Cycling 74 » Topic: Grain Analysis – Mean Amplitude and Dominant Frequency

Grain Analysis – Mean Amplitude and Dominant Frequency

ComfortableInClouds — Thu, 25 Feb 2010 19:10:14 +0000

Hi – I am trying to analyze the mean amplitude and dominant frequencies of individual grains within a larger sample, then organize those grains in a list according to these attributes. I realize that this is a job better suited for non-real time analysis, such as MATLAB, but would like to be able to do it in Max as to record a sample and organize its grains in real time. I am struggling with an approach making use of [avg~], [pitch~] and [gate] but am not having very much luck. I was curious if anyone could give some suggestions or post a basic patch to nudge me in the right direction.

Thanks for your help!

Re: Grain Analysis – Mean Amplitude and Dominant Frequency

MIB — Thu, 25 Feb 2010 19:24:42 +0000

I don’t really have anything overly useful to say other than you might want to have a look at the IRCAM ftm library for storage and sorting. It’s very fast and flexible. There is also gbr from IRCAM (might come with ftm, can’t remember) which does some nifty stuff with audio…

Re: Grain Analysis – Mean Amplitude and Dominant Frequency

Pierre Alexandre Tremblay — Thu, 25 Feb 2010 20:19:39 +0000

ftm.ircam.fr

check the catart package, it does exactly this

Re: Grain Analysis – Mean Amplitude and Dominant Frequency

Brad Garton — Thu, 25 Feb 2010 21:05:32 +0000

Do you know lisp programming? This would be easy to do in lisp:

http://music.columbia.edu/~brad/maxlispj/

brad

http://music.columbia.edu/~brad

Re: Grain Analysis – Mean Amplitude and Dominant Frequency

ComfortableInClouds — Thu, 25 Feb 2010 23:07:03 +0000

Thanks for the replies :)

i should stress that i’m not very concerned about the list sorting, that’s simple enough to do with coll and a few objects, or even with js. i’m much more interested in solutions for the grain amp and freq analysis. would lisp help for this, brad?

are the ftm objects useful for the grain analysis? Or just list sorting? on my computer, it seems the ftm objects can’t be opened. im on mac os x, 10.6. It says “the following disk image cannot be recognized.” would someone be able to post the externals (if they are useful for grain analysis) ?

Re: Grain Analysis – Mean Amplitude and Dominant Frequency

Brad Garton — Fri, 26 Feb 2010 00:34:37 +0000

on a sample (or event vector) level, lisp probably wouldn’t be best. It’s good at structuring lists, doing all kinds of data-manipulation, etc. If you’re asking about the direct analysis of the incoming audio data stream, then you’ll probably have to do some C-coding or find an external that can do this (maybe FTM? I don’t know that package well… or maybe Eric Lyon’s FFTease objects have something that could help).

brad

http://music.columbia.edu/~brad

Re: Grain Analysis – Mean Amplitude and Dominant Frequency

tdaeik — Fri, 26 Feb 2010 03:45:25 +0000

for the frequency analysis, you could maybe use zsa.freqpeak~ from the zsa.descriptors (http://www.e–j.com/?page_id=83) package to get the highest n peaks from a signal. run it over your windowed data.

Re: Grain Analysis – Mean Amplitude and Dominant Frequency

ComfortableInClouds — Fri, 26 Feb 2010 15:57:38 +0000

the zsa objects are incredible. precisely the kind of thing i was looking for. many thanks, tdaeik (and to mikhail and ej).