how to calculate digital volume and average frequency data from recording

[saturna]

Hi;

I am a programmer (numerous languages) and I have been asked by an artist friend to help him with a project. His project involves visualizing an audio stream, sort of like those 1990's screen savers that responded to the music being played.

He wants to keep it pretty simple to start. He'd like to digitally represent the "average frequency" and the "volume." He has matched the colours of the spectrum to the frequency range of the sounds which he has recorded and he'd like the "intensity" to vary according to the volume.

I think I can handle most of this but I do not know of tools that can turn audio recordings into a stream of data values (volume and frequency). I am sure that such libraries exist, I just don't know them. Some initial internet searches have not been very productive.

Can anyone point me in the right direction to get started?

Thanks, saturna

 

[Orb]

Hi Saturna,
unfortunately the only software analysis I personally know of is not available in software form beyond its creator and its use in a specific audio analysis hardware measurement-analysis product (still no good for what you want and rather expensive anyway, especially when not used to full capability-functionality).
If no-one has any suggestions here then another good place for such a request as this would be http://www.hydrogenaud.io/forums/
They have a fair few developers on there, although many there seem DSP focused in a slightly different way to your request.
There is one other I may know of but need to find out where he currently posts and userid to contact as I have dropped out of following him for a little while; if I find it will post or PM you.
In the meantime no harm asking on hydrogenaudio, just be aware some may be a bit hard work but please do not quote me saying that
Cheers
Orb

 

[DonH50]

Just process the raw data using an FFT (many canned packages available for various languages). The FFT gives you frequency and amplitude over a time window you determine by record length.