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. -- Vittorio _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel