Freeview HD goes live
Technical details emerge as DVB-T2 service activated
Although Freeview wouldn’t be drawn on too many of the details of exactly which IPTV services will be coming – there’s no confirmed date for BBC iPlayer, for example – it’s certainly in the road map. Another potential IP services mentioned was SeeSaw, previously known as the BBC’s Project Kangaroo but now owned by transmission operator Arqiva, though its representatives declined to comment.
One surprise is that receivers will have to have the Freeview branding, including the logo, on the electronic programme guide screen, to qualify for the Freeview HD badge. The design of the EPG itself isn’t as rigidly specified as the one maintained by Freesat, from what we could gather, but the logo will be there. On the Sony prototype television, the EPG features a small live preview top left, a programme synopsis, and a Freeview logo top right, with several lines of EPG grid below.
Launch channels are BBC HD on EPG channel 50, and ITV 1 HD on position 51. The latter will be a live simulcast of ITV 1, including a large proportion of upscaled material, rather than a red button-activated interactive stream, as is the case on Freesat. The mux will have space for four channels, though it’s anticipated that that could rise to five, depending on improvements in encoders, between 2012 and 2015.
And the system has been designed from the start to allow regional variations in the broadcast schedule.
Another change from Freesat, where BBC HD transmits using a fixed bit rate, is that the services will be statistically multiplexed – which means bandwidth is dynamically allocated between channels, depending on the complexity of the images – with the aim of maintaining a consistent quality, rather than a specific bit rate. Video for each channel can range between 3Mb/s and 17Mb/s. Dolby Digital audio will be transmitted at 320Kb/s for 5.1 surround, with stereo audio at 128Kb/s; audio description takes up 64Kb/s, subtitles 200Kb/s and the data stream, for interactive applications, just 50Kb/s.
On the vexed subject of content management, the final decision won’t, Freeview assured us, make any difference to the availability of consumer equipment, as it will all be done in software. If Ofcom doesn’t give the go-ahead, then the EPG tables will simply be transmitted in the clear, but the boxes will still contain the decoding software should it become necessary to support DRM - if the BBC gets its way - at a later date.
Freeview’s website will be sporting a new coverage checker, which is due to be available to the public in early January, and will allow visitors to check which HD channels they’ll receive and when. ®
Freeview HD - Your questions answered
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