Popular Post Thomas Worth Posted April 9, 2014 Popular Post Share Posted April 9, 2014 Hey guys, I've written a really simple command line app for Mac that will resample GH4 footage from 4K 4:2:0 to 2K 4:4:4 using pixel summing. This will give you real 10 bit data in the luminance channel, so it's not just doing a brute-force bump from 8 bits to 10 bits. There actually is some interesting pixel finagling going on here: http://www.mediafire.com/download/f7h950spj5hrn9f/gh444.dmg There's no GUI, so you'll need to run it from the terminal. Do this by copying the app into the directory that contains the GH4 MOV files and using the following command in a terminal: ./gh444 INPUTFILE.MOV Make sure you cd to the current directory first if necessary. You can do this by typing "cd" into the terminal, add a space, and then drag the folder containing the MOV files into the terminal window. It will automatically add the path to the cd command. It'll look like this: cd /path/to/gh4/files The app will spit numbered DPX frames out in a folder named "dpx_out." I'd love for you guys to give it a try and see if you find it useful! Loma Graphics Oy, Nick Hughes, Richard Wait and 7 others 10 Quote Link to comment Share on other sites More sharing options...
jonpais Posted April 9, 2014 Share Posted April 9, 2014 Sounds great. I'm sure I'll have questions for you once I actually have the camera in my hands. Any idea about the processing power required to handle 10 bit 4:4:4? Same as 4K? Quote Link to comment Share on other sites More sharing options...
Thomas Worth Posted April 9, 2014 Author Share Posted April 9, 2014 Sounds great. I'm sure I'll have questions for you once I actually have the camera in my hands. Any idea about the processing power required to handle 10 bit 4:4:4? Same as 4K? It's typically easier for the CPU to process uncompressed data, but disk bandwidth is more of an issue. Since this app is designed mainly for testing, the DPX files will be large and require lots of storage bandwidth. If it makes sense, I can add the ability to save ProRes 4444 files at 2K. Generally speaking, ProRes footage is much easier to decompress and display than H.264 footage, even when it's 444/RGB. I haven't run into any problems with GH4 footage, though. The files are relatively small and any recent system should have enough CPU power to play them back in realtime. Quote Link to comment Share on other sites More sharing options...
Richard Wait Posted April 9, 2014 Share Posted April 9, 2014 Not to look a gift horse in the mouth! Any thoughts on a GUI? How do you program something like this anyway! (I'm really impressed!) and what are DPX files? Quote Link to comment Share on other sites More sharing options...
Julian Posted April 9, 2014 Share Posted April 9, 2014 Windows version? ;) I'd give that a try for sure. Getting my hands on a GH4 v 1.0 in a few days... Quote Link to comment Share on other sites More sharing options...
Administrators Andrew Reid Posted April 9, 2014 Administrators Share Posted April 9, 2014 Great news. How are you finding the 2k images Thomas? Does it smooth the slight aliasing on the car windows in the Porsche shot? Quote Link to comment Share on other sites More sharing options...
Thomas Worth Posted April 9, 2014 Author Share Posted April 9, 2014 Here's a 16 bit PNG file, converted from a DPX file output by gh444: '> Andrew Reid 1 Quote Link to comment Share on other sites More sharing options...
Sean Cunningham Posted April 9, 2014 Share Posted April 9, 2014 Forgive the re-post from Andrew's other thread on the subject but I wonder how hard would it be to, instead of summing, do a poisson disc sample to arrive at the 2K image? Quote Link to comment Share on other sites More sharing options...
Administrators Andrew Reid Posted April 10, 2014 Administrators Share Posted April 10, 2014 Here's a 16 bit PNG file, converted from a DPX file output by gh444: '> Impressive. Quote Link to comment Share on other sites More sharing options...
KarimNassar Posted April 10, 2014 Share Posted April 10, 2014 very interesting thank you. Can you share just 1 frame of the original 4k and the same frame downsample to 2k 10bit? Just to experiment in post to test the difference Richard Wait, HurtinMinorKey and Julian 3 Quote Link to comment Share on other sites More sharing options...
thementalist Posted April 10, 2014 Share Posted April 10, 2014 +1 for windows version It's not about gh4, it's how we say fuck to firmware limits on panasonic, canon, Nikon, etc Quote Link to comment Share on other sites More sharing options...
JLemos Posted April 10, 2014 Share Posted April 10, 2014 What could be the resulting file converted to 2.5K? I think that in terms of size it could be of general interest, or at least of my general interest. :) Quote Link to comment Share on other sites More sharing options...
Jack Danini Posted April 10, 2014 Share Posted April 10, 2014 +1 for Windows Please! :) Thanks Quote Link to comment Share on other sites More sharing options...
etidona Posted April 10, 2014 Share Posted April 10, 2014 Too much numbers for my tastes: someone could please verify if the downscaled version grades better than the original? Julian 1 Quote Link to comment Share on other sites More sharing options...
Guest Ebrahim Saadawi Posted April 10, 2014 Share Posted April 10, 2014 Please show us examples. Proof. That is awesome and well done Thomas if true Quote Link to comment Share on other sites More sharing options...
James_H Posted April 10, 2014 Share Posted April 10, 2014 Here's a GUI I quickly put together: http://www.mediafire.com/download/s9wyyfw9qvh8cfl/GH444_GUI.dmg You still need to download the original gh444 file. Let me know if it's broken. It's super basic. It doesn't provide any info on progress, but it'll let you know when it's done. Edit: A little explanation: Download the file, mount it and copy "GH444 GUI" to your computer somewhere (e.g. Applications). Open the app, click "Browse" to specify which file you want to convert. The output will be in a folder called dpx_output in the same folder as the 4K file. Click "Start" Select the gh444 file that Thomas Worth provided Wait. A popup with the word "Done" will been shown when it's done. Known issues: It doesn't show progress. If you cancel it, it will still say "Done" Not sure if it works with OS X 10.7 or earlier, I haven't tested. No way to set the output directory Richard Wait 1 Quote Link to comment Share on other sites More sharing options...
Administrators Andrew Reid Posted April 10, 2014 Administrators Share Posted April 10, 2014 Here's a GUI I quickly put together: http://www.mediafire.com/download/s9wyyfw9qvh8cfl/GH444_GUI.dmg You still need to download the original gh444 file. Let me know if it's broken. It's super basic. It doesn't provide any info on progress, but it'll let you know when it's done. Great stuff!! Thanks a million James. James_H 1 Quote Link to comment Share on other sites More sharing options...
Julian Posted April 10, 2014 Share Posted April 10, 2014 Here's a 16 bit PNG file, converted from a DPX file output by gh444: '> Can someone (Andrew?) grab the exact same frame from the 4K source file and post it as a 16 bit PNG file? Quote Link to comment Share on other sites More sharing options...
morsafr Posted April 13, 2014 Share Posted April 13, 2014 Hi all, I experimented with this piece of software but I get inconsistent results with some bad frames. I tried both with and without the GUI. My setup : Mac Pro 2013 with Mavericks, using Resolve 10.1.4 for grading the DPX files. Thanks for your feedback. Quote Link to comment Share on other sites More sharing options...
dash__dot Posted April 13, 2014 Share Posted April 13, 2014 I can post some 10 bit and 8bit 4k files that can be downsampled and the grade compared if it would help the discussion about how much it helps? I am on PC so I can't do the comparison myself unfortunately. Quote Link to comment Share on other sites More sharing options...
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