[mythtv] Test (crude) patch for commercial skipping

Doug Zobel lists at h4.dougzobel.com
Tue Feb 18 21:55:10 EST 2003

I forwarded this to a friend who works in television production for a
local NBC affiliate about this and here was his repsonse:

I can look on an underscan monitor, but I've never heard of that, and I've
made a LOT of commercials.  And ultimately, if EVERYONE doesn't do it (i.e.
at both the network and local level, broadcast or local cable ad insertion),
the skipping software wouldn't work consistently.  The fact is that
especially with locally-made spots, the video may be shifted one way or the
other or have garbage in the H and V intervals because of crappy equipment.
You never know what you're going to get.

<snip>Talks about his experience with Tivo commercial skipping</snip>

Formats for each network show indicating local break times are distributed
mostly via the web now, or Fax or e-mail.  It's up to the station to
retrieve those times and either use them for a reference (for a human
operator) or program them into their automated hardware.  Without a format,
a good master control op might be able to make an educated guess as to when
the breaks are coming, as they are often preceeded by a :10 or :20 network
promo that is sometimes identifyable.  It's easy to mix them up, though.
But that would only provide you a cue to local spots (not national ones).

Hope that helps...


> On Tue, 18 Feb 2003 17:07:14 +0000
> matt.jarvis at philips.com wrote:
>> On terrestrial UK television, there is a small black and white square
>> which appears in the top right hand corner of the frame briefly before
>> an  advertisement, called a cue dot in tv production speak. This is
>> used to  signal to certain equipment and personnel in the production
>> chain that an  advertisement is approaching in 30 seconds I believe.
>> There used to be  VCR's on the market which could detect the cue dot
>> and pause. I don't know  if this helps, or even if it is used in
>> digital broadcasting, I'll check  when watching TV tonight and see if
>> it used on Sky's satellite service.  Detecting this dot in the frame
>> would be a much more reliable method than  using blank frames, if it
>> used everywhere, as it is always in the same  position and always
>> contains the same number of pixels etc. since it is  machine generated
>> and used to automate other equipment.
> Same effect for NTSC/USA, except bottom right.  But you have to patch
> bttv to support 720x486 (full NTSC) to be able to see it.
>> Matt Jarvis
> --
> -Monty Walls (mwalls at castor.oktax.state.ok.us)
> -	MIS, Oklahoma Tax Commission
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> - My opinions are my own, my employer knows nothing about it.
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