wave file analysis

[Boorgy]

Hey folks!!

Does anubody know how to manipulate wave files from inside a C++ program? I would need to do some rythmic analysis on it, like determining the main and secondary beat rates, or maybe finding some pattern in the sound (if there is little or no bass). Any tip would be useful and welcome as I don't even really know where to start!
Thanx!!

Nick

 

[DavesTips]

Well, this is a fairly specialised area as far as I know, involving mathematical stuff like Fourier Transforms. No doubt there's toolkits and so available to help. I'd search in Google for something like "sound wave analysis", if you feel up to something like this. Hope that this helped! ;-)

 

[Boorgy]

Thanx Dave, I'll look into that. But at a more starting level, how do I even refer to the conent of a wave file?

 

[DavesTips]

OK, this is hardly my speciality - actually I'm a manager who doesn't know much about anything All files are just streams of bytes, so you can read them with normal file operations. There's numerous sound file formats, most of them compressed in some way. There'd be maybe little point in processing an mpg say, since it has already been subjected to a lot of complex mathematical transformations (same for any compressed file), unless you want to study these formats - and good luck to you. AFAIK a .wav file for example is basically a set of samples which are the value of the signal at that point in time, which is the input for your kind of analysis. The exact format of such a (relatively simple?) file is no doubt documented somewhere. There's a site

http://www.wotsit.org/

where they have infos of that sort. CD formats are described in various Philips publications like "Red Book" etc (see

http://searchstorage.techtarget.com/sDefinition/0,,sid5_gci503642,00.html

for example). Hope that this helped! ;-)

 

[Boorgy]

Thanks Dave that's real cool!!