1 /*
2 * Copyright (c) 2012
3 * MIPS Technologies, Inc., California.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the MIPS Technologies, Inc., nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE MIPS TECHNOLOGIES, INC. ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE MIPS TECHNOLOGIES, INC. BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * Author: Nedeljko Babic (nbabic@mips.com)
30 *
31 * This file is part of FFmpeg.
32 *
33 * FFmpeg is free software; you can redistribute it and/or
34 * modify it under the terms of the GNU Lesser General Public
35 * License as published by the Free Software Foundation; either
36 * version 2.1 of the License, or (at your option) any later version.
37 *
38 * FFmpeg is distributed in the hope that it will be useful,
39 * but WITHOUT ANY WARRANTY; without even the implied warranty of
40 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
41 * Lesser General Public License for more details.
42 *
43 * You should have received a copy of the GNU Lesser General Public
44 * License along with FFmpeg; if not, write to the Free Software
45 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
46 */
47
48 #ifndef AVUTIL_FIXED_DSP_H
49 #define AVUTIL_FIXED_DSP_H
50
51 #include <stdint.h>
52 #include "attributes.h"
53 #include "common.h"
54 #include "libavcodec/mathops.h"
55
56 typedef struct AVFixedDSPContext {
57 /* Assume len is a multiple of 16, and arrays are 32-byte aligned */
58 /* Results of multiplications are scaled down by 31 bit (and rounded) if not
59 * stated otherwise */
60
61 /**
62 * Overlap/add with window function.
63 * Result is scaled down by "bits" bits.
64 * Used primarily by MDCT-based audio codecs.
65 * Source and destination vectors must overlap exactly or not at all.
66 *
67 * @param dst result vector
68 * constraints: 16-byte aligned
69 * @param src0 first source vector
70 * constraints: 16-byte aligned
71 * @param src1 second source vector
72 * constraints: 16-byte aligned
73 * @param win half-window vector
74 * constraints: 16-byte aligned
75 * @param len length of vector
76 * constraints: multiple of 4
77 * @param bits scaling parameter
78 *
79 */
80 void (*vector_fmul_window_scaled)(int16_t *dst, const int32_t *src0, const int32_t *src1, const int32_t *win, int len, uint8_t bits);
81
82 /**
83 * Overlap/add with window function.
84 * Used primarily by MDCT-based audio codecs.
85 * Source and destination vectors must overlap exactly or not at all.
86 *
87 * @param dst result vector
88 * constraints: 32-byte aligned
89 * @param src0 first source vector
90 * constraints: 16-byte aligned
91 * @param src1 second source vector
92 * constraints: 16-byte aligned
93 * @param win half-window vector
94 * constraints: 16-byte aligned
95 * @param len length of vector
96 * constraints: multiple of 4
97 */
98 void (*vector_fmul_window)(int32_t *dst, const int32_t *src0, const int32_t *src1, const int32_t *win, int len);
99
100 /**
101 * Fixed-point multiplication that calculates the entry wise product of two
102 * vectors of integers and stores the result in a vector of integers.
103 *
104 * @param dst output vector
105 * constraints: 32-byte aligned
106 * @param src0 first input vector
107 * constraints: 32-byte aligned
108 * @param src1 second input vector
109 * constraints: 32-byte aligned
110 * @param len number of elements in the input
111 * constraints: multiple of 16
112 */
113 void (*vector_fmul)(int *dst, const int *src0, const int *src1,
114 int len);
115
116 void (*vector_fmul_reverse)(int *dst, const int *src0, const int *src1, int len);
117 /**
118 * Calculate the entry wise product of two vectors of integers, add a third vector of
119 * integers and store the result in a vector of integers.
120 *
121 * @param dst output vector
122 * constraints: 32-byte aligned
123 * @param src0 first input vector
124 * constraints: 32-byte aligned
125 * @param src1 second input vector
126 * constraints: 32-byte aligned
127 * @param src2 third input vector
128 * constraints: 32-byte aligned
129 * @param len number of elements in the input
130 * constraints: multiple of 16
131 */
132 void (*vector_fmul_add)(int *dst, const int *src0, const int *src1,
133 const int *src2, int len);
134
135 /**
136 * Calculate the scalar product of two vectors of integers.
137 *
138 * @param v1 first vector, 16-byte aligned
139 * @param v2 second vector, 16-byte aligned
140 * @param len length of vectors, multiple of 4
141 *
142 * @return sum of elementwise products
143 */
144 int (*scalarproduct_fixed)(const int *v1, const int *v2, int len);
145
146 /**
147 * Calculate the sum and difference of two vectors of integers.
148 *
149 * @param v1 first input vector, sum output, 16-byte aligned
150 * @param v2 second input vector, difference output, 16-byte aligned
151 * @param len length of vectors, multiple of 4
152 */
153 void (*butterflies_fixed)(int *av_restrict v1, int *av_restrict v2, int len);
154 } AVFixedDSPContext;
155
156 /**
157 * Allocate and initialize a fixed DSP context.
158 * note: should be freed with a av_free call when no longer needed.
159 *
160 * @param strict setting to non-zero avoids using functions which may not be IEEE-754 compliant
161 */
162 AVFixedDSPContext * avpriv_alloc_fixed_dsp(int strict);
163
164 void ff_fixed_dsp_init_x86(AVFixedDSPContext *fdsp);
165
166 /**
167 * Calculate the square root
168 *
169 * @param x input fixed point number
170 *
171 * @param bits format of fixed point number (32 - bits).bits
172 *
173 * note: input is normalized to (0, 1) fixed point value
174 */
175
fixed_sqrt(int x,int bits)176 static av_always_inline int fixed_sqrt(int x, int bits)
177 {
178 int retval, bit_mask, guess, square, i;
179 int64_t accu;
180 int shift1 = 30 - bits;
181 int shift2 = bits - 15;
182
183 if (shift1 > 0) retval = ff_sqrt(x << shift1);
184 else retval = ff_sqrt(x >> -shift1);
185
186 if (shift2 > 0) {
187 retval = retval << shift2;
188 bit_mask = (1 << (shift2 - 1));
189
190 for (i=0; i<shift2; i++){
191 guess = retval + bit_mask;
192 accu = (int64_t)guess * guess;
193 square = (int)((accu + bit_mask) >> bits);
194 if (x >= square)
195 retval += bit_mask;
196 bit_mask >>= 1;
197 }
198
199 }
200 else retval >>= (-shift2);
201
202 return retval;
203 }
204
205 #endif /* AVUTIL_FIXED_DSP_H */
206