On 10/10/07 19:24, "Brian Butterworth" <[EMAIL PROTECTED]> wrote: > > But it could be done on analogue - you could never see the join in the switch > to regional programmes on the BBC even back as far as "Sixty Minutes", so it > MUST be possible. > On analogue Satellite? I don¹t think so. After all, the regional join works very well on digital terrestrial ... the same way as it did on analogue terrestrial. Why? Because a different video stream is fed to the coding and mux for the transmitter in each region. Regionality on terrestrial broadcasting is achieved through plain and simple video mixing at broadcast presentation. This form of regionality has the side effect that a viewer who lives on the wrong side of a hill near a region¹s border often gets the wrong region!
In contrast, satellite transponders cover the whole of the UK different ball game to your ³Sixty Minutes² scenario. In general, a set-top-box is not video mixing hardware and the DVB broadcasting standards are not designed to synchronise frame-accurate edits between streams ... especially streams on different transponders that require a frequency change when you only have one tuner! > > If the MPEG-2 streams collapse, the "opportunistic data" on the interactive > systems could claim all the spare bandwidth automatically.... > You can¹t run an interactive service with that kind of interrupted bandwidth ... ³we interrupt this match at Wimbledon because Scotland and London have some regional programming now². Automatic opportunistic insertion of data for interactive services is technically hard to do, but even harder is finding an editorial requirement for an interactive service with random holes punched through the middle of its bandwidth. What is far more realistic is the possibility to download programmes and data to a PVR using spare broadcast capacity, perhaps combined with the delivery of ultra local programming via a broadband link. These pushed PVR programmes could be SD, HD, interactive features (like DVD extras), games etc.. > Richard -- Dr Richard Cartwright media systems architect portability4media.com [EMAIL PROTECTED] mobile +44 (0)7792 799930
