The Raspberry Pi 4 has hardware HEVC decoding so it could make a very nice display device for UltraGrid. With VLC and ffmpeg I'm able to get smooth playback of 4K 10-bit (limited to 4:2:0) with about 30% CPU usage.
From what I've read, the HEVC decoder uses a custom pixel format known as "sand". Converting this to a standard pixel format is too slow for realtime, so I think the only option is to pass the opaque sand buffers to the HDMI output which knows how to display it.
Example ffmpeg command (built from https://github.com/popcornmix/FFmpeg/tree/kodi_v4l2_4_2_2):
ffmpeg -hwaccel rpi -i uhd40Mb-420_23.ts -f vout_rpi -
The Raspberry Pi 4 has hardware HEVC decoding so it could make a very nice display device for UltraGrid. With VLC and ffmpeg I'm able to get smooth playback of 4K 10-bit (limited to 4:2:0) with about 30% CPU usage.
From what I've read, the HEVC decoder uses a custom pixel format known as "sand". Converting this to a standard pixel format is too slow for realtime, so I think the only option is to pass the opaque sand buffers to the HDMI output which knows how to display it.
Example ffmpeg command (built from https://github.com/popcornmix/FFmpeg/tree/kodi_v4l2_4_2_2):