Signal/noise/silence analysis

[pljones]

I've posted in a few places now about this and got little response. I'm after a command line tool that will process a WAV file to determine the start and end points of each "signal" burst and write out the positions (to stdout, preferably).

The files are multisampled single notes separated by ambient noise rather than silence. For low volume notes, the signal to noise ratio isn't that hot - but I can visually resolve the points at which the note starts using a wave editor. I'm hoping that means it's possible to identify the same point algorithmically (to save the tedium).

Any clues? Full source..? Win32 binary.....?

(I have no DSP knowledge, unfortunately, so I don't even know if this is theoretically possible.)

[texture]

There's an auto split feature in wavelab. Or perhaps you could use Recycle.

If you wanted a command line tool to do it (or a little windosw app), I'd suggest downloading libsndfile for handling the wave files and writing an app yourself. Shouldn't be that difficult - just have a parameter for the detection threshold setting. You could get it to back-track slightly and quick fade the ends of the sliced samples.

You could do it a little more cleverly by using fft analysis to figure out what is noise and whats not. I don't really think it would be worth the effort though.