Hence a set of coders statmuxing for each region is more or less the only way but at a cost. ( times number of regions )....
I'd assumed (wrongly) that at some point all the UK PSB muxes would migrate to DVB_T2/HD only.
Clearly, this isn't going to happen, but as coder capability has increased (for a variety of reasons including the capacity of the mux chain to handle more complex software and the capability of the installed base of receivers) - perhaps a swap may occur. Two PSB T2 muxes with services balanced by regionally and one legacy DVB_T mux carrying all the SD PSB content.
Yes, that's a big compromise on SD service, both in number and quality, but a bonus for HD as only one of the muxes need by sub-regional, the other universal. The challenge presumably would be to balance the national -vs- sub regional element between England and Scotland.
If there was one UK wide mux, then Scotland would need 5 (or is it 6) sub-regional muxes to support all its sub-regions and overlaps, with BBC1, BBC2, BBC Scotland, BBC Alba, C4(S), STV Angus, Durris, Craigkelly, Blackhill and Border (S).
That leaves an English mux per sub-region or overlap with BBC1, BBC2, ITV's sub-region and C4 (L, E, M, N). There's still a lot of coding of BBC2, C4 etc into BBC/ITV's sub-regions and overlaps.
Perhaps you took the view that the nature of sub-regional content
demanded a lighter code, as its heavy on simple images like talking heads, or scenes of places ...etc. The most critical content you could imagine would be sporting clips, which might be pre-treated to code more neatly? If that were so then a compromise of BBC1 dropping into a CBR at op-out times allowing down-stream MPEG splicing at GOP frame boundaries, providing the rest of the mux is protected by having some pretty swinging parameter restrictions - say 4 Mbits
for a BBC1 opt-out.
The same for ITV, except of course that most of their "
" are ad spot insertions where quality may not be compromised, and anyway happen at odd times, so it would be inconvenient to shove the whole of ITV into a restrictive CBR code, whilst some sub-regional spots happen somewhere. The HD PSB mux has already shaped itself into a mux that's driven by ITV's macro-regions (eg Anglia and Meridian are one), so possibly a compromise may be for a regional mux to be based on ITV region, with ITV taking a commercial view on the value of sub-regional spots?
How many sub-regional codes do you actually need?
Presumably, this is determined by how committed broadcasters are to their current arrangements? So C4's
macro-region would be separately coded into :
Bilsdale (possibly - but do ITV actually sell it separately any more?)
Caldbeck (E) (Yes I know that this is traditionally in the C4 (S) macro-region, but is this so after DSO?)
South Lakes - BBC/ITV overlap (see Isle of Man)
Isle of Man (is this still BBC N West/ Border (E) as South Lakes?
Emley Moor (BBC Leeds and Calendar North
Belmont (BBC Hull and Calander South)
Crosspool/ Chesterfield (BBC Leeds and Calendar South)
- are there any relays in the Peak District that take ITV Calendar South and BBC East Midlands?
- is Scarborough a copy of Emley Moor, or does it have Belmont ITV?
Obviously, the legacy SD mux would need all of these as well. The number of services that it has to carry would tend to mitigate against BBC1 and ITV being permanent CBR codes; otherwise, they'd probably get squished into something like 1.2 Mbits/s
Last edited by TedJrr on 9 July 2019 4:55pm - 2 times in total