2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of Libav.
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * common internal and external API header
26 #ifndef AVUTIL_COMMON_H
27 #define AVUTIL_COMMON_H
37 #include "attributes.h"
38 #include "libavutil/avconfig.h"
41 # define AV_NE(be, le) (be)
43 # define AV_NE(be, le) (le)
46 //rounded division & shift
47 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
49 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
50 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
51 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
53 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
54 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
55 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
56 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
58 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
59 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
60 #define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
62 /* misc math functions */
63 extern const uint8_t ff_log2_tab[256];
65 extern const uint8_t av_reverse[256];
67 static av_always_inline av_const int av_log2_c(unsigned int v)
83 static av_always_inline av_const int av_log2_16bit_c(unsigned int v)
95 #ifdef HAVE_AV_CONFIG_H
100 /* Pull in unguarded fallback defines at the end of this file. */
104 * Clip a signed integer value into the amin-amax range.
105 * @param a value to clip
106 * @param amin minimum value of the clip range
107 * @param amax maximum value of the clip range
108 * @return clipped value
110 static av_always_inline av_const int av_clip_c(int a, int amin, int amax)
112 if (a < amin) return amin;
113 else if (a > amax) return amax;
118 * Clip a signed integer value into the 0-255 range.
119 * @param a value to clip
120 * @return clipped value
122 static av_always_inline av_const uint8_t av_clip_uint8_c(int a)
124 if (a&(~0xFF)) return (-a)>>31;
129 * Clip a signed integer value into the -128,127 range.
130 * @param a value to clip
131 * @return clipped value
133 static av_always_inline av_const int8_t av_clip_int8_c(int a)
135 if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
140 * Clip a signed integer value into the 0-65535 range.
141 * @param a value to clip
142 * @return clipped value
144 static av_always_inline av_const uint16_t av_clip_uint16_c(int a)
146 if (a&(~0xFFFF)) return (-a)>>31;
151 * Clip a signed integer value into the -32768,32767 range.
152 * @param a value to clip
153 * @return clipped value
155 static av_always_inline av_const int16_t av_clip_int16_c(int a)
157 if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
162 * Clip a signed 64-bit integer value into the -2147483648,2147483647 range.
163 * @param a value to clip
164 * @return clipped value
166 static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
168 if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;
173 * Clip a signed integer to an unsigned power of two range.
174 * @param a value to clip
175 * @param p bit position to clip at
176 * @return clipped value
178 static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
180 if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
185 * Clip a float value into the amin-amax range.
186 * @param a value to clip
187 * @param amin minimum value of the clip range
188 * @param amax maximum value of the clip range
189 * @return clipped value
191 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
193 if (a < amin) return amin;
194 else if (a > amax) return amax;
198 /** Compute ceil(log2(x)).
199 * @param x value used to compute ceil(log2(x))
200 * @return computed ceiling of log2(x)
202 static av_always_inline av_const int av_ceil_log2_c(int x)
204 return av_log2((x - 1) << 1);
208 * Count number of bits set to one in x
209 * @param x value to count bits of
210 * @return the number of bits set to one in x
212 static av_always_inline av_const int av_popcount_c(uint32_t x)
214 x -= (x >> 1) & 0x55555555;
215 x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
216 x = (x + (x >> 4)) & 0x0F0F0F0F;
218 return (x + (x >> 16)) & 0x3F;
222 * Count number of bits set to one in x
223 * @param x value to count bits of
224 * @return the number of bits set to one in x
226 static av_always_inline av_const int av_popcount64_c(uint64_t x)
228 return av_popcount(x) + av_popcount(x >> 32);
231 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
232 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
235 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
237 * @param val Output value, must be an lvalue of type uint32_t.
238 * @param GET_BYTE Expression reading one byte from the input.
239 * Evaluated up to 7 times (4 for the currently
240 * assigned Unicode range). With a memory buffer
241 * input, this could be *ptr++.
242 * @param ERROR Expression to be evaluated on invalid input,
243 * typically a goto statement.
245 #define GET_UTF8(val, GET_BYTE, ERROR)\
248 int ones= 7 - av_log2(val ^ 255);\
253 int tmp= GET_BYTE - 128;\
256 val= (val<<6) + tmp;\
261 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
263 * @param val Output value, must be an lvalue of type uint32_t.
264 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
265 * to native byte order. Evaluated one or two times.
266 * @param ERROR Expression to be evaluated on invalid input,
267 * typically a goto statement.
269 #define GET_UTF16(val, GET_16BIT, ERROR)\
272 unsigned int hi = val - 0xD800;\
274 val = GET_16BIT - 0xDC00;\
275 if (val > 0x3FFU || hi > 0x3FFU)\
277 val += (hi<<10) + 0x10000;\
282 * @def PUT_UTF8(val, tmp, PUT_BYTE)
283 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
284 * @param val is an input-only argument and should be of type uint32_t. It holds
285 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
286 * val is given as a function it is executed only once.
287 * @param tmp is a temporary variable and should be of type uint8_t. It
288 * represents an intermediate value during conversion that is to be
289 * output by PUT_BYTE.
290 * @param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
291 * It could be a function or a statement, and uses tmp as the input byte.
292 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
293 * executed up to 4 times for values in the valid UTF-8 range and up to
294 * 7 times in the general case, depending on the length of the converted
297 #define PUT_UTF8(val, tmp, PUT_BYTE)\
305 bytes = (av_log2(in) + 4) / 5;\
306 shift = (bytes - 1) * 6;\
307 tmp = (256 - (256 >> bytes)) | (in >> shift);\
309 while (shift >= 6) {\
311 tmp = 0x80 | ((in >> shift) & 0x3f);\
318 * @def PUT_UTF16(val, tmp, PUT_16BIT)
319 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
320 * @param val is an input-only argument and should be of type uint32_t. It holds
321 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
322 * val is given as a function it is executed only once.
323 * @param tmp is a temporary variable and should be of type uint16_t. It
324 * represents an intermediate value during conversion that is to be
325 * output by PUT_16BIT.
326 * @param PUT_16BIT writes the converted UTF-16 data to any proper destination
327 * in desired endianness. It could be a function or a statement, and uses tmp
328 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
329 * PUT_BYTE will be executed 1 or 2 times depending on input character.
331 #define PUT_UTF16(val, tmp, PUT_16BIT)\
338 tmp = 0xD800 | ((in - 0x10000) >> 10);\
340 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
349 #ifdef HAVE_AV_CONFIG_H
350 # include "internal.h"
351 #endif /* HAVE_AV_CONFIG_H */
353 #endif /* AVUTIL_COMMON_H */
356 * The following definitions are outside the multiple inclusion guard
357 * to ensure they are immediately available in intmath.h.
361 # define av_log2 av_log2_c
363 #ifndef av_log2_16bit
364 # define av_log2_16bit av_log2_16bit_c
367 # define av_ceil_log2 av_ceil_log2_c
370 # define av_clip av_clip_c
372 #ifndef av_clip_uint8
373 # define av_clip_uint8 av_clip_uint8_c
376 # define av_clip_int8 av_clip_int8_c
378 #ifndef av_clip_uint16
379 # define av_clip_uint16 av_clip_uint16_c
381 #ifndef av_clip_int16
382 # define av_clip_int16 av_clip_int16_c
384 #ifndef av_clipl_int32
385 # define av_clipl_int32 av_clipl_int32_c
387 #ifndef av_clip_uintp2
388 # define av_clip_uintp2 av_clip_uintp2_c
391 # define av_clipf av_clipf_c
394 # define av_popcount av_popcount_c
396 #ifndef av_popcount64
397 # define av_popcount64 av_popcount64_c