From 9bf37cc9712506b2483650c82d3c41152337ef7e Mon Sep 17 00:00:00 2001
From: Dave Burke <daveburke@google.com>
Date: Tue, 17 Apr 2012 09:51:45 -0700
Subject: Fraunhofer AAC codec.

License boilerplate update to follow.

Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5
---
 libFDK/include/FDK_trigFcts.h | 169 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 169 insertions(+)
 create mode 100644 libFDK/include/FDK_trigFcts.h

(limited to 'libFDK/include/FDK_trigFcts.h')

diff --git a/libFDK/include/FDK_trigFcts.h b/libFDK/include/FDK_trigFcts.h
new file mode 100644
index 0000000..19ab0b8
--- /dev/null
+++ b/libFDK/include/FDK_trigFcts.h
@@ -0,0 +1,169 @@
+/***************************  Fraunhofer IIS FDK Tools  **********************
+
+                        (C) Copyright Fraunhofer IIS (2005)
+                               All Rights Reserved
+
+    Please be advised that this software and/or program delivery is
+    Confidential Information of Fraunhofer and subject to and covered by the
+
+    Fraunhofer IIS Software Evaluation Agreement
+    between Google Inc. and  Fraunhofer
+    effective and in full force since March 1, 2012.
+
+    You may use this software and/or program only under the terms and
+    conditions described in the above mentioned Fraunhofer IIS Software
+    Evaluation Agreement. Any other and/or further use requires a separate agreement.
+
+
+   $Id$
+   Author(s):   Haricharan Lakshman, Manuel Jander
+   Description: Trigonometric functions fixed point fractional implementation.
+
+   This software and/or program is protected by copyright law and international
+   treaties. Any reproduction or distribution of this software and/or program,
+   or any portion of it, may result in severe civil and criminal penalties, and
+   will be prosecuted to the maximum extent possible under law.
+
+******************************************************************************/
+
+
+
+#include "common_fix.h"
+
+#include "FDK_tools_rom.h"
+
+/* Fixed point precision definitions */
+#define Q(format)        ((FIXP_DBL)(((LONG)1) << (format)))
+
+#ifndef M_PI
+#define M_PI      (3.14159265358979323846f)
+#endif
+
+/*!
+ * Inverse tangent function.
+ */
+
+// --- fixp_atan() ----
+#define Q_ATANINP   (25)    // Input in q25, Output in q30
+#define Q_ATANOUT   (30)
+#define ATI_SF              ((DFRACT_BITS-1)-Q_ATANINP)  // 6
+#define ATI_SCALE           ((float)(1<<ATI_SF))         //
+#define ATO_SF              ((DFRACT_BITS-1)-Q_ATANOUT)  // 1   ] -pi/2 .. pi/2 [
+#define ATO_SCALE           ((float)(1<<ATO_SF))         //
+// --- fixp_atan2() ---
+#define Q_ATAN2OUT  (29)
+#define AT2O_SF             ((DFRACT_BITS-1)-Q_ATAN2OUT) // 2   ] -pi   .. pi   ]
+#define AT2O_SCALE          ((float)(1<<AT2O_SF))        //
+// --------------------
+
+FIXP_DBL fixp_atan(FIXP_DBL x);
+FIXP_DBL fixp_atan2(FIXP_DBL y, FIXP_DBL x);
+
+FIXP_DBL fixp_cos(FIXP_DBL x, int scale);
+FIXP_DBL fixp_sin(FIXP_DBL x, int scale);
+
+#define FIXP_COS_SIN
+
+#ifndef CORDIC_SINCOS
+
+#include "FDK_tools_rom.h"
+
+#define SINETAB SineTable512
+#define LD 9
+
+#endif
+
+#ifndef FUNCTION_inline_fixp_cos_sin
+
+#define FUNCTION_inline_fixp_cos_sin
+
+/*
+ * Calculates coarse lookup index and sign for sine.
+ * Returns delta x residual.
+ */
+static inline FIXP_DBL fixp_sin_cos_residual_inline(FIXP_DBL x, int scale, FIXP_DBL *sine, FIXP_DBL *cosine)
+{
+    FIXP_DBL residual;
+    int s;
+    int shift = (31-scale-LD-1);
+    int ssign = 1;
+    int csign = 1;
+
+    residual = fMult(x, FL2FXCONST_DBL(1.0/M_PI));
+    s = ((LONG)residual) >> shift;
+
+    residual &= ( (1<<shift) - 1 );
+    residual = fMult(residual, FL2FXCONST_DBL(M_PI/4.0)) << 2;
+    residual <<= scale;
+
+    /* Sine sign symmetry */
+    if (s & ((1<<LD)<<1) ) {
+      ssign = -ssign;
+    }
+    /* Cosine sign symmetry */
+    if ( (s + (1<<LD)) & ((1<<LD)<<1) ) {
+      csign = -csign;
+    }
+
+    s = fAbs(s);
+
+    s &= (((1<<LD)<<1)-1); /* Modulo PI */
+
+    if (s > (1<<LD)) {
+      s = ((1<<LD)<<1) - s;
+    }
+
+    {
+      LONG sl, cl;
+      /* Because of packed table */
+      if (s > (1<<(LD-1))) {
+        FIXP_STP tmp;
+        /* Cosine/Sine simetry for angles greater than PI/4 */
+        s = (1<<LD)-s;
+        tmp = SINETAB[s];
+        sl = (LONG)tmp.v.re;
+        cl = (LONG)tmp.v.im;
+      } else {
+        FIXP_STP tmp;
+        tmp = SINETAB[s];
+        sl = (LONG)tmp.v.im;
+        cl = (LONG)tmp.v.re;
+      }
+
+#ifdef SINETABLE_16BIT
+      *sine   = (FIXP_DBL)((sl * ssign) << (DFRACT_BITS-FRACT_BITS));
+      *cosine = (FIXP_DBL)((cl * csign) << (DFRACT_BITS-FRACT_BITS));
+#else
+      *sine   = (FIXP_DBL)(sl * ssign);
+      *cosine = (FIXP_DBL)(cl * csign);
+#endif
+    }
+
+    return residual;
+}
+
+/**
+ * \brief Calculate cosine and sine value each of 2 angles different angle values.
+ * \param x1 first angle value
+ * \param x2 second angle value
+ * \param scale exponent of x1 and x2
+ * \param out pointer to 4 FIXP_DBL locations, were the values cos(x1), sin(x1), cos(x2), sin(x2)
+ *            will be stored into.
+ */
+static inline void inline_fixp_cos_sin (FIXP_DBL x1, FIXP_DBL x2, const int scale, FIXP_DBL *out)
+{
+    FIXP_DBL residual, error0, error1, sine, cosine;
+    residual = fixp_sin_cos_residual_inline(x1, scale, &sine, &cosine);
+    error0 = fMultDiv2(sine, residual);
+    error1 = fMultDiv2(cosine, residual);
+    *out++  = cosine - (error0<<1);
+    *out++  = sine   + (error1<<1);
+
+    residual = fixp_sin_cos_residual_inline(x2, scale, &sine, &cosine);
+    error0 = fMultDiv2(sine, residual);
+    error1 = fMultDiv2(cosine, residual);
+    *out++  = cosine - (error0<<1);
+    *out++  = sine   + (error1<<1);
+}
+#endif
+
-- 
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