Diff: DuerOS-Light-SDK-v1.1.0/duer-os-light/external/speex/libspeex/math_approx.h

Revision:

47:9e361da97763

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DuerOS-Light-SDK-v1.1.0/duer-os-light/external/speex/libspeex/math_approx.h	Tue Jul 18 16:54:45 2017 +0800
@@ -0,0 +1,62 @@
+/* Copyright (C) 2002 Jean-Marc Valin */
+/**
+   @file math_approx.h
+   @brief Various math approximation functions for Speex
+*/
+/*
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions
+   are met:
+   
+   - Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+   
+   - Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+   
+   - Neither the name of the Xiph.org Foundation nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+   
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
+   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef MATH_APPROX_H
+#define MATH_APPROX_H
+
+#include "misc.h"
+
+spx_word16_t spx_cos(spx_word16_t x);
+spx_int16_t spx_ilog2(spx_uint32_t x);
+spx_int16_t spx_ilog4(spx_uint32_t x);
+#ifdef FIXED_POINT
+spx_word16_t spx_sqrt(spx_word32_t x);
+spx_word16_t spx_acos(spx_word16_t x);
+spx_word32_t spx_exp(spx_word16_t x);
+spx_word16_t spx_cos_norm(spx_word32_t x);
+
+/* Input in Q15, output in Q14 */
+spx_word16_t spx_atan(spx_word32_t x);
+
+#else
+
+#define spx_sqrt sqrt
+#define spx_acos acos
+#define spx_exp exp
+#define spx_cos_norm(x) (cos((.5f*M_PI)*(x)))
+#define spx_atan atan
+
+#endif
+
+#endif