FFmpeg: libavcodec/mathops.h Source File

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mathops.h

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1 /*

2 * simple math operations

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

25 #include <stdint.h>

27 #include "libavutil/common.h"

28 #include "config.h"

30 extern const uint32_t ff_inverse[257];

31 extern const uint8_t ff_reverse[256];

32 extern const uint8_t ff_sqrt_tab[256];

34 #if ARCH_ARM

35 # include "arm/mathops.h"

36 #elif ARCH_AVR32

37 # include "avr32/mathops.h"

38 #elif ARCH_BFIN

39 # include "bfin/mathops.h"

40 #elif ARCH_MIPS

41 # include "mips/mathops.h"

42 #elif ARCH_PPC

43 # include "ppc/mathops.h"

44 #elif ARCH_X86

45 # include "x86/mathops.h"

46 #endif

48 /* generic implementation */

50 #ifndef MUL64

51 # define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))

52 #endif

54 #ifndef MULL

55 # define MULL(a,b,s) (MUL64(a, b) >> (s))

56 #endif

58 #ifndef MULH

59 static av_always_inline int MULH(int a, int b){

60 return MUL64(a, b) >> 32;

61 }

62 #endif

64 #ifndef UMULH

65 static av_always_inline unsigned UMULH(unsigned a, unsigned b){

66 return ((uint64_t)(a) * (uint64_t)(b))>>32;

67 }

68 #endif

70 #ifndef MAC64

71 # define MAC64(d, a, b) ((d) += MUL64(a, b))

72 #endif

74 #ifndef MLS64

75 # define MLS64(d, a, b) ((d) -= MUL64(a, b))

76 #endif

78 /* signed 16x16 -> 32 multiply add accumulate */

79 #ifndef MAC16

80 # define MAC16(rt, ra, rb) rt += (ra) * (rb)

81 #endif

83 /* signed 16x16 -> 32 multiply */

84 #ifndef MUL16

85 # define MUL16(ra, rb) ((ra) * (rb))

86 #endif

88 #ifndef MLS16

89 # define MLS16(rt, ra, rb) ((rt) -= (ra) * (rb))

90 #endif

92 /* median of 3 */

93 #ifndef mid_pred

94 #define mid_pred mid_pred

95 static inline av_const int mid_pred(int a, int b, int c)

96 {

97 #if 0

98 int t= (a-b)&((a-b)>>31);

99 a-=t;

100 b+=t;

101 b-= (b-c)&((b-c)>>31);

102 b+= (a-b)&((a-b)>>31);

103

104 return b;

105 #else

106 if(a>b){

107 if(c>b){

108 if(c>a) b=a;

109 else b=c;

110 }

111 }else{

112 if(b>c){

113 if(c>a) b=c;

114 else b=a;

115 }

116 }

117 return b;

118 #endif

119 }

120 #endif

121

122 #ifndef sign_extend

123 static inline av_const int sign_extend(int val, unsigned bits)

124 {

125 unsigned shift = 8 * sizeof(int) - bits;

126 union { unsigned u; int s; } v = { (unsigned) val << shift };

127 return v.s >> shift;

128 }

129 #endif

130

131 #ifndef zero_extend

132 static inline av_const unsigned zero_extend(unsigned val, unsigned bits)

133 {

134 return (val << ((8 * sizeof(int)) - bits)) >> ((8 * sizeof(int)) - bits);

135 }

136 #endif

137

138 #ifndef COPY3_IF_LT

139 #define COPY3_IF_LT(x, y, a, b, c, d)\

140 if ((y) < (x)) {\

141 (x) = (y);\

142 (a) = (b);\

143 (c) = (d);\

144 }

145 #endif

146

147 #ifndef MASK_ABS

148 #define MASK_ABS(mask, level) do { \

149 mask = level >> 31; \

150 level = (level ^ mask) - mask; \

151 } while (0)

152 #endif

153

154 #ifndef NEG_SSR32

155 # define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))

156 #endif

157

158 #ifndef NEG_USR32

159 # define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))

160 #endif

161

162 #if HAVE_BIGENDIAN

163 # ifndef PACK_2U8

164 # define PACK_2U8(a,b) (((a) << 8) | (b))

165 # endif

166 # ifndef PACK_4U8

167 # define PACK_4U8(a,b,c,d) (((a) << 24) | ((b) << 16) | ((c) << 8) | (d))

168 # endif

169 # ifndef PACK_2U16

170 # define PACK_2U16(a,b) (((a) << 16) | (b))

171 # endif

172 #else

173 # ifndef PACK_2U8

174 # define PACK_2U8(a,b) (((b) << 8) | (a))

175 # endif

176 # ifndef PACK_4U2

177 # define PACK_4U8(a,b,c,d) (((d) << 24) | ((c) << 16) | ((b) << 8) | (a))

178 # endif

179 # ifndef PACK_2U16

180 # define PACK_2U16(a,b) (((b) << 16) | (a))

181 # endif

182 #endif

183

184 #ifndef PACK_2S8

185 # define PACK_2S8(a,b) PACK_2U8((a)&255, (b)&255)

186 #endif

187 #ifndef PACK_4S8

188 # define PACK_4S8(a,b,c,d) PACK_4U8((a)&255, (b)&255, (c)&255, (d)&255)

189 #endif

190 #ifndef PACK_2S16

191 # define PACK_2S16(a,b) PACK_2U16((a)&0xffff, (b)&0xffff)

192 #endif

193

194 #ifndef FASTDIV

195 # define FASTDIV(a,b) ((uint32_t)((((uint64_t)a) * ff_inverse[b]) >> 32))

196 #endif /* FASTDIV */

197

198 static inline av_const unsigned int ff_sqrt(unsigned int a)

199 {

200 unsigned int b;

201

202 if (a < 255) return (ff_sqrt_tab[a + 1] - 1) >> 4;

203 else if (a < (1 << 12)) b = ff_sqrt_tab[a >> 4] >> 2;

204 #if !CONFIG_SMALL

205 else if (a < (1 << 14)) b = ff_sqrt_tab[a >> 6] >> 1;

206 else if (a < (1 << 16)) b = ff_sqrt_tab[a >> 8] ;

207 #endif

208 else {

209 int s = av_log2_16bit(a >> 16) >> 1;

210 unsigned int c = a >> (s + 2);

211 b = ff_sqrt_tab[c >> (s + 8)];

212 b = FASTDIV(c,b) + (b << s);

213 }

214

215 return b - (a < b * b);

216 }

217

218 #endif /* AVCODEC_MATHOPS_H */

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