DPX to prores 4444
I'm trying to convert a DPX sequence to ProRes 4444. The alpha works well, but the color shifts, and I don't know why. Here is the command line I am using:
I looked for a pix_fmt that started with RGB but didn't find one. I am rendering the DPX sequence out of After Effects using "trillions of colors+" (16bit?).
Hi there Seth,
So, the ProRes4444 format is a little weird, and a little weirder still in FFmpeg. Since it's nothing but a 'profile' to the prores_ks encoder, it works like any other Prores encode would, and that (plus some reverse engineering done on the Apple decoder) suggests that ProRes even at 4444 is an YUV / Y'CbCr codec. That's also what you told ffmpeg to export, and even when you input an rgb(a) it should default to yuva444p10le as the output:
(single frame output for example)
Secondly, as far as I know, currently FFmpeg does not support encoding deeper than 10bit pixel formats. (as suggested by the 'p10le' tail on the pix_fmt you supplied in your arguments). Reading a deeper-than-10-bit ProRes file will also give you the estimated yuva444p10le pixel format.
So that is where the colorshift might originate from. And that's as much explanation as I can give you, considering I don't know the system you're working in or what color shift exactly happens.
If you need to encode to a mastering _video_ format in RGB, consider Apple Animation as it's a RLE (linear) encoder that supports RGB pixel information.
For windows, I think you'd be stuck exporting a 10bit uncompressed video? (Which will be giant in filesize)
as an aside, ffmpeg will display the supported pixel formats when you input:
You can pipe the output and grep to 'filter' strict rgb formats. Note that pixel ordening will mean they're not all labeled rgb, some will be bgr, grb, etc.