lumi masking

[iago]

Hi everybody,

I wonder if it's time to say our last words (or to share our opinions and experiences once again) on the formerly "handle-with-care" option, lumi masking, with Koepi's 08082002-1 build. I recall that not a long while ago lumi masking in both passes was a big no-no.

And today... is it one of our generally-agreed-upon issues that it is better to use lumi masking in both passes for a better curve treatment (as Koepi advised for the test encodes when he released the 08082002-1 build) Or is it still an option to *handle with care*, likely to ruin some encodes and produce artifacts, without which you can feel much safer?

I'd be very pleased if you share your opinions on this subject.

best regards,
iago (still unsure )

[ookzDVD]

@iago,

I'm just finishing my Kate and Leopold, with Koepi's latest build
08082002, and luma enabled in the both pass.

I think the result is fine (at least for me).

[rui]

I also have used lumi, both the old(new) and the new (old) code , in both passes, and never had problems with it.

In the case of the old(new) code, the one that created such a fuss in SPR, i never encoutered those problems, but like i said in one post, i never encoded SPR with it. But, after those events, i got some movies i had encoded using it, and looked with special attention to the most darker scenes, and must say that i could spot some imperfections, mostly blocks jumping around in the dark.

Using the new (old) lumi code, i already encoded Galdiator, using ogg quality 0,4 sound, to 1 cd , and must say that, after browsing the movie a little, for a 1 cd encode, it looks mighty good. But i didn't watched the all movie yet.

So my vote is for lumi in both passes.

[BiaTch 5.0]

I used 27072002-1 to encoded from hell (PAL/Field De)both passes & I got pinky arifacts in the background then just second pass and all was fine.

[iago]

@BiaTch 5.0

I was especially referring to the 08082002-1 build .

thanks everybody,
iago

[rui]

Originally posted by iago
@BiaTch 5.0

I was especially referring to the 08082002-1 build .

thanks everybody,
iago

To BiaTch 5.0: I believe that the 2707 build was using the old (new) lumi code. Maybe that's the cause of your results. Did you tried with the new build?

[iago]

@ookzDVD and rui

Well... I generally hold the same opinion as you, and my vote is for lumi masking in both passes too . Still, I'll do another test encode (to make myself absolutely believe in this) with the 08082002-1 build. Two rips of the same movie, heading for 640000 kb video size with the exact same parameters (without AltCC in order not to put the blame on it later ), except that one will be with lumi masking in both passes, and the other with no lumi masking at all.

Then I'll compare the results in terms of both visual quality/artifacts especially in dark scenes and compressibility/average quants. If I notice any problems after watching and frame-by-frame analyzing both encodes, I'll let you know, together with the screenshots for comparison.

But I guess it will take some time, 'cause currently I've already been doing some other encodes.

with my best regards to all,
iago

[iago]

After Koepi's reply to my question in the "Results of some Alt.CC testing" thread, which was about altCC and default two pass CC, I decided to make the above mentioned test about lumi masking using the altCC parameters Koepi suggests:

altCC: medium aggression/high500/low90/strength30/I-frame boost: 0/payback delay: 250

so long,
iago

[BiaTch 5.0]

Originally posted by rui


To BiaTch 5.0: I believe that the 2707 build was using the old (new) lumi code. Maybe that's the cause of your results. Did you tried with the new build?

No, I have not got the dvd any more, but if I get it again I'll show my results.

[iago]

Hello everybody,

Here are the results of the lumi masking test done with the 08082002-1 build. The same movie is encoded twice, with the exact same parameters, except that in one encode lumi masking is used in both passes, and in the other no lumi masking is used at all. Respectively, I'll refer to these encodes as "LUMI" and "NOLUMI" here and in the screenshots I provide for comparison.


Movie: The Score (119 min)
resolution/resize: 640*272/neutral bicubic
video size: 645000 kb

First Pass:
UltraHigh
H.263

Second Pass:
UltraHigh
Modulated
Min-Max I-frame: 2-4
Min-Max P-frame: 2-8
I-frame boost: 0
Below I-frame: 10
I-frame bitrate reduction: 30
Bitrate payback: 250 (bias)
AltCC: medium/500/90/strength:30
Enabled automatic bonus bias calc.

Max-Min I-frame intervals: 250-1 (both passes)
SCD threshold: 50 (both passes)

credits: 31quant


Results (LUMI)

DebugView analyzer for XviD codec v0.10 by MoonWalker
e-mail : s_ilias@gmx.net

Quantizers Analisis
---------------------

Quantizers Used For Movie :
------------------------------
Quant 2 Used : 2783 Times, Percentage Used : 1.63%
Quant 3 Used : 101929 Times, Percentage Used : 59.86%
Quant 4 Used : 61221 Times, Percentage Used : 35.95%
Quant 5 Used : 3476 Times, Percentage Used : 2.04%
Quant 6 Used : 519 Times, Percentage Used : 0.30%
Quant 7 Used : 258 Times, Percentage Used : 0.15%
Quant 8 Used : 99 Times, Percentage Used : 0.06%

Average Quantizer Used for Movie : 3.402

Quantizers Used For Credits :
--------------------------------
Quant 31 Used : 8293 Times.

MPEG Quantization Type Used 113005 timed, Percentage Used : 63.28%

H.263 Quantization Type Used 65573 timed, Percentage Used : 36.72%

Quantizers prevented from rising too steeply 0 times


Intra-Frame (Key-Frame) Quantizers
------------------------------------

Movie
-------
Quant 3 Used : 536 Times, Percentage Used : 79.29%
Quant 4 Used : 98 Times, Percentage Used : 14.50%

Credits
---------
Quant 31 Used : 42 Times, Percentage Used : 6.21%

Number Of Consecutive I-Frames : 9

Inter-Frame (P-Frame) Quantizers
------------------------------------

Movie
-------
Quant 2 Used : 2783 Times, Percentage Used : 1.56%
Quant 3 Used : 101393 Times, Percentage Used : 56.99%
Quant 4 Used : 61123 Times, Percentage Used : 34.36%
Quant 5 Used : 3476 Times, Percentage Used : 1.95%
Quant 6 Used : 519 Times, Percentage Used : 0.29%
Quant 7 Used : 258 Times, Percentage Used : 0.15%
Quant 8 Used : 99 Times, Percentage Used : 0.06%

Credits
---------
Quant 31 Used : 8251 Times, Percentage Used : 4.64%


Frame Analisis
----------------

Number Of Intra-Frames (Key-Frames) : 676
Number Of Inter-Frames (P-Frames) : 177902
Total Number Of Frames : 178578

0.38% of the Movie is Intra-Frames (Key-Frames)
99.62% of the Movie is Inter-Frames (P-Frames)


Size Analysis
----------------

1-Pass Size : 1210679771 Bytes or 1182304 KBytes
Scaled Size : 656193554 Bytes or 640814 KBytes
Actual Size : 656176664 Bytes or 640797 KBytes

Usefull Statistics
------------------
Compressibility : 54.20%
Relative Quality of XviD avi : 58.79%
Absolute Quality of XviD avi : 95.79%


Results (NOLUMI)

DebugView analyzer for XviD codec v0.10 by MoonWalker
e-mail : s_ilias@gmx.net

Quantizers Analisis
---------------------

Quantizers Used For Movie :
------------------------------
Quant 2 Used : 1704 Times, Percentage Used : 1.00%
Quant 3 Used : 93312 Times, Percentage Used : 54.80%
Quant 4 Used : 73227 Times, Percentage Used : 43.00%
Quant 5 Used : 1925 Times, Percentage Used : 1.13%
Quant 6 Used : 113 Times, Percentage Used : 0.07%
Quant 7 Used : 3 Times, Percentage Used : 0.00%
Quant 8 Used : 1 Times, Percentage Used : 0.00%

Average Quantizer Used for Movie : 3.445

Quantizers Used For Credits :
--------------------------------
Quant 31 Used : 8293 Times.

MPEG Quantization Type Used 103309 timed, Percentage Used : 57.85%

H.263 Quantization Type Used 75269 timed, Percentage Used : 42.15%

Quantizers prevented from rising too steeply 0 times


Intra-Frame (Key-Frame) Quantizers
------------------------------------

Movie
-------
Quant 3 Used : 1218 Times, Percentage Used : 86.75%
Quant 4 Used : 144 Times, Percentage Used : 10.26%

Credits
---------
Quant 31 Used : 42 Times, Percentage Used : 2.99%

Number Of Consecutive I-Frames : 51

Inter-Frame (P-Frame) Quantizers
------------------------------------

Movie
-------
Quant 2 Used : 1704 Times, Percentage Used : 0.96%
Quant 3 Used : 92094 Times, Percentage Used : 51.98%
Quant 4 Used : 73083 Times, Percentage Used : 41.25%
Quant 5 Used : 1925 Times, Percentage Used : 1.09%
Quant 6 Used : 113 Times, Percentage Used : 0.06%
Quant 7 Used : 3 Times, Percentage Used : 0.00%
Quant 8 Used : 1 Times, Percentage Used : 0.00%

Credits
---------
Quant 31 Used : 8251 Times, Percentage Used : 4.66%


Frame Analisis
----------------

Number Of Intra-Frames (Key-Frames) : 1404
Number Of Inter-Frames (P-Frames) : 177174
Total Number Of Frames : 178578

0.79% of the Movie is Intra-Frames (Key-Frames)
99.21% of the Movie is Inter-Frames (P-Frames)


Size Analysis
----------------

1-Pass Size : 1265838928 Bytes or 1236170 KBytes
Scaled Size : 656193878 Bytes or 640814 KBytes
Actual Size : 656182560 Bytes or 640803 KBytes

Usefull Statistics
------------------
Compressibility : 51.84%
Relative Quality of XviD avi : 58.06%
Absolute Quality of XviD avi : 95.67%

-----------------------------------------------------------

Finally, I'm making no comments this time, and leaving the evaluation job up to you . Also I'm providing screenshots (taken in VirtualDub) of both encodes (LUMI/NOLUMI) for those who are interested.

so long,
iago

[iago]

Sorry for the double post; it was not my fault, though. (Must be some problem occured related with the "preview reply" button.) Two posts above are exactly the same .

Hope the screenshots attachment gets approved soon so we can talk about the results more accurately.

best regards to all,
iago

[Koepi]

Which double post?

Just kidding. I delted one of them

Regards,
Koepi

[iago]

@Koepi

LOL! Either need my glasses or have to sober up soon . Thanks anyway.

iago

[iago]

Hello again,

Well, after so much trying and spending long hours on test encodes and after watching both encodes (LUMI and NOLUMI) very carefully, I would like to comment a bit on the results.

First of all, it is very clear that using lumi masking in both passes is very helpful in terms of increasing compressibility (LUMI: 54.20%, NOLUMI: 51.84%) and in terms of reaching lower quantizers (obviously more 2 and 3 quantizers) for the movie.

Secondly, comparing the two encodes frame by frame and judging by (only) the screenshots (of the darkest and most likely-to-be-problematic scenes) would be absolutely misleading (after all, you can't see much difference, can you? ), since when you watch and compare the two encodes (using ffdshow and of course choosing "decode using XviD" in the codecs tab and selecting "IDCT: XviD" in the Miscallenous tab), you can't spot any quality loss or artifacts in the "both passes LUMI" encode.

Next, the settings used in the first and second passes and the AltCC parameters (suggested by Koepi) really seem to work fine and both encodes (LUMI/NOLUMI) are really impressing and of pretty high quality .

Finally, of course I choose to keep the "both passes LUMI" encode for my 1cd rip (with 0.100q ogg) of this movie. And my vote is now (with much more certainty) for "lumi masking in both passes" .

best regards to all,
iago

[ookzDVD]

@iago,

Thank you for your testing, I really apreciate that,
and I really support your test result.

[MaTTeR]

Originally posted by BiaTch 5.0
I used 27072002-1 to encoded from hell (PAL/Field De)both passes & I got pinky arifacts in the background then just second pass and all was fine.

I'm actually seeing these artifacts also on 3 out of the last 6 movies I ripped using the 08-08 build. I thought the culprit might be the alt-cc settings so I disabled and still seeing the same issue. Hope to post full details and screenshots about it this weekend.


In regards to Lumi...I've never stopped using it since day one on both passes. It was always clear to me the advantages of using it, especially since the old code provides more compressibility over all. Remember, lumi-masking is going to work on bright scenes just as well as drak scenes. So for a bright movie(Mary Poppins? LOL), you should see some nice results with it as well.

[BiaTch 5.0]

Originally posted by MaTTeR


I'm actually seeing these artifacts also on 3 out of the last 6 movies I ripped using the 08-08 build. I thought the culprit might be the alt-cc settings so I disabled and still seeing the same issue. Hope to post full details and screenshots about it this weekend.


In regards to Lumi...I've never stopped using it since day one on both passes. It was always clear to me the advantages of using it, especially since the old code provides more compressibility over all. Remember, lumi-masking is going to work on bright scenes just as well as drak scenes. So for a bright movie(Mary Poppins? LOL), you should see some nice results with it as well.

Have you tried encoding with Lumi disabled or only In second pass?.

[MaTTeR]

Originally posted by BiaTch 5.0

Have you tried encoding with Lumi disabled or only In second pass?.

I actually tried with it disabled and still had nasty artifacts appearing. I have not tried just using it in the 2nd pass alone though. I'll give that a shot before I post the screenshots tomorrow.

[Koepi]

There might be no need for screenshots, it's possibly a bug which is investigated ATM.

Hopefully the fix is in CVS soon

Regards,
Koepi

[MaTTeR]

Thanks so much Koepi Do let me know if you need the screenshots and encoding details.