Germany and the Netherlands are using 1080p50 HEVC/h.265 over DVB-T2 terrestrially - though I suspect a lot of the content will be 1080p25 and 1080i25 to 1080p50 deinterlaces. (Germany have ditched SD interlaced entirely from their upgraded DVB-T2 platform - and introduced 540p50 to replace it, alongside 720p50 and 1080p50 modes in their standard. Though 1080i25 may also be supported - there's no real point in using it)
Before the regular service started there was a test broadcast in Berlin with DVB-T2 and HEVC where they also tested a 1080i broadcast.
Yep - 1080i is included in the German DVB-T2 set-top box/TV reference standard ISTR, 576i is not. (That's the equivalent of our D-book)
Section 5.1 appears to mandate support for :
1080i25, 1080p50, 720p50 and 540p50.
Most TVs and set-top-boxes that did have a HEVC decoder couldn't display it, software like VLC thought it was 1920x540 and, as you suspected, at lower bitrates it performed pretty much like 1080p.
Ah - I guess those TVs weren't tested against the German reference standard, or were built prior to it being ratified? 1080i HEVC is part of the standard and was added prior to ratification. I've played it on a couple of platforms OK. Though it's a pretty pointless thing to do...
(By the way no 720p broadcasts on DVB-T2 in Germany those are also upscaled to 1080p. ZDF already anounced they want to have native 1080p50 and HDR "some time next year).
Ah - I thought some of the Freenet encrypted stuff was 720p50. I know the shopping stuff is 540p50 (which is the replacement for 576i25)
Interlaced was basically an afterthought in the development of HEVC and was only added in the later revisions.
Yes - it's implemented like the early h.264 interlaced support - which is separated fields (so it's treated as 1920x540p50 effectively in encoding terms) with each interlaced field compressed in intra-field mode only. h.264 added PAFF and MBAFF that allow two interlaced fields to be compressed in the frame domain (either across the whole frame - PAFF - or at a macroblock level - MBAFF) to increase encoder efficiency.
As a result h.265 is far poorer in compression terms with an interlaced source than a progressive source, and for interlaced content offers little advantage over h.264. However deinterlacing 1080i25 to 1080p50 and then compressing is a far better approach and delivers better encodes. Which is presumably what Germany is doing. Chatting to people at ZDF they are still running 1080i25 internally.
(Almost all broadcasters that until recently broadcast only in 720p50 operated internally at 1080i25 and cross-converted on playout. Very few originated anything in 720p50)