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Freeview resolution changes (for the Olympics..? I'd bet not!)


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Old 26-07-2012, 08:33
tghe-retford
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As per this post in the Freeview changelog:

http://forums.digitalspy.co.uk/showp...postcount=1054

BBC Three and Four facing 544x576 resolution whilst all the main channels are now down to 192Kbps joint stereo. I can imagine the BBC Four viewership are gathering their pitchforks and torches as the BBC Radio 3 listenership did when sound quality was reduced on DAB to 160Kbps.

And I would wager money on the resolution and sound quality staying as it is after the Olympics have ended.

Plus, DAB bitrates have also been reduced across many of the BBC's services to 112Kbps joint stereo (has the same happened on DTT?).

Is this the beginning of the BBC matching the poorer quality pictures and sound of the commercial sector. If they're prepared to lower quality for the UK's biggest event in a very long time, I can't foresee quality improving afterward.

And beyond the BBC, who will be the first commercial channel to go mono or 480x576? I can bet that'll happen sometime too - probably a shopping or "babe" channel.
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Old 26-07-2012, 08:58
kasg
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BBC Three and Four facing 544x576 resolution whilst all the main channels are now down to 192Kbps joint stereo. I can imagine the BBC Four viewership are gathering their pitchforks and torches as the BBC Radio 3 listenership did when sound quality was reduced on DAB to 160Kbps.

And I would wager money on the resolution and sound quality staying as it is after the Olympics have ended.
Very bad news for BBC Four especially but, unlike you, I would be surprised if it did not revert to 720*576 after the Olympics.
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Old 26-07-2012, 09:09
technologist
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But how else can you increase the number of streams on a mux ??
Here the BBC has decided to give as much content for the Olympics - which will not be there after the end of the paralympics so the world will return to as it was before
Except for HD .....!
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Old 26-07-2012, 09:32
kasg
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Can anyone confirm the current resolution of CBBC and CBeebies? CBeebies looks OK to me but I can't check it for sure at the moment. Is this because 302 will only be broadcasting after 7pm so only needs to steal bandwidth from BBC Four?
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Old 26-07-2012, 09:33
EEPhil
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But how else can you increase the number of streams on a mux ??
Here the BBC has decided to give as much content for the Olympics - which will not be there after the end of the paralympics so the world will return to as it was before
Except for HD .....!
Isn't the paralympics down to Channel 4 to deal with? So it may all return to normality after the main olympics.
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Old 26-07-2012, 09:40
a516
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Can anyone confirm the current resolution of CBBC and CBeebies? CBeebies looks OK to me but I can't check it for sure at the moment. Is this because 302 will only be broadcasting after 7pm so only needs to steal bandwidth from BBC Four?
CBBC and CBeebies are using 544x576.
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Old 26-07-2012, 10:24
Ray Cathode
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CBBC and CBeebies are using 544x576.
Fairly obvious since they are timesharing with 302 & BBC FOUR which are also 544x576. BBC THREE remains at 720x576.

The generous BBC radio bitrates can't be dropped without affecting BBC ALBA.
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Old 26-07-2012, 10:25
Greebo
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Also noted in Ray Cathode's changelog post - " At 2am the second 302 audio was not working."...

Just after 10am this morning, PID 706 appeared on the BBCA mux, so the channel 302 section now looks like this:

Code:
PID found:  700 (0x02bc)  [SECTION: Program Map Table (PMT)]
PID found:  701 (0x02bd)  [PS/PES: ITU-T Rec. H.262 | ISO/IEC 13818-2 or ISO/IEC 11172-2 video stream]
PID found:  702 (0x02be)  [PS/PES: ISO/IEC 13818-3 or ISO/IEC 11172-3 audio stream]
PID found:  705 (0x02c1)  [unknown]
PID found:  706 (0x02c2)  [PS/PES: ISO/IEC 13818-3 or ISO/IEC 11172-3 audio stream]
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Old 26-07-2012, 10:26
kasg
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CBBC and CBeebies are using 544x576.
Thanks - should have read your blog first!
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Old 26-07-2012, 10:43
2Bdecided
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The generous BBC radio bitrates
"Generous?!". I think the word you're looking for is "adequate". 320kbps would be "generous".

Cheers,
David.
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Old 26-07-2012, 11:07
DragonQ
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Originally Posted by tghe-retford
Freeview resolution changes (for the Olympics..? I'd bet not!)
You'd bet wrongly. This is quite obviously for the Olympics.

The reason for this is that there's more stuff crammed into the BBC A multiplex than normal. Before it was this:

BBC One
BBC Two
CBBC/BBC Three
CBeebies/BBC Four
BBC News
BBC Parliament*
BBC 301*

*544x576

So that's 5 full resolution streams and 2 lower resolution streams. During the Olympics we have this:

BBC One
BBC Two
BBC Three
CBBC*/BBC 302*
CBeebies*/BBC Four*
BBC News*
BBC 301*

*544x576

I'm not sure why so many streams needed changing to 544x576. Surely changing BBC News would've been enough to match the pre-Olympics configuration. Maybe they just want to get the very best quality on BBC One, Two and Three for the Olympics? If they use an average of 4 Mbps for BBC One & BBC Three (talking about video only), plus 3 Mbps for BBC Two, that leaves ~9 Mbps for the other 4 channels to share, which'd definitely require a resolution reduction to prevent blockiness.

In any case, this is largely irrelevant for HD viewers and completely irrelevant for Freesat viewers. I can't imagine anyone that is discerning over image quality using Freeview unless they couldn't get a satellite signal.
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Old 26-07-2012, 11:12
kasg
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I'm not sure why so many streams needed changing to 544x576.
Neither am I. Based on your list, there were seven streams before the changes and ... erm ... seven streams after the changes. What have I missed?
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Old 26-07-2012, 11:32
AngusMast
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Neither am I. Based on your list, there were seven streams before the changes and ... erm ... seven streams after the changes. What have I missed?
BBC Parliament is usually a lot less demanding on bandwidth than a sports programme.
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Old 26-07-2012, 11:41
Martin Phillp
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When did BBC News reduce resolution? Was watching overnight and the picture was grainy in comparision to the other day.
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Old 26-07-2012, 11:44
Spot
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Why on earth would this be anything other than a temporary measure?
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Old 26-07-2012, 12:11
AngusMast
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This got me wondering. When they generate a 544x576 picture, I assume it's usually down-converted from a 720x576 picture. Do the broadcasters have a higher quality source from which a 544 picture could be generated directly and reducing degredation?

Do you think Sky News goes straight from HD to 544x576?

Another issue may be that receivers will have 720 the default resolution and for some 544 picture may be a slight botch.
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Old 26-07-2012, 12:18
OwenSmith
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In any case, this is largely irrelevant for HD viewers and completely irrelevant for Freesat viewers. I can't imagine anyone that is discerning over image quality using Freeview unless they couldn't get a satellite signal.
I'm discerning over image quality and I use Freeview. I don't use satellite simply because I don't want an ugly dish cluttering up the outside of my house. My TV aeriel is in the loft for the same reason. I also don't have random cables tacked all over the exterior walls of my house as many people do these days, I think it looks awful. Most people don't seem to care what the outside of their houses look like these days, it's depressing.
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Old 26-07-2012, 14:25
Ray Cathode
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"Generous?!". I think the word you're looking for is "adequate". 320kbps would be "generous".

Cheers,
David.
Generous compared to other platforms
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Old 26-07-2012, 14:37
DragonQ
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I'm discerning over image quality and I use Freeview. I don't use satellite simply because I don't want an ugly dish cluttering up the outside of my house. My TV aeriel is in the loft for the same reason. I also don't have random cables tacked all over the exterior walls of my house as many people do these days, I think it looks awful. Most people don't seem to care what the outside of their houses look like these days, it's depressing.
Interesting. I care more about image quality on TV than I do about what the back of my house looks like when I go in the garden.

My dish is very high up though and the cables are neat and run over the conservatory roof so not much of them is actually on the brickwork. If the dish would have to be on the front of your house I guess I could understand that position, even if it wouldn't bother me personally.
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Old 26-07-2012, 14:52
stanandjan
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My wife was watching the Olympic Ice skating the other night on Freeview within the Panny TV..
Most unusual for her .
Despite recent Specsavers Annual visit .I kid you not..the picture at times seemed Blury..
She switched back to Plain old FreeSkySat and it was akin to watching HD for the first time....
My gardener has been most erratic with all this rain..the lawn looks so unsightly..but the flowers are so gorgeous ..
that i very much doubt anyone looks above eye-level to see our Dish..
We do however like the Dinky elements needed for CP..I do hope you do not have those larger ones need for local stations!
and we so hate those Plastic Doors which stand out a mile compared to aluminium ones..
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Old 26-07-2012, 15:01
2Bdecided
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I'm discerning over image quality and I use Freeview. I don't use satellite simply because I don't want an ugly dish cluttering up the outside of my house.
I used to think like that. But given the choice between analogue terrestrial or Freesat, I put up a dish! No way I'm swapping Freesat for the Freeview lite that's now available.

If you have a suitable garden, it's possible to hide a dish in a way that's impossible with an outdoor aerial. Sadly, that doesn't work out for us.

There are other locations where a dish would be less obvious, but they're not as easy to access for maintenance and knocking snow off of it - so slap bang in the middle of the front of the house it is .

I might spend much time looking at the TV compared to most, but I spend even less time looking at the front of my house.

Cheers,
David.
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Old 26-07-2012, 16:19
kasg
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This got me wondering. When they generate a 544x576 picture, I assume it's usually down-converted from a 720x576 picture. Do the broadcasters have a higher quality source from which a 544 picture could be generated directly and reducing degredation?
I would expect the BBC channels to convert from 1920x1080.
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Old 26-07-2012, 16:21
kasg
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BBC Parliament is usually a lot less demanding on bandwidth than a sports programme.
Even so, I'm still surprised they needed to downgrade so many streams to 544x576.
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Old 26-07-2012, 16:26
DragonQ
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Why would they convert from 1920x1080 to 720x576 then to 544x576? This isn't the days of analogue, they'd just use a digital video resizing algorithm that will do it in a single step whilst changing the pixel aspect ratio from 1:1 (square) to 1.88:1 (544x576 @ 16:9).

The downside of course is that maximum quality is achieved when you do deinterlacing before resizing. Resizing whilst the image is still interlaced is not ideal but kind of unavoidable since these days most SD channels are really simulcasts of their HD equivalents (assuming an HD equivalent exists). It's also the reason why a 1080i output from a Sky box, for example, isn't ideal either.

The quicker we get rid of archaic interlacing the better.
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Old 26-07-2012, 16:54
Ray Cathode
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Even so, I'm still surprised they needed to downgrade so many streams to 544x576.
Parliament used an average 1Mbps whereas BBC THREE uses 3Mbps on average. Cutting the res from 720 to 544 saves ~25% bitrate approx 750k per stream. The 2Mbps was accounted for with 2 x 750ks for res reduction, plus 400k on the main text stream and 256k on audio bitrate reductions, plus 50k for the Engineering channel making 2.2Mbps. They probably went over the 2Mbps because Scotland bitrates have already been pruned for ALBA. 301 and 302 were always 544x576 so CBBC had to reduce too.

To go further and keep the 301 simulcast they would have had to lower BBC TWO resolution which was probably a step too far.

More on my website under latest news.

I will be watching on satellite.
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