it seems that the coefficient can go up to 127, so no need to change a thing
__________________
And if the band you're in starts playing different tunes
I'll see you on the dark side of the Moon...
Boulder is offline   Reply With Quote
Old 18th May 2004, 20:37   #9  |  Link
manolito
Registered User
 
manolito's Avatar
 
Join Date: Sep 2003
Posts: 1,984
@Boulder
Did you find some time to do a comparison between Bach1 and Jawor_1? I did 2 encodes with Jawor's matrix, ultra low bitrate, and compared to the Bach1 matrix my Q dropped by about 5%. The quality looked quite good, but I do not have a direct comparison to another encode done with Bach. In Jawor's thread some people say that Jawor's matrix emphasizes grain, but I could not confirm this on my standard 28" TV.

Cheers
manolito
manolito is offline   Reply With Quote
Old 18th May 2004, 20:57   #10  |  Link
Boulder
Pig on the wing
 
Boulder's Avatar
 
Join Date: Mar 2002
Location: Hollola, Finland
Posts: 4,287
I didn't have the time to do any extensive testing, but I compared Jawor's matrix to KVCD notch. Compressibility was bigger with Jawor's but low-lit areas showed some DCT blocks. Sharpness was nearly the same. My opinion is that Jawor's could be quite good for TV caps (more noise in the source) whereas the notch matrix would suit DVD sources (usually clean sources) better.
__________________
And if the band you're in starts playing different tunes
I'll see you on the dark side of the Moon...
Boulder is offline   Reply With Quote
Old 19th May 2004, 03:03   #11  |  Link
DDogg
Retired, but still around
 
DDogg's Avatar
 
Join Date: Oct 2001
Location: Lone Star
Posts: 3,058
Well I am continuing to use Bach as it does less damage to the encode than Notch, IMO. Also using Bach results in a smaller file size and better Q within a given filesize. As always, I caveat the comments with the fact that my viewing method is an older 32 inch JVC.
Quote:
but I compared Jawor's matrix to KVCD notch.
At what bitrate? What Q? Was the bitrate matched to the source? Both encodes were done at the same Q using OPV, correct?

Last edited by DDogg; 19th May 2004 at 03:07.
DDogg is offline   Reply With Quote
Old 19th May 2004, 09:48   #12  |  Link
Boulder
Pig on the wing
 
Boulder's Avatar
 
Join Date: Mar 2002
Location: Hollola, Finland
Posts: 4,287
Hey, I have a 27" 4:3 TV set

For my analog capture test the average bitrate was ~1500kbps, resolution 704x576. Jawor's matrix gave a lower Q in CCE, I don't remember the exact values but it was a bit lower than 70 whereas the notch matrix gave a bit over 70. Jawor's matrix reduces the noise level quite nicely as even with Avisynth filters it's very hard to get a clean result without destroying the details completely. That's the reason why I favor it for encoding the captured clips. The noise in the source will keep the DCT blocks away at those low-lit areas of the image.

For the DVD test the avg bitrate was around 2200kbps, resolution 704x576 and Q somewhere between 20 and 30. To my eyes, the notch matrix gave a slightly sharper image. Like I said, the low-lit areas looked better with the notch matrix and that's the main reason why it is my choice for DVD sources.

Have you done any tests regarding this "dancing DCT blocks in low-lit areas" with Bach's matrix?

And yes, OPV was used in both cases with a little help from QCCE (where are the new versions?)
__________________
And if the band you're in starts playing different tunes
I'll see you on the dark side of the Moon...
Boulder is offline   Reply With Quote
Old 24th May 2004, 13:38   #13  |  Link
yaz
n00b ever
 
Join Date: May 2002
Posts: 627
@ddogg (teegy)
i've tested 16 matrices with mencoder all hvs included. they performed pretty well (as expected :-). it would worth to try them w/cce. bach1, jawor, avamat made me a hard time at higher bitrates but performed well in the lower region (<1500kbps). note, bach1 seems to be a slight mod of notch but the difference is significant as regards performance.
another funny thing. i've tried xvid default matrix too (xvid mpeg?) just for fun & it was striking good in the range 1500-2000. the same psnr as with mpeg standard but compressibility was higher (~10-15%!) give it also a try !
the bests
y
yaz is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 01:24.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.