Gaussian Blur on Eurovision

Is there any chance it might also have something to do with an attempt
to reduce the picture disturbance caused by the two large displays at
the sides of the stage. Unlike the central backdrop the side displays
comprised of circular pixels as if projected onto a patterned grid.
This seemed to generate enormous amounts of noise and shimmer at
medium camera distances and robbed most of the bandwidth. I'm just
thinking how bad this would have been had the production team not
smoothed it out a bit.

Just my 2p!

"Halmyre" wrote in message
...
In article ,
_SPAM says...
I think I've worked out the reason for the radius 1 Gaussian Blur

Gaussian Blur? Which country were they?

--
Halmyre

Don't laugh, 30 odd years ago I almost called my mobile
disco "Blue Lateral"

Bloody hell, http://www.bluelateral.com/
I thought of it first!!!

--

Graham.
%Profound_observation%

"Owain" wrote in message
...
Paul Martin wrote:
For a non-host broadcaster, it's a very cheap three hours of telly.

I thought we had to pay vast sums of money as a "founder member" to
be in the contest every year, even when we would in the past have
been relegated.


Indeed, but the UK would be paying that regardless, the actual "three
hours telly" is cheap as it's in effect all but free by TX date [1] -
if the BBC were to drop the broadcast they would have to spend more
money to fill get gap!

[1] I know that there is some expenditure on com-links and pres etc.

On Wed, 16 May 2007 18:24:30 +0100, "Agamemnon"
wrote:

I think I've worked out the reason for the radius 1 Gaussian Blur on the
BBC's coverage of the Eurovision. It's there to remove dot crawl and other
PAL artefacts because somewhere along the line the BBC has converted the
digital feed into composite PAL analogue in order to insert its own

Since the broadcast looked pretty stunning on BBC HD (apart from the
irritating BBC HD logo) and I remember thinking at the time how sharp
the phone number captions were, I doubt any artifacts are occurring
before your receiver. ;-)

Rgds
Jonathan

"Owain" wrote in message
...
Paul Martin wrote:
For a non-host broadcaster, it's a very cheap three hours of telly.

I thought we had to pay vast sums of money as a "founder member" to be in
the contest every year, even when we would in the past have been
relegated.

That's just a myth invented by Sir Terry of Wogan.


Owain

"JC" wrote in message
...
On Wed, 16 May 2007 18:24:30 +0100, "Agamemnon"
wrote:

I think I've worked out the reason for the radius 1 Gaussian Blur on the
BBC's coverage of the Eurovision. It's there to remove dot crawl and other
PAL artefacts because somewhere along the line the BBC has converted the
digital feed into composite PAL analogue in order to insert its own

Since the broadcast looked pretty stunning on BBC HD (apart from the
irritating BBC HD logo) and I remember thinking at the time how sharp
the phone number captions were, I doubt any artifacts are occurring
before your receiver. ;-)

Pity the SD version was a blurred mess.


Rgds
Jonathan

"Gareth Rowlands" wrote in message
news
On Wed, 16 May 2007 21:17:18 +0100, Agamemnon wrote:

You are assuming it was done in TV Centre. They could have done it in
Finland on a mobile vision desk which was fed with a composite signal.

I need to add the disclaimer that I didn't watch the 2007 contest or
participate in any way, but I think readers ought to know that the EBU has
a strict protocol surrounding the Eurovision Song Contest and particularly
the conduct of the voting operation.

Although each participating country has its own commentary box operation,
there are no unilaterals during the contest and the only way the
host originated pictures and music leave the venue is via EBU approved
multilateral routes. If a broadcaster wishes to add their own captions
then this must be done after the broadcaster has received the signal off
the bird(s) or the EBU tubes.

Apart from the audio facilities one would normally expect within
commentary boxes, individual broadcasters do not have their own programme
mixing points at the contest venue for the purpose of producing their
own version of the host based feed, and would not be allowed to do so in
the interests of assuring a fair vote.

My simple opinion of what is being reported on is that the originated
pictures are rich in fine detail and the chained digital video compression
systems used are unable to cope.

So why is this?

The recordings I have made of SD Doctor Who off-air from an analogue
composite signal fed into my capture card originating from a Sony STB and
then recorded in DivX at 3080/4096kbps interlaced, no B-VOP's and then
converted to DivX at 2037kbps look completely sharp. For example the amount
of detail in the TARDIS console room in the opening scene of The Lazarus
Experiment is amazing on my 2037 DivX single pass conversion is amazing. So
why can't the BBC provide a decent quality SD Eurovision transmission when I
can maintain the detail after 3 generations of MPEG encoding including an
analogue resample?


Gareth.

--
http://www.rat.org.uk gareth at rat dot org dot uk

On Wed, 16 May 2007 21:17:18 +0100, Agamemnon wrote:

You are assuming it was done in TV Centre. They could have done it in
Finland on a mobile vision desk which was fed with a composite signal.

I need to add the disclaimer that I didn't watch the 2007 contest or
participate in any way, but I think readers ought to know that the EBU has
a strict protocol surrounding the Eurovision Song Contest and particularly
the conduct of the voting operation.

Although each participating country has its own commentary box operation,
there are no unilaterals during the contest and the only way the
host originated pictures and music leave the venue is via EBU approved
multilateral routes. If a broadcaster wishes to add their own captions
then this must be done after the broadcaster has received the signal off
the bird(s) or the EBU tubes.

Apart from the audio facilities one would normally expect within
commentary boxes, individual broadcasters do not have their own programme
mixing points at the contest venue for the purpose of producing their
own version of the host based feed, and would not be allowed to do so in
the interests of assuring a fair vote.

My simple opinion of what is being reported on is that the originated
pictures are rich in fine detail and the chained digital video compression
systems used are unable to cope.

Gareth.

--
http://www.rat.org.uk gareth at rat dot org dot uk

"Agamemnon" wrote in message
. uk...

"JC" wrote in message
...
On Wed, 16 May 2007 18:24:30 +0100, "Agamemnon"
wrote:

I think I've worked out the reason for the radius 1 Gaussian Blur on the
BBC's coverage of the Eurovision. It's there to remove dot crawl and
other
PAL artefacts because somewhere along the line the BBC has converted the
digital feed into composite PAL analogue in order to insert its own

Since the broadcast looked pretty stunning on BBC HD (apart from the
irritating BBC HD logo) and I remember thinking at the time how sharp
the phone number captions were, I doubt any artifacts are occurring
before your receiver. ;-)

Pity the SD version was a blurred mess.

Perhaps the problem was with whatever equipment the BBC used to down-convert
the HD picture from Finland to SD. It might come down to the user settings
on the down converter. There are probably no rigorous guidelines for
settings like these, it may have been left on default, or someone may have
been fiddling with it.

If there are knobs to tweak they tend to get tweaked, and the result may be
worse than if no adjustment were provided. Standards converters for analogue
were a good example. The worst hue errors I've seen were because of people
mistweaking the hue control on a standards converter, not because of any
gross hue error in the original NTSC video arriving from America.

"Gareth Rowlands" wrote in message
news
On Thu, 17 May 2007 00:53:09 +0100, Agamemnon wrote:

My simple opinion of what is being reported on is that the originated
pictures are rich in fine detail and the chained digital video
compression
systems used are unable to cope.

So why is this?

When a picture is acquired in High Definition, the detail augmentation
('Contour correction') in the camera head takes place at a frequency 'out
of band' of the SD signal. What is a significant 'quantity' of medium
detail in the HD picture will then appear as a significant quantity of
fine detail in an SD signal after downconvertion.

I more or less said that my self in my argument in the Eurovision sound and
picture thread where I calculated you would need just as much bandwidth to
encode the SD transmission in MPEG-2 as you would need for the HD signal in
MPEG-4 but instead of both the SD and HD being broadcast as 12Mbps the SD is
broadcast at 4Mbps. I assumed you were referring to generation losses
instead because you said chained compression systems. I must have read it
wrong.


Where lossy compression is in use, fine detail is often squeezed out
by compression systems, especially when there is high demand on available
bandwidth caused by motion portrayal. If you watch sports like rugby and
football on digital tv, note how the detail in the crowd and the pitch
reduce as the camera pans, giving a subjective impression most accurately
described as 'blurring'.

Yes, blocking, the crowd and camera break up into huge blocks when the
camera pans. The solution is to increase the exposure time of each frame and
reduce the camera aperture to compensate. This will produce more natural
motion blur and therefore present the codec with less information that needs
encoding.


G.