Poor Picture on BBC Satellite Channels

[Johndm]

I recently posted about the recent drop in BBC picture quality.

Has anyone else noticed this??? It seems to me, that since they changed satellites, and introduced all the regional stuff, the picture has got VERY mpegy and pixilated when there are fast moving or 'complex' things on screen.
On news 24, there was a scene of waves on a beach, and it was nearly unwatchable!
When all the regional evening programmes come online, they also seem to have awful quality.

I emailed the BBC regarding this, and their reply is below.

Opinions chaps...............
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Further to yesteday's e-response I have a view from the Broadcast Systems Specialist:

The launch of the regional services on satellite will have no direct consequence to existing BBC services as these have been launched on a new transponder and hence do not share bitrate with any of the services mentioned.

There have not been any changes which would impact the quality, however we will carefully monitor these services and assess them.

I cannot throw any light on what has caused the step change in your perception of picture quality from this source.
Within the statistical multiplexing system (which allocates data capacity to the various channels within the particular multiplex) there are various variable channel demands which sometimes lead to headroom difficulty.
The ceiling parameters are controlled and likely heavy demand on data capacity should be strategically avoided by scheduling.

Programme material demanding the most data tends to be Children's bright coloured fast moving stuff and material collected with semi-pro hand held cameras in low lighting conditions. You may note the artefacts increase at these times.

No transmission system is perfect.

Regards

Dan Smith
BBC Reception Advice.
020-8225-8839
<http://www.bbc.co.uk/reception>

[Chris Muriel]

I see no difference here.

It was refreshing though to see a broadcaster admit to the downside (or trade-offs) present when statistical multiplexing is used.
The bit-rates looked fine when I checked the BBC transponder 2 days ago with an MPEG Transport Stream Reader.

Chris Muriel, Manchester.

I saw this effect and called a local installer in. We ended up chopping 6 feet off the tops of a neighbour's trees. It was only the top six inches affecting the signal but it was easier to saw the trees nearer the ground!

Once we'd sorted out the picture problems in this way, I went next door and asked for permission. Luckily he agreed!

Fman

[Gazkicka54]

Nice of them to be so honest!!!

Further, the trouble is they broadcast BBC1, 6 times on 2 of their transponders. So for example, they are all showing 'bright, poorly shot fast moving actions sequences' at the same time, as 95% if the programming is the same across the network - each feed is going to need 10Mbit/sec at least, and considering a transponder has a max rate of 27-33Mbits/s this is going to cause pixelation via simple mathematics!

ITV do they same daft thing, the idea of stat multiplexing is that you mix channels - Sports (bandwidth hungry), Films, series and news channels...

Not have 6/7 channels showing exactly the same material at the same time, therefore all requesting bandwidth at the same time, causing a MPEG-mess!

Hope that makes sense?
Gar

[Chris Muriel]

I assume that is different regions.
Therefore at times the content will be different between them.
Same would apply during ITV commercial breaks.

Chris Muriel, Manchester.

[Wayne Moule]

Has anyone noticed the intermittent VHS quality of Sky Sports and Five though?

[Gazkicka54]

Yep indeed... Five is better (more consistant) on DTT, must be lower resolution, almost ubwatchable somethimes... VHS eat your heart out! LP more like...

Gaz

[Wayne Moule]

Originally posted by Gazkicka54
Yep indeed... Five is better (more consistant) on DTT, must be lower resolution, almost ubwatchable somethimes... VHS eat your heart out! LP more like...

Gaz

You're the first one I've got to admit this.The engineer saw it when I showed him some recorded examples as well.

Five is perfect on DTT,as are all channels.

Sky have the problem and they know about it,they've told me via the engineer.It's something they've done to the software since the last update.

I only had Sky last December and noticed it straight away on Five and then Sky Sports.Both channels are on the same Multiplex you see.

It's been like this for 8 months or more now,which is very poor indeed.

I haven't watched it since and thus went out and bought Freeview.I now have the best DTV box ever!I'm not putting up with VHS quality on Sky and will cancel it at the year end unless they sort it out.

I am surprised no one has noticed this with all them sports fans watching the footy etc and kicked up a fuss.

Shame,because Sky have the best choice.

[Gazkicka54]

Its basicly the stat. multiplex algo - its old, it too quick to lower the bit rate to the bare minimum, causing the picture to blur and smudge. On DTT the rate is much more static.

Watch a for example the news, action sequences are fine, as soon as the picture calms, the bit-rate is lowered - you can actually see the picture blurring in front of your eyes, sharpness drop considerably...

The European broadcasters are so much better in general.

And a lot of Sky channels use poor resolutions as well.
IMHO, they should all use 720 DVD quality(or 704 - Sky News)x576, BBC and Ideal World do for theirs...
544x576 is common on many channels, LP DVD quality QVC 480x576 is even more common. And even some shopping use 340x576, unbelievable VCD res.

Hope that depress's you more, sorry!!!
Gar

[Starburst]

Originally posted by Wayne Moule
You're the first one I've got to admit this.The engineer saw it when I showed him some recorded examples as well.

Five is perfect on DTT,as are all channels.

Sky have the problem and they know about it,they've told me via the engineer.It's something they've done to the software since the last update.

I only had Sky last December and noticed it straight away on Five and then Sky Sports.Both channels are on the same Multiplex you see.

It's been like this for 8 months or more now,which is very poor indeed.

I haven't watched it since and thus went out and bought Freeview.I now have the best DTV box ever!I'm not putting up with VHS quality on Sky and will cancel it at the year end unless they sort it out.

I am surprised no one has noticed this with all them sports fans watching the footy etc and kicked up a fuss.

Shame,because Sky have the best choice.

Five has been the most consistent high bitrate channel on digital satellite (UK specific), I find it very hard to believe anyone would consider it to be anything other than exceptional.
Considering it shares a full transponder with only two other full time channels there would be ample capacity to go around assuming Five allow their capacity to be part of a stat muxing system (Which is doubtful).

A SKY engineer actually told you they had a software fault which degraded the picture on selected channels?
That must be a beauty of a fault which causes so much trouble yet has gone unnoticed by millions of people

You do know of course you can downgrade your package and save a bit of money, lets face it there is not a system wide fault with SKY D so any problems are localised and won't go away unless you do something about it.

[Wayne Moule]

Originally posted by Starburst
A SKY engineer actually told you they had a software fault which degraded the picture on selected channels?
That must be a beauty of a fault which causes so much trouble yet has gone unnoticed by millions of people

You do know of course you can downgrade your package and save a bit of money, lets face it there is not a system wide fault with SKY D so any problems are localised and won't go away unless you do something about it.

That's what I thought and it just shows you what people put up with or haven't noticed.

I did lower my package and bought Freeview.

[Wayne Moule]

Is it me or has five been fixed now?

I can't see any intermittent picture detail like before,though I am still keeping an eye on this.

This has only happened in the last couple of weeks.

[Wayne Moule]

http://forum.digitalspy.co.uk/board/t/100677/ds.html