SPDIF delay question.
 

In article , David Looser
wrote:
"Jim Lesurf" wrote in message
...
In article , Adrian C
wrote:


The "correct" answer is to get a proper television set with a full
box of glass and air behind it, decent contrast and dynamics, and no
fancy video processing nonsense ;-)

In time - I hope - the alternative proper answer will be that the
makers of pixel-based screens actually give them the same number and
arrangement of pixels as the images, and can update pixels without so
much faffing about 'processing'. But as yet, I'd not hold my breath.
Too many 'HD ready' (i.e. not actually HD) screens to shift out of
the warehouse before that...


That would be a lot easier if all images had the same number and
arrangement of pixels, but the chance of that happening any time soon
is minimal.

You presume also that the entire display area, and every pixel, *must* be
used at all times. :-)

However, I draw your attention again to my use of the phrase, "in time...".
And agree that the determination of set makers and broadcasters to keep
mixing up varying numbers of pixels with pixel-based images is a PITA. As
is the poorly-thought-out ways the 'faffing' seems to be done in some
cases.

Even with a "proper" television set with glass (but no air, the CRT
contains a vacuum) a lot of "faffing about" is needed to cope with
different aspect ratios etc.

....but with an analogue CRT none of the 'faffing about' causes any addition
delays for the displayed image. One of those cases where a simple analogue
method works quite neatly. In such cases the image data isn't 'processed',
so no 'faffing' about of it is required. In principle, all that happens
with CRT is some analogue scan waveforms are altered, essentially just in
amplitude.

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

SPDIF delay question.
 

"Eiron" wrote in message


You know how it goes. You have to replace one thing, then
nothing else works quite right, so you end up replacing
everything else....
I need to add a delay to my digital audio to sync it with
the digital TV. Any recommendations, that don't include
listening to the TV speakers? Are there AV amps with
variable delay on the SPDIF (coax or optical) inputs?
Standalone boxes? Or just build one with a couple of ICs such as
http://focus.ti.com/docs/prod/folder...t/tpa5052.html
?

I have a friend who had this problem and corrected it with this:

http://www.felston.com/

SPDIF delay question.
 

Arny Krueger wrote:
"Eiron" wrote in message


You know how it goes. You have to replace one thing, then
nothing else works quite right, so you end up replacing
everything else....
I need to add a delay to my digital audio to sync it with
the digital TV. Any recommendations, that don't include
listening to the TV speakers? Are there AV amps with
variable delay on the SPDIF (coax or optical) inputs?
Standalone boxes? Or just build one with a couple of ICs such as
http://focus.ti.com/docs/prod/folder...t/tpa5052.html
?

I have a friend who had this problem and corrected it with this:

http://www.felston.com/

Replacing the old AV amp with one of these
http://www.yamaha-uk.com/av_amps_rec...product_id=206
seems to be the easiest solution with the highest WAF.

Most modern amps seem to have lip-sync delay built in.
It's just not something you think about until your CRT TV dies.

--
Eiron.

SPDIF delay question.
 

In article , Eiron

wrote:

Most modern amps seem to have lip-sync delay built in. It's just not
something you think about until your CRT TV dies.

For me, it is the other way around. Having thought about the lip synch
problems, I decided to stay with CRT. :-)

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

SPDIF delay question.
 

"Jim Lesurf" wrote in message
...

You presume also that the entire display area, and every pixel, *must* be
used at all times. :-)

No I'm not, quite the opposite.

...but with an analogue CRT none of the 'faffing about' causes any
addition
delays for the displayed image. One of those cases where a simple analogue
method works quite neatly.

Only if that option exists. DVD players and DVB boxes can optionally convert
16:9 material to either "pan & scan" or letterboxed 4:3, This is a digital
process. I do agree that this is performed fast enough not to cause lip-sync
problems, but it is very definitely "faffing about".

The letterbox option *can* be acheived simply by reducing the vertical scan
amplitude, but only a minority of 4:3 TV sets have that facility.

In such cases the image data isn't 'processed',
so no 'faffing' about of it is required. In principle, all that happens
with CRT is some analogue scan waveforms are altered, essentially just in
amplitude.

When done by the TV, yes. When done in the DVD player or DVB box, no.

David.

SPDIF delay question.
 

Jim Lesurf wrote:
In article , Eiron

wrote:

Most modern amps seem to have lip-sync delay built in. It's just not
something you think about until your CRT TV dies.

For me, it is the other way around. Having thought about the lip synch
problems, I decided to stay with CRT. :-)

Slainte,

Jim


Not an answer I'm afraid Jim. I have CRT and lip sync problems. My
answer is to give up and listen to records. TV programmes are a total
disgrace these days.

d

SPDIF delay question.
 

In article , David Looser
wrote:
"Jim Lesurf" wrote in message
...

You presume also that the entire display area, and every pixel, *must*
be used at all times. :-)

No I'm not, quite the opposite.

OK. Then given a display with a number of pixels to match the highest
definition in use, you could choose to use a subset for low definitions,
and then no processing of the image data would be required.


...but with an analogue CRT none of the 'faffing about' causes any
addition delays for the displayed image. One of those cases where a
simple analogue method works quite neatly.

Only if that option exists.

....as is true for anything. I agree, though, that if you don't have CRT,
then you can't use it. :-) Doesn't make my point invalid, though.


DVD players and DVB boxes can optionally convert 16:9 material to either
"pan & scan" or letterboxed 4:3, This is a digital process. I do agree
that this is performed fast enough not to cause lip-sync problems, but
it is very definitely "faffing about".

....and you are referring to the source behaviour, not the display.

With a CRT in principle all you have to do is allow the CRT to switch scan
width. No need for any 'pan and scan' or 'letterbox' processing by either
source or display.

The letterbox option *can* be acheived simply by reducing the vertical
scan amplitude, but only a minority of 4:3 TV sets have that facility.

In such cases the image data isn't 'processed', so no 'faffing' about
of it is required. In principle, all that happens with CRT is some
analogue scan waveforms are altered, essentially just in amplitude.

When done by the TV, yes. When done in the DVD player or DVB box, no.

I had thought we had been discussing lip synch delays caused by *displays*.
For fairly obvious reasons, if a source like a DVD player or tuner has to
have a process delay for the image it can easily then apply a similar delay
to the sound. This just requires the designer to know what they are doing.
However when the display has a vision delay, the designer may have no
control over the sound path from an external source feeding video to the
display.

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

SPDIF delay question.
 

Don Pearce wrote:

TV programmes are a total disgrace these days.

Like "Britain's Got Talent" ? and "America's Stupidest Police Chases".God
preserve us.

The new Dr Who hasn't been too bad though, shame they hads to dumb down
Donna ? so she sounded like a halfwit though. Must be the need to appeal to
the chavs and general low-life. She'd have been seriously HOT otherwise.

Graham

SPDIF delay question.
 

Eeyore wrote:

Don Pearce wrote:

TV programmes are a total disgrace these days.

Like "Britain's Got Talent" ? and "America's Stupidest Police Chases".God
preserve us.

The new Dr Who hasn't been too bad though, shame they hads to dumb down
Donna ? so she sounded like a halfwit though. Must be the need to appeal to
the chavs and general low-life. She'd have been seriously HOT otherwise.

Graham


Dr. Who is genuine quality. Well written and produced but unfortunately
with some serious over-acting from Ms Tate. I never seem to be in to see
it on TV, but iPlayer is very good.

d

SPDIF delay question.
 

In article , Don
Pearce
wrote:
Jim Lesurf wrote:
In article , Eiron
wrote:

Most modern amps seem to have lip-sync delay built in. It's just not
something you think about until your CRT TV dies.

For me, it is the other way around. Having thought about the lip synch
problems, I decided to stay with CRT. :-)


Not an answer I'm afraid Jim. I have CRT and lip sync problems. My
answer is to give up and listen to records. TV programmes are a total
disgrace these days.

I occasionally notice lip synch problems on DTTV broadcasts, but it seems
rare in my experience. Mind you, my eyesight isn't marvellous... and when I
use a DTTV box to pick up R3/4 I'm not looking. :-)

Can't comment on satellite TV as I don't have a way to receive it.

What DTTV RX are you using? What stations?

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html