Volume and Uniformity

Here you can ask your questions on how to use Comskip for the detection of commercials. Also questions on how to remove commercials are welcome
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Mike-EEE
Posts: 12
Joined: Sat Aug 10, 2019 6:38 am

Volume and Uniformity

Post by Mike-EEE »

I am running comskipGUI.exe on a football game recorded last night and looking for guidance on some issues that I found:

1) V=-1S is prevalent throughout the entire video. From what I have read in the tuning page, this seems to suggest that there is no audio during the frames, correct? I can confirm when loading/playing the video that sound is present.
2) Uniformity. I would like to better understand what this means. Doing a search here in the forums did not return anything obvious.

FWIW I feel I am really close to a solid .ini file. It's been doing a great job removing commercials up until this game last night when lots got through. There were technical issues during the game though which understandably threw it for a loop. The station even cut to Friends for about 20 minutes. xD I am thinking uniformity/volume is the issue here which is why I inquire.

erik
Site Admin
Posts: 3344
Joined: Sun Aug 21, 2005 3:49 pm

Re: Volume and Uniformity

Post by erik »

Did you read the manuals?
Did you read comskip.txt?
Comskip is unable to decode the audio on some types of recordings.
I welcome receiving a short recording where this happens.

Mike-EEE
Posts: 12
Joined: Sat Aug 10, 2019 6:38 am

Re: Volume and Uniformity

Post by Mike-EEE »

To start, I would like to kindly remind you that I have contributed $20 to ComSkip. If I am not mistaken, $10 is required for the donators version, which technically means $10 could be seen as a donation towards reasonable support questions such as this while I get on my feet.

So, a little patience, please?

I was reading this:

http://www.kaashoek.com/files/manual.htm

This appears to be the manual.

I did a search for "uniformity" on that page which, again, is described as the manual in the URL. It returns five instances, none of which really describe what this is.

It would seem that if something was important and described, it would be included in the manual, not another document? Having multiple "manuals" seems confusing, especially when the official manual does not have much to it. You're basically forcing your newb users to hunt down different, multiple documents which only puts further burden on you when you snap at them for not having read (or knowing about) these documents.

In any case, as I also mentioned, I did do a search here in the forums for "uniformity" but nothing obvious was presented.

Finally, a search in comskip.txt only returns two instances of "uniformity" but neither of them really describe what it is.

So, I guess the better question is... have YOU read the manuals? ;)

As for the volume, I am also confused on why the volume appears to be detected in the green-colored graph and not the "V=" field. It would seem that sound is detected in the green graph but not being registered with the V= field.

If this is due to a possible bug, I am willing to assist, of course.

Unfortunately, the video that I have is 3 hours long. I will have to trim it with handbrake and send it over. What is a good amount of time for you? 5 minutes?

erik
Site Admin
Posts: 3344
Joined: Sun Aug 21, 2005 3:49 pm

Re: Volume and Uniformity

Post by erik »

I provide support to everyone that asks for help, regardless of their donation. I never check if someone did donate before answering questions.
Suggest you look at CheckSceneHasChanged inside comskip.c, in particular this piece of code

Code: Select all

    uniform = 0;
    for (i = 255; i > brightness + noise_level; i--)
    {
        uniform +=  histogram[i] * (i - brightness);
    }
    for (i = brightness - noise_level; i >= 0; i--)
    {
        uniform +=  histogram[i] * (brightness - i);
    }
    uniform = ((double)uniform) * 730/pixels;
So uniform is a number indicating the amount of pixels with a brightness different from the average brightness +/- a certain amount of noise.

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