Intel Kabylake Quicksync and HDR encoding in FFmpeg

[BearV]

Hey all,

I'm new to the forums here, but it looks like a great community which has helped me already with a few issues I've faced. Perhaps you could assist me with my own problem.

Anyway, I'm looking for help with a certain issue with Intel Quicksync and FFmpeg. I'm currently experimenting with file sizes and quality tradeoffs of x265 HDR content. I've searched the forums and have managed to figure out how to retain HDR content through color settings when transcoding media, which works fine in FFmpeg through software transcoding. However CPU transcoding 2160p content as you're aware takes a loong time. I do have a Kabylake CPU with hardware encoding capabilities though and I want to try and take advantage of that. I've already tested with some x265 content and the speed is incredibly fast, and I want to try it this way to see if the speed/quality tradeoff is worth it; However I can't seem to retain the original files' HDR settings when using hardware endcoding within FFmpeg.

Is anyone knowledgeable able to tell me what's wrong here? Is this a Quicksync or FFmpeg limitation? How would I go about remedying this?

Thanks for any help.

[pandy]

Check https://github.com/rigaya/QSVEnc side to existing ffmpeg documentation (where seem hevc_vaapi encoder should have possibility to add HDR metadata), confirm also with Intel Quicksync API (or ask Intel Developer support).

[BearV]

Sorry, not sure I understand. What does QSVEnc help with exactly?

So as the documentation stipulates, it is definitely possible for HDR 10. I wonder what's going wrong here...

Edit:

I actually use myFFMmpeg as a front end to help me with code parameters. Here is the code it is ouputting to ffmpeg:

-map 0:0 -map 0:2 -map 0:1 -map 0:3 -c:a:0 copy -disposition:a:0 default -c:a:1 copy -disposition:a:1 0 -async 1 -c:v hevc_qsv -load_plugin hevc_hw -b:v 18314.04k -maxrate 36628.08k -bufsize 36628.08k -r 24000/1001 -s 3840x2160 -aspect 16:9 -pix_fmt yuv420p10le -map_metadata 0 -c:s copy -x265-params profile=main10:me=hex:scenecut=40:bframes=4:min-keyint=24:keyint=48 -color_primaries bt2020 -color_trc smpte2084 -colorspace bt2020_ncl -qmin 3 -qmax 51 -map_metadata 0

[pandy]

Sorry, not sure I understand. What does QSVEnc help with exactly?

It helps to document Intel API capabilities, ffmpeg documentation is quite limited.

So as the documentation stipulates, it is definitely possible for HDR 10. I wonder what's going wrong here...

Edit:

I actually use myFFMmpeg as a front end to help me with code parameters. Here is the code it is ouputting to ffmpeg:

-map 0:0 -map 0:2 -map 0:1 -map 0:3 -c:a:0 copy -disposition:a:0 default -c:a:1 copy -disposition:a:1 0 -async 1 -c:v hevc_qsv -load_plugin hevc_hw -b:v 18314.04k -maxrate 36628.08k -bufsize 36628.08k -r 24000/1001 -s 3840x2160 -aspect 16:9 -pix_fmt yuv420p10le -map_metadata 0 -c:s copy -x265-params profile=main10:me=hex:scenecut=40:bframes=4:min-keyint=24:keyint=48 -color_primaries bt2020 -color_trc smpte2084 -colorspace bt2020_ncl -qmin 3 -qmax 51 -map_metadata 0

Well if you say so... x265 private options and different codec used... also it looks like few other metadata missing...