MA
IIRC different regions on the same transponder are deliberately out of sync so that they aren't displaying exactly the same thing at exactly the same time - there's obviously no point statmuxing several streams which are identical most of the time. This would mean therefore that the gap between analogue terrestrial and DSAT would depend on the region you are watching. Westcountry on DSAT is certainly a good 5 seconds behind the analogue terrestrial broadcast
I've seen all the ITV channels at once on a monitor wall at the uplink site's control room. There certainly are delays between them, plus delays incurred in the to'ing and fro'ing of feeds between London and Leeds, and from UTV, and STV as well.
cwathen posted:
Quote:
ITV's channels certainly do incur much more of a delay which may be deliberate to try and make the multiplexing more efficient. Picture quality's still crap though.
IIRC different regions on the same transponder are deliberately out of sync so that they aren't displaying exactly the same thing at exactly the same time - there's obviously no point statmuxing several streams which are identical most of the time. This would mean therefore that the gap between analogue terrestrial and DSAT would depend on the region you are watching. Westcountry on DSAT is certainly a good 5 seconds behind the analogue terrestrial broadcast
I've seen all the ITV channels at once on a monitor wall at the uplink site's control room. There certainly are delays between them, plus delays incurred in the to'ing and fro'ing of feeds between London and Leeds, and from UTV, and STV as well.
TJ
I too lament the demise of clocks before the news, they sort of added gravitas which is presumably not cewel enough for today's BBC? Must sday though that the BBC Midlands clock mock is rather cool.
The issue of digital dalay may seem rther straightforward when considering transmission path and reference code/decode periods rekative to groups of pictures (GOPs), but the complications result frem different implementations in reciver builds.
Im a right in assuming that the root cause of all of this is the lack of a true refernce model for reciever performance, meaning that there is no way any broadcaster could transmit an in-vision second hand with any data regaring the display timing accross a disparate fleet of DTT boxes. D-SAT is presumably more predictable, the delay characteristics of the differing builds of Sky box may be comparible - but that's not going to be relevent when FreeSat actually (eventually) kicks off.
The issue of digital dalay may seem rther straightforward when considering transmission path and reference code/decode periods rekative to groups of pictures (GOPs), but the complications result frem different implementations in reciver builds.
Im a right in assuming that the root cause of all of this is the lack of a true refernce model for reciever performance, meaning that there is no way any broadcaster could transmit an in-vision second hand with any data regaring the display timing accross a disparate fleet of DTT boxes. D-SAT is presumably more predictable, the delay characteristics of the differing builds of Sky box may be comparible - but that's not going to be relevent when FreeSat actually (eventually) kicks off.