[vdr] Re: Proposal: cutting out advertising automatically

[Matthias Schniedermeyer <ms@citd.de>]

On Tue, Oct 22, 2002 at 09:57:51AM +0200, Steffen Koch wrote:
> Andreas Mair wrote:
> >>2. We could analyze the MPEG-2 data stream for a number of sensible
> >>criteria (sender logo present; average loudness; ratio of scene change;
> >>etc, anything else?, then produce a probability for commercials) and
> >>produce a suggestion for cutting.
> >I like this idea. There had been some discussion on this list some time 
> >ago.
> >I believe that commercials shouldn't be cut automatically, but the marks 
> >should be set. So it would be possible to skip a commercial while viewing 
> >or manually start cutting when the marks are verified. With this method 
> >you won't cut/miss part of the recording.
> This sounds indeed good.

Not when you think about it.

Verify takes longer than creating cutting marks yourself.
(I mean "real" verify, where you have to check a) The Position of the
marks and b) if all marks are there or if a pair is missing.)

"Blindly" trusting other to make all marks correct is another story. I
would not use "forgein" cutting-marks without checking if they are
correct and as i said this takes longer than you need for creating your
own cutting-marks.

(Taking aside that i use my own cutting-software which takes only a few
seconds for a whole recording (on Premiere. ("Begin -> End -> Ready")
and a few seconds more for a FreeTV-Recording ("Begin -> End -> Begin ->
End -> Begin -> End -> Begin -> End -> Ready"). I have around 4-10
cuttings per day so an efficient cutting-tool is essential for me. (And
when i wrote my cutting-software VDR didn't had any cutting at all. (>2
Years ago)))

> >Don't like this idea. How would you manage the data? There has to be an 
> >entry for every recording any time it started. I mean MovieXYZ at 20:15 
> >o'clock will have commercials placed different then the same movie 
> >repeated at 03:00 o'clock. Not to speak of the movie repeated a year later 
> >at another channel. And finally, how do you want to handle the leading 
> >minutes before the movie starts (everyone can set it to his/her 
> >preference)?
> This is IMHO no problem. You could use the PTS for that.

Just remember the marginstart.

The bigger problem here is the time. Not all VDR-machines have the same
time, so the recording start can vary everywhere from nothing to a few
seconds to some minutes. You could make "md5sum"s of some I-Frames to
find corrosponding I-Frames on both sides. This way you get the
clock-difference between the two systems. (I-Frame XY is at offset 512
on Machine A and at offset 656 on Machine B. So the clock-difference ist
656-512 = 144 frames = 5.76 seconds)




Bis denn

-- 
Real Programmers consider "what you see is what you get" to be just as 
bad a concept in Text Editors as it is in women. No, the Real Programmer
wants a "you asked for it, you got it" text editor -- complicated, 
cryptic, powerful, unforgiving, dangerous.



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