NG
http://www.digitalvibe.f9.co.uk/philhead.jpg
Hmm, not just my head that just flew over then!
Basically - DTT and Sky work differently when it comes to switching between 4:3 and 16:9 broadcasts. If the Sky boxes work the same way on the BBC One regional feeds as they do on the current 101 feeds then they aren't be fed identically to DTT. However the service may not be fully set-up yet so it is not possible to accurately tell for sure in all cases.
noggin
Founding member
Jamez posted:
noggin posted:
I REALLY HATE HTV WEST - I've had a thought...
If the BBC One regions on DSat start dropping into 4:3 12F12, and don't display as 12P16, then they must be MPEG2 encoded separately from the DTT services, as the DTT services are permanent 16:9 with AFDs to trigger aspect changes in the receiver when 12P16 or 16F16 is broadcast.
Sky receivers don't support AFDs so for DSat broadcasters have to produce a signal that is either 12F12 or 16F16. This could not be derived from the same MPEG2 encoder - as the ARC would need to be before the coder. Also using split encoders would allow the DSat feeds to be dogged independently of the DTT feeds. (I would not be at all surprised if the Beeb dogged the DSat feeds initially so that viewers were aware which one they were getting on 101...)
So :
DTT SDI feed ---------> DTT MPEG Encoder
|
------> switchable ARC------->DSat MPEG Encoder
If the BBC One regions on DSat start dropping into 4:3 12F12, and don't display as 12P16, then they must be MPEG2 encoded separately from the DTT services, as the DTT services are permanent 16:9 with AFDs to trigger aspect changes in the receiver when 12P16 or 16F16 is broadcast.
Sky receivers don't support AFDs so for DSat broadcasters have to produce a signal that is either 12F12 or 16F16. This could not be derived from the same MPEG2 encoder - as the ARC would need to be before the coder. Also using split encoders would allow the DSat feeds to be dogged independently of the DTT feeds. (I would not be at all surprised if the Beeb dogged the DSat feeds initially so that viewers were aware which one they were getting on 101...)
So :
DTT SDI feed ---------> DTT MPEG Encoder
|
------> switchable ARC------->DSat MPEG Encoder
http://www.digitalvibe.f9.co.uk/philhead.jpg
Hmm, not just my head that just flew over then!
Basically - DTT and Sky work differently when it comes to switching between 4:3 and 16:9 broadcasts. If the Sky boxes work the same way on the BBC One regional feeds as they do on the current 101 feeds then they aren't be fed identically to DTT. However the service may not be fully set-up yet so it is not possible to accurately tell for sure in all cases.