[linux-audio-user] Applications for Automated Audio Analysis

[Pete C]

>From 8am-11pm I am recording the audio from a lecture theatre.  I want to be 
able to programatically and/or visually identify when the lecture theatre is 
in use -- the audio feed is silent when not in use.  I don't know what tools 
could do this.  Here are my ideas/desires (the first two are preferable):

-- Every 20 seconds, take a numerical reading of the amplitude level 
currently being captured, like a "VU meter" with a "data logger" attached. 
(This number would then be saved to a database along with a timestamp and 
later processed -- the saving is the easy bit, it's just getting that 
number.)  I know ecasignalview shows the current level but it requires: 
ecasound, ncurses (not possible to automatically grab relevant output so 
useless here), and an open audio device (disadvantage).

-- After 11pm, process the audio file and record the amplitude level every 
few seconds to a database.

-- Continually save a "spectrum analysis" of the live stream as an image 
(eg. JPG) that could be viewed at any time.

-- After 11pm, get a "spectrum analysis" of the whole static file and save 
it as an image (eg. JPG).  The file is AAC within MP4, but I could convert 
it to a compatible format (eg. WAV) with FAAD just for the analysis if 
necessary.  I don't think this could be done via an X GUI application as it 
needs to be automated.

Do you know which application(s) will help in these situations?

Many thanks!

- pete <><

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