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GH2 and other MTS source long GOP artefacts in Premiere Pro CS6 – Work around
Hi all
After much discussion on the Adobe and Personal View forums there is a problem with GH2 MTS (and apparently other long GOP files) when imported into Premiere CS6.
This is CS6 specific. CS5 or CS5.5 does not exhibit this fault) This may well be due to the Main concept Filters used for decoding the AVC files. No one has been able to find where the exact problem is however a “rain” effect of artefacts and noise is noticeable on GH2 footage when imported. This is very noticeable with underexposed large areas of light saturation. An underexposed painted wall shows it nicely. You will be hard pressed to see the fault with outdoor shots with movement and lots of detail but I am guessing there is still a degradation going on, it is just not that noticeable.
So there are 2 solutions:
1) Shoot with ptools modified firmware set to I frame only (GOP=1). The fault seems to be GOP related so by shooting I frame only your removing the problem of the decoder. Obviously you need to up your bit rate to to compensate for the reduced compression.
2) Convert to ProRes. This seems the better option as you get the smoother clip scanning and you get much better range for your grading. Just uses a lot more storage. I had thought this negated the time advantage of direct import to PP but you can always use the MTS files to edit with then render to ProRes overnight and replace the clips with the converted ProRes.
If you allready know all this then sorry for the time waste but there seems to be enough confusion out there around the GH2 rain effect that, having spent days working through the issue, I thought it was worth putting what I have found on the forum. Please note this does not appear to be a fault with the GH2 just a compatibility issue between the MTS AVC files and the CS6 filters. There are also advantages I mention below to converting prior to using in PP anyway for AVC, 264 files.
If your like me and running Windows 7 the in spite of what many threads tell you, you can encode ProRes in Windows, just not directly from PP for an export. You use FFMPEG with a GUI and it is free. If you need instructions have written some below, hope it helps someone else 🙂
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I use 2 pieces of software for conversion. FFMPEG and Another Gui. FFMPEG is command line only but incredible versatile and quick at transcoding. In tests it uses all my CPU cores at full tilt. Another GUI is the nice GUI interface for FFMPEG, it takes the hassle out of typing in long lines of parameters for FFMPEG. There are many GUI’s out there for FFMPEG but I chose Another Gui as it has a ton of presets on the webpage which avoids you having to make your own up.
FFMPEG Download page – Download the latest widows version. For example the latest 64 bit is this one: https://ffmpeg.zeranoe.com/builds/win64/static/ffmpeg-20130302-git-4f0d 4ac-win64-static.7z
(By the way, FFMPEG works better than FFMBC if you use FFMBC. The current version of FFMBC uses all the CPU cores but not at full speed so takes longer. The latest FFMPEG runs all cores at full tilt).
Another gui webpage – And download the latest version
Install Another GUI and then unzip the FFMPEG into the same folder. It can be anywhere but same folder is easier to find. Run Another Gui and agree to load factory presets. Then click on “edit” and for Executable click “add” then choose where your FFMPEG.exe is. It will be in the “bin” directory in the FFMPEG folder structure.
To use Another Gui you select your source file then a conversion preset, choose and out put directory then click “go”. Another gui passes the settings to FFMPEG which opens in a command line window which closes once the conversion is done. The command window gives you an update on progress and frames/sec conversion rate. To get a bleep when the conversion is finished, right click in Another GUI, preferences and tick the bleep box. And you should have you transcoded MTS to ProRes files. PP opens them fine for me and you get much improved seeking and more range with your grading. Of course no rain effect which is the whole point
Another GUI comes with standard presets but to add others including ProRes, go to the Another Gui webpage and the presets page. scan down the list till you find a preset you want to use and download it. Then in Another GUI, click edit under the preset box and click import. Then find your downloaed preset and import it. There are 4 ProRes presets so download all 4 and import them one at a time. Download and import any other presets you want to use.
Cheers
Andy -
1 Reply
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As a follow up I did some more testing in combination with Jim over on Adobe Forums. Using the same firmware version that he does “Driftwood Cluster v7 ‘Apocalypse Now’ – 6 GOP Nebula ‘444 seti” my GH2 MTS files import and export form PP CS6 without fault so the camera is not at fault as such.
At least we know it is a combination of GH2 stock compression settings and the Main Concept filters used in PP CS6. Since both sides will point the finger at the other the solution seems to be using Pro-Res transcoding or custom firmware.
So no definitive reason for the problem but a better understanding I guess.
Editing is why people like movies. Because in the end, wouldn’t we all want to edit our own lives?
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