Gstreamermm parsing question

[José Tomás Tocino García <theom3ga gmail com>]

Hi,

I'm new to gstreamer; I'm developing a C++ game and I need to apply a
FFT to the microphone input in order to get the pitch. Previously I
was using Portaudio and a separate fft library, but now that I'm
trying to switch to GStreamer looks like the "spectrum" element could
do the job. I've managed to set up an example that creates a small
program that links a pulsesrc with a spectrum and the to pulsesink,
but I don't know how to parse the messages that spectrum sends.

In the spectrum reference [1], it says that the structure has an
attribute called "magnitudes", which is a "GstValueList of gfloat",
but I don't know how to parse it, because Gst::Structure [2] hasn't
got any appropiate get_field method. However, there's the method
called get_field_type, but I don't know what to do with the GType it
returns.

As a side question, would it be possible to get the raw stream for me
to manually parse it?

Thanks

[1]: http://www.gstreamer.net/data/doc/gstreamer/head/gst-plugins-good-plugins/html/gst-plugins-good-plugins-spectrum.html
[2]: http://library.gnome.org/devel/gstreamermm/unstable/classGst_1_1Structure.html

-- 
José Tomás Tocino García