Gh2 hdmi

B

BlackWolf

Active member
Hello all.
I have some questions regarding the GH2's HDMI output, as i'm planning on purchasing the Atomos Ninja along with the GH2. From what i've read so far is that it doesn't output 1080p, but interlaced. Does the same hold true for the 720 mode? Also, does the hdmi port provide an uncompressed video stream (no artifacts) and 4:2:2?

In short: is it worth it to buy an external recorder for the GH2?
Any help would be much appreciated. :- )
 
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Doesn't output anything in 720p mode. It is an unrewarding pursuit. Many have tried and have been frustrated. There is a sticky discussing a software work around at the top of the forum. It seems to work but imagine doing that for every clip. Your mileage may vary.

My advice - buy the ninja for any camera that outputs uncompressed HDMI. But for hassle free performance - the GH2 ain't one of them
 
BlackWolf said:
From what i've read so far is that it doesn't output 1080p, but interlaced.
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Correct, but there is a script that can extract 24p out of its 1080i.

Does the same hold true for the 720 mode?
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Plugging in an HDMI recorder disables 720p mode entirely.

Also, does the hdmi port provide an uncompressed video stream (no artifacts) and 4:2:2?
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No, it provides a broken-chroma 4:2:0. There's no compression artifacts, but the chroma is messed up and it's only 4:2:0. You can fix the chroma to restore it back to a normal 4:2:0.

In short: is it worth it to buy an external recorder for the GH2?
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That's an individual question -- only you can determine whether it's worth it to you. From my experience using my Nano with it, I say resoundingly no. Plugging in a recorder means you have to forego 720p mode, you have to forego the excellent highlight flashing zebra indicator, and you have to give up the excellent low-skew Extended Teleconversion mode. And an external recorder will not be recording any audio whatsoever because the GH2's HDMI output doesn't transmit audio. And, on top of all that, the color that the HDMI outputs isn't comparable to the color that the internal codec records -- it's a lot flatter and muted as compared to the internal.

It will, however, not have any AVCHD compression artifacts on it. If you use a high-bandwidth external codec you can end up with less-compressed footage. But you will have to post-process every clip you record through Ralph B's excellent AVISynth script in post. Whether that one compression benefit is worth the cost and the loss of features is up to you.
 
Colour issues aside (which for practical purposes might be insurmountable), for producers who shoot in 1080i, do you think the GH2's HDMI would work?

What would a Nano or Ninja do with the exactly 60fps HDMI output? Can they record that video at 59.94 f/s anyway or is this best converted to 59.94 in FCP?

The audio would be recorded directly to the external recorder.

RBG
 
If you only wanted to shoot 1080/60i, and you didn't mind post processing every clip (which is required to turn it into a video-compatible 59.94i and to fix the nasty chroma), and you don't mind losing the zebra highlight feature and you don't mind losing the ETC mode and you don't mind that the color is inaccurate and that you always will have to record on both the camera and the external recorder in order to make the external look "right", and you don't ever want to turn the LCD around (because that will make your HDMI recording turn upside down) and you don't mind using an external audio recorder and a clapper slate and having to sync up all your audio manually in post (because you can't use PluralEyes or any type of automated sync software)...

... then sure, it'll work fine.

I can't speak for the Ninja, but the Nano has the ability to record the 60.00i. You then have to run Ralph's script to strip out the added pulldown and turn it back into 59.94i.
 
Muted colors are fine. Looks more like less saturation. I think the image is still noticably sharper. I don't use ETC mode personally. Audio? Dual record "on cam" while recording HDMI.

For me...the whole benefit of recording HDMI on this camera is.... 1. no compression noise, 2. cleaner shadows (at least from the examples I've seen).

There's more but these are enough.
 
Barry,

how I can verifying that the HDMI out is messed up from 4:2:0 to 4:2.2. I ask because e.g. MediaInfo is recognizing the file prop. as 4:2:2...so I guess that other tools don't tells the truth too?

thanks
 
Amadeus5D2 said:
how I can verifying that the HDMI out is messed up from 4:2:0 to 4:2.2. I ask because e.g. MediaInfo is recognizing the file prop. as 4:2:2...so I guess that other tools don't tells the truth too?
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The file that gets recorded will be recording in 4:2:2 color sampling, yes -- but the signal the GH2 is outputting isn't a proper 4:2:2, it's a messed-up sawtooth-edged chroma signal embedded in a legit 4:2:2 file. You can repair it by using Ralph's script and running the appropriate chroma fixing option.
 
Lee Saxon said:
There's no way Panasonic $#*%$# up the HDMI out this bad by accident. Which really pisses me off.
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The GH2 prototypes that were issued were outputting HDMI @ 59.94i, only the production models were changed to 60i. So yes was no accident.
 
Thanks for that, Barry.

'Course, everyone's needs are a little different. In my case, I always hire a righteous camera dude & HDCAM gear. But really wanted a way to shoot a good, cheap HD shot: that cutaway suddenly required during post; that unexpected beauty shot needing a camera; maybe one or two Merlin steadicam shots; a couple camera B shots, etc. But always 1080i 60fps. That's why I remain interested and willing to explore the GH2 possibilities. Else hurry up Nikon (with no high-end video sacred cows) and give us a useful HDMI DSLR.

Don't the video recorders (the Ninja, anyway) record single sound & video? Or are we talking about losing synch as a result of the required video processing that you indicate?

So I take it you can't force the Nano to record 59.94 off of a 60fps signal?

RBG


Barry_Green said:
If you only wanted to shoot 1080/60i, and you didn't mind post processing every clip (which is required to turn it into a video-compatible 59.94i and to fix the nasty chroma), and you don't mind losing the zebra highlight feature and you don't mind losing the ETC mode and you don't mind that the color is inaccurate and that you always will have to record on both the camera and the external recorder in order to make the external look "right", and you don't ever want to turn the LCD around (because that will make your HDMI recording turn upside down) and you don't mind using an external audio recorder and a clapper slate and having to sync up all your audio manually in post (because you can't use PluralEyes or any type of automated sync software)...

... then sure, it'll work fine.

I can't speak for the Ninja, but the Nano has the ability to record the 60.00i. You then have to run Ralph's script to strip out the added pulldown and turn it back into 59.94i.
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The GH2 will do exactly what you're asking, if you don't bother with an external recorder. Why do you think you want/need an external recorder?

And yes, the Ninja and other external recorders will record sound and video. The problem is that the GH2's HDMI output doesn't carry any audio on it, so there's nothing for the external recorder to record.

And no, you can't force the Nano to strip out the pulldown from 59.94->60.00. It can strip out 2:3 but it records the 60.00i as 60.00i.
 
For the obvious reason that a data recording rate of 220 Mb/s (ie: via Ninja ProRes 422) produces better quality than the 17 Mb/s AVCHD data rate?

Why would you use the GH2 audio recording when you could use the external recorder's own audio record capabilities?

And I now must ask a basic technical question inspired by your use of the term "pulldown." But on a separate thread.

RBG


Barry_Green said:
The GH2 will do exactly what you're asking, if you don't bother with an external recorder. Why do you think you want/need an external recorder?

And yes, the Ninja and other external recorders will record sound and video. The problem is that the GH2's HDMI output doesn't carry any audio on it, so there's nothing for the external recorder to record.

And no, you can't force the Nano to strip out the pulldown from 59.94->60.00. It can strip out 2:3 but it records the 60.00i as 60.00i.
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Thanks for all the replies! Too bad it's kinda useless for the job i had in mind. I would've atleast expected a proper HDMI out.
I guess panny didn't want the gh2 to cannibalize the AF100 too much. Oh well, we can still hope vitaly manages to pull off something great with the hack. :D
 
Barry_Green said:
and you don't mind using an external audio recorder and a clapper slate and having to sync up all your audio manually in post
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The Ninja has a 3.5mm audio in so shouldn't you be able to go from something like the "tape out" on a MixPre directly into that?
 
Lee Saxon said:
The Ninja has a 3.5mm audio in so shouldn't you be able to go from something like the "tape out" on a MixPre directly into that?
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Ok so the fix there would be to either come from the audio out on the camera into the Ninja or plug the mic directly into the Ninja.
 
we have here another strange thing with the gh2 (european pal model - dmc - gh2k): the hdmi out works fine with a panasonic beamer but not with an adapted Samsung Syncmaster (which never before had a problem to show 1080 50i !). Also we tried to connect to AJA IO express - no succes. I am already thinking that there might be a HDCP implementation on the hdmi on the camera side. Maybe someone here has some idea about that. of course i disabled the strange "viera link" in the camera menue and as well tested with all output settings...
seems to be strange...
Any ideas? would help me a lot!
thanks in advance -

Tobias
 
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