December 29, 2009

No cut in Virgin Media BBC HD bit rate

As not everyone reads the Comments posted on this blog, here's some information that will be of interest to those following the BBC HD debate (thanks to Erich and BikeNutt)
Andy Quested, Principal Technologist, BBC Future Media & Technology: "We don't do the encoding for the Virgin platform. The signal from the playout and continuity area goes straight to an inject point somewhere in the bottom of Television Centre and (I assume) off to Virgin's distribution centre. The Virgin distributed HD signal MPEG2 at around 17Mbs and has been for sometime. In fact I believe there has only been one encoder change since the test channel launched. MPEG2 is a mature codec so updates (hard and soft) don't come along very often."

So the BBC HD picture we get hasn't had its bitrate cut like the channel has on either of the satellite platforms, which means the degradation we're seeing is down to other factors. Interesting.
Incidentally, anyone relying on the HD section on BBC iPlayer catch up this Christmas is going to be sorely disappointed: it's missing most of the main Christmas shows (Doctor Who, Cranford, Day of the Triffids, Outnumbered etc). They're there in standard def, but no HD.


tvsersity said...

My view is that the BBC are not being open about this mess, and have been softening the raw HD video to aid the low bit-rate H.264 stream on satellite. That same feed is being given to Virgin who, with the detail long gone, can't magically bring it back.

I assume there must have been some financial reason why the BBC had to slash their satellite bit-rate, but it's too bad that Virgin evidently have no access to the original, un-blurred video.

Erich said...

Judging purely by the cable version, I don't think there's been any deliberate softening or decrease in quality at all. It seems more likely that there's simply less "reference quality" material being broadcast on BBC HD than in the early days, and that the original quality of a lot of UK produced HD content just isn't all that good. Some of the content on C4, MTV and Living looks absolutely atrocious as well, and I'm not talking about their upscaled stuff.

tvsersity said...

If anything would have been reference quality, it would have been 'Life'. It should have been comparable to Planet Earth, but it wasn't. Instead it lacked definition and looked very soft throughout, often looking like an SD upscale. (which I can't imagine it ever was)

There was some video posted on the BBC HD blog by a commenter recently which showed a clip of Life from BBC HD UK, and the same clip from BBC HD in (if memory serves) Norway. There was a big difference, with the Norwegian clip looking much more detailed, and totally free of the mosquito noise which plagues BBC HD UK.

Erich said...

Have you got a link to the BBC HD Norway comparison video? I must have missed that?

tvsersity said...

Not to hand. It was in the comments thread beneath one of the BBC HD entrys on the BBC blog.

Westburne said...

Very interesting post here.