Thank you gents.
That proved to be spot on and having disabled "Allow using DRM PRIME decoder" normal service is resumed.
This is not an area in which I have any knowledge and I would not have guessed the reason or resolution so I appreciate the help and expertise.
I decided it was time to update my Pi 2 running 9.2.8 to a Pi4 running 11.0.3. which was easy to do but now I have some changed behaviour with video orientation:
On some of my home videos which were shot inverted I could change the orientation using either the metadata or by 180 degree rotation, no problem and it seemed to work seamlessly on the earlier version.
With the newer version on the same videos from my server I can change the orientation by 90 degrees but selecting metadata or 180 degrees still leaves me with inverted video.
So, am I missing something basic (I can't find it referenced anywhere on the forum) or should I be reporting it as a bug?
To answer my own query (if it helps someone else) the MPEG2 licence did indeed resolve things and SDTV works.
Overall the Pi Zero just about runs LibreElec adequately. It's noticably slower than a 3 or 4, HD occasionally a shows a slight hesitation on some sources and the CPU usage looks quite high, but for me it means I can run LibreElec on a Pi zero attached to a projector which does not quite have room to attach a full-sized Pi and so would need trailing wires. This makes for a neater and more portable sytem for domestic bliss but otherwise I'd duck the problem and use a Pi 3 or 4!
Oh, Incidentally, I used a usb adaptor for a wireless remote which was cheap and worked without any fuss but, because the two micro USB sockets are quite close, it did require a bit of 'mechanical easing' to make the usb adaptor fit next to the USB power connector
I have just assembled TVHeadend with a couple of tuners on a Pi4 and using Libreelec running on a Pi 3B to view the result which seems to all work as intended (OK, I won't pretend I managed it first go!)
I made another player using a pi 4 with similar results and then tried it with a pi zero which plays HD terrestrial and my own videos well (but perhaps using a lot of the available processing) but no pictures on SDTV.
I'm imagining this is because I need an MPEG licence for the zero and the others are coping with just software decoding, but I'll admit to being a bit surprised it doesn't even try.
I don't mind paying the modest sum for the licence and even rolling my sleeves up to install it via SSH ( as seems neccessary) but I'd like to know if this really is the issue or if I'm just missing something...
I hope I haven't missed looking in the right places but I was surprised not to find any discussion on this hence the question...
