[time-nuts] New Years Eve TV countdown

Attila Kinali attila at kinali.ch
Thu Jan 1 07:41:38 EST 2015


On Thu, 01 Jan 2015 02:08:04 -0800
Rex <rexa at sonic.net> wrote:

> TV doesn't seem to care about time sync much these days. It also depends 
> a lot on the path getting to you,

Oh, they do. Just ask Magnus :-)

The thing is, that video delay in digital systems is hard to keep down
with all the intermediate processing steps. Video is processed in groups
of pictures (GOP) that can be anything from a single frame to several hundred.
AFAIK DVB based systems are around 8 to 30 or so. Which makes already
up to a second delay at the recording point. And every time you need to
process a complete GOP at once, it adds another second.
 

> One thing annoys me though. Many channels don't care much about start 
> and stop times. If I program something to record using the schedule, 
> often I miss the end of it. They frequently go over the half-hour or 
> hour mark by a minute or two. Occasionally they complicate it more by 
> starting a show a little early too. That irks me.

That's what we have VPS for, or PDC for digital systems[1].

[1] http://en.wikipedia.org/wiki/Programme_Delivery_Control 


			Attila Kinali
-- 
It is upon moral qualities that a society is ultimately founded. All 
the prosperity and technological sophistication in the world is of no 
use without that foundation.
                 -- Miss Matheson, The Diamond Age, Neil Stephenson


More information about the time-nuts mailing list