How to create a VP9 HDR encoding?

[Ta Dev]

Hi,

I'm currently experimenting with ffmpeg HDR encoding. 

As input I'm using the HDR demos you can find at http://demo-uhd3d.com/categorie.php?tag=hdr and on some other sites.

To be able to do so I've built ffmpeg by myself so that 10 (and 12) bit support is generally provided. If you search around for a while you will find encoding examples for HEVC. 

The creation of a "standard HDR 10 enocding" using HEVC for a 2k video can e.g. look as follows:

ffmpeg -i chess_hdr.mp4 -vf scale=2560:1440 -c:v libx265 -preset:v fast \

-x265-params "colorprim=bt2020:transfer=smpte-st-2084:colormatrix=bt2020nc:master-display=G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,500):max-cll=0,0" \

-crf 18 -ac 2 -c:a aac -b:a 192k -y chess_hdr-1440p.ts

If you have a closer look at the command, you will see, that the only "trick" is to set some HDR related x265-params.

It would be great to do the same with VP9. But unfortunately I couldn't find any encoding example how to do so.

Is there somebody who can help me?

The most promising way I can currently imagine would be to create the VP9 stream, mux it into an mkv container and set HDR metadata with the help of mkvmerge.

Is there a way to do that with webm (instead of mkv), too?

Thank you in advance