Jimmyjames
Elite Member
- Joined
- Jul 13, 2022
- Posts
- 1,192
Not sure if this belongs in the Apple section? It involves Apple, but is more technical really.
Elgato, maker of capture cards (among other things) has just released a new usb capture device called the “4K X”. Looks great and allows 4K 144fps capture over usb 3.2 (I think). It’s also Mac compatible. Yay!
The one wrinkle, HDR is not supported on macOS but is on Windows. Dissapointing. I asked one of Elgato’s representatives what prevents HDR capture on macOS and the reply was:
"No HDR capture on Mac is a MacOS limitation. macOS does not support the P010 video format which 4K X (and other capture cards) use for HDR. When Apple adds P010 support HDR capture in apps like OBS Studio will be possible."
OK. Interesting. I am surprised this is the case but at least it’s something to file a feedback for. Nevertheless there was something at the back of my mind nagging me. I was sure I had seen mention of P010 when converting videos in ffmpeg previously, so I open Termina.app, run ‘ffmpeg -h encoder=hevc_videotoolbox’ and see the output. Among the instructions was:
'Supported pixel formats: videotoolbox_vld nv12 yuv420p bgra p010le'
Hmmm, that last one looks like the supposed missing HDR pixel format. I then decide to go to GitHub and look at the ffmpeg source code. A relevant file called ‘videotoolbox.c'
I search for P010 and find this code:
Ok, so that looks promising. I then search for ‘KCVPIXELFORMATTYPE_420YPCBCR10BIPLANARVIDEORANGE’ and a page on Apple’s dev site returns this page
developer.apple.com
So now I’m in the position to think that macOS does indeed support P010, and either Elgato doesn’t know that , or they are…I don’t know.
After that long opening, my request is…am I right? I am not the most familiar with low level code and pixel formats. Have I missed something?
Elgato, maker of capture cards (among other things) has just released a new usb capture device called the “4K X”. Looks great and allows 4K 144fps capture over usb 3.2 (I think). It’s also Mac compatible. Yay!
The one wrinkle, HDR is not supported on macOS but is on Windows. Dissapointing. I asked one of Elgato’s representatives what prevents HDR capture on macOS and the reply was:
"No HDR capture on Mac is a MacOS limitation. macOS does not support the P010 video format which 4K X (and other capture cards) use for HDR. When Apple adds P010 support HDR capture in apps like OBS Studio will be possible."
OK. Interesting. I am surprised this is the case but at least it’s something to file a feedback for. Nevertheless there was something at the back of my mind nagging me. I was sure I had seen mention of P010 when converting videos in ffmpeg previously, so I open Termina.app, run ‘ffmpeg -h encoder=hevc_videotoolbox’ and see the output. Among the instructions was:
'Supported pixel formats: videotoolbox_vld nv12 yuv420p bgra p010le'
Hmmm, that last one looks like the supposed missing HDR pixel format. I then decide to go to GitHub and look at the ffmpeg source code. A relevant file called ‘videotoolbox.c'
I search for P010 and find this code:
C:
#if HAVE_KCVPIXELFORMATTYPE_420YPCBCR10BIPLANARVIDEORANGE
if (depth > 8) {
return AV_PIX_FMT_P010;
}
Ok, so that looks promising. I then search for ‘KCVPIXELFORMATTYPE_420YPCBCR10BIPLANARVIDEORANGE’ and a page on Apple’s dev site returns this page

kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange | Apple Developer Documentation
There's never been a better time to develop for Apple platforms.
So now I’m in the position to think that macOS does indeed support P010, and either Elgato doesn’t know that , or they are…I don’t know.
After that long opening, my request is…am I right? I am not the most familiar with low level code and pixel formats. Have I missed something?