Disable "DRM PRIME" at Settings -> Player -> Videos.
That did help with the black screen issue. However I'm still getting blurry elements most of the time, s. below. Network connection is stable as other videos run smooth. Also, other devices habe no such problems with the tested rtsp stream.
I'm fuzzy on the precise details in some areas ( popcornmix can probably describe things more accurately) but I think this is broadly what's happening:
The H264 hardware decoder supports a maximum 1920x1080 resolution on both boards (RPi4 inherited the same IP block as RPi3) and you are trying to play 2560x1440 resolution media on a 1024x768 monitor. As hardware decoding cannot be used because the resolution is too large the boards fall back to software decoding + resizing to match the output resolution + adjusting from 15fps to 60fps refresh rate (the only easy bit). RPi4 has the CPU grunt for the task so you see output. I'm unsure why RPi3 shows a blank screen where RPi4 shows output, but this is probably due to a capability difference between RPi3 (1080p max) and RPi4 (4K capable) so display pipelines are not equial. Disabling DRMPRIME in Kodi disables hardware decode and changes rendering in the kernel DRM layer; hence you now see something on RPi3 instead of nothing, but I'd guess it's still beyond the capabilities elsewhere in the pipeline so it's not usable output.
You could try overclocking. If not working afterwards, post the media info of the stream.
Is it a security camera?
the 3B+ only offers 640x480, 800x600 and the selected 1024x768. I couldn't get it to set higher one, or any in the correct format.
The display pipeline on RPi0/1/2/3 is 1920x1080 maximum and supports a specific set of configurations. The much newer RPi4/5 can handle 4096x2160 max and a wider variety of configurations.
If you can capture/share some examples of the stream we can look deeper.
The monitor is actually 16:9 and supports a higher resolution. The 4B also makes use of this, but the 3B+ only offers 640x480, 800x600 and the selected 1024x768. I couldn't get it to set higher one, or any in the correct format.
Hi, I didn't seen any 16:9 display with 1024x768 max resolution (the 1024x768 isn't a 16:9 resolution at all). What's the maximum display resolution detected with RPi4B and 3B+? Looks like the 3B+ using only max. 1024x768, and if the display able for something better, it's a display detection issue there (HDMI cable?). Could you try with an another HDMI cable and/or display? Probably that isn't the main issue, but should be clarified to exclude any conection with it.
Hi, I didn't seen any 16:9 display with 1024x768 max resolution (the 1024x768 isn't a 16:9 resolution at all). What's the maximum display resolution detected with RPi4B and 3B+? Looks like the 3B+ using only max. 1024x768, and if the display able for something better, it's a display detection issue there (HDMI cable?). Could you try with an another HDMI cable and/or display? Probably that isn't the main issue, but should be clarified to exclude any conection with it.
Different cable and display show same result. Only those three 4:3 resolutions are available on 3B+, even after fresh installation on formatted SD card.
The 4B connects at 1920x1080 automatically with the same cable. But I agree, this is probably a secondary issue.
You could try overclocking. If not working afterwards, post the media info of the stream.
Is it a security camera?
Yes, an IP camera offering RTSP steam. The information window in Kodi player only says "Not available" and below:
H.264 / 4K / 1.78:1 / AAC / 1.0
The display pipeline on RPi0/1/2/3 is 1920x1080 maximum and supports a specific set of configurations. The much newer RPi4/5 can handle 4096x2160 max and a wider variety of configurations.
If you can capture/share some examples of the stream we can look deeper.
Just to be clear, by capture examples you mean screenshots`?
H.264 / 4K / 1.78:1 / AAC / 1.0
Bingo! RPi4 can play 4K, but RPi3B+ can't. That's part of the official hardware specs.
by capture examples you mean screenshots`?
No, a sample of the stream (recording). Something that can be used to replicate the issue.
