I know... many attempts have been made to get a comprehensive guide for GH2 hack beginners going. This is the next such attempt. I created this file for my own reference, but feel that it might be helpful to others, so here it is.

I have borrowed from @driftwood , @OSGondar and Thorsten Ott @ zeroplusplus.com . I hope that's all right. Thank you guys for your work.

Please feel free to correct or add, I'll be glad to work your suggestions into the text.



PTOOL DEFINITIONS

(1)
The GH2 Firmware v1.0E is the current hack for the GH2 firmware. It allows to change bitrate settings (that are fixed in the factory settings), as well as other manipulations that Panasonic locked in their version.

(2)
The "PTool v3.62d" is a Windows based software that lets you load the hacked GH2 Firmware v1.0E and marry it with a patch (group of settings) that you may select. The PTool will create a new firmware package, called something like "GH2_V11.bin", which can be uploaded into the camera via an SC card through a special procedure (see below, "PTOOLS PROCEDURE").

(3)
A "patch" is a specially formatted text document (ending with .ini) that contains a unique set of user-defined bitrate (and other) settings. Many creative useres on this forum have been extensively playing around with the numbers in these settings, trying to find a balance between stability (i.e. no crashes, freezes, drops etc.) and highest possible image quality - sometimes knowingly sacrificing some of one to benefit the other.
The naming of patches is as follows: "set" plus a letter (a-j). Hence, a typical patch name would be seta.ini or setf.ini. The last letter refers to the patch number which PTool will identify. PTool has 10 buttons on the bottom of the window, labeled a through j. If there is a patch in the same folder as PTool, the program will recognize it and make the button green as to indicate the availibility of the patch. This way you can have up to 10 patches readily available in PTools (as long as they are named correctly and reside in the same folder as PTools).

(4)
In order to use a different bitrate setting, one needs to use a different patch, and hence go back into the PTool, load another patch, output a new .bin firmware, and load that into the camera via the SDC card again.
Hence, within one firmware, one cannot switch between different patches, or settings. Once uploaded into the camera, there is exactly one 24H setting, one 24L setting and so forth one can use. To use a different bitrate, one has to go through the PTool process again.
Alternatively, one could just get a few cheap 2GB or so SD cards, and load a different firmware/patch on each one. This way, in the field new patches could be loaded at liberty, without the need of a computer or going back to the PTool. (Of course, these cards would not be used for recording, but ONLY to load firmware patches.

(5)
In order to get a new patch into PTool, one just saves the selected patch .ini in the same folder than the PTool. Once starting the PTool, it will recognize the patch, the corresponding letters at the bottom of PTool will be green and can be clicked.

(6)
The most conservative and highly tested bitrate suggested by Master Vitaliy is 42M. The highest bitrate that seems to be absolutely stable is 66M, provided by CBRADIN (66M_44M stable or 66M_44M max variation patch). The most popular patches are usually uploaded by the masters who create them at http://www.personal-view.com/talks/discussion/953/gh2-patch-vault-most-popular-patches-in-one-place#Item_10

(7)
The highest bitrate that can span is 32M. "Spanning" refers to a writing limitation on the SD card, which cannot write file sizes larger than 4GB. If the 4GB file size of the recorded clip is reached, the GH2 will start writing a new file, "spanning" the information between the two files. In the hacked GH2 with with patches containig higher bitrates than 32M, the GH2 will simply stop recording once the 4GB limit is reached.

(8)
Higher bitrates create bigger file sizes. The factory setting bitrate of 24M will record about 5 minutes per 1GB, the Vitaliy recommended stable 42M patch records only about 3mins per 1 GB (which means it has a maximun recording time of around 12min - as it does not span and is limited to 4GB file size).


_______________________________________

PTOOL PROCEDURE (based on @OSGondar and Thorsten Ott @ zeroplusplus.com)

(01) download these files: GH2 Firmware v1.0E ("GH2__V10.bin"); PTool Firmware Manipulation Tool v3.61d ("ptool3.exe") at http://www.personal-view.com/talks/discussion/332/ptool-3.60d-topic/p1

(02) format the SD card in the camera

(03) fully charge battery; do not use DC coupler; this is ESSENTIAL - low battery or fluctuations in power during the firmware upgrade can "brick" the camera and turn it into junk

(04) mount camera on PC using provided cable (or on Mac: use SD card reader and mount card on Desktop)

(05) Windows: open the "ptool3.exe" file; Mac: make sure you have Winebottler installed, right-click "ptool3.exe" and choose "Open with Wine App"

(06) Ptool asks for fimware; click "Load Firmware" and point at your download ("GH2__V10.bin")

(07) IMPORTANT: make sure "Version increment" on the top is checked, and enter "10" in the first green line below; this allows to at some point revert back to the default Panasonic firmware

(08) PAL only: check the "30 minute time removal" and "PAL<->NTSC Menu" boxes

(09) under "Patches for end users" click on "AVCHD Compression" and from that drop down check all of 4 options; when you highlight each option it literally pops up and tells you type in this number instead of current number; type in that number for each of these 4 options; this value is a recommended stable setting (42mbs in AVCHD 24H)

(10) check "Auto Quantizer for 1080 (&720) modes", and select "3" in green pull down below - this will increase the minimum bit rate for less detailed scenes

(11) optional: set GOP for 1080 24p to 3; some argue this gives a more film-like handling

(12) save the settings to one of the letters

(13) save firmware; use same file name as original except change the last digit to anything else; DO NOT use the same last digit "0"

(14) drag or copy and paste your new firmware that you made over to camera's card and wait until transferred

(15) unplug and restart the camera (or on Mac: make sure camera is off and insert SC card)

(16) once camera is back on, wait a second and push "play/preview" button; it asks you "would you like to update?" - hit "yes"

(17) DO NOT TOUCH anything or mess with camera during update, that's the only DANGER of this process (next to the power issue outlined in (3))

(18) the update should take about 1-4 minutes

(19) before reusing the card, format it in camera


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ADVANCED (based "Basic Facts" by @driftwood)


1. GOP DEFINITIONS

GOP (= "group of pictures") begins with an I-frame ("intra-coded"), followed usually by an number of P ("predictive") and B ("bidirectional") frames

I-frame
"intra-coded" frames, key frames
= frames that are coded without reference to any frame except themselves; a "whole picture"
average about 7:1 reduction

P-frame
= predicted frame, based on prior I or P-frame plus the addition of data for changed macroblocks
have to be decoded before the B frames between them
average about 20:1 reduction, or about half the size of I-frames

B-frame
= bidirectionally predicted frames based on appearance and positions of past and future frame macroblocks
require more decoder buffer memory because 2-4 frames are compared during the reconstruction process
require manipulation of the coding order: frames moving from the coder to the decoder are NOT in presentation sequence
the use of B-Frames does improve the compression/quality of the codec by a considerable amount but requires a lot more motion estimation (a large portion of the encoding time) to be done, hence the much longer encoding times; B frames are typically 1/2 the size of P-Frames but require more encoding and decoding
average about 50:1 reduction

each GOP is independent; all frames needed for predictions are contained within each GOP

GOPs can be as small as a single I-frame or (usually) up to 15 frames in length

"Open GOP" - compression more efficient; if B-frame used, the last B is dependent on next I-frame, which makes the movie harder to cut - you have to delete the last two B-frames and cut between the P and I
"Closed GOP" - compression less efficient, but you can cut between B and I-frame


2. GOP LENGTH

Long GOP
= GOP with many frames, such as 12, 15 etc.
the longer the GOP, the lower the bitrate you can use and still get the same quality
advantage: recording at the same bitrate, it achieves better compression (and thus yields higher video quality) than a shorter GOP

Short GOP
= GOP with few frames, such as 1, 3, etc.
a short GOP with high bitrate gives a 'cinematic motion' look and is preferable for some filmmakers

GOP1 - all I-frames
GOP3 - sequence of IBB frames in the recording and no further P frames after the initial first half second burst (GH2)
GOP5 - sequence of IBBPB frames and no further P frames after the initial first half second burst (GH2)

as you go from a GOP length of 1 through 4, the filesize and bitrate drops dramatically but after about a GOP length of 5-6 the filesize and bitrate levels out. i.e. there is not much to gain in terms of filesize and bitrate by using a longer GOP than 5 or 6

its best to run GOPs in multiples of 3 (ie 1, 3, 6, 12, 15, etc...) to avoid problems like losing P frames

the standard unhacked or base GOP of a GH2 (AVCHD standard) at 1080p24H is GOP12 = IBBPBBPBBPBB

MPEG2 GOP encoding works by referring to one frame before the current frame and one frame after; AVCHD H.264 encoding is more powerful in that it uses four frames at a time, consequently more blocks in these frames can be used for compression of the intended block in the current frame, thus enhancing effeciency


3. MISC

QUANTIZATION MATRIX
Image degredation due to data compression is often more noticeable in flat patterns (such as gradients) and can be visually disregarded in detailed patterns. Employing a "quantisation matrix" enables the retention of high image quality by applyiing low compression ("fine quantization") to the flat areas of an image, and high compression ("rough quantization") for busyer parts of the image.

AVCHD ("Advanced Video Coding High Definition")
= 1080p video format developed by Sony and Panasonic, that uses MPEG-4 AVC/H.264 codec

PIXEL ACCURACY
A 1/4 Pixel accuracy is used in motion estimation to get the best fit for each macro-block. Say you have a panning camera and each frame the picture hasn't moved an entire number of pixels across the screen then 1/4 accuracy helps get the predicted macro-blocks in a much better possition. This isnt used in I-Frames because motion estimation isnt used in I-frames as it is basically a JPEG encoded frame using a different Quant value (typically 16).

BITRATES
Always keep lower bitrate settings within 95-70% of high bitrate settings; otherwise, you'll see a dramatic bitrate drop in the low modes. (GH2)
There is currently a known drop in bitrate in the first frame set or GOP - known as the blip. Still to find out a definitive answer as to why. (GH2)

post moved

so what's the ultimate final working settings hack for the GF1?

As I download new ini / settings patches and include them in my bin, how do I switch between the various modes? from 44 to 66 to 176mbit etc? How do I know they are applied and working? Thanks for your hard work, I just got my GH2 yesterday and am having a blast!!!

You can reuse the same number time and time again :-) ie save your bin as GH2__V18.bin everytime if u like, or save it as GH2__V11.bin etc... so long as it isnt GH2__V10.bin. If you need to store your bins and ie u want more than 89 bins just save a new batch of 89 bins to another folder!
So long as your higher than GH2__V10.bin youre ok.

@vitaliy
my initial understanding when i downloaded the ptools i also dl with it the gh2 fw, so reading along the lines here i assumed that the gh2 fw is already applicable to all G series camera.

it's clear now that i should use the proper GF1 fw. thanks for clearing this up.

As suggested, i'm moving my inquiry here.
I have not seen or read in the threads about GH2 fw to GF1 camera. Still uncertain for some reason and questions.
does the GH2__v10 fw loaded into ptools and saving to another __v11 or v12, works for GF1?
or do i have to use and load the GF1_122 fw in ptools and save to as GF__123 for the GF1?

Sorry what i mean is when I check the 8 volume indicators and the 4 levels of AGC
nothing changes in the GH2 menus after applying the new firmware .. compared to default menu settings (all other changes Bit-rate etc work .. so patch is working)

I assumed the microphone patch gave more options .... in level setting

Getting the MIC enhancements to stick


Just applied the 24p enhancements .... I tried various patches till I found reliable settings for my SD card's

One thing the MIC enhancements giving far more level and compression control will NOT stick, am I doing something wrong
eg. do you have to input values or just accept the defaults ???

Thanks for any help

One thing useful would be NO compression like with the Canon 5Dm2

Cheers

@qrede Just put the ini-files into the same folder as PTool and then start PTool. The corresponding letters at the bottom of PTool will be green and can be clicked.

For all of you: why don't you just click on the filename of the old firmware, so it get's copied and then only change the last number to avoid mistyping?

How do I use a patch .ini file ..
I have my GH2 hacked - but I would like to use someone elses settings.
I have downloaded the .ini file - but how do I use this files settings in ptool?

Thanks in advance :)

I have a question regarding video monitoring with the Gh1 while recording, is that possible somehow, according to my small research it is not, but maybe someone found a workaround?