1 files changed, 85 insertions, 0 deletions
diff --git a/lib/equ/iir.c b/lib/equ/iir.c
new file mode 100644
index 000000000..9d826b86c
--- /dev/null
+++ b/lib/equ/iir.c
@@ -0,0 +1,85 @@
+/*
+ *   PCM time-domain equalizer
+ *
+ *   Copyright (C) 2002-2005  Felipe Rivera <liebremx at users sourceforge net>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *   $Id: iir.c,v 1.15 2005/10/17 01:57:59 liebremx Exp $
+ */
+
+#include <math.h>
+#include "iir.h"
+
+/* Coefficients */
+sIIRCoefficients *iir_cf;
+
+/* Volume gain 
+ * values should be between 0.0 and 1.0 
+ * Use the preamp from XMMS for now
+ * */
+float preamp[EQ_CHANNELS];
+
+#ifdef BENCHMARK
+#include "benchmark.h"
+double timex = 0.0;
+int count = 0;
+unsigned int blength = 0;
+#endif
+
+/* 
+ * Global vars
+ */
+int rate;
+int band_count;
+
+void set_preamp(int chn, float val)
+{
+  preamp[chn] = val;
+}
+
+/* Init the filters */
+void init_iir()
+{
+  calc_coeffs();
+#if 0
+  band_count = cfg.band_num;
+#endif
+
+  band_count = 10;
+
+  rate = 44100;
+
+  iir_cf = get_coeffs(&band_count, rate);
+  clean_history();
+}
+
+#ifdef ARCH_X86
+/* Round function provided by Frank Klemm which saves around 100K
+ * CPU cycles in my PIII for each call to the IIR function with 4K samples
+ */
+__inline__ int round_trick(float floatvalue_to_round)
+{
+  float   floattmp ;
+  int     rounded_value ;
+
+  floattmp      = (int) 0x00FD8000L + (floatvalue_to_round);
+  rounded_value = *(int*)(&floattmp) - (int)0x4B7D8000L;
+
+  if ( rounded_value != (short) rounded_value )
+    rounded_value = ( rounded_value >> 31 ) ^ 0x7FFF;
+  return rounded_value;
+}
+#endif