Measuring TV delays
Are there any events similar to New Years where some specific countdown time
is shown on TV?
How about some show where they just show a good picture of a reliable clock?
Or do we have to wait a whole year to be able to measure things?
--
These are my opinions. I hate spam.
Hal,
Bloomberg TV, a financial news channel, has a continuous clock in the
lower left corner.
Other financial channels may also do that, as time is of the essence.
Especially opening and closing times.
Bill Hawkins
-----Original Message-----
From: Hal Murray
Sent: Wednesday, January 01, 2014 8:50 PM
Are there any events similar to New Years where some specific countdown
time is shown on TV?
How about some show where they just show a good picture of a reliable
clock?
Or do we have to wait a whole year to be able to measure things?
From: Hal Murray
Are there any events similar to New Years where some specific countdown time
is shown on TV?
How about some show where they just show a good picture of a reliable clock?
Or do we have to wait a whole year to be able to measure things?
Hal,
I already mentioned Formula 1 Motor Races (when shown live, obviously).
Seem to be quite consistent here.
David
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Cable here had about a 10 second latency. HNY - Mike
Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell
Moon Pie Drop Mobile, Alabama as watched in Birmingham 7 sec delay over the
air, 9 sec analog cable, digital cable not checked. In fact it maybe
possible the Satellite back feed is in the clear, something to check next
year. Now I need a high speed multi channel CCTV setup to Capture this with
predictable delays. Sure this will keep me busy till next year :-) Happy new
year to all ! ( sorry for the 32 hour delay )
Stanley
----- Original Message -----
From: "David J Taylor" david-taylor@blueyonder.co.uk
To: time-nuts@febo.com
Sent: Thursday, January 02, 2014 12:28 AM
Subject: Re: [time-nuts] Measuring TV delays
From: Hal Murray
Are there any events similar to New Years where some specific countdown
time
is shown on TV?
How about some show where they just show a good picture of a reliable
clock?
Or do we have to wait a whole year to be able to measure things?
Hal,
I already mentioned Formula 1 Motor Races (when shown live, obviously).
Seem to be quite consistent here.
David
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
On 1/1/14 10:28 PM, David J Taylor wrote:
From: Hal Murray
Are there any events similar to New Years where some specific countdown
time
is shown on TV?
Rocket launches, although typically not on live TV any more. More likely
streamed (at least that's how I watch them). In the "post launch
tracking" part, there's usually a display showing TAI/UTC along with
various parameters (perigee, apogee, etc). I always wait until perigee
is >100km before really believing it's successful.
But if you can get a feed from China or India, they're pretty big on
publicizing their space program, so they might have live news feeds.
Typically, cable receives the signal off air or via fiber.
They decode the digital signal to baseband.
They reencode the signal to their distribution format.
They mux all the channels together.
All of this is transmitted as packets.
Each channel has a PID assigned in the header of the packet.
Your TV or set top box decodes the packets and displays the ones for
the channel that you have selected.
The decode and encode time at the cable plant is part of this.
Most of the latency is that you would not pay for a fast enough
processor in your TV or set top box to process all of the packets faster.
The more channels in the cable system, the longer the latency.
73
Glenn
WB4UIV
At 08:31 AM 1/2/2014, you wrote:
Cable here had about a 10 second latency. HNY - Mike
Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
When they broadcast "live" TV like from a sports vent I wonder if the time
code generated by the camera is preserved? But then even if it were the
time might have been set manually to match the display on the camera
operator's cell phone.
Same for scenes with clacks in the background. Do you trust them to be
on-time? They might even have ben intentionally set wrong to hide the
transmit delay.
On Wed, Jan 1, 2014 at 10:28 PM, David J Taylor <
david-taylor@blueyonder.co.uk> wrote:
From: Hal Murray
Are there any events similar to New Years where some specific countdown
time
is shown on TV?
How about some show where they just show a good picture of a reliable
clock?
Or do we have to wait a whole year to be able to measure things?
Hal,
I already mentioned Formula 1 Motor Races (when shown live, obviously).
Seem to be quite consistent here.
David
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
--
Chris Albertson
Redondo Beach, California
On 1/2/14 11:56 AM, Chris Albertson wrote:
When they broadcast "live" TV like from a sports vent I wonder if the time
code generated by the camera is preserved? But then even if it were the
time might have been set manually to match the display on the camera
operator's cell phone.
Depends on how the "live" feed is derived. If it's an analog signal,
there's no "time setting" involved. If it's B-roll from a GoPro, then
yes, it's based on the camera person's watch.
Same for scenes with clacks in the background. Do you trust them to be
on-time? They might even have ben intentionally set wrong to hide the
transmit delay.
Unlikely that they'd fool with clocks in the background. Why would they
care (except if they're faking the 1969 moon landing or something.. then
they've got enough budget for someone to make sure the clocks in the
fake mission control read correctly).
They DO have people to set the clocks in filming for subsequent editing:
it's just part of "continuity" like making sure cigarettes are the right
length, the ice in the glasses has melted the right amount, etc.
Not a job I would want.
From: Chris Albertson
When they broadcast "live" TV like from a sports vent I wonder if the time
code generated by the camera is preserved? But then even if it were the
time might have been set manually to match the display on the camera
operator's cell phone.
Same for scenes with clacks in the background. Do you trust them to be
on-time? They might even have ben intentionally set wrong to hide the
transmit delay.
Can't comment on the camera time-code, Chris, but I would hope it was
centralised rather than being off the operator's phone!
The clocks I mentioned, F1 races, do appear to be accurate (observations
partially from being present at the event), and certainly /not/ skewed to
compensate for broadcast delay. Other times are when you see "behind the
scenes" and a control-room clock is visible. Usually these are centrally
synced, and can give a fair impression of the broadcast delays.
All this from UK television observations - and the programs don't have a
"bleep offensive content delay" - no nanny state here! (Others may differ
in that view - <G>) I recall what Alan Jones once called Michael Schumacher
on live TV, and the adjective was edited out on the repeat broadcast.
Cheers,
David
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk