/*
  * Various fixed-point math operations
  *
  * Copyright (c) 2008 Vladimir Voroshilov
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 

 #ifndef AVCODEC_CELP_MATH_H
 #define AVCODEC_CELP_MATH_H

 #include <stdint.h>
 

 typedef struct CELPMContext {
     /**
      * Return the dot product.
      * @param a input data array
      * @param b input data array
      * @param length number of elements
      *
      * @return dot product = sum of elementwise products
      */
     float (*dot_productf)(const float* a, const float* b, int length);
 
 }CELPMContext;
 
 /**
  * Initialize CELPMContext.
  */
 void ff_celp_math_init(CELPMContext *c);
 void ff_celp_math_init_mips(CELPMContext *c);
 

 /**

  * fixed-point implementation of exp2(x) in [0; 1] domain.
  * @param power argument to exp2, 0 <= power <= 0x7fff

  *

  * @return value of (1<<20) * exp2(power / (1<<15))

  *         0x8000c <= result <= 0xfffea
  */
 int ff_exp2(uint16_t power);
 
 /**

  * Calculate log2(x).

  * @param value function argument, 0 < value <= 7fff ffff

  *

  * @return value of (1<<15) * log2(value)

  */

 int ff_log2_q15(uint32_t value);

 
 /**

  * Calculate the dot product of 2 int16_t vectors.
  * @param a input data array
  * @param b input data array
  * @param length number of elements
  *
  * @return dot product = sum of elementwise products
  */
 int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length);
 
 /**

  * Shift value left or right depending on sign of offset parameter.
  * @param value value to shift
  * @param offset shift offset

  *

  * @return value << offset, if offset>=0; value >> -offset - otherwise

  */
 static inline int bidir_sal(int value, int offset)
 {
     if(offset < 0) return value >> -offset;
     else           return value <<  offset;
 }
 

 /**

  * Return the dot product.

  * @param a input data array
  * @param b input data array
  * @param length number of elements
  *
  * @return dot product = sum of elementwise products
  */

 float ff_dot_productf(const float* a, const float* b, int length);

 #endif /* AVCODEC_CELP_MATH_H */