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
31 #ifdef HAVE_AV_CONFIG_H
32 /* only include the following when compiling package */
42 #endif /* HAVE_AV_CONFIG_H */
44 #define AV_GCC_VERSION_AT_LEAST(x,y) (defined(__GNUC__) && (__GNUC__ > x || __GNUC__ == x && __GNUC_MINOR__ >= y))
46 #ifndef av_always_inline
47 #if AV_GCC_VERSION_AT_LEAST(3,1)
48 # define av_always_inline __attribute__((always_inline)) inline
50 # define av_always_inline inline
55 #if AV_GCC_VERSION_AT_LEAST(3,1)
56 # define av_noinline __attribute__((noinline))
63 #if AV_GCC_VERSION_AT_LEAST(3,1)
64 # define av_pure __attribute__((pure))
71 #if AV_GCC_VERSION_AT_LEAST(2,6)
72 # define av_const __attribute__((const))
79 #if (!defined(__ICC) || __ICC > 1100) && AV_GCC_VERSION_AT_LEAST(4,3)
80 # define av_cold __attribute__((cold))
86 #ifdef HAVE_AV_CONFIG_H
87 # include "internal.h"
88 #endif /* HAVE_AV_CONFIG_H */
90 #ifndef attribute_deprecated
91 #if AV_GCC_VERSION_AT_LEAST(3,1)
92 # define attribute_deprecated __attribute__((deprecated))
94 # define attribute_deprecated
100 # define av_unused __attribute__((unused))
108 //rounded divison & shift
109 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
111 #define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
112 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
113 #define FFSIGN(a) ((a) > 0 ? 1 : -1)
115 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
116 #define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
117 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
118 #define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
120 #define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
121 #define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
123 /* misc math functions */
124 extern const uint8_t ff_log2_tab[256];
126 static inline av_const int av_log2(unsigned int v)
129 if (v & 0xffff0000) {
142 static inline av_const int av_log2_16bit(unsigned int v)
155 static inline av_const int mid_pred(int a, int b, int c)
172 int t= (a-b)&((a-b)>>31);
175 b-= (b-c)&((b-c)>>31);
176 b+= (a-b)&((a-b)>>31);
196 * clip a signed integer value into the amin-amax range
197 * @param a value to clip
198 * @param amin minimum value of the clip range
199 * @param amax maximum value of the clip range
200 * @return clipped value
202 static inline av_const int av_clip(int a, int amin, int amax)
204 if (a < amin) return amin;
205 else if (a > amax) return amax;
210 * clip a signed integer value into the 0-255 range
211 * @param a value to clip
212 * @return clipped value
214 static inline av_const uint8_t av_clip_uint8(int a)
216 if (a&(~255)) return (-a)>>31;
221 * clip a signed integer value into the -32768,32767 range
222 * @param a value to clip
223 * @return clipped value
225 static inline av_const int16_t av_clip_int16(int a)
227 if ((a+32768) & ~65535) return (a>>31) ^ 32767;
232 * clip a float value into the amin-amax range
233 * @param a value to clip
234 * @param amin minimum value of the clip range
235 * @param amax maximum value of the clip range
236 * @return clipped value
238 static inline av_const float av_clipf(float a, float amin, float amax)
240 if (a < amin) return amin;
241 else if (a > amax) return amax;
245 #define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))
246 #define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24))
249 * \def GET_UTF8(val, GET_BYTE, ERROR)
250 * converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
251 * \param val is the output and should be of type uint32_t. It holds the converted
252 * UCS-4 character and should be a left value.
253 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
254 * a function or a statement whose return value or evaluated value is of type
255 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
256 * and up to 7 times in the general case.
257 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
258 * from GET_BYTE. It should be a statement that jumps out of the macro,
259 * like exit(), goto, return, break, or continue.
261 #define GET_UTF8(val, GET_BYTE, ERROR)\
264 int ones= 7 - av_log2(val ^ 255);\
269 int tmp= GET_BYTE - 128;\
272 val= (val<<6) + tmp;\
277 * \def PUT_UTF8(val, tmp, PUT_BYTE)
278 * converts a 32-bit unicode character to its UTF-8 encoded form (up to 4 bytes long).
279 * \param val is an input only argument and should be of type uint32_t. It holds
280 * a ucs4 encoded unicode character that is to be converted to UTF-8. If
281 * val is given as a function it's executed only once.
282 * \param tmp is a temporary variable and should be of type uint8_t. It
283 * represents an intermediate value during conversion that is to be
284 * outputted by PUT_BYTE.
285 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
286 * It could be a function or a statement, and uses tmp as the input byte.
287 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
288 * executed up to 4 times for values in the valid UTF-8 range and up to
289 * 7 times in the general case, depending on the length of the converted
292 #define PUT_UTF8(val, tmp, PUT_BYTE)\
300 bytes = (av_log2(in) + 4) / 5;\
301 shift = (bytes - 1) * 6;\
302 tmp = (256 - (256 >> bytes)) | (in >> shift);\
304 while (shift >= 6) {\
306 tmp = 0x80 | ((in >> shift) & 0x3f);\
312 #endif /* AVUTIL_COMMON_H */