[opendtv] Re: Two (hopefully tough) trivia questions

  • From: "John Willkie" <johnwillkie@xxxxxxxxxxxxx>
  • To: <opendtv@xxxxxxxxxxxxx>
  • Date: Wed, 3 Dec 2008 13:10:16 -0800

Could be; I only know that the delta is about 4 seconds per day.


It's been long enough. 967,887,927 nanoseconds is the repetition rate of an
ATSC 8-VSB :"frame" (probably best to call it a data frame, to make the
distinction between video frames clear) and is ALSO the rate for an ATSC M/H
frame.  Oops, I probably shouldn't have said the latter.


It's rounded to 968 ms.


John Willkie



De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En
nombre de Hughes Gary-DJWV76
Enviado el: Wednesday, December 03, 2008 12:59 PM
Para: opendtv@xxxxxxxxxxxxx
Asunto: [opendtv] Re: Two (hopefully tough) trivia questions


Not certain, but I suspect it is the difference between time in siderial
seconds and UTC (atomic) seconds and we are coming up on a leap second, so
GPS_UTC_offset will change.




Gary Hughes
Distinguished Member, Technical Staff

Advanced Engineering
Motorola On Demand Video, MA34
80 Central St.
Boxborough, MA  01719
Email: ghughes@xxxxxxxxxxxx
Office: 978 266 7269

Mobile: 978 339 3615
Fax: 978 264 9108





From: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] On
Behalf Of John Willkie
Sent: Wednesday, November 26, 2008 1:54 PM
To: opendtv@xxxxxxxxxxxxx
Subject: [opendtv] Re: Two (hopefully tough) trivia questions

Correction: that should be 967,887,927 nanoseconds.





De: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx] En
nombre de John Willkie
Enviado el: Wednesday, November 26, 2008 1:47 AM
Para: opendtv@xxxxxxxxxxxxx
Asunto: [opendtv] Two (hopefully tough) trivia questions


I probably won't be able to answer both these questions until early next
week, but here goes:


1)                   What is the significance of 967,887,927 picoseconds?

2)                   How will that figure become even more significant in
the near future?


And, I've checked - this one doesn't seem - at this point to be solvable via
Google.  I can give one hint: the figure is relevant to digital television.


John Willkie





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