Please Help: Problem with my GH2 Footage

spikedurden

My GH2 footage has been having this terrible, terrible flickering. I've attached an example. In the first couple clips, look at the lightning-like flickers on the left side. On the last two clips, which I've looped since they're so short, it's just ridiculous. The footage is ruined.

Some info:

This is the Sedna patch. Can't remember which Sedna. At first I thought it might've been the new lens I bought, 20mm f/1.7, but I realized that can't be it because I went back to footage from a few months ago before I had the camera and it had the same problem.

Is something wrong with my camera? Should I change patches? What is this terrible, footage-ruining flickering? It has happened at all different ISO, different f stops, shutter speeds, etc... So it's not a problem, or at least it shouldn't be a problem, between my shutter speed and the lights. At first I thought it might be the weird electrical current in my girlfriend's apartment but again, I saw that it happens in all kinds of settings with all kinds of lighting, natural daylight, indoor lights, outside light posts, etc... It also seems to be worst on the left side of the frame.

Here's the thing though: It doesn't always happen. I took some footage of a Halloween parade in low light last week and it was fine. This is really frustrating. Here's a link to the video for an example of what's happening:

Edit: I just realized after compressing it for Vimeo that it's not showing up AS much. Uncompressed it looks god awful. But still, the last clip that's looped is probably the best example of what I'm talking about. Any help would be much appreciated. Thank you!

MRfanny

looks like you brought the rain with you everywhere you shot. i've never seen that before.

simple test. revert back to original or different firmware and observe.

spikedurden

Yeah exactly. It's like digital rain. Not something I've seen before. I think I'm just going to revert to original firmware, do some tests and then try a reliable hack like Sanity v5. But still, if anyone has seen this before, I'd love to hear about it.

kris

I think this can help

driftwood

Sedna isnt doing that to your footage. Goto beginners thread with your question.

abraham1307

@spikedurden same thing happened to me using flowmotion.

spikedurden

Interesting, considering the fact that I changed hack to Sanity 5 and the problem was solved.

I'm not going to post in beginner's because it's not a beginner's question on how to use or install hacks or best camera settings. It's a question about hack behavior. I've used at least 10 different hacks over the past year and this is the only time something like this has happened. It ruined a lot of my footage so it's a big deal to me.

If the hack wasn't doing it to my footage, what was? The solution to my problem was switching hacks.

fredfred27

By any chance are you using After Effects CS6? In another thread a few weeks ago, someone was having what appears to be the same problem with Flowmotion 2.0 footage. I was doing greenscreen tests at the time and saw the same problem in my footage. I tested the footage in CS5.5, CS6 and Avid Media Composer 6. The problem only appeared in CS6. My conclusion was that CS6 (as it stands now)and Flowmotion 2.0 do not play well together.

fredfred27

By the way, I am doing tests with Sedna AQ1 in After Effects CS6, and this problem is not happening. Are you sure it was a Sedna matrix?

kris

If the video works properly with Media Player, then the problem is with the encoder programs & files : . MTS. Yes with ss6, edius for me works perfectly- AVCHD2HQ converter

spikedurden

Interesting stuff. Yes, I am using CS6, but not After Effects, Premiere Pro. I guess that could be an issue, however I recall seeing the problem in FCP as well. And no, I'm not positive it's Sedna responsible. All I know is I changed hacks to Sanity 5 and shot in the same places and lighting settings as where I saw the problems. Haven't seen any issues since...

vicharris

Just put up a video shot with Sedna AQ1 and it's clean but I'm cutting on FCP converted with 5DRGB.

driftwood

@spikedurdenTry a clean install of Sedna:redownload ptools,firmware and sedna into their own directory.Reflash. It could very well be your workflow.

svart

These are the flickers I've always been talking about and nobody seems to take it seriously. It's present in the stock firmware under certain conditions and is also present in every patch that I've tried under the same conditions, low light with large area underexposed. It's even present in the GH3 footage out there. If you go frame by frame, some frames will have different tints of color in the noise over large areas of the underexposed places.

tetakpatak

@spikedurden I've had similar problem almost one year ago, probably because I've accidentally added something in Ptool while loading one @driftwood 's patch. Do just as driftwood adviced to, it should solve the problem. @driftwood I tought the flickering had to do with PAL/NTSC but reflashing solved the issue....maybe my cat walked over the keyboard when I wasn't watching (I am serious....)

thepalalias

@svart I've also talked about the intermittent "shadow flicker issue" several times. I sometimes go to great lengths to shoot to avoid it. I was hoping it would be fixed in the GH3.

The issue you and I encountered is (as you said) not hack related, but it seems some people may be encountering a workflow issue on top of that...

svart

@thepalalias I usually see it in a frame with a large area of midtone that is slightly underexposed. The exposure meter may or may not show underexposure and there may even be am overexposed area. A good place to recreate it is a fairly dark bedroom with gray walls. The practical lighting will show a normal exposure but gray walls and dark floor/bedding will randomly show this strange tinting. It seems rather random in timing too. I can step through a scene frame by frame and it doesn't seem to happen with any type of cadence and it usually shows only in the midtones but not the brighter areas and sometimes not in the blacks. I showed a screenshot of it in the GH3 thread from Bloom's video. I'll see if I can find it..

http://www.personal-view.com/talks/uploads/FileUpload/f1/5cc8e5d622aa870a29e4d606be5744.png

And look in the carpet and walls. Different tints.

It seems to be an artifact of the codec itself. Because the GH3 shows this, it's pretty obvious that they used the same code base from the GH2 and just updated it with the improvements. This is one thing I wish panny would fix rather than some of the other benign stuff people are asking for.

balazer

This problem has been discussed before:

http://www.personal-view.com/talks/discussion/3804/strange-pulsing-diagonal-pattern-in-gh2-hack-footage/p1

pc_bel

Same problem for me with Flowmotion 2.02. But I'm almost sure problem is not recorded in the MTS file. I can see the problem in AE CS6 and in VLC player, but not in Media Player Classic, if diagonal rain was in the original file I could see it always... Transcoding with 5DtoRGB and problem goes away too...

kurt10

I have this problem with Flowmotion 2.02... Driftwood Canis Majoris Pm works perfect..

sam_stickland

I've seen this problem with Flowmotion 2.02 and CS6 but not CS5.5. Transcoding via 5d2RGB will fix your footage. I remember there being a suggestion that this might be being caused by incorrect handling of b-frames in the decoder. I've been meaning to open a support case with Adobe about this, but I've been busy.

skydragon

I've also experienced this exact same issue with flow motion 2.02 in 24p mode.....'digital rain'

It mainly occurs on darker/underexposed areas of a shot and is definitely something to do with how the .MTS file is decoded and played back. I get it happening in Premiere Pro CS6 and with VLC, but not in Media Player Classic.

If I transcode the .MTS files to DNxHD format using FFMBC then the problem seems to disappear and the files then play back ok in Premiere Pro CS6 and VLC... however if I transcode to DNxHD in Adobe Media Encoder CS6 then the problem still persists.

I never see the issue on well lit shots, only on darker footage.

skydragon

I've just done another test.

GH2 with Flow Motion 2.02, 24P, shot 10 secs of indoor footage in a dimly lit room.

If I play back the raw .MTS file in Premiere Pro CS6 I can see the digital rain/snow/lightening (pick your own description) on playback.

If I take the same .MTS and use FFMBC to transcode to DNxHD 175M the resulting file now plays back on the timeline 100% ok.

Conclusion;

a) The hacked GH2 is not producing a 'correct' .MTS file and as such PP CS6 can't be expected to work with it.

or

b) PP CS6 does not work fully ok with .MTS files

what is puzzling is why this only happens on underexposed, dim parts of GH2 footage and not on well-lit footage??

skydragon

This is a pretty big issue for some GH2 users if one of the world's leading NLE's (Premiere Pro CS6) won't play back some hacked GH2 MTS files without the possibility of introducing this 'digital rain' noise on certain types of footage.

To assist other PC users having this problem, I suggest you transcode your AVCHD .MTS files to DNxHD .MOV

I'm shooting in 24p (23.976 fps) and use the following workflow on my PC;

First you'll need the Avid DNxHD codec pack, which you can download free at http://avid.force.com/pkb/articles/en_US/Download/en423319?retURL=%2Fpkb%2Farticles%2Fen_US%2FDownload%2Fen423319&popup=true

Then download FFMBC which you can download free from http://code.google.com/p/ffmbc/

Install the DNxHD codec pack, then create a new folder containing the FFMBC app file you downloaded and create a batch file in the same folder containing the following line;

for %%a in ("*.mts") do ffmbc -i "%%a" -vcodec dnxhd -b 175M -acodec pcm_s16le -ar 48000 -ac 2 -threads 4 "%%a"-Transcoded.MOV

Place the MTS files you want to convert in this new folder (along with FFMBC and the batch file) and when you run the batch file, this will then take your 23.976fps AVCHD .MTS files and batch convert and rename them into 23.976fps 175 Mbps DNxHD .MOV files

These DNxHD files (appear) to then play back in Premiere Pro CS6 100% ok. There will be some very small loss in quality in the transcode process, but it is so slight that I would suggest it is not of consequence.

If you are using a different framerate than 23.976 fps you will have to alter the '175M' part of the batch file line to the appropriate codec rate, see the table for details on bitrates versus framerates in the link below (example; if you were using 25fps or 50i footage you would convert using 185M and not 175M which is for 23.976 fps and 24 fps)

http://www.itbroadcastanddigitalcinema.com/ffmpeg_howto.html

It's worth noting that the resulting DNxHD .MOV files will be far larger than the original .MTS files, as the Avid codec is approx 175Mbps. This is a negative in terms of HDD storage, but if it ensures the media plays back and can be used 100% ok in Premiere Pro CS6 then it has to be worth it.

I've run several tests on different MTS files which display the 'rain noise' in Premiere Pro and looking at before/after the original MTS files display the problem consistently and the DNxHD files play back 100% ok consistently.

An alternative workflow is to use 5DtoRGB (at http://rarevision.com/5dtorgb/ ) which will enable you to create 10 bit DNxHD files which may be better quality for some purposes (the workflow I've highlighted above creates 8 bit files) although currently the PC version of the program has no batch conversion facilities for PC and therefore you have to transcode one single file at a time. I have not been able to locate a batch conversion solution that will handle MTS files via 5DtoRGB on PC.

IMPORTANT NOTE - I tried using several other transcoding methods, including using Adobe Media Encoder CS6 to try and transcode the MTS files to DNxHD .MOV. Although the transcode took place successfully, all the media files still had the same 'digital rain' noise when played back in Premiere pro CS6. The only two methods I have tried that seem to work 100% ok are either using FFMBC or using 5DtoRGB.

Hope this helps.

driftwood

Also try remuxing without re-encoding (lots of remuxer/ffmpeg plugins/GUIs like mp4tools out there) and change the profile level to something higher - like 5. Sometimes NLEs and players get confused.

tusoli5

I had the same problem with the smooth patches... It is hard to remove on your shots, it only happens on dark zones. I could remove most of it by blackening but your shots are allready quite dark...

Howdy, Stranger!

Categories

Tags in Topic

Top Posters