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mathops.h
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1 /*
2  * simple math operations
3  * Copyright (c) 2001, 2002 Fabrice Bellard
4  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> et al
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 #ifndef AVCODEC_MATHOPS_H
23 #define AVCODEC_MATHOPS_H
24 
25 #include <stdint.h>
26 
27 #include "libavutil/common.h"
28 #include "config.h"
29 
30 #define MAX_NEG_CROP 1024
31 
32 extern const uint32_t ff_inverse[257];
33 extern const uint8_t ff_reverse[256];
34 extern const uint8_t ff_sqrt_tab[256];
35 extern const uint8_t ff_crop_tab[256 + 2 * MAX_NEG_CROP];
36 extern const uint8_t ff_zigzag_direct[64];
37 
38 #if ARCH_ARM
39 # include "arm/mathops.h"
40 #elif ARCH_AVR32
41 # include "avr32/mathops.h"
42 #elif ARCH_MIPS
43 # include "mips/mathops.h"
44 #elif ARCH_PPC
45 # include "ppc/mathops.h"
46 #elif ARCH_X86
47 # include "x86/mathops.h"
48 #endif
49 
50 /* generic implementation */
51 
52 #ifndef MUL64
53 # define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))
54 #endif
55 
56 #ifndef MULL
57 # define MULL(a,b,s) (MUL64(a, b) >> (s))
58 #endif
59 
60 #ifndef MULH
61 static av_always_inline int MULH(int a, int b){
62  return MUL64(a, b) >> 32;
63 }
64 #endif
65 
66 #ifndef UMULH
67 static av_always_inline unsigned UMULH(unsigned a, unsigned b){
68  return ((uint64_t)(a) * (uint64_t)(b))>>32;
69 }
70 #endif
71 
72 #ifndef MAC64
73 # define MAC64(d, a, b) ((d) += MUL64(a, b))
74 #endif
75 
76 #ifndef MLS64
77 # define MLS64(d, a, b) ((d) -= MUL64(a, b))
78 #endif
79 
80 /* signed 16x16 -> 32 multiply add accumulate */
81 #ifndef MAC16
82 # define MAC16(rt, ra, rb) rt += (ra) * (rb)
83 #endif
84 
85 /* signed 16x16 -> 32 multiply */
86 #ifndef MUL16
87 # define MUL16(ra, rb) ((ra) * (rb))
88 #endif
89 
90 #ifndef MLS16
91 # define MLS16(rt, ra, rb) ((rt) -= (ra) * (rb))
92 #endif
93 
94 /* median of 3 */
95 #ifndef mid_pred
96 #define mid_pred mid_pred
97 static inline av_const int mid_pred(int a, int b, int c)
98 {
99 #if 0
100  int t= (a-b)&((a-b)>>31);
101  a-=t;
102  b+=t;
103  b-= (b-c)&((b-c)>>31);
104  b+= (a-b)&((a-b)>>31);
105 
106  return b;
107 #else
108  if(a>b){
109  if(c>b){
110  if(c>a) b=a;
111  else b=c;
112  }
113  }else{
114  if(b>c){
115  if(c>a) b=c;
116  else b=a;
117  }
118  }
119  return b;
120 #endif
121 }
122 #endif
123 
124 #ifndef median4
125 #define median4 median4
126 static inline av_const int median4(int a, int b, int c, int d)
127 {
128  if (a < b) {
129  if (c < d) return (FFMIN(b, d) + FFMAX(a, c)) / 2;
130  else return (FFMIN(b, c) + FFMAX(a, d)) / 2;
131  } else {
132  if (c < d) return (FFMIN(a, d) + FFMAX(b, c)) / 2;
133  else return (FFMIN(a, c) + FFMAX(b, d)) / 2;
134  }
135 }
136 #endif
137 
138 #ifndef sign_extend
139 static inline av_const int sign_extend(int val, unsigned bits)
140 {
141  unsigned shift = 8 * sizeof(int) - bits;
142  union { unsigned u; int s; } v = { (unsigned) val << shift };
143  return v.s >> shift;
144 }
145 #endif
146 
147 #ifndef zero_extend
148 static inline av_const unsigned zero_extend(unsigned val, unsigned bits)
149 {
150  return (val << ((8 * sizeof(int)) - bits)) >> ((8 * sizeof(int)) - bits);
151 }
152 #endif
153 
154 #ifndef COPY3_IF_LT
155 #define COPY3_IF_LT(x, y, a, b, c, d)\
156 if ((y) < (x)) {\
157  (x) = (y);\
158  (a) = (b);\
159  (c) = (d);\
160 }
161 #endif
162 
163 #ifndef MASK_ABS
164 #define MASK_ABS(mask, level) do { \
165  mask = level >> 31; \
166  level = (level ^ mask) - mask; \
167  } while (0)
168 #endif
169 
170 #ifndef NEG_SSR32
171 # define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
172 #endif
173 
174 #ifndef NEG_USR32
175 # define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
176 #endif
177 
178 #if HAVE_BIGENDIAN
179 # ifndef PACK_2U8
180 # define PACK_2U8(a,b) (((a) << 8) | (b))
181 # endif
182 # ifndef PACK_4U8
183 # define PACK_4U8(a,b,c,d) (((a) << 24) | ((b) << 16) | ((c) << 8) | (d))
184 # endif
185 # ifndef PACK_2U16
186 # define PACK_2U16(a,b) (((a) << 16) | (b))
187 # endif
188 #else
189 # ifndef PACK_2U8
190 # define PACK_2U8(a,b) (((b) << 8) | (a))
191 # endif
192 # ifndef PACK_4U2
193 # define PACK_4U8(a,b,c,d) (((d) << 24) | ((c) << 16) | ((b) << 8) | (a))
194 # endif
195 # ifndef PACK_2U16
196 # define PACK_2U16(a,b) (((b) << 16) | (a))
197 # endif
198 #endif
199 
200 #ifndef PACK_2S8
201 # define PACK_2S8(a,b) PACK_2U8((a)&255, (b)&255)
202 #endif
203 #ifndef PACK_4S8
204 # define PACK_4S8(a,b,c,d) PACK_4U8((a)&255, (b)&255, (c)&255, (d)&255)
205 #endif
206 #ifndef PACK_2S16
207 # define PACK_2S16(a,b) PACK_2U16((a)&0xffff, (b)&0xffff)
208 #endif
209 
210 #ifndef FASTDIV
211 # define FASTDIV(a,b) ((uint32_t)((((uint64_t)a) * ff_inverse[b]) >> 32))
212 #endif /* FASTDIV */
213 
214 #ifndef ff_sqrt
215 #define ff_sqrt ff_sqrt
216 static inline av_const unsigned int ff_sqrt(unsigned int a)
217 {
218  unsigned int b;
219 
220  if (a < 255) return (ff_sqrt_tab[a + 1] - 1) >> 4;
221  else if (a < (1 << 12)) b = ff_sqrt_tab[a >> 4] >> 2;
222 #if !CONFIG_SMALL
223  else if (a < (1 << 14)) b = ff_sqrt_tab[a >> 6] >> 1;
224  else if (a < (1 << 16)) b = ff_sqrt_tab[a >> 8] ;
225 #endif
226  else {
227  int s = av_log2_16bit(a >> 16) >> 1;
228  unsigned int c = a >> (s + 2);
229  b = ff_sqrt_tab[c >> (s + 8)];
230  b = FASTDIV(c,b) + (b << s);
231  }
232 
233  return b - (a < b * b);
234 }
235 #endif
236 
237 static inline int8_t ff_u8_to_s8(uint8_t a)
238 {
239  union {
240  uint8_t u8;
241  int8_t s8;
242  } b;
243  b.u8 = a;
244  return b.s8;
245 }
246 
247 #endif /* AVCODEC_MATHOPS_H */