Dolby Digital/Prologic
Craig Henry
broadcast in dolby prologic and if so is it supported by any/all of the
set-top boxes?
John Russell
"Craig Henry" <craig...@btinternet.com> wrote in message
news:aq687l$kos$1...@sparta.btinternet.com...
> I'm new to digital TV so this may be a stupid question! Are the programs
> broadcast in dolby prologic and if so is it supported by any/all of the
> set-top boxes?
>
>
channels and is broadcast using the ordinary stereo channels. Even NICAM
stereo can be used. However you will need an external decoder.
Loz
"Craig Henry" <craig...@btinternet.com> wrote in message
news:aq687l$kos$1...@sparta.btinternet.com...
> broadcast in dolby prologic and if so is it supported by any/all of the
> set-top boxes?
Dolby Prologic can be send as part of the stereo signal, and is hence just passed through the set
top box via its stereo outputs. However, many people seem to complain that the compression applied
to the signal adversely affects the prologic content.
As for Dolby Digital 5.1 surround sound, only a Sky+ box outputs this via its optical output
Loz
Craig Henry
"Craig Henry" <craig...@btinternet.com> wrote in message
news:aq687l$kos$1...@sparta.btinternet.com...
David G. Bell
nolawre...@nowilkesspamworld.co.uk "Loz" wrote:
> "Craig Henry" <craig...@btinternet.com> wrote in message
> news:aq687l$kos$1...@sparta.btinternet.com...
> > I'm new to digital TV so this may be a stupid question! Are the programs
> > broadcast in dolby prologic and if so is it supported by any/all of the
> > set-top boxes?
>
> Dolby Prologic can be send as part of the stereo signal, and is hence just
> passed through the set
> top box via its stereo outputs. However, many people seem to complain that the
> compression applied
> to the signal adversely affects the prologic content.
The main source of Prologic sound is films from the last 25 years or so.
The way it works, some ordinary stereo material may give a partial
effect. The centre channel comes from summing the two stereo channels,
so anything equally on both channels will come through on the centre
speaker -- this is common for lead singers on music recordings, for one.
The surround sound channel is recorded on the two stereo channels in
antiphase, so it vanishes from the centre speaker. It's a bit unlikely
that a stereo recording will have anything that accidentally gets
extracted as surround sound.
The centre channel can make a big difference when watching TV, it
anchors the sound to the picture. If you have an amp that can easily be
switched to different speaker combinations, stereo+centre is a good bet
for routine use. (And if you only have a stereo amp, try switching the
TV speakers to mono, and fiddling with the volume. Turn it up until get
the feel that the people are talking from the TV, while music is more
spread out.)
So you just connect the stereo output from the STB to one of the
surround-sound amplifier's inputs. If there aren't any sockets on the
STB, Maplin have a couple of SCART-to-SCART cables with phono plugs to
extract the stereo signals. Part numbers VA23A and QS04E. And various
other options if you want a switchbox.
As for the effect of the digital-TV processing on the Pro Logic content,
I'm not so sure. One of the tricks used for audio compression is to
drop sounds that are masked by other sounds. But Pro Logic, especially
the more recent version, does a lot of processing to seperate sounds in
space, These could conflict. "Saving Private Ryan" and the Omaha Beach
sequence is still pretty intense.
--
David G. Bell -- SF Fan, Filker, and Punslinger.
"Let me get this straight. You're the KGB's core AI, but you're afraid
of a copyright infringement lawsuit over your translator semiotics?"
From "Lobsters" by Charles Stross.
Julie Brandon
>As far as content is concerned, many films shown are in Pro-Logic and
>Sky broadcast their football in it, but with the exception of a few
>others, eg, The Simpsons, I don't think there are very many programs
>with DPL content. Most of them are just in stereo.
IIRC Lots of BBC & ITV Dramas and the similar used to be done in ProLogic,
or rather, surround information included in a Dolby Pro Logic compatible
way, no official ProLogic symbol given of course 'cos that'd cost real
money.
--
Julie Brandon http://www.computergeeks.co.uk/
______________________________________________________________________________
DILBERT - Season 2 (not the ones on the DVD/Videos)
Late night daily slot on Sky 1 from 10th November 2002
John Russell
> or rather, surround information included in a Dolby Pro Logic compatible
> way, no official ProLogic symbol given of course 'cos that'd cost real
> money.
I've only ever seen 2 series indicate Dolby Surround (at the beginning of
the program) and that's Frost and the last Jeremy Brett Holme's series.
I also think that the lack of Pro-logic programmes is a bit of a Myth, a bit
like all those people who insist most widescreen programs are just zoomed
4:3 broadcasts. I must have been imagining the Star Ship zooming over my
head in the intro credits to DS9!
David Quinton
("David G. Bell") wrote:
>The main source of Prologic sound is films from the last 25 years or so.
>The way it works, some ordinary stereo material may give a partial
>effect. The centre channel comes from summing the two stereo channels,
>so anything equally on both channels will come through on the centre
>speaker -- this is common for lead singers on music recordings, for one.
>The surround sound channel is recorded on the two stereo channels in
>antiphase, so it vanishes from the centre speaker. It's a bit unlikely
>that a stereo recording will have anything that accidentally gets
>extracted as surround sound.
>
As an aside (I love asides) I can remember creating "pseudo" surround
probably 20+ yrs ago after reading an article somewhere.
On simply connected a (pair of?) speaker across the non-common side of
both stereo channels. ISTR that any out of phase information would
then come from the new speaker(s) creating a "spacey" effect.
I think...
--
Karma Chameleon phone - as seen on BT Ad: <http://www.thisbritain.com/karma_chameleon/>
Discount Chart music: <http://www.ThisBritain.com/Am100music_1.php>
John Russell
"metn41" <met...@dsl.pipex.com> wrote in message
news:km5fsuca5i8i7hcam...@4ax.com...
> On 04 Nov 2002 21:26:21 GMT,
> nos...@honeypot.computergeeks.me.uk.invalid (Julie Brandon) wrote:
>
> >no official ProLogic symbol given of course 'cos that'd cost real money.
>
> DD5.1 :-)
>
> Regards,
>
> metn41.
Terrestrial Digital is already suffering from cramming in the video for so
many channels. Adding DD 5.1 to that is not going to help. The decision was
takon in the 80's (by the then government and the TV companies) to go down
the path of normal quality/ lots of channels. The alternative could have
been to add 2 or 3 more channels compared to analog and going down the path
of HDTV with spare capacity for the like of DD 5.1. That would have been
very expensive for the TV companies and viewers alike.
David G. Bell
<a9uesu0jl7anlrbcc...@4ax.com>
dav...@BizOrg.co.uk "David Quinton" wrote:
> On Mon, 04 Nov 2002 18:40:18 +0000 (GMT), db...@zhochaka.demon.co.uk
> ("David G. Bell") wrote:
>
> >The main source of Prologic sound is films from the last 25 years or so.
> >The way it works, some ordinary stereo material may give a partial
> >effect. The centre channel comes from summing the two stereo channels,
> >so anything equally on both channels will come through on the centre
> >speaker -- this is common for lead singers on music recordings, for one.
> >The surround sound channel is recorded on the two stereo channels in
> >antiphase, so it vanishes from the centre speaker. It's a bit unlikely
> >that a stereo recording will have anything that accidentally gets
> >extracted as surround sound.
> >
>
>
> As an aside (I love asides) I can remember creating "pseudo" surround
> probably 20+ yrs ago after reading an article somewhere.
>
> On simply connected a (pair of?) speaker across the non-common side of
> both stereo channels. ISTR that any out of phase information would
> then come from the new speaker(s) creating a "spacey" effect.
>
> I think...
It sounds right, but it would be a bit approximate.
It wouldn't be difficult to knock up a low-fi pre-amp that would take a
line-level source, and produce sum and difference signals from the
stereo channels.
The Dolby system limits the surround channel to 7kHz, and uses a
modified Dolby-B noise reduction on it. That's the more difficult
element, but a passive decoder isn't so difficult a gadget to build.
The trouble is that there are a lot of extra tweaks on current hardware.
You can read up on all this at http://www.dolby.com/tech/whtppr.html
Richard Revis
>>no official ProLogic symbol given of course 'cos that'd cost real money.
>
> And people are still asking when the BBC are going to start using
> DD5.1 :-)
Even though it would have no benefit on most of their good programming -
repeats from their comedy archive :o)
--
That money talks, I will not deny; I heard it once, it said 'goodbye'.
R. Mark Clayton
"John Russell" <jo...@johnerussell.worldonline.co.uk> wrote in message
news:3dc6f...@mk-nntp-2.news.uk.tiscali.com...
> > IIRC Lots of BBC & ITV Dramas and the similar used to be done in
ProLogic,
> > or rather, surround information included in a Dolby Pro Logic compatible
> > way, no official ProLogic symbol given of course 'cos that'd cost real
> > money.
>
> I've only ever seen 2 series indicate Dolby Surround (at the beginning of
> the program) and that's Frost and the last Jeremy Brett Holme's series.
Lots of series use Dolby Pro Logic effectively. Try a scene in the Rovers
on Coronation Street. The bar chatter and clinking of glasses will come out
of the rear speakers.
OTOH a lot of programs have very basic sound and don't even use stereo
properly.
The best use of Pro Logic I have noticed was in a clip of the [film?] Three
Musketeers. Ochestral music out of left and right. Dialogue inside the
stage coach on centre and the sound of horses hooves of the pursing then in
the rears.
No where near as good as Dobly Digital (as in Saving Private Ryan) though.