Re: BBC HD on Freeview proposal

On 27 Sep, 20:50, "DAB sounds worse than FM" <dab.is@dead> wrote:
davidrobin...@xxxxxxxxxxxxxxxx wrote:

Let me summarise this discussion.

We're looking at three different scenarios...

1. Keep the BBC muxes almost as they are.
(BBC HD is either Dsat only, or on another mux, or in space overnight
by removing some repeat showings from BBC Four, Parliament, 301 and
302.)
Impact on existing viewers: barely registers.
Impact on BBC HD: reduced hours, timeshifted, reasonable quality.

2. Keep all services, trash all bitrates, broadcast BBC HD live.
Impact on existing viewers: reduced quality.
Impact on BBC HD: standard hours, lower quality.

3. Remove interactive services, reduce bitrates slightly, broadcast
BBC HD live.
Impact on existing viewers: loss of services.
Impact on BBC HD: standard hours, lower quality.

2 and 3 are what you have proposed, with 3 being your preferred route.
1 is what the BBC have proposed, and asked whether they should bother
at all.


I don't think it's worth reducing quality or losing service to put BBC
HD on DTT, you do.

My arguments:

1. Don't care, but sounds like it could cause confusion.

2. It's not worth making the SD channels _even_ worse to launch a
comparatively low bitrate HD channel.

3. It's not worth removing services with unique valued content to add
a simulcast / repeat channel in higher (but not "very high") quality.

The arguments regarding it being "a confusing temporary solution for
the BBC only" still stand for all proposals.

I also suspect that DSat hits more TVs where HD will be noticed
(living room), and DTT hits more TVs where HD is nearly irrelevant
(bedroom / kitchen).


In detail...

Your unintentional irony is staggering. It's DAB all over again.
"Miraculous" new encoders that are used to do nothing more than
achieve the same mediocre quality at a slightly lower bitrate.

There's absolutely no irony. I think a lot of people have been impressed by
the new encoders that the commercial broadcasters installed a couple of
years ago, because if they hadn't installed them then the bit rates of the
files I mentioned above would have produced truly diabolical quality. But
it's not that bad AND we're only talking about a 0.2 Mbps drop on average
AND the average bit rates would still be far higher than the commercial
channels are using.

You only get the 0.2Mbps drop by killing 301, 302, four news
multiscreens, reducing BBC parliament to 1/4 screen, and giving a
pathetic 10Mbps to the HD service. None of this is acceptable (though
I guess 10Mbps is better than nothing at all - but not at the
expensive of all the other changes you propose).


When the commercial broadcasters proposed this on DAB, you screamed
blue murder.

In terms of acceptability, the picture quality at the low bit rates the
commercial TV channels are using is VASTLY superior to the audio quality of
128 kbps stations, and the DAB broadcasters wanted to reduce the bit rates
down to 112 kbps once they'd bought new encoders. The two situations are
nowhere near being the same.

You clearly have better audio equipment than video equipment. Which is
fine - so do I. However, I observe that more and more people are
getting large screen TVs. Fewer and fewer people give space to a hi-
fi.

3Mbps MPEG-2 interlaced SD content on a large screen TV is as horrible
an experience as 112kbps mp2 on a good stereo.

The two situations are not only comparable, but equivalent. The
quality has been driven to the lowest common denominator in both. In
terms of discernment and level of equipment required to realise the
quality is poor, they're comparable. The only difference is more
people seem to spend the money on video than audio, which weakens your
argument still further.

Now, let me think - if I was Steve Green and someone was claiming a
poor quality service was in fact good quality, what would I say? I'd
post a helpful link. Probably Google RNIB or something. ;-)


This has to split across two muxes, keeping the "more important"
channels on Mux 1 (wider coverage) so I'm not sure you quite have
flexibility you hope for, but anyway...

Do you mean flexibility in terms of reorganisation for digital switchover?

I mean you've drafted this as one 32Mbps pot of bits. It's actually 2
16Mbps pots of bits (or whatever the actual numbers are). This reduces
the efficacy of the stat mux a little, and obviously means you have to
plan the two 16Mbps separately.


I don't care what they carry, to be honest. In terms of priority they come
last out of all the BBC's services, and if it's them or the BBC HD channel
there is absolutely no contest.

Hang on a second - BBC HD will carry zero unique content. It will be a
high resolution simulcast or repeat of something from the BBC SD
channels. BBCi carries plenty of unique content. It's the only chance
people will have to see that content. Sometimes it's high value, high
profile, _good_ content. Sometimes it's actually a lot more deserving
than the worst dross that finds its way onto BBC One - but just
happens to occur at a time when there's already something worthwhile
on BBC One and Two, so gets pushed onto BBCi.

Another problem (and it'll be a perpetual problem) is that at the
times when BBCi is most valued, BBC HD will also be most valued (e.g.
Olympics, Last Night of the Proms, etc etc). This makes switching one
off to make way for the other a really bad approach for live events.


However, I'm sure, for some people, they constitute the biggest
benefit of Freeview. Extra sporting events, extra music - unique
content that never makes it onto any of the other channels.

I don't buy that the BBCi video channels have anything more than a tiny
audience, so if they need to cease in ordere for BBC HD to transmit they
should cease.

from 2004(!)...

http://news.bbc.co.uk/1/hi/entertainment/3588876.stm

"Over six million viewers have used the channel's interactive Olympics
service since the Games began on 13 August.

The previous highest figure for the BBC's interactive services was
4.1m during this year's Wimbledon."

That was in 2004. I wonder what the figures will be in 2008? I wonder
what the figures for BBC HD on DTT would be in 2008?


To be bluntly honest, you can shove either BBCi onto DSat only, or you
can shove BBC HD onto DSat only. If we're talking about public value
BBCi wins just on audience, potential audience, and the fact DSat hits
more main TVs

BBCi video streams don't come close to the BBC HD channel in terms of public
value. The BBC HD channel would be the only HD channel on Freeview until
2012 at a time when satellite and cable are getting more and more HD
channels. To rank BBCi video streams in the same league as the BBC HD
channel in terms of public value would be giving it far too much credit.

There isn't an inverse relationship between audiences and public value you
know. HDTV is looked upon by many as the most significant development since
black and white went to colour, and you're comparing BBCi video streams with
HDTV? Do me a favour.

I think it matches the introduction of colour.

No one switched off B&W services to introduce colour!

They did switch off all B&W only services decades later (with the shut
down of 405-line VHF). They decided not to bodge colour onto those
obsolete services, but make a clean break. It meant waiting a long
time for colour, but the system we got was arguably worth waiting for.

I think that's a fair comparison.


I've recorded 301 and 302 numerous times on my PC card to see how much bit
rate they're wasting to encode a still image, and they were *invariably*
being encoded at about the 3 Mbps mark. Either that or Windows Explorer was
lying about the size of their file on my hard drive.

The bitrates were 1.5Mbps at one time. This gave a visible help to BBC
Four. As I said, I have no idea what happens now - it's been
completely re-engineered to enable BBC parliament in full screen, and
hence also extra news loops.


You should know from DAB that the BBC allocates bit rates on the basis of
what is the best configuration for them in terms of politics - R3 gets 192
kbps whereas R1 and R2 get 128k. R4 gets 128k when if it were listened to by
teenagers it would be in mono at 64k, no question. The same applies to TV.

That's just not true. The babies and teenager channels do as well
(usually better!) in bitrate terms as BBC Two. Until 301+302 were re-
engineered, the bitrates across the board reflected purely technical
concerns, and were independent of content and politics. Now BBCi is
lower than the other channels, but other than that it's an even split
(BBC One excepted for technical reasons).


Same goes with BBC Parliament - why has it just gone to
full screen?

Because parliament demanded it.

Seriously? That's outrageous.

What, that the channel showing our democracy at work should have a
picture that's watchable? It's probably more important than anything
else in this thread.


Why don't you try _watching_ those Sky HD channels you report the
bitrate for on your website?

It is common knowledge that MPEG-4 H.264 is twice as efficient as MPEG-2 -
look at any text book on H.264 or any article that's been written about it.

Why not just look at the output of actual encoders - the ones the
broadcasters can buy today and use today?


For example:

http://www.ebu.ch/en/technical/trev/trev_293-schaefer.pdf

page 9:

"the bit-rates for TV or HD video (at broadcast and DVD quality) are
reduced by a factor of between 2.25 and 2.5 - when using H.264/AVC coding."

HD using MPEG-2 was being broadcast at 20 Mbps, so the bit rates will come
down with H.264 once the developers understand the codec better.

Of course they will. That's inevitable. We're not there yet. In fact
current MPEG-4 has been quite disappointing in terms of the gains it
has delivered for HD.


I do it in the local Sony Centre (who I
have a good relationship with). I don't think you'll be begging for
10Mbps then!

We'll see.


You'll see. I've seen!

I bet you won't be begging for 1080i at 10Mbps! I bet they'll use 720p
if that's all they can muster - but I suspect they won't do HD unless
they can get a similar bitrate to DSat and stick with 1080i.

Still it would be nice if the BBC would go back to 20Mbps on DSat (as
Sky Sport HD uses), at least until we see some miraculous new
encoders. Maybe the current 16Mbps in DSat is to reduce the disparity
between what they can provide on DSat, and what they hope to provide
overnight on DTT.

Cheers,
David.

.

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