HDR subtitles are displayed incorrectly in many cases. Judging solely from the code, it seems that Amlogic chips support OSD2. Is there any possibility of separating the subtitles independently from the GUI?
Im happy what I see. Whats an example of your issue. CE lets you move the subtitle etc.
PGS subtitles, like videos, come in two formats: SDR and HDR. PGS subtitles cannot be moved.
Currently, some user-customized builds on GitHub use the interface CSysfsPath(“/sys/module/am_vecm/parameters/osd_pq_bypass”, enable) together with corresponding shader calculations to accurately restore the color of HDR PGS subtitles.
However, this approach is not very user-friendly for owners of S905X2 and S905X4 devices, as it often leads to issues such as high CPU usage and video stuttering.
If the GUI and subtitle layers could be separated, using different OSD layers at the hardware level, this would be much more efficient for A53 and A55 SoCs.
Does the kernel support OSD2 though?
Seems to suggest it doesn’t. drm/meson AmLogic Meson Video Processing Unit — The Linux Kernel documentation
I don’t think even kodi support such item.
They use libGLES for rendering, same for GUI and subtitles.
One item AML extra support is a subtitle decoder. But this is not very usefull as this is not the problem at all and the current ffmpeg decoder works fine and is enough.