HDMI Capture Problem SOLVED - AviSynth RULES!

Danielvilliers said:
Very very affordable recorder from blackmagic http://www.blackmagic-design.com/products/hyperdeckshuttle/ with it and atomos making the gh2 hdmi output camera a very viable and cost effective solution. Who would have thought that we would be able to get that level of quality for less than $ 1500. Thanks to everyone who has made it possible on this thread :-)
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Amazing price, but probably not the best choice for the GH2 because it doesn't have analog audio inputs. Remember, if the HDMI capture device has audio inputs, you can record audio along with the HDMI picture, and then correct the time delay when you process the files in Avisynth. The beauty of that, is your clips are ready for editing - no manually syncing up audio.
 
Just getting caught up with this thread, been busy. Glad we're still going strong.

Upon reading I've heard the color (saturation/etc) differences between the AVCHD and HDMI brought up. Once by Barry's anti-GH2 HDMI manifesto and then here...

PDR said:
BUT what do you want it to look like ? The AVCHD or the Ninja footage ? Which one is "correct" ? I would say the AVCHD footage should be the goal, but your starting footage (before processing or DNxHD) is already mismatched.
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If I recall correctly, it's been brought up before that the AVCHD footage can be slightly oversaturated in certain situations which can sometimes slightly obscure some finer detail. In which case, having the slightly muted HDMI footage is actually a slightly better starting point before post-production if your trying to extract/optimize every last bit of color/luma detail.

Obviously the difference can be a pain when monitoring, as Barry was saying, but it really depends on your workflow and needs. If your using a monitor exclusively with the GH2, I might imagine you can just adjust the monitor (+saturation/etc) accordingly to compensate. For some, all these "adjustments" may not be worth it, but that really depends on which side of the thought process, time-constraint, and/or budget line your on.

Some would much rather pay a premium for things that are as quirk free and versatile as possible... that's one reason professional equipment is so expensive... at times overly expensive. The other side of the coin are people who are on a budget or otherwise just prefer the "makeshift" way-of-life. Those, like myself, who don't find "jimmy rig" to be a dirty word. For these people, all these little adjustments or having to do some extra post-processing on something, is completely exceptable and worth it. There's many types of equipment, from rigging to lighting, that you can put together much much cheaper yourself, it just takes time and some extra thought to accomplish. I find projects like this (GH2 HDMI output) to fall under that same catagory. Obviously, again, aside from budget, time contraints can also be a factor, but for those with a lax turnaround on whatever they're doing.. letting your computer render while you catch some Zs isn't a problem.

Even, if your not on that much of a budget, GH2 HDMI can still prove useful in things such as long continuous recording (assuming you have the HDD space or capture device card swappability to surpass the record time on your SD card). If for whatever reason you need to record in very low light, without extra lighting, and post production is still required even with a fast lens, the GH2 HDMI footage can certainly come in handy in preserving those dark details. Also, if your doing noise reduction in post, having the cleaner (finer noise) footage is a plus as well.

:costumed-smiley-047
 
GH 2 capture problems

GH 2 capture problems

We also have a GH 2 , european PAL model (DMC - GH2K) since a few Days. There seems to be a problem with the HDMI out. we tried to connect it to some devices - including AJA IO express - the camera signal will not come in. we tried on a panasonic beamer too and it works - so it seems not to be a hardware problem. I was already thinking if there could be a HDCP implementation (which would be really mean...) ? Anybody here have some idea about?
thanks in advance -

tobias
 
mambomobil said:
We also have a GH 2 , european PAL model (DMC - GH2K) since a few Days. There seems to be a problem with the HDMI out. we tried to connect it to some devices - including AJA IO express - the camera signal will not come in. we tried on a panasonic beamer too and it works - so it seems not to be a hardware problem. I was already thinking if there could be a HDCP implementation (which would be really mean...) ? Anybody here have some idea about?
thanks in advance -

tobias
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It sounds like something's going on with the AJA device. People have successfully captured HDMI output from PAL GH2's with Blackmagic Intensity, Atomos Ninja, and Convergent Nanoflash.

Double check to make sure your input setting is 50i.

You mention "some devices". What else besides the AJA have you tried?
 
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hi Ralph,

thank you for your fast answer. we tried the gh2 also on a Samsung Syncmaster which has a "native" hdmi in (not converted from DVI or something...). This monitor never had a problem to show 50i (we tried that before many times with different cameras). Tomorrow i will do another test with the AJA. The strange thing is: our panasonic beamer (pt-ae 1000) shows the picture...
thanks again - will come back tomorrow.

Tobias
 
GrgurMG said:
Even, if your not on that much of a budget, GH2 HDMI can still prove useful in things such as long continuous recording (assuming you have the HDD space or capture device card swappability to surpass the record time on your SD card). If for whatever reason you need to record in very low light, without extra lighting, and post production is still required even with a fast lens, the GH2 HDMI footage can certainly come in handy in preserving those dark details. Also, if your doing noise reduction in post, having the cleaner (finer noise) footage is a plus as well.

:costumed-smiley-047
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Amen. This is what I've been saying all along.
 
I have an advanced 24P script in the works that fixes the residual problems of the original script. Stay tuned.
 
I have tried to wrap things up for the readers of our blog at http://marvelsfilm.wordpress.com
Jorgen Escher at http://colorbyjorg.wordpress.com has made things even more digestible by making a zipped folder with all you need, to get you up and running with AviSynth. It's targeted towards Ninja (ProRes HQ) and Mac users, but apart from some minor script and batch changes, the bulk remains the same. Jorgen's zip file contains everything you need to install including a predefined directory structure and the scripts that feature in this thread.
Both Jorgen and i are no cracks on the subject, but we hope it helps people getting started.

Martin Beek.
 
Ralph - are you referring to missing fields, dupe detection + decimation, and interpolating a new frame using mvtools ? (are you "rec" on D9) ?

If so, the dupe detection isn't the problem - the problem is interpolation often isn't very "clean", often worse than a dupe

In the examples so far, the dropped field has another field pair you can use to reconstruct the frame, that would give a much cleaner frame. The problem is there is no way of knowing if it's the top field or bottom field that has been dropped when you are field matching. e.g. IF you use AssumeTFF() you might miss the "good" field , but if you used AssumeBFF(), you might miss the other good field in other field drops. You would have to somehow adaptively switch field order

I can explain in more detail if this is what you're talking about

But if you're thinking about something else, then disregard this
 
martinbeek said:
I have tried to wrap things up for the readers of our blog at http://marvelsfilm.wordpress.com
Jorgen Escher at http://colorbyjorg.wordpress.com has made things even more digestible by making a zipped folder with all you need, to get you up and running with AviSynth. It's targeted towards Ninja (ProRes HQ) and Mac users, but apart from some minor script and batch changes, the bulk remains the same. Jorgen's zip file contains everything you need to install including a predefined directory structure and the scripts that feature in this thread.
Both Jorgen and i are no cracks on the subject, but we hope it helps people getting started.

Martin Beek.
Click to expand...

Hey Martin, that's great! I'm all for making things easy for people to use, and I've endeavored to do that in the first post. But, this takes it to another level. Good job!
 
ADVANCED SCRIPT IS HERE!

I have updated the first post with an advanced script for processing HDMI 24P footage.
This new script solves the known issues of the original script, plus it runs faster!

The original script worked well most of the time, but occasionally a duplicate frame would slip through. On closer investigation, I discovered the problem wasn't the script, but that the GH2 never sent the frame across the HDMI in the first place! At this point, one might throw up one's hands and declare, "you can't fix what isn't there!" Or can you? ...

Most of you have experienced motion vector technology, even if you don't know it by name. It's the process utilized in televisions to create new frames so you can watch a 24 fps movie at 120 fps. (whether that's good or bad is of no concern here). Avisynth has motion vector capabilty in the form of mvtools, and I have used it to recreate the missing frames.

Here is an example. This is a scene processed with the original script. As the car approaches the stop sign, you will see it stutter. These are duplicate frames that fill in for missing frames that were never sent across the HDMI.
http://www.sendspace.com/file/89g6ja

And here's the same scene processed with the advanced script.
http://www.sendspace.com/file/6k4g78

There's more good news. Another issue of the original script was a few duplicate frames that would appear in the first second of each clip. This seemed to be a problem of fdecimate, but no matter, motion vector technology fixes them, too!

I reprocessed every HDMI clip I have with the advanced script, and I had 100% success - clean, smooth motion - not one stutter or duplicate frame.

In order to run the advanced script, you will have to download mvtools2.dll and place it in your Avisynth plugins folder. Get it here:
http://avisynth.org.ru/mvtools/mvtools2.html

The other area of improvement concerns the Chroma Fix. Taking PDR's suggestion, I carefully examined his "short" Chroma Fix and compared it to GrgurMG's "long" Chroma Fix. There was an infinitesimal difference, but I literally had to put a magnifying glass up to the screen to see it. At any normal viewing distance, they were identical. But, the "short' Chroma Fix renders twice as fast! I think most people will prefer that, and so that's what I put in the advanced script. However, you're always free to use the "long" one if you want, and I left it in the first post.
 
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what do i have to change in the script to get 25p instead of 24p?

what do i have to change in the script to get 25p instead of 24p?

finally i found the problem with the AJA IO express - with the PAL GH2 it does not work because there is no 50i input... - but i made a test with the NINJA and it works perfectly!
Since the camera outputs 50i at the HDMI and i would love to convert it to 25p instead of 24p but keep the advantages of this great scripts. I was trying around with the "Assume(24000,1001)" line, changing it to "Assume(25,1)" - without result. So i guess i will have to get rid of the pulldown??
Thanks for your help -

Tobias
 
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