GH2 GH2vk hack fun!

Peter J. DeCrescenzo

Peter J. DeCrescenzo

Veteran
I installed Vitaliy's 3.61d firmware hack on my GH2 (currently the only feature I'm using is 42 mbits/sec 1080p24 AVCHD), and shot some brief, informal tests. Fun!

See Vimeo page for details & camera-original .MTS files.

Lumix 100-300mm zoom lens at 300mm + Extra Tele Conversion mode:

"50mm" angle of view for the same scene:

(Garbled 1st few frames is a known issue w. hack set to 42 mbits/sec.)

So far, so good. Thanks Vitaliy!
 
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In terms of comparison with a stock GH2, do you really notice much difference? I don't have anything close to the 300mm range, nor did I download the original files. But I'm curious as to your findings.
 
Thanks Peter for making this little test shot!

peripatew said:
In terms of comparison with a stock GH2, do you really notice much difference?...
Click to expand...

This is also my question. The 1080p24 mode of the gh2 is already very good. And at the direct comparisons that I´ve seen so far I couldn´t perceive any difference. And this is a quite static shot. But I downloaded the original mts and made a more or less heavy grading test. And by doing this I felt that the codec holds up pretty well - most likely better than the original files. But its only a feeling. A final verdict could only be done with a side by side comparison with unhacked footage of the same scene.
The little grading test: http://www.vimeo.com/26796571
password: hack_grading
 
Nice CC, Uwe!

I'll be doing a lot of shooting along the US Pacific NW coast for the next several days, which is what prompted me to install the hack. My assumption is that the extra bits per frame will help record the water (and foliage) detail more cleanly. We shall see.

The one other setting change I made with the hack is to set my GH2's "24L" mode to record at up to 24 mbits/sec. If in fact this results in video identical to factory-standard "24H" mode, then switching between my GH2's hacked 24H & 24L modes will allow me to shoot "side-by-side" tests relatively easily. Kinda. ;-)

From what I've seen so far, the hack setting of 24H @ 42 mbits/sec seems to render moving/splashing water more cleanly than what I remember the factory-standard configuration achieving. But I hope to know for sure over the course of the next few days.

I'll be watching this forum & Vitaliy's forum for other people's results, too. I'm especially interested in seeing if a consensus develops as to whether or not using the hack to adjust the GH2's GOP settings can result in improved footage that plays & edits reliably.

Cheers.
 
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Peter J. DeCrescenzo said:
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The one other setting change I made with the hack is to set my GH2's "24L" mode to record at up to 24 mbits/sec. If in fact this results in video identical to factory-standard "24H" mode, then switching between my GH2's hacked 24H & 24L modes will allow me to shoot "side-by-side" tests relatively easily. Kinda. ;-)
...
Click to expand...

That is a really great idea. Did you also change the hack settings for 720p60? If so, I would appreciate it if you could do the same thing in this mode. I have the gut feeling that in 720p60 is more room for IQ improvements with the hack. But don´t stress yourself out...
 
Uwe Lansing said:
That is a really great idea. Did you also change the hack settings for 720p60? If so, I would appreciate it if you could do the same thing in this mode. I have the gut feeling that in 720p60 is more room for IQ improvements with the hack. But don´t stress yourself out...
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No, I haven't changed my GH2's 720p or MJPEG settings. I almost always shoot 1080p24 "24H" AVCHD. But I might try some other mods when I have time.
 
Looks great, is there any safe hack by Vitaliy or anyone, that has a higher bit rate and plays well on cards type 10?
Or should I keep trying? So far do not see a difference!
 
OlegKalyan said:
Looks great, is there any safe hack by Vitaliy or anyone, that has a higher bit rate and plays well on cards type 10?
Or should I keep trying? So far do not see a difference!
Click to expand...

Use mpgxvcd's 32mb patch...very stable and remove the mud from the other film modes.
 
I have noticed that footage shot at 42Mbits is cleaner in the shadows.
That is a good idea to set 24L at the same setting as the unhacked GH2 24H setting.

Has anyone played with the audio settings???
 
I upped the audio bit-rate to 448 Kb/s and it works fine. For video, I've been using a variation of KAE's high bit-rate, low-gop settings over at www.personal-view.com, the only difference being I set my 1080i50 and 1080p24 GOP size to 6 instead of 3, and have been getting really great results. Go to page 3 of the "low gop" topic at personal-view and scroll down to KAE's most recent post and you'll find his settings.

Vincent
 
Vincent, I'm doing the same thing. It's probably a trade-off, but 6 GOP looks great for motion. Better than the stock 12 GOP (IMO). Just load Cae's latest ini file and as Vincent mentioned, change the 1080i50 / 1080P24 setting to 6. I need to experiment more, but shadow detail that would normally be grunge now is resolving.
 
Uwe Lansing said:
Interesting. Can you (or somebody else) explain to me what the difference is between the 3 and the 6-gop in terms of the look? And what about 720p50/60? Did you also change this gop?
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*In my experience, 3 and 6 GOP look identical, but that's not saying there could be a certain shot where they look different. However, with GOP 3 the camera locked up in variable movie mode. So, for 24P I settled on GOP 6, and all is fine. For 720 60P, GOP 5 works well.

Of course, this is all dependent on the bitrates you use. Here's the set.ini I'm using:

[Information]
Comment= GOP6 42mbps for all
SD_Card=Any
Camera=GH2 v1.0E
[Settings]
Version increment=1
720p30 width=1920
720p30 height=1080
E1 Quality=280
E1 Table=4
E2 Quality=250
E2 Table=10
E3 Quality=225
E3 Table=24
E4 Quality=200
E4 Table=48
Video Bitrate FSH/SH=42000000
Video Bitrate FH/H=35000000
Video Bitrate 24H=42000000
Video Bitrate 24L=35000000
720p50 GOP Size=4
720p60 GOP Size=5
1080i50 and 1080p24 GOP Size=6
1080i60 GOP Size=15
Video Bitrate 24H ADD=48000000
Overall Bitrate=48000000
Overall Bitrate 2=48000000
Video buffer=0x3000000
Video buffer 24p=0x3600000
1080p24 High Top Setting=42418
1080p24 High Bottom Setting=29692
1080p24 Low Top Setting=31178
1080p24 Low Bottom Setting=21824

These are not the most agressive settings that you find out there, but it's stable and the quality is excellent.
Note: You definitely need a class 10 card.
 
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I'm back from my 7-day cruise along the Alaskan coast. It was my first cruise, and all I can say is wow!

Here's a very brief taste of what I saw & shot with my hacked "GH2vk" (details on the Vimeo page):


Cheers!
 
I'm using the following settings for 720P presently - completely stable on Transcend Calss 10, fairly conservative in fact, but with a nice improvement in the image.

Video Bitrate FSH/SH=28000000
720p Top Setting=31878
720p Bottom Setting=22314
 
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