Odd snow-like compression artifacts on hacked GH2 (lpowell flow motion)

C

CColton

Well-known member
I've been using lpowell's flow motion patch, and the quality and stability is great, but I repeatedly get some odd compression artifacts in the blacks of images or in areas that are large spaces of a single color (walls, tables, etc.). They are diagonal, thin artifacts that are slightly brighter than their surrounding pixels. They can almost make it look like it was lightly snowing in a shot. There artifacts appear on all lenses, especially in the blacks. At ISO 160 they still show up so I know they aren't noise from the sensor. At high ISO the expected sensor noise actually masks the artifacts a bit.

Does anyone have any idea what could be going on?
 
The "digital rain" artifacts are a decoding flaw that afflicts the MainConcept decoder bundled with Adobe CS6, in both Premiere Pro and After Effects. This issue has been reported to both MainConcept and Adobe but neither company has publicly responded. Since the problem doesn't appear to afflict the decoders bundled in Adobe CS5 and CS5.5, I recommend using After Effects CS5.x to transcode MTS footage to Cineform, ProRes, DNxHD, or MP4 formats before importing the clips into Premiere Pro. Personally, I've uninstalled CS6 for this and other reasons, and am hoping that CS7 will prove to be a more reliable platform.

Here's a link to a previous thread on this topic:
http://www.dvxuser.com/V6/showthrea...quot-digtial-rain-quot&highlight=digital+rain
 
Lpowell said:
The "digital rain" artifacts are a decoding flaw that afflicts the MainConcept decoder bundled with Adobe CS6, in both Premiere Pro and After Effects. This issue has been reported to both MainConcept and Adobe but neither company has publicly responded. Since the problem doesn't appear to afflict the decoders bundled in Adobe CS5 and CS5.5, I recommend using After Effects CS5.x to transcode MTS footage to Cineform, ProRes, DNxHD, or MP4 formats before importing the clips into Premiere Pro. Personally, I've uninstalled CS6 for this and other reasons, and am hoping that CS7 will prove to be a more reliable platform.

Here's a link to a previous thread on this topic:
http://www.dvxuser.com/V6/showthrea...quot-digtial-rain-quot&highlight=digital+rain
Click to expand...

That's unfortunate. I have Creative Cloud so reverting to a previous version is not possible and I love some CS6-specific features. I also prefer Premiere to Avid for its native editing abilities so that I don't have to waste time and drive space with transcoding. Obviously I'd only transcode clips that were displaying the "rain" but I'd still prefer not to.

That thread reported users having no digital rain problems with intra-frame-only hacks. I've tried Driftwood's Moon I-frame hack and it was extremely unstable. Lpowell, do you have an I-frame hack that I could try, by chance? That could solve this problem and potentially also improve PPro performance.
 
Lpowell said:
Sorry, I don't have an intra-frame hack for you. If you have no other options besides CS6, I'd recommend transcoding to Cineform using GoPro Cineform Studio, which is available for download free of charge:

http://gopro.com/3d-cineform-studio-software-download/
Click to expand...

Thank you, I use Cineform frequently to store lossless copies of my final products so I'd either use that or ProRes. Do you know if they were correct in saying that intra-frame hacks solve the problem? I hate to ask you to promote someone else's hack I'm just curious. I've always stuck with your hacks so unless another one is as stable and fixes the rain I'm sticking with you :)
 
CColton said:
Do you know if they were correct in saying that intra-frame hacks solve the problem?
Click to expand...
The MainConcept AVCHD decoding flaw involves the built-in H.264 Deblocking Filter, which is used on both I-frames and B-frames. It's an elusive bug that appears to only afflict certain video files, though I can't really be sure whether it's latently affecting all videos or not. I've read reports that it can afflict non-hacked video files as well, but I haven't seen an example myself.
 
Will Premiere open DPX, ProRes or DNxHD files? I use 5DtoRGB (though I use FCP- and am sold on APR 422 flavors) which has a free non-batch version. Canon and Panasonic specific settings. With or without the hack, this is better. Personally, I'll do whatever it takes at the point that the footage is in the can to sacrifice no quality. Fortunately, I don't need this for any other camera i use. Why go to the trouble to get the best image you can from the camera (like with flow motion) and then compromise downstream? Like complaining about bigger files while simultaneously wanting higher bit rate quality. Choose

And maybe give Adobe an earful.

http://rarevision.com/5dtorgb/

sensible settings:
http://www.crossbowfilms.net/5dtorgb-settings-for-panasonic-gh2/
 
Lpowell said:
I've read reports that it can afflict non-hacked video files as well, but I haven't seen an example myself.
Click to expand...

I can confirm that it does, though I've had zero issues with AVCHD from the C100. It may be something specifically about the GH2 that causes this, because surely they would fix it if it was more widespread than just that camera.

Would love to hear if anyone has seen this artifacting from any other AVCHD cameras.
 
xenic said:
Will Premiere open DPX, ProRes or DNxHD files? I use 5DtoRGB (though I use FCP- and am sold on APR 422 flavors) which has a free non-batch version. Canon and Panasonic specific settings. With or without the hack, this is better. Personally, I'll do whatever it takes at the point that the footage is in the can to sacrifice no quality. Fortunately, I don't need this for any other camera i use. Why go to the trouble to get the best image you can from the camera (like with flow motion) and then compromise downstream? Like complaining about bigger files while simultaneously wanting higher bit rate quality. Choose

And maybe give Adobe an earful.

http://rarevision.com/5dtorgb/

sensible settings:
http://www.crossbowfilms.net/5dtorgb-settings-for-panasonic-gh2/
Click to expand...

I was simply asking if there was another workaround that saved space, obviously if transcoding is the best option, that's what I'll do :)
 
Did anyone ever figure out a way to get a fully edited CS6 project to export without the digital rain?
Either through Premiere CS6 or an export to anther NLE?
 
Richy Lacey said:
Did anyone ever figure out a way to get a fully edited CS6 project to export without the digital rain?
Either through Premiere CS6 or an export to anther NLE?
Click to expand...

Easiest way is probably to transcode the clips that are giving you trouble to ProRes/Cineform/DNxHD (any lossless codec) and then replace the clips in the timeline with the transcoded files. If for some reason that's not feasible, you can send the clips from the timeline to After Effects and apply very very very light noise reduction (I usually turn off the noise reduction and just use very light temporal filtering) and that should take care of the rain.
 
hi all
for transcoding i found this,it easy, fast, batch processing and it's free http://hdcinematics.com/tools/AWProClient.html
just in case! i had trouble installing it because windows 7 64bit kept saying the installer in the file was 16bit .MSI file and needed to be 32bit ,the work around was to extract the MSI file into a folder and use it from there instead of installing it
i'll post the instructions on extracting the MSI when i find them

To extract files from a .msi file at the command line, type:msiexec /a PathToMSIFile /qb TARGETDIR=DirectoryToExtractTo

For example, to extract files from f:\zenworks\zfdagent.msi into c:\zfd701 you would type:
msiexec /a f:\zenworks\zfdagent.msi /qb TARGETDIR=c:\zfd701
The destination directory does not need to exist prior to running this command.
For those who don't know how to get to the command line, go to START and type in the search window at the bottom cmd.exe you'll see the at the top cmd.exe , right click on it and chose run as administrator just to be on the safe side, and follow the instructions above
As far as i know this is only for windows but try emailing wayne at wnorton@hdcinematics.com and see if he has anything for mac
hope i could help
FLY

 
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