HDR encoding best practices?

[Blue_MiSfit]

Hey folks,

Any thoughts on best practices for using ffmpeg and x265 for encoding HDR content coming from IMF masters? These generally are very high quality lossy j2k, using either rec 2020 or p3 color.

[FranceBB]

@Blue_MiSfit... I don't know how to handle IMF master properly. I had many issues back then and I still have issues now: https://forum.doom9.org/showthread.php?t=173372
As far as I know, in an IMF master, you should be able to choose the output using the OPL which would let you choose your target for the conversion.
Avisynth still can't handle IMF master files and I bet ffmpeg can't either.
At the end, we "solved" asking production companies to convert their master in an Intra Class 300 file in order to properly handle it and encode it to HEVC 25 Mbit/s 10bit to air it.
It would be interesting to have an opensource Avisynth decoder (like FFMpegSource2, LWLibavVideoSource etc) to support it.
No progress since 2016, I think, but I might be wrong. I haven't tried lately.

[Blue_MiSfit]

Seems like ffmpeg can decode the j2k mxf files that are typically included in IMF. I've also managed to get a filtering pipeline working that converts P3 D65 RGB into rec 2020 4:2:0 10 bit suitable for HEVC encoding. Hopefully my content providers can give me rec 2020 ycbcr j2k in the future, since I'm willing to guess mastering tools like Clipster and Transkoder do a better job than ffmpeg at this delicate process.

I've made files that play on a TV, but I was just curious what people have learned from transcoding HDR content with HEVC.

I've utterly abandoned AviSynth at this point :)