GH2 Cake v2.3: reliability and spanning in 720p, HBR, 24p, and VMM at 2-2.5x stock bit rates

pvdog

Thank balazer for creating the most ideal patch so far!

Inspired by your dynamic quantizer, I've created such a patch for my GF2 (I don't have a GH1/2). I don't like GOP 3, so I use GOP 6 and make the B frames as good as I and P like LPowell's Flow Motion (another most inspiring patch so far). To make 1080i60 absolutely stable (panning quickly from a very dark area to a very bright and detailed area such as pavement), I have to change the GOP table from:

10 20 20 10 0 0

to:

10 20 20 10 10 10

or:

8 16 16 8 8 8

What's interesting is: not just no more crash, the video look better with more contrasty (or darker) and sharper. I like this result, just wonder why. Balazer and others, could you please explain?

My other key changes:

FSH/SH Bitrate: 99000000 All Top Setting: 90000 All Bottom Setting: 80000 All Scaling Fallback: same as I/P/B

The idea is to make no any other bitrate limiting other than GOP table. The average peak data rate is about 48Mbps, absolutely stable so far, no failure yet even at the most difficult conditions where failed before, 4GB spanning fine with a 32GB Samsung microSD class-10 card. Even class-4 cards work fine, just no spanning.

I've tried 44000000 AQ4, 66000000 QP 30 worse B-frame and QP 35 same I/P/B and played with many other settings, nothing compares to this GOP table method.

My GF2 is now like a new born. Clicking on the donate button... few dollars make my $200 camera a $$$$ video gear, the freedom of configuring my own device and so much fun!

oronce

Thanks. I think I got it.

Mark_the_Harp

@balazer. Haven't tried Cake 2.0 because I use 1.2 and love it. Is 2.0 better for 24p (I'm talking image / motion quality here)? And if so, how exactly? Looks like the bitrate is lower in 2.0 so that's why I ask.

I would like to settle on a good setting, because at some point you have to stop trying these different settings and actually use them for real. For me, Cake 1.2 is the one I've been really happy with and the one I always return to.

nomad

For a documentary, I'd first think about intended screening. If aimed at (HD)TV, I'd rather go 1080i50 or 720p50. For the internet or the big screen it's 30, 25 or 24 (all progressive).

oronce

@balazer. Thanks a million for the info and for the work. 12 years ago I stopped working as assistant director on feature films and my last short movie is 20 years old and shot in super 16, so video is very new to me. I am planning to shoot a documentary in pal, so I will set it HBR pal. Thanks again.

balazer

Don't worry about stress. The encoder with these settings should handle whatever you throw at it. 1080i (FSH) will look like video due to the field rate of 50 fields per second. HBR mode will look more like film, because of the frame rate of 25 frames per second. Also, HBR is a lot sharper on the GH2 than 1080i is. 1080i needs to be displayed as interlaced, or de-interlaced for display progressively. If you just want to play files on your PC or upload to YouTube, HBR is the better choice (and switch from PAL to NTSC in the setup menu so you get 30 fps instead of 25).

oronce

@balazer. I tried two settings. 1st Creative mode on Manual movie mode, then on Motion picture: Rec Mode AVCHD (1080i) and Rec Quality: FSH. 2nd mode is HBR (don't have to select anything on "Motion Picture) Both are seen by StreamParser as 1080/50i. My GH2 is a pal one. Hope it's clear. About stress it appears on my last test that the bitrate was the highest as i was shooting in an almost completely dark room with almost no motion. Is bitrate meaningful in term of stress? Sorry for the candid question.

balazer

Thanks for the report, oronce. You seem to be confusing the mode names. Tell us exactly what you set in the menus, e.g. HBR PAL, or 1080i PAL FSH.

Duartix, it depends what you mean my stress. High detail that continually changes will induce high bit rates or QPs. Modest motion can cause unpredictable frames sizes.

oronce

@duartix. Ok, I will try. As for the difference between hbr and 1080i25p, I was able to check on my tv. HBR appears to be flashier, more video. Am I right or is it the vision of a novice.

duartix

@oronce : Unless you are using an extremely high shutter speed, violently moving the camera will not tax the encoder because there will be a lot of motion blur. There are 2 things that will tax an encoder: detail and non linear motion. Mix them both and it's better than a torture chart. Surf, grass or trees under wind are usually tough subjects...

oronce

I tested spanning on Extreme HD video 16GB / 30mb/s with Panasonic lens in violent movements. It spans for close to 50 minutes. it's great. I have a doubt. Being a pal country guy I tried HBR and Variable FSD 25p, my computer is old and I can't really check the difference. Waiting for the new computer! Is there a difference? Thanks and a great bravo to balazer who solved my duration problems. Thanks to every great tester & creator and hacker of this site.

leejb4

Any Updates On Cake 2.0? How are you guys liking it? Anyone have test videos shot with it?

feha

I tested spanning on Variable frame rate 300% works great ... Extreme HD video 32GB / 30mb/s

feha

Great, lets go out and shoot some real life video ... @safari yes i use it with GH2 ...

jam

Agree. Frame grabs from stationary image, but focus point does differ. Should have picked one object to focus/frame on. That said, i think you can say there aren't large differences in resolution. So for me helpful as going on extended trip with only a laptop sans my 8 tb raid. Actually, the Manfrotto has a fixing plate, albeit petite (if you mean the mounting plate on camera). The rig is very stable when locked down, so vibration not an issue.

duartix

@jam :

Using a tripod with fixing plates will give you a much more consistent test environment. Your shots aren't equally composed nor equally focused, making it very difficult to draw any conclusions at all... :(

safari

Nice @feha ....colors are great ...I like your Gini rig too...do you use that with the GH2 also? I have one but haven't tried it with the GH2 yet.

Rambo

feha >re stock matrix> sure:-) ....Haha ..lets give Panny some credit!!

jam

@feha Sorry -2, -2, -0, -2. I, too, saw little difference. After exporting the sequence and viewing at full resolution, the only discernable difference I see is in motion with panning. Orion X Sedna AQ1 matrix has less "judder" in 24p, especially at highlighted vertical edges, than any of the other firmwares. But, my video head (old Manfrotto) is not the best, nor am I (old as well) the best technician. I also filmed some movement (Gambel Quail) using ECT mode with the 14-140 lens and Cake yielded a very smooth and clean image.

feha

@balazer , sure :-) @duartix thank you ... I am happy with Cake 2.0 for now and won't touch and mess with it :-)

balazer

I don't know anything about matrices. Knock yourself out. I'm perfectly happy with what the stock matrices are doing.

duartix

@feha : Using a higher quality matrix will have a similar effect to lowering the quantiser. Surely it can break it. Can it be counteracted by raising the quantizer? Who knows? You have to test. Is it worth it in the end? It depends on what they do... The matrix settings are found in "Patches for Testers\AVCHD Movie Mode\Scaling Tables"

feha

@jam thanks for the test, frankly I don't see much difference ?! "Standard -2-2-0-2-2. Ir and Ic off." Also where do you find 5 parameters in "Standard" ?

jam

Comparison of Orion Sedna AQ1, Gopzilla3 Sedna AQ1, Cake and Sanity

Not sure where this topic belongs. I, like many, are puzzling about which firmware to use for various purposes. To start, I compared these four firmware settings under typical daylight conditions with a complex subject, my spouses studio. Light: Mixed artificial and indirect. ISO 160, f1.7mm F20 Panasonic lens @ F2.2, 24p, 1/50 shutter. Film mode Standard -2-2-0-2. Ir and Ic off.

These are ungraded screen grabs taken from the source file in Premiere Pro 5.5, adjustments at all (no level, color, etc. adjustments).

My conclusion: For this kind of environment (good light, high detail subject, not too much contrast) the higher bit rate firmware gives little advantage for the non-professional. I have a much more demanding series of tests with a more challenging environment (high contrast lighting, large areas of similar color/texture, a reddish wall, etc) that does show significant differences. Also as Driftwood has pointed out, stock firmware is good as well.

Finally a note to the noobs like me: Be careful that you reload the original firmware or reset all options before you run PTools - you can (and will) get some very strange results if you inadvertently mix settings!

Thanks to all for these remarkable tools, of course especially VK.

feha

@balazer, how would i apply only matrix form other settings as @driftwood ? what part of settings consist just matrix ? Would this destabilize Cake 2.0 ?

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