[mythtv-users] Re: Torrentocracy Patch against Mythtv-cvs

Brad Templeton brad+myth at templetons.com
Thu Mar 3 19:51:28 UTC 2005


On Thu, Mar 03, 2005 at 08:53:01AM -0800, Chris Petersen wrote:
> This is pretty standard -- shows are edited such that there are 
> commercial breaks in certain places.  However, it does NOT account for 
> the commercial breaks being the same length in each region (remember, 
> commercials are regional things).

Over time this is solved once you have enough people watching your
exact profile of show.   That's easy for all the cable networks,
everybody watches exactly the same show on Discovery Channel (even the
same east and west.)   I think it's also true for prime time network
programming, they are all on the same tight schedule.  If not, you need
to find other people in your town, which will eventually happen.

If you are tired of waiting for this, there are ways to make this work.

You start by building a signature map for the program based on detection
of scene transitions (key frames etc.) and all the other transitions the
commercial flagger uses.   These transitions form a fingerprint for
sections of the show.   Ie. this section had a 20 second scene, followed
by a 31.5 second scene, and a 8.3 second scene etc.  Such fingerprints
would be unique.

You can also, when there is closed captioning, and it's coming from the
network feed, just not the exact frames of the exact pieces of text.
Highly precise.

Anyway, now you record user actions not just based on the NTP time,
but relative to these points.   Ie. "The user hit fast forward 9.3
seconds after the frame with the closed caption text 'foo'".

Now you have something that works everywhere.

> 
> Also, don't forget that some people record before/after shows, and myth 
> is never 100% accurate in the time you give it (I'm set to record an 

Actually, my myth is _always_ 100% accurate on the time.  It is the
networks that are off.  If you run NTP and are live on the internet,
you will always have very very good time.



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