BBC2 Freeview bit rate decreased?
 

It's fairly well known that Freeview squeezes down the bit rates of
its MPEG-2 broadcasts, in order to fit as many digital channels as
possible into the six available muxes. However, the BBC-exclusive mux
was the exception to this rule: it only carried four channels (BBC1,
BBC2, BBC3/CBBC, and News 24), at significantly higher bit rates.

Recently this seems to have changed. I've noticed that, although BBC1
is still broadcast at 2.0GB/hour, BBC2 broadcasts have reduced from
1.7GB/hour to 1.3GB/hour.

Does anyone know of any specific reason for this change?

BBC2 Freeview bit rate decreased?
 

On Sat, 2 Aug 2008 15:35:13 -0700 (PDT), "A. J. Moss"
wrote:

It's fairly well known that Freeview squeezes down the bit rates of
its MPEG-2 broadcasts, in order to fit as many digital channels as
possible into the six available muxes. However, the BBC-exclusive mux
was the exception to this rule: it only carried four channels (BBC1,
BBC2, BBC3/CBBC, and News 24), at significantly higher bit rates.

Recently this seems to have changed. I've noticed that, although BBC1
is still broadcast at 2.0GB/hour, BBC2 broadcasts have reduced from
1.7GB/hour to 1.3GB/hour.

Does anyone know of any specific reason for this change?

Greed?

BBC2 Freeview bit rate decreased?
 

"A. J. Moss" wrote in message
...
It's fairly well known that Freeview squeezes down the bit rates of
its MPEG-2 broadcasts, in order to fit as many digital channels as
possible into the six available muxes. However, the BBC-exclusive mux
was the exception to this rule: it only carried four channels (BBC1,
BBC2, BBC3/CBBC, and News 24), at significantly higher bit rates.

Recently this seems to have changed. I've noticed that, although BBC1
is still broadcast at 2.0GB/hour, BBC2 broadcasts have reduced from
1.7GB/hour to 1.3GB/hour.

Does anyone know of any specific reason for this change?

BBC2 is stat-muxed so the bitrate will vary depending on the content of the
other channels on the same mux. BBC1 in England (except London) is a fixed
bitrate.

BBC2 Freeview bit rate decreased?
 

A. J. Moss wrote:
It's fairly well known that Freeview squeezes down the bit rates of
its MPEG-2 broadcasts, in order to fit as many digital channels as
possible into the six available muxes. However, the BBC-exclusive mux
was the exception to this rule: it only carried four channels (BBC1,
BBC2, BBC3/CBBC, and News 24), at significantly higher bit rates.

Recently this seems to have changed. I've noticed that, although BBC1
is still broadcast at 2.0GB/hour, BBC2 broadcasts have reduced from
1.7GB/hour to 1.3GB/hour.

Where did you find this information? I'd be interested to know what it is
for BBC4; I was watching the 2007 Arena programme on the London Underground
last night, and the picture quality was awful.


--
Jeff
(cut "thetape" to reply)

BBC2 Freeview bit rate decreased?
 

On Sun, 3 Aug 2008 08:40:40 +0100, "dB" wrote:


"A. J. Moss" wrote in message
...
It's fairly well known that Freeview squeezes down the bit rates of
its MPEG-2 broadcasts, in order to fit as many digital channels as
possible into the six available muxes. However, the BBC-exclusive mux
was the exception to this rule: it only carried four channels (BBC1,
BBC2, BBC3/CBBC, and News 24), at significantly higher bit rates.

Recently this seems to have changed. I've noticed that, although BBC1
is still broadcast at 2.0GB/hour, BBC2 broadcasts have reduced from
1.7GB/hour to 1.3GB/hour.

Does anyone know of any specific reason for this change?

BBC2 is stat-muxed so the bitrate will vary depending on the content of the
other channels on the same mux. BBC1 in England (except London) is a fixed
bitrate.

How does this work in Scotland? I assume BBC1 Scotland is a fixed
bitrate. Is BBC2 Scotland also a fixed bitrate?

BBC2 Freeview bit rate decreased?
 

Scott wrote:

Does anyone know of any specific reason for this change?
BBC2 is stat-muxed so the bitrate will vary depending on the content of the
other channels on the same mux. BBC1 in England (except London) is a fixed
bitrate.

How does this work in Scotland? I assume BBC1 Scotland is a fixed
bitrate. Is BBC2 Scotland also a fixed bitrate?

BBC 1 and 2 in Scotland (and Wales, and NI) are 'repackaged' into local
versions. In other words the network programming is fed as clean feeds without
the London announcer's voice over and all the squished up credits, so that
this vandalism can be done locally. The result is, that opting in and out of
the London networks is a more complex process, and therefore BBC 1 and 2 are
locally coded and muxed. Therefore BBC 1, 2, 3,and News 24 are all in the same
stat mux pool. The same applies in London. The English regions 'cut and paste'
their local version of BBC 1 into an English-nationally assembled mux, this
can only work if the gap for BBC 1 is a fixed size. So a 4.5 Mb/s 'hole' is
provided for BBC 1. BBC 2, 3, and N24 all fight for bits in a stat-mux .

--
Mark
Please replace invalid and invalid with gmx and net to reply.

BBC2 Freeview bit rate decreased?
 

On Sun, 03 Aug 2008 11:22:40 +0100, Mark Carver
wrote:

Scott wrote:

Does anyone know of any specific reason for this change?
BBC2 is stat-muxed so the bitrate will vary depending on the content of the
other channels on the same mux. BBC1 in England (except London) is a fixed
bitrate.

How does this work in Scotland? I assume BBC1 Scotland is a fixed
bitrate. Is BBC2 Scotland also a fixed bitrate?

BBC 1 and 2 in Scotland (and Wales, and NI) are 'repackaged' into local
versions. In other words the network programming is fed as clean feeds without
the London announcer's voice over and all the squished up credits, so that
this vandalism can be done locally. The result is, that opting in and out of
the London networks is a more complex process, and therefore BBC 1 and 2 are
locally coded and muxed. Therefore BBC 1, 2, 3,and News 24 are all in the same
stat mux pool. The same applies in London. The English regions 'cut and paste'
their local version of BBC 1 into an English-nationally assembled mux, this
can only work if the gap for BBC 1 is a fixed size. So a 4.5 Mb/s 'hole' is
provided for BBC 1. BBC 2, 3, and N24 all fight for bits in a stat-mux .

So BBC1 and BBC2 both have a variable bitrate?

BBC2 Freeview bit rate decreased?
 

Scott wrote:
On Sun, 03 Aug 2008 11:22:40 +0100, Mark Carver
wrote:

BBC 1 and 2 in Scotland (and Wales, and NI) are 'repackaged' into local
versions. In other words the network programming is fed as clean feeds without
the London announcer's voice over and all the squished up credits, so that
this vandalism can be done locally. The result is, that opting in and out of
the London networks is a more complex process, and therefore BBC 1 and 2 are
locally coded and muxed. Therefore BBC 1, 2, 3,and News 24 are all in the same
stat mux pool. The same applies in London. The English regions 'cut and paste'
their local version of BBC 1 into an English-nationally assembled mux, this
can only work if the gap for BBC 1 is a fixed size. So a 4.5 Mb/s 'hole' is
provided for BBC 1. BBC 2, 3, and N24 all fight for bits in a stat-mux .

So BBC1 and BBC2 both have a variable bitrate?

On DTT, in Scotland, Wales, NI, and the London region, yes I believe they both do.


--
Mark
Please replace invalid and invalid with gmx and net to reply.

BBC2 Freeview bit rate decreased?
 

In article , Jeff Layman
scribeth thus
A. J. Moss wrote:
It's fairly well known that Freeview squeezes down the bit rates of
its MPEG-2 broadcasts, in order to fit as many digital channels as
possible into the six available muxes. However, the BBC-exclusive mux
was the exception to this rule: it only carried four channels (BBC1,
BBC2, BBC3/CBBC, and News 24), at significantly higher bit rates.

Recently this seems to have changed. I've noticed that, although BBC1
is still broadcast at 2.0GB/hour, BBC2 broadcasts have reduced from
1.7GB/hour to 1.3GB/hour.

Where did you find this information? I'd be interested to know what it is
for BBC4; I was watching the 2007 Arena programme on the London Underground
last night, and the picture quality was awful.



Yes wasn't it!, but the content in this instance:-)


Tho the older stuff looked good for its age..

Excellent prog and just what BBC 4 is good at!.

BBC 3 OTOH total waste of spectrum:(....
--
Tony Sayer

BBC2 Freeview bit rate decreased?
 

In article ,
Jeff Layman wrote:
here did you find this information? I'd be interested to know what it
is for BBC4; I was watching the 2007 Arena programme on the London
Underground last night, and the picture quality was awful.

I'm not surprised - reception in tunnels is always poor.

--
*My dog can lick anyone

Dave Plowman London SW
To e-mail, change noise into sound.

BBC2 Freeview bit rate decreased?
 

In article , Dave Plowman (News)
scribeth thus
In article ,
Jeff Layman wrote:
here did you find this information? I'd be interested to know what it
is for BBC4; I was watching the 2007 Arena programme on the London
Underground last night, and the picture quality was awful.

I'm not surprised - reception in tunnels is always poor.


LOL!, and they used the same bit of tunnel footage or is that "bitage"
now for a fair old bit of the prog?..

Perhaps thats it!, they can send those bits, TV stores 'em then plays
that stored sequence when it gets a simple command;)..
--
Tony Sayer

BBC2 Freeview bit rate decreased?
 

On 3 Aug, 11:51, Signal wrote:
"Jeff Layman" wrote:
"A. J. Moss" wrote:
Recently this seems to have changed. I've noticed that, although BBC1
is still broadcast at 2.0GB/hour, BBC2 broadcasts have reduced from
1.7GB/hour to 1.3GB/hour.

Where did you find this information? *I'd be interested to know what it is
for BBC4; I was watching the 2007 Arena programme on the London Underground
last night, and the picture quality was awful.

2nded AJ, how did you retrieve the bitrate.

I recorded a few programmes from BBC2 with a USB Freeview stick onto a
computer.

I happen to know that it streams the demuxed transport stream (as an
interleaved MPEG-2 file) straight onto the hard disk. Unlike most
Freeview DVD recorders, which unhelpfully decompress the MPEG-2 input,
and recompress it at a fixed bit rate, before burning it to DVDR.

I've recorded these files recently. These are the raw files, with
trailers still needing to be cut out of them, and so are slightly
longer than the broadcast programmes.

Burn Up, e01: 5287 s (1:28:07), 2005 MB = 1365 MB/h
Burn Up, e02: 5362 s (1:29:22), 1995 MB = 1339 MB/h
Saddam, e01: 3563 s (0:59:23), 1261 MB = 1274 MB/h

Granted, a programme that was shown later at night (a repeat of a BBC4
programme) has better statistics.

Steve Ditko : 3565 s (0:59:25), 1548 MB = 1563 MB/h

And BBC1 still seems unaffected, even in prime time.

Jaguar, e01: 3544 s (0:59:04), 2048 MB = 2080 MB/h

My original question was really, are there plans to squeeze another
channel into the BBC's own mux (such as BBC4, BBCi or BBC Parliament)
in order to make room for another commercial channel in a different
mux?

BBC2 Freeview bit rate decreased?
 

A. J. Moss wrote:

I recorded a few programmes from BBC2 with a USB Freeview stick onto a
computer.

[snip]

Interesting, here's my figures from my Toppy PVR:-

BBC 2 Burn Up Ep 1 3.285 Mb/s
BBC 2 Burn Up Ep 2 3.199 Mb/s

BBC 2 Long Way Round (13 July|) 3.737 Mb/s

BBC 4 Neil Diamond at Glastonbury 5.234 Mb/s (Mux B of course)
BBC 4 The Thirties in Colour 4.787 Mb/s (Mux B of course)

All BBC 1 programmes come out at 4.75ish Mb/s

ITV-1 Typically 1.65 Mb/s !

C4 Typically 2.6 Mb/s

This data is derived from info provided by the 'Filer' TAP as installed on the
machine. It basically takes the amount of space consumed on the HD, and
divides it by the recording's duration.

--
Mark
Please replace invalid and invalid with gmx and net to reply.

BBC2 Freeview bit rate decreased?
 

"A. J. Moss" wrote in message
...
It's fairly well known that Freeview squeezes down the bit rates of
its MPEG-2 broadcasts, in order to fit as many digital channels as
possible into the six available muxes. However, the BBC-exclusive mux
was the exception to this rule: it only carried four channels (BBC1,
BBC2, BBC3/CBBC, and News 24), at significantly higher bit rates.

Recently this seems to have changed. I've noticed that, although BBC1
is still broadcast at 2.0GB/hour, BBC2 broadcasts have reduced from
1.7GB/hour to 1.3GB/hour.

Does anyone know of any specific reason for this change?

Depends what you are watching - action movie = high data rate; golf (lots of
unmoving shots of fiarways and putting greens) = low data rate.

BBC2 Freeview bit rate decreased?
 

On Sun, 3 Aug 2008 15:04:52 +0100, "R. Mark Clayton"
wrote:


Depends what you are watching - action movie = high data rate; golf (lots of
unmoving shots of fiarways and putting greens) = low data rate.

Cricket =bits/hr

Geo

BBC2 Freeview bit rate decreased?
 

A. J. Moss wrote:
On 3 Aug, 11:51, Signal wrote:
"Jeff Layman" wrote:
"A. J. Moss" wrote:
Recently this seems to have changed. I've noticed that, although
BBC1 is still broadcast at 2.0GB/hour, BBC2 broadcasts have
reduced from
1.7GB/hour to 1.3GB/hour.

Where did you find this information? I'd be interested to know what
it is for BBC4; I was watching the 2007 Arena programme on the
London Underground last night, and the picture quality was awful.

2nded AJ, how did you retrieve the bitrate.

I recorded a few programmes from BBC2 with a USB Freeview stick onto a
computer.

I happen to know that it streams the demuxed transport stream (as an
interleaved MPEG-2 file) straight onto the hard disk. Unlike most
Freeview DVD recorders, which unhelpfully decompress the MPEG-2 input,
and recompress it at a fixed bit rate, before burning it to DVDR.

I've recorded these files recently. These are the raw files, with
trailers still needing to be cut out of them, and so are slightly
longer than the broadcast programmes.

Burn Up, e01: 5287 s (1:28:07), 2005 MB = 1365 MB/h
Burn Up, e02: 5362 s (1:29:22), 1995 MB = 1339 MB/h
Saddam, e01: 3563 s (0:59:23), 1261 MB = 1274 MB/h

Granted, a programme that was shown later at night (a repeat of a BBC4
programme) has better statistics.

Steve Ditko : 3565 s (0:59:25), 1548 MB = 1563 MB/h

And BBC1 still seems unaffected, even in prime time.

Jaguar, e01: 3544 s (0:59:04), 2048 MB = 2080 MB/h

My original question was really, are there plans to squeeze another
channel into the BBC's own mux (such as BBC4, BBCi or BBC Parliament)
in order to make room for another commercial channel in a different
mux?

Ah, now I understand. I had assumed that you were measuring the bitrate
"live". I will now use my Humax to do the same thing as you are doing.

Thanks.

--
Jeff
(cut "thetape" to reply)

BBC2 Freeview bit rate decreased?
 

On 03/08/2008 19:30, Jeff Layman wrote:

Ah, now I understand. I had assumed that you were measuring the bitrate
"live". I will now use my Humax to do the same thing as you are doing.

Depends which streams it includes, e.g. with mythtv it saves the video,
main audio, audio description and MHEG streams.

BBC2 Freeview bit rate decreased?
 

On Sun, 03 Aug 2008 00:06:41 +0100, zumoz wrote:
Greed?

Well do not forget that the BBC have to get people acclimatized to lower
quality SD pictures for when the BBC services on multiplex B (QAM16) get
squeezed into the somewhat enlarged multiplex PSB-1 (QAM64) during the
DSO process.

This is necessary to clear multiplex B to allow it to change to DVB-t2
MPEG4 to carry 4 HD services and some new "innovative" stations, and
presumably bring in more licence money to the coffers of OfCon.