2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
6 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 float value into the amin-amax range.
174 * @param a value to clip
175 * @param amin minimum value of the clip range
176 * @param amax maximum value of the clip range
177 * @return clipped value
179 static av_always_inline av_const float av_clipf_c(float a, float amin, float amax)
181 if (a < amin) return amin;
182 else if (a > amax) return amax;
186 /** Compute ceil(log2(x)).
187 * @param x value used to compute ceil(log2(x))
188 * @return computed ceiling of log2(x)
190 static av_always_inline av_const int av_ceil_log2_c(int x)
192 return av_log2((x - 1) << 1);
196 * Count number of bits set to one in x
197 * @param x value to count bits of
198 * @return the number of bits set to one in x
200 static av_always_inline av_const int av_popcount_c(uint32_t x)
202 x -= (x >> 1) & 0x55555555;
203 x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
204 x = (x + (x >> 4)) & 0x0F0F0F0F;
206 return (x + (x >> 16)) & 0x3F;
209 #define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((d) << 24))
210 #define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((a) << 24))
213 * Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form.
215 * @param val Output value, must be an lvalue of type uint32_t.
216 * @param GET_BYTE Expression reading one byte from the input.
217 * Evaluated up to 7 times (4 for the currently
218 * assigned Unicode range). With a memory buffer
219 * input, this could be *ptr++.
220 * @param ERROR Expression to be evaluated on invalid input,
221 * typically a goto statement.
223 #define GET_UTF8(val, GET_BYTE, ERROR)\
226 int ones= 7 - av_log2(val ^ 255);\
231 int tmp= GET_BYTE - 128;\
234 val= (val<<6) + tmp;\
239 * Convert a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form.
241 * @param val Output value, must be an lvalue of type uint32_t.
242 * @param GET_16BIT Expression returning two bytes of UTF-16 data converted
243 * to native byte order. Evaluated one or two times.
244 * @param ERROR Expression to be evaluated on invalid input,
245 * typically a goto statement.
247 #define GET_UTF16(val, GET_16BIT, ERROR)\
250 unsigned int hi = val - 0xD800;\
252 val = GET_16BIT - 0xDC00;\
253 if (val > 0x3FFU || hi > 0x3FFU)\
255 val += (hi<<10) + 0x10000;\
260 * \def PUT_UTF8(val, tmp, PUT_BYTE)
261 * Convert a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
262 * \param val is an input-only argument and should be of type uint32_t. It holds
263 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
264 * val is given as a function it is executed only once.
265 * \param tmp is a temporary variable and should be of type uint8_t. It
266 * represents an intermediate value during conversion that is to be
267 * output by PUT_BYTE.
268 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
269 * It could be a function or a statement, and uses tmp as the input byte.
270 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
271 * executed up to 4 times for values in the valid UTF-8 range and up to
272 * 7 times in the general case, depending on the length of the converted
275 #define PUT_UTF8(val, tmp, PUT_BYTE)\
283 bytes = (av_log2(in) + 4) / 5;\
284 shift = (bytes - 1) * 6;\
285 tmp = (256 - (256 >> bytes)) | (in >> shift);\
287 while (shift >= 6) {\
289 tmp = 0x80 | ((in >> shift) & 0x3f);\
296 * \def PUT_UTF16(val, tmp, PUT_16BIT)
297 * Convert a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
298 * \param val is an input-only argument and should be of type uint32_t. It holds
299 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
300 * val is given as a function it is executed only once.
301 * \param tmp is a temporary variable and should be of type uint16_t. It
302 * represents an intermediate value during conversion that is to be
303 * output by PUT_16BIT.
304 * \param PUT_16BIT writes the converted UTF-16 data to any proper destination
305 * in desired endianness. It could be a function or a statement, and uses tmp
306 * as the input byte. For example, PUT_BYTE could be "*output++ = tmp;"
307 * PUT_BYTE will be executed 1 or 2 times depending on input character.
309 #define PUT_UTF16(val, tmp, PUT_16BIT)\
316 tmp = 0xD800 | ((in - 0x10000) >> 10);\
318 tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
327 #ifdef HAVE_AV_CONFIG_H
328 # include "internal.h"
329 #endif /* HAVE_AV_CONFIG_H */
331 #endif /* AVUTIL_COMMON_H */
334 * The following definitions are outside the multiple inclusion guard
335 * to ensure they are immediately available in intmath.h.
339 # define av_log2 av_log2_c
341 #ifndef av_log2_16bit
342 # define av_log2_16bit av_log2_16bit_c
345 # define av_ceil_log2 av_ceil_log2_c
348 # define av_clip av_clip_c
350 #ifndef av_clip_uint8
351 # define av_clip_uint8 av_clip_uint8_c
354 # define av_clip_int8 av_clip_int8_c
356 #ifndef av_clip_uint16
357 # define av_clip_uint16 av_clip_uint16_c
359 #ifndef av_clip_int16
360 # define av_clip_int16 av_clip_int16_c
362 #ifndef av_clipl_int32
363 # define av_clipl_int32 av_clipl_int32_c
366 # define av_clipf av_clipf_c
369 # define av_popcount av_popcount_c