AnalysisGrabber documentation

Free tools
1

Hello,

Is there any “extended” documentation on AnalysisGrabber? Or maybe someone has a link to the documentation of a similar software?

I can’t make sense of multiple things, fast slopes, quick slopes, slope offset, smoothing milliseconds.

I am really wondering how one does learn to use it without documentation and I’m guessing those are “industry” standards that I’m not familiar with?

Thanks in advance!

2

Hi sefss, thanks for posting.

Correct, AnalysisGrabber is definitely not as well documented as it should be. Indeed you’d have to know the background of the onset detection technique used in this plugin to fully understand how it works.

When we have time, we’ll work on a proper manual!

3

Thanks for your answer.

Would you give some link, reference papers, anything that would explain how it works? Maybe you implemented a known algorithm? Having the name of it would be a good start.

Thanks

4

Hello,

Would you have the name of the algorithm used for onset detection?

Thanks!

5

Unfortunately I have been unable to find a paper or description of the used technique in a few quick online searches.

The alternative is to do a short explanation here but so far other things kept taking priority so I kept postponing a reply, sorry for that.

I wanted to give you an update today; as soon as some time opens up I’ll get back to you with a short overview.

6

Anybody else would have the beginning of a description?

Thanks!

7

Hi sefss,

So sorry for the late reply, I guess this is what we get for providing free tools.

In short: for each filter band there are two envelope followers, one fast, one slow. The slow one has an offset, setting it generally at a higher level than the fast one, unless there is a rapid change in the audio level. In that case, the fast follower momentarily crosses the level of the slow follower. Whenever that happens, a message is sent out for the Lo, Mid or Hi Trigger entries.

In the AnalysisGrabber interface, the number boxes next to the envelope follower graphs represent, from top to bottom:

  • Slow envelope follower interpolation time
  • Fast envelope follower interpolation time
  • Offset between two envelope followers

The graphs themselves serve only as a visual indicator of the relative values.

To calibrate the values, I personally tend to play a simple loop that is representative of the important triggers I expect, then for every band I click the monitor button that solos it (the Lo, Mid or Hi buttons) and first tweak its filter settings to properly isolate the part of the audio I want to get triggers for. Mostly, the default settings of the envelope followers give me pretty good results. Otherwise, tweaking the follower speeds and offset for a filter band allows you to determine how quickly it triggers, in other words, how sudden the changes need to be to detect an onset.

Hope that helps to get you started!
Mattijs