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celp_math.h
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1 /*
2  * Various fixed-point math operations
3  *
4  * Copyright (c) 2008 Vladimir Voroshilov
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #ifndef AVCODEC_CELP_MATH_H
24 #define AVCODEC_CELP_MATH_H
25 
26 #include <stdint.h>
27 
28 typedef struct CELPMContext {
29  /**
30  * Return the dot product.
31  * @param a input data array
32  * @param b input data array
33  * @param length number of elements
34  *
35  * @return dot product = sum of elementwise products
36  */
37  float (*dot_productf)(const float* a, const float* b, int length);
38 
40 
41 /**
42  * Initialize CELPMContext.
43  */
46 
47 /**
48  * fixed-point implementation of exp2(x) in [0; 1] domain.
49  * @param power argument to exp2, 0 <= power <= 0x7fff
50  *
51  * @return value of (1<<20) * exp2(power / (1<<15))
52  * 0x8000c <= result <= 0xfffea
53  */
54 int ff_exp2(uint16_t power);
55 
56 /**
57  * Calculate log2(x).
58  * @param value function argument, 0 < value <= 7fff ffff
59  *
60  * @return value of (1<<15) * log2(value)
61  */
62 int ff_log2_q15(uint32_t value);
63 
64 /**
65  * Calculate the dot product of 2 int16_t vectors.
66  * @param a input data array
67  * @param b input data array
68  * @param length number of elements
69  *
70  * @return dot product = sum of elementwise products
71  */
72 int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length);
73 
74 /**
75  * Shift value left or right depending on sign of offset parameter.
76  * @param value value to shift
77  * @param offset shift offset
78  *
79  * @return value << offset, if offset>=0; value >> -offset - otherwise
80  */
81 static inline int bidir_sal(int value, int offset)
82 {
83  if(offset < 0) return value >> -offset;
84  else return value << offset;
85 }
86 
87 /**
88  * Return the dot product.
89  * @param a input data array
90  * @param b input data array
91  * @param length number of elements
92  *
93  * @return dot product = sum of elementwise products
94  */
95 float ff_dot_productf(const float* a, const float* b, int length);
96 
97 #endif /* AVCODEC_CELP_MATH_H */
void ff_celp_math_init_mips(CELPMContext *c)
const char * b
Definition: vf_curves.c:113
int ff_exp2(uint16_t power)
fixed-point implementation of exp2(x) in [0; 1] domain.
Definition: celp_math.c:48
float(* dot_productf)(const float *a, const float *b, int length)
Return the dot product.
Definition: celp_math.h:37
float ff_dot_productf(const float *a, const float *b, int length)
Return the dot product.
Definition: celp_math.c:109
GLsizei GLsizei * length
Definition: opengl_enc.c:115
static const uint8_t offset[127][2]
Definition: vf_spp.c:92
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:109
void ff_celp_math_init(CELPMContext *c)
Initialize CELPMContext.
Definition: celp_math.c:120
static int bidir_sal(int value, int offset)
Shift value left or right depending on sign of offset parameter.
Definition: celp_math.h:81
static AVCodec * c
int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length)
Calculate the dot product of 2 int16_t vectors.
Definition: celp_math.c:98
int ff_log2_q15(uint32_t value)
Calculate log2(x).
Definition: celp_math.c:78