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option to only cut on logo + black frame?

Posted: Wed Aug 17, 2016 12:46 am
by zhaian
Hi,

I'm trying to skip commercials on a video where the logo disappears halfway through the first show segment. If I enable logo detection, comskip adds a cutpoint in the middle of the show segment. If I disable logo detection, it gets the first segment right but later gets confused about which blocks are show and which are commercial. I've tried various settings for min_show_segment_length, max_commercial_size, and min_commercial_size as suggested on the tuning page.

It seems like comskip would be able to get the right answer if there were an option to only cut when a logo appears/disappears AND there are black frames nearby. Does such an option exist? Or if I could tell it that blocks longer than 100ms are show segments (setting min_show_segment_length didn't seem to help here) I think that would work too.

Also on an unrelated topic if I can ask a general question, what is the significance of capital letters vs lower-case letters in the final block table at the end of the output? And what is meant by "strict" vs "non-strict" ...I wasn't able to find definitions in the included html files.

Thanks!
Ryan

Re: option to only cut on logo + black frame?

Posted: Thu Aug 18, 2016 3:15 pm
by erik
You should enable logo detection but disable cutting on logo (dis)-appearing
The upper case letter define what is used for scoring the segment and the lower case letters indicate the cause for the cutpoint at the end of the segment
Strict identifies a commercial segment that complies with more "strict" requirements then a non strict segment.

Re: option to only cut on logo + black frame?

Posted: Thu Aug 18, 2016 6:49 pm
by zhaian
Thanks for the explanation.

Follow up questions,

1) How do I enable logo detection but disable cutting on logo (dis)appearing?
2) What are "strict" requirements?

If this is already documented somewhere please let me know, so far I've read the manual, tuning guide and comments in the provided comskip.ini file.

Re: option to only cut on logo + black frame?

Posted: Fri Aug 19, 2016 7:28 am
by erik
Cutting on logo

before_logo=0 ;Cutpoints can be inserted just before the logo appears. Set value set is the amount of seconds to start a search for a silence before the logo appears. 0 = disabled
after_logo=0 ;Cutpoints can be inserted just after the logo disappears. Set value set is the amount of seconds to start a search for a silence after the logo disappears. 0 = disabled

Strict is "more like a commercial" then non strict

Re: option to only cut on logo + black frame?

Posted: Fri Aug 19, 2016 7:59 am
by zhaian
I see... I was already using after_logo=0, though I didn't know setting to 0 disabled cutting on logo. The comment in the .ini just says:

after_logo=0 ; set to number of seconds after logo disappears comskip should start to search for silence to insert an additional cutpoint

so I figured 0 meant it would start searching for silence to add a cutpoint 0 seconds after the logo disappears.

Anyway I see now in the table that the the reason for the cut is "b" ...I suppose it would be "l" if the cut were made due to additional black frames added by after_logo? I don't notice any black frames during playback but I guess I need to open up the debug window and take a closer look.

Re: option to only cut on logo + black frame?

Posted: Wed Jul 24, 2019 8:35 pm
by markn62
That's because setting before/after_logo=0 doesn't disable logo cutting. I have much documentation showing that it does still cut and that the remark is accurate that it is to "set to number of seconds after logo disappears/disappears".