[mythtv-users] Commercial Flagging Problem

[James Armstrong]

Chris Pinkham wrote:

>>On Sun, Jan 30, 2005 at 11:27:12AM -0500, Chris Pinkham wrote:
>>    
>>
>>>commercials and eliminate false positives.  I've got code started in
>>>my source tree to try using aspect ratio changes to help detect when
>>>commercials start and stop.  There are also a few other detection ideas
>>>on my TODO to add that will help the ALL method be more accurate.
>>>      
>>>
>
><long utopia commercial detection description deleted> :)
>
>  
>
>>This is bluesky for now, but I expect something like this will happen
>>in the future.
>>
>>Today, however, I will put in one suggestion that I have made before but
>>may bear repetition.  Quite often, and almost always on HDTV, commercials
>>are in a different aspect ratio from the regular show, and if you can
>>detect the black bars, you can have very accurate elimination.
>>    
>>
>
>Did you even read what you quoted from my post above? :)  I said I'm
>starting working on code to detect the aspect ratio changes.  I record
>a few shows that are letterboxed and have been putting some thought into
>this lately.  I also have some code that should allow the flagger to
>use the aspect changes detected in the decoder as well, but I don't have
>a sample file to test that with yet.  Should have one soon.  So anyway,
>aspect ratio detection will probably be the next thing added to "ALL",
>since it's fairly easy to implement and is a very good indicator of
>the distinction between what is show and what is commercial.  This will
>be after 0.17 though, I don't plan on adding any new detection
>functionality to the flagger before 0.17.  (Don't want to break it
>and have a bunch of angry 0.17 users). :)
>
>  
>
This will be nice to use on HD shows. Most of them are widescreen and 
the commercials switch to SD 4:3 format. I was thinking about a way that 
would just watch for the framerate changes. I notice that HD content 
plays at 24fps and commercials switch to 29~30fps.

- James