[mythtv] alternative method for commercial skipping

[Ben Bucksch]

Chris Pinkham wrote:

>>>If you want to go with that fullscreen logo route (not sure, if your 
>>>stations also do that), you could let the user hit a key when he sees 
>>>that ad-start and end and then just store that frame for that station.
>>>      
>>>
>I was keying off "store that frame".
>
Yes, but what I meant what to store one frame (picture) out of that 
video clip. If you found that frame, you also found the clip, because 
the logo won't appear in a movie.

I said "*store* that frame", because every station of course has 
different clips, and each station has a set of several clips (5-10?) 
they use at any given time, and the sets also change over time 
(months/years).

>unless someone wants to put up some sample .nuv files for me to download.
>
Will do so, URL per private mail.

>>involving the logo somewhere, e.g. some children playing ball with the 
>>logo in the background as well as the word "Werbung" (advertizing) 
>>somewhere etc.. In other words, if you look for a non-moving picture, 
>>you'd probably fail.
>>    
>>
>If someone could think up a way to detect things like this on-the-fly
>it would be great.
>
Not sure what you mean with "on the fly". What I meant with "hit a key": 
If I see such an intro/outro for commercials, I would hit a certain key, 
telling mythtv "that is the start for commercials" and later "that is 
the end". mythtv then just stores that frame and from now on searches 
for that frame (and the others I added previously) on that channel.
I see that this is inconvient setup-work, but I'd think that this intro 
recognition is the most reliable way to detect commercials.

Hm, if you want to avoid any setup, maybe comparing different recordings 
from the same station and checking for overlaps?
If you exclude programmes with the same title, you wouldn't hit (how are 
the "intros" called where all the names appear, but no actual playing, 
the same in every episode of the series?), but maybe that's wanted, 
depends on the user and maybe show, I know I don't want to see the 
"intro" for ST TNG all the time again.
Are there any other cases where video clips of a few (1-5) seconds are 
identical across several (5?) different recordings of the same station? 
I guess cartoons recycle parts of the animation, but that long and that 
often?

>No one (or even 5) detection methods will catch everything, so I think it's going to have to be a combination of things. I thought about trying to have some sort of rating system to detect commercials.
>
I don't have a problem with a hit rate of only 70-90%, as long as I can 
be 100% sure that I see everything of the movie. The more fancy it gets, 
the less predicatable it gets and the less likely it is that bugs are 
found, so my confidence declines. But maybe I am just paranoid, and it's 
up to you anyways.

>[trailers]
>If they are fixed-length (ie, 10 seconds always), that's easier to detect.
>If they vary then other methods will have to be used.
>
I don't know, maybe 10 seconds and 30 seconds or so. I never really 
cared much so far.

>If you're scared it might cut off part of a show then don't turn on
>auto skipping.  wait and hit the 'Z' key yourself.
>
Yes, but what if it skips too far?

>I just back up 5 seconds and double-check.
>
nod, but that destroys some of the convience intended. Thus the 
suggestion to always display the last n seconds of the commercial block.

>The current code shows you how many seconds it skipped
>when you hit 'Z' or 'Q' so that's another indicator to make sure it
>didn't skip too far.
>
Ah, good, that avoids skipping 20 minutes or longer.

>Just committed it now.  Let me know if (or how well) it works.
>
It only processes new recordings, right?