added Ooura implementation to repository

1 files changed, 21 insertions, 0 deletions

diff --git a/src/fftsg.h b/src/fftsg.h
new file mode 100644
index 0000000..eb7fc8a
--- /dev/null
+++ b/src/fftsg.h
@@ -0,0 +1,21 @@
+/* FFT functions */
+void cdft(int n, int isgn, double *a, int *ip, double *w);
+void rdft(int n, int isgn, double *a, int *ip, double *w);
+void ddct(int n, int isgn, double *a, int *ip, double *w);
+void ddst(int n, int isgn, double *a, int *ip, double *w);
+void dfct(int n, double *a, double *t, int *ip, double *w);
+void dfst(int n, double *a, double *t, int *ip, double *w);
+
+/* Auxiliary functions */
+void makewt(int nw, int *ip, double *w);
+void bitrv2(int n, int *ip, double *a);
+void bitrv2conj(int n, int *ip, double *a);
+void cftfsub(int n, double *a, double *w);
+void cftbsub(int n, double *a, double *w);
+void makect(int nc, int *ip, double *c);
+void rftfsub(int n, double *a, int nc, double *c);
+void rftbsub(int n, double *a, int nc, double *c);
+void dctsub(int n, double *a, int nc, double *c);
+void dstsub(int n, double *a, int nc, double *c);
+void cft1st(int n, double *a, double *w);
+void cftmdl(int n, int l, double *a, double *w);