Hi Vittorio, Vittorio Giovara <vittorio.giov...@gmail.com> writes:
> On Fri, Feb 8, 2019 at 3:22 AM Harish Krupo <harish.krupo....@intel.com> > wrote: > >> Hello, >> >> We are in the process of implementing HDR rendering support in the >> Weston display compositor [1] (HDR discussion here [2]). When HDR >> and SDR surfaces like a video buffer and a subtitle buffer are presented >> together, the composition would take place as follows: >> - If the display does not support HDR metadata: >> in-coming HDR surfaces would be tone mapped using opengl to SDR and >> blended with the other SDR surfaces. We are currently using the Hable >> operator for tone mapping. >> - If the display supports setting HDR metadata: >> SDR surfaces would be tone mapped to HDR and blended with HDR surfaces. >> >> The literature available for SDR->HDR tone mapping varies from simple >> linear expansion of luminance to CNN based approaches. We wanted to know >> your recommendations for an acceptable algorithm for SDR->HDR tone mapping. >> >> Any help is greatly appreciated! >> >> [1] https://gitlab.freedesktop.org/wayland/weston >> [2] >> https://lists.freedesktop.org/archives/wayland-devel/2019-January/039809.html >> >> Thank you >> Regards >> Harish Krupo >> > > In *theory* the tonemapping functions should be reversible, so if you use > vf_tonemap or vf_tonemap_opencl and properly expand the range via zimg > (vf_zscale) before compression it should work fine. However I have never > tried it myself, so I cannot guarantee that those filters will work as is. > Of course haasn from the libplacebo project might have better suggestions, > so you should really reach out to him. Thanks, will try reversing the algorithms. Sure, will contact Haasn. Regards Harish Krupo _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
