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Freeview: The DTT Thread

Retune on Sept 3rd (January 2009)

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BA
bilky asko
noggin posted:
dbl posted:
http://www.reghardware.co.uk/2009/12/03/freeview_hd_launch_report/

Report on Freeview HD, and its also saying quality wise:
Quote:
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.


I think that Freeview HD supports newer codecs than Dolby Digital for audio doesn't it (5.1 AAC, Dolby Digital Plus etc.)? If not 320k is very low for regular Dolby Digital. BBC HD on DSat uses 384k and doesn't sound great (SVT HD in Sweden uses 640k...)

Good news about the statmuxing though - that should mean that all the channels benefit from better picture quality than if they had a fixed 9-12Mbs slot? (It would be great if ITV HD weren't a simulcast of ITV1 and instead just carried the static 'unavailable' caption when not showing HD - as then the other channels would get a MUCH better quality result!)


320kbit/s is the equivalent of that used in film prints. Compare that to 448kbit/s used in DVDs.
NG
noggin Founding member
bilky asko posted:

320kbit/s is the equivalent of that used in film prints. Compare that to 448kbit/s used in DVDs.


I guess they've stayed with AC3/DD for surround because you can bitstream it to amps, whereas the newer codecs (HE-AAC for example) would need to be decoded to PCM 5.1/7.1 in the receiver (and thus only output over HDMI or analogue) or transcoded to DD/DTS, as most amps wouldn't support bitstreaming of them?

320k sounds very low for stuff like The Proms, which isn't great at 384k...

23 days later

NE
newsfan1
Just did a channel scan on my TV and lost a lot of channels inculuding ITV1, C4, C5, ITV2 etc in Northern Ireland - Help - anyone know why?
DA
David
newsfan1 posted:
Just did a channel scan on my TV and lost a lot of channels inculuding ITV1, C4, C5, ITV2 etc in Northern Ireland - Help - anyone know why?


Snow?
IT
itsrobert Founding member
On that subject, the new super-strong post-DSO signal from Winter Hill came up trumps today. My aerial was absolutely covered in snow, yet the signal strength and quality remained rock solid on all channels. Neither of the signal meters budged an inch from their usual readings.
BR
Brekkie
itsrobert posted:
On that subject, the new super-strong post-DSO signal from Winter Hill came up trumps today. My aerial was absolutely covered in snow, yet the signal strength and quality remained rock solid on all channels. Neither of the signal meters budged an inch from their usual readings.

A very good point actually which I'd completely taken for granted - though pre-DSO my aerial often coped better with this sort of weather then lost everything in light drizzle.

34 days later

DV
DVB Cornwall
BBC, Arqiva to sell DTT slots

UK media regulator Ofcom has given its consent for the BBC and platform infrastructure company Arqiva to jointly sell multiplex capacity, enabling two new additional national TV channels to be broadcast over DTT.

more….

c21media
BR
Brekkie
Now really in that case the new capacity should be used to replace the recently axed interactive stream, rather than sold to the highest shopping/gambling/soft porn bidder.
DV
DVB Cornwall
The DTG have issued a notice which seems to clarify the issue and seems to indicate that this process could work like this.

Pre DSO areas - Two Channels on the cleared BBC'B' multiplex.
As areas switch the channels move across to the Arqiva Muxes

Post DSO areas - These channels start on the Arqiva Multiplexes COM1 and COM2.

Edit ...

Mediaweek in another release confirms this scenario.
Last edited by DVB Cornwall on 8 February 2010 5:04pm
:-(
A former member
Might I be right in thinking, then, that for those people with Freeview Lite, they will briefly get another two channels - only to lose them following switchover? Shame, really - though only as long as they're not shopping, gaming or porn channels.
DV
DVB Cornwall
DELETED ..... Content was stupid, reading the post below.
Last edited by DVB Cornwall on 8 February 2010 9:16pm
MI
Mike516
No, The two services on the BBC's multiplex refers to the pre-switchover Mux B. There are no Freeview Lite transmitters in pre-switchover areas. The only way you can get multiplex B in a pre-switchover area is from a transmitter that carries all other multiplexes.

So everyone with Freeview before switchover will get the two services on multiplex B and will all get the two services on the Arqiva multiplexes after switchover.

Freeview Lite is only on the smaller relays that didn't carry Freeview before switchover (just the four analogue services).

Freeview Lite consists of: post switchover Mux BBC-A; post switchover Mux D3&4 and post switchover HD Mux.

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