+void gnome_canvas_waveview_set_gradient_waveforms (int);
+
+typedef gulong (*waveview_length_function_t)(void*);
+typedef gulong (*waveview_sourcefile_length_function_t)(void*, double);
+typedef void (*waveview_gain_curve_function_t)(void *arg, double start, double end, float* vector, gint64 veclen);
+typedef void (*waveview_peak_function_t)(void*,gulong,gulong,gulong,gpointer,guint32,double);
+