Audio File Matching Program

Question

I'm trying to write a program in iPhone than can take two audio files (e.g. WAV) as inputs, compare them, and spit out a number that tells you how similar the audio files are.

If someone has done something like this, know how to go about doing it, or just have some ideas, please let me know. Anything will be greatly appreciated.

Specific questions: What language is suitable? How hard is it to do (how many hours, roughly)? Where can I find a good source of audio library/tools?

Thanks!

Answer 1

I'd say it's pretty hard, not so much the implementation, but coming up with a reasonable definition of 'similar'.

That said, you're probably looking at techniques like autocorrelation and FFT, both of which are CPU-intensive tasks, so I'd say a fully-compiled language (C, C++, don't know about Objective-C) would be most suitable at least for the actual calculations. Also, you're facing a somewhat underpowered platform for such tasks (if only because uncompressed audio files are pretty large), so you're in for quite some optimization.

This book: http://www.dspguide.com/ is quite concise reading for all things DSP-related.