[gst-devel] Audio pipeline: how to detect beats, BPM counter

[Sebastian Dröge]

Am Montag, den 24.09.2007, 12:37 +0200 schrieb Thijs Vermeir:
> Hi
> 
> On 9/24/07, Florent THIERY <fthiery at gmail.com> wrote:
> > Hi,
> >
> > I'm looking for hints about implementing a gstreamer-based BPM counter
> > and beat detector (from alsasrc).
> >
> > The first approach i though of would be using frequency filters
> > (low-band filter for beats), but then how to get a numerical value of
> > the volume in output  (and emit a corresponding gobject bus signal
> > when threshold is passed) ?
> >
> > I'd appreciate any hints towards pre-investigated beat detection /
> > sound analysis tips and tricks.
> >
> 
> There is a spectrum plugin (gst-plugins-bad) that can inspect (fft
> transform) a audio stream and outputs spectrum data.
> 
> The "BPM counter plugin" can a Bin that has this spectrum element and
> analyses the data.

Well, and probably one of the two lowpass elements (lpwsinc /
audiofreqlimit, the latter is faster and probably better for this use
case) we have before spectrum if the described BPM detection algorithm
should be implemented.