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:
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!