offbeat if you have video sample which causes out of CMA memory issue, I would appreciate if you can provide it to me. However, this should soon become issue of the past, I'm working for some time now on fixing all IOMMU issues and once fixed, Cedrus will use normal memory allocator instead of CMA. Interestingly, IOMMU is great debugging tool. If there is access outside of designated buffer, it complains. This already allowed me to fix some Cedrus bugs. Anyway, if you want to see current progress (some H264 videos and HW deinterlacing doesn't work), you can check https://github.com/jernejsk/LibreELEC.tv/commits/iommu
GPU suspend issue is really unfortunate, but no panfrost developer on IRC seems to be particularly interested in fixing that (at least at time of asking some time ago). I looked into this quickly, but it's way over my head, GPU drivers are not my cup of tea.
HDMI output can randomly drop out for a second, both during playback and in menu. Probably some output timings issues, since sometimes (rare though) TV gets confused and refuses to display certain Hz videos, requiring on/off cycle, which never happened outputing from my other STBs.
I went over BSP HDMI driver code many times now and I believe everything is as it should be with latest nightly images, except maybe some minor HDMI PHY settings. I haven't experience any HDMI related issue for a long time. I learned the hard way that HDMI signal quality also depends on board design. During development of H616 HDMI driver I didn't have any luck of getting 4k output on OrangePi Zero2 board. It turns out, 4k also doesn't work with BSP kernel image. However, on H616 TV box, everything work as expected.
H6 still needs algorithmdirtyregions=0 set in Kodi, otherwise any video will stutter.
I don't experience that, not sure why.
10bit HEVC plays just fine, 10bit VP9 isn’t really working yet (decodes to garbled pixels). Can’t vouch for colors, most likely TV only gets 8bit for now.
True on all counts. VP9 driver is pretty new, nobody really worked on 10-bit support. I did a quick check, but nothing stands out. It needs detailed analysis. 10-bit HDMI output is being worked on.
Note that ffmpeg decoding loop is not optimized for speed, ideally RPi ffmpeg code for HEVC should be reused (it uses same interface as Cedrus) since it was already improved for speed. Also HEVC supports AFBC "compression", which makes memory accesses more efficient and that translates to higher decoding speed. Needless to say, that also needs to be added.
So, H6 still has a lot of untapped potential. Many issues/missing features are being worked on, but currently I'm busier than expected, so progress is slow. Some issues are not addressed at all, mostly because I don't experience them, so any kind of detailed analysis is impossible.