LOW LIGHT TESTS

3 SETTING FILES:

1. STOCK
2. 66M AQ2 CHRIS AUG. 29th
3. 88M AQ2 MAX VAR STRAY

All conditions are constant:
Light: Daylight Lamps
f-stop: f/5.6
ISO 320
Shutter: 1/250
stock 42
Camera reports 3 stops under exposed
Motion tests were done on a motorized tripod base.
The speed control for motion was fixed and the same for all.
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Stock:
min i-frame: 420K
max i-frame: 476K
ave p-frame: 174K
ave b-frame: 47K

Images attached below:
stock static.png
stock Motion.png
stock chart.png

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66M AQ2:
min i-frame: 786K
max i-frame: 876K
ave p-frame: 480K
ave b-frame: 250K

66 AQ2 static.png
66 AQ2 motion.png
66M AQ2 chart.png

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88M AQ2:
min i-frame: 801K
max i-frame: 943K
ave p-frame: 533K
ave b-frame: 287K

88 AQ2 static.png
88 AQ2 motion.png
88M AQ2 chart correct image.png (Note ignore the first 88M A2 image. It's incorrect.)

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SUMMARY AND FINAL THREE WAY ANALYSIS IMAGE (STATIC)

Based on the amount of detail, low light images can suffer.
Detail scenes such as landscape with trees and grass will ask for a higher bitrate
to resolve the complex fine detail. Shadow detail will be the first to go which causes detail loss
and smearing from macroblocking in the shadows.
I chose to shoot this test on my bass traps front cloth. The cloth has "some" fine detail
which forces a higher bitrate. Granted, the bitrate is not at it highest limits, but is reasonably
high enough to show differneces between the stock 22Mb/s settings compared to 66M and 88M.
Both 66M and 88M are real close in this example. The stock setting falls short here as you can see.

Check the ALL THREE COMPARE.png static image file for a quick three way comparison.

Stray,
Yes, I remember Chris mentioned the lack of color in the pappas chart a while back.
These look excellent and should be very helpful.
thanks!

@Stray Do you have a softcopy of the color test chart? Can you share it please?

Oh. I was looking at those files via iPhone. I'm seeing them in a big screen now. Thanks.

Houston, we have a problem...

I've been testing driftwood's 55M 1080 60i settings, and there is a unique problem I have not seen on any of the 24P patches. The noise varies in a three frame cycle - Frame 1 has high resolution noise (good), Frame 2 has blurred noise (bad), Frame 3 has blurred noise (bad), and then the cycle repeats.

Here is a Photoshop TIF with 4 layers, each layer being a consecutive frame. This is a 1:1 crop at ISO 6400. As you turn the layers on and off, you can see the changes in the noise. Look in the orange area of the far building and the greenish area of the near house.

[url]http://www.sendspace.com/file/9s5zg6[/url]

This 3 frame cycle is not unique to driftwood's 55M. Chris's 32M 1080 60i also has it. It's obvious that interlace is a different animal. And this is definitely noticable when you watch the movie at speed. The picture really does appear smeared because the blurred frames outnumber the clean ones 2:1.

I ran these clips through stream parser and there is no indication that anything is askew. This is one of those times where real world testing is critical.

Progressive mode is clean. This is an interlace problem only.

RE: stock mode - I examined some pre-hack nighttime shots and I do indeed see something similar, EXCEPT it's one clean frame follwed by fourteen smeared frames - in other words, the GOP 15.

What's wierd with the current problem is neither of the settings is a GOP 3 - Chris's 32M is GOP 15 and driftwood's 55M is GOP 30.

I don't think anything's wrong per say, at the stock setting. That's just what 17 mbps 60i GOP 15 looks like.

I use an old setting that @vitaliy suggested at the very top of this topic. I know, it probably doesn't give all the nice values as the new tweaks do, but the images look good to me and the files are spanning at 24H:

44/35 gop12 aq3

Nothing else patched.

EDIT: even 50i runs at 35mbit/s. Not as nice as 24p but better than the original setting.

@Tomaso Hell, I can't find where the settings were posted. I went through all the old topics that I could think of. the only thing close to that is this post by @OSGondar: http://www.personal-view.com/talks/discussion/comment/11765#Comment_11765

@stonebat mentions below to stay below 44. Maybe that is how I assembled this setting? Tricks of the brain?

I attach my ini. But I suggest, you stick to @cbrandin's settings, as they are all tested throughly. The ones I got are not, as I work on a mac and don't have the software to stream parse and what else. Only thing I am saying is, I like the image that is coming out and the files are spanning. i50 FSH with 44M is not working – only FH.

@Ralph_B Nice testing mate. Awesome. What would you say if I told you we just found another 14% performance increase in i frames and lower bitrate for GOP1 ?

I'll be damned if I can get 1080/60i to work on GOP1 - shame cus reading your smear test I have to agree. It seems just as soon as I fix 720p60, 1080i60 goes crud on me. Ive got every other setting working on GOP1 bar that bleeder... I'll keep trying... :-) May have to try a GOP30 on it for now just to enable people to use it and with less smears.
The problem it seems is 1080i60 is remarkably underpowered - by the buffer charts that is. So I'm trying very hard to balnce out the bitrate between 720p60 and 1080i60, bloody ridiculous. 108050/720p50 is fine!

@neveraholiday Thanks! I will test, but probably stick to Cris's 44/32