GH2 Hack Recap

F

Frame

Member
I am missing a short recap of what the GH2 hacks can achieve for
an -almost- professional workflow.
Maybe this thread can sum it down for users like me who consider buying a GH2:

Higher bitrates - no question.

BUT:

1) Can the Film-Modes be enhanced with a hack? (especially the gamma curve, to get more detail in dark areas
and a soft rolloff in the highlights): Yes/No?
If yes, must it be done in the hack or do the menus of the Film Modes get enhanced?

2) As far as I know, the GH2 uses a built in compressor/limiter for sound,
independent of the recording level.
If true, can this compressor/limiter be defeated with the hack?

3) As far as I know, AC3 ist the recording format for sound.
Can the bitrate of the audio be increased?

This is all I need to know for a start...
All the best,
Frame
 
1. The high bitrate hacks (Driftwood's Smackmybitchup is my personal preference at the moment) allow you to film with extremely clean noise. It is not so much an 'enhancement' (it doesn't magically make the GH2 shoot 4:2:2 or anything) as it is the preservation of what the GH2 is capturing. I shot an event the other day using the hack in a very dark bar. Manual focus the entire time, 20mm pancake lens... The footage came out GORGEOUS. The darks actually have data (used Smooth -2, -1, 0, -2) and if I had needed to (which I didn't) I could have graded beautifully in post. So yes, higher bitrate means less compression artifacts, which means clean noise and more retained CLEAN detail. It is akin to taking the sunglasses off your camera. No mud, film-like noise.

2. If you drop the 'level' down to 1, you will not notice the compression. The hack does not modify this setting although Vitality is working on a new version of Ptools and who knows what will be possible with that version. I have recorded audio using the in-camera input (level always dialed down to 1) and have never had any problems, but I usually use my Tascam field recorder for anything serious.

3. This goes hand in hand with the above point.. If you are looking for professional high-end audio out of a camera, the GH2 will disappoint you. It is very capable, and the audio is fairly clean when using the input, but if you are looking for 24bit 48kHz clean PCM audio, then don't look to a camera that only has a micro audio plugin!! If you are just recording a lavalier, so forth, you probably wont notice anything. If you need lossless audio, just use a field recorder and sync in post!

GH2 rocks brother!
 
Thanks HotConductor!
"(used Smooth -2, -1, 0, -2)" are values you set the "Film Mode" Menu of the GH2, or in the hack?

I am not looking for PCM-Audio. But I guess the bitrate of the AC3 will not be above 192kbit, so when it comes
up to cleaning up audio from ambient noise with complex filters in post, the artifacts are a drawback - the same thing like
grading heavily with low bitrates.
AC3 Bitrates above 348kbit are safer, 448 is the standard´s upper limit.

I always use a field mixer who can do moderate and proper, non-audible limiting.
I am used to the old fashioned way of filming with 16mm, where in documentary work you do a quick pan to the soundguy/girl
who does a slate by by tapping on the mic.
But very often I will not have one. So I will have built me an adapter
attached to the camara´s baseplate,to connect from my field mixer´s XLR to the 2,5mm mic input of the camera.
(The mixer ´s output can be switched from line level to mic-level)

A Zoom H4n would be used for ambient recording and as a backup for Interviews, running from the same mixer.
All the best, Frame
 
@HotConductor

If I may throw in a question: You´re saying that if the audio doesn´t need to be touched (or touched much) in-camera audio is sufficient, right? For which purposes would you say that? Right now I´m recording in-camera audio through a NTG2->H4N->Att. cable->GH2 (audio levels set on 1). Sure I know that H4N records better audio. But I´d love to get some usable audio right in my mts-files. So, for what would you say is in-camera audio usable?
 
The Smooth -2, -1, 0, -2 is my personal preference 'film mode' in camera. It is something you set in the menu, not a part of the firmware hack. Others prefer a highly modified version of 'Nostalgia' and so on. Its all personal preference. I just like grading in post, and that setting produces a great image that retains detail.

Jack, I said 'If you are just recording a lavalier, so forth, you probably wont notice anything.' I never said anything about whether the audio would need to be touched or not. Some people on these forums record with ancient staticy lav mics and horrible cables from the 80s. I cant assume that everyone has good audio gear to start with! =) BUT, I am saying that MOST people will never know, on simple projects, whether a lav mic was recorded through a GH2 (with the AGC all the way down and wind filter off) to a Tascam or H4N. MOST people.....

On-camera audio is pretty decent as long as the auto-gain is turned all the way down to 1 (I believe is the lowest setting, cam is not nearby me at the moment) and wind cut filter is OFF. If you turn it all the way up, auto-gain compresses the heck out of the footage. Turn it all the way down and the auto-gain is at its lowest setting. It cannot be completely 'disengaged' but at its lowest setting it is VERY bearable.

I use a Tascam field recorder for anything serious, but I frequently run the Tascam audio, as you do with your H4N, into the GH2 via cable. The main trick is to get the level hot but not peaking (audio meter on screen is a must), and to have that AGC turned all the way down. I had one failure (forgot to hit record on the Tascam during an interview) and the on-cam recorded audio sounded almost identical to my Tascam, so we used it. Its always great to have a backup, just match levels.

You mentioned situations where the audio would need to be cleaned up/mixed, and those are situations where it would be plain stupid/last resort tactic, to use the on-camera audio. If I am recording a concert I will likely multi-track it using my dual MOTU 896s and a laptop, or at bare minimum use my Tascam to get a clean 24bit 48kHz (or higher) soundboard tap. If someone uses the GH2 to record a rock band off a soundboard, the quality will be mediocre at best. HOWEVER, a simple interview with a lavalier mic, THAT you can get away with using the on-board input. One person speaking is easy for the Dolby Digital codec to handle. A full band at AC3 192kHz is going to be alright, but nowhere near a FLAC recording.

On other forums (Rolling Stones site, private music collection sites) my handle is Flacnvinyl. Compression is a killer, but for voice is it simply not a huge deal breaker. People don't download flac audio books!
 
According to osgfilms
http://osgfilms.com/improve-gh2-audio/

the audio bitrate from the GH2 can be raised from 192Mbps to 400mbps.
(I Iguess he means 448mbps, because AVCHD records AC3 audio. So safer data rates like 384 should be possible)
But you loose the ability of playing back the recordings in the camera.
But all in all, it is a YES.

Maybe we should try to keep posts as short as possible, to make this thread a recap for GH2 beginners.

So, next question:

Any advatage of the newer UHS-I over the old SDXC memory card system?

Will the CH2 be faster with UHS-1?

Is UHS-1 as reliable as SDXC with spanning?
All the best,
Frame
 
The GH2's Dolby Digital encoder records stereo at the standard bitrate of 192kbps. Higher bitrates are intended for encoding 5.1 channels of surround sound, not for stereo. While it may not add much to the total bitrate to increase the audio bitrate beyond 192kbps, it is unlikely that it will perceptibly improve the sound quality.
 
Hello Ipowell,
thank You very much for your reply! (And your work!)
But I would like to keep this thread to a minimum of answers, just Yes (probably with a "but") or No,
for beginners like me to get a quick overview about the possibilities offered by the hacks.
About audio bitrate:
Aim in soundmixing ist the same as in color correction.
Imagine an audio denoising plugin as "heavy grading".
The lesser artifacts from codec-compression, the better the results in filtering.
It is just like the green screen work from GH2 you proudly present the compositing guy.
He will probably like to kill you, because with keying, you´ll suddenly see the artifacts.
And:
Audio and Video will be reencoded for tapeless distribution
So high bitrates matter for both.
All the best,
Frame

BTW:
Will the CH2 be faster with UHS-1?

Is UHS-1 as reliable as SDXC with spanning?
 
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I recently bought the GH-2 to use as a "plan b" backup for my AF100 should it fail while on the road. I am fascinated & overwhelmed by all the hack info. I am wondering if anyone could recommend the GH2 hack that might most likely resemble the 1080/30p F1 film cam setting on the AF100? thanks.
 
I deleted this post because one of the URL mentioned seems to have changed, so the link was no longer valid.
 
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