Statistics
| Branch: | Revision:

ffmpeg / libavutil / common.h @ 91cc5d37

History | View | Annotate | Download (9.14 KB)

1
/*
2
 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3
 *
4
 * This file is part of FFmpeg.
5
 *
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.
10
 *
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.
15
 *
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
19
 */
20

    
21
/**
22
 * @file libavutil/common.h
23
 * common internal and external API header
24
 */
25

    
26
#ifndef AVUTIL_COMMON_H
27
#define AVUTIL_COMMON_H
28

    
29
#include <ctype.h>
30
#include <errno.h>
31
#include <inttypes.h>
32
#include <limits.h>
33
#include <math.h>
34
#include <stdio.h>
35
#include <stdlib.h>
36
#include <string.h>
37

    
38
#ifdef HAVE_AV_CONFIG_H
39
#include "config.h"
40
#endif
41

    
42
#ifdef __GNUC__
43
#    define AV_GCC_VERSION_AT_LEAST(x,y) (__GNUC__ > x || __GNUC__ == x && __GNUC_MINOR__ >= y)
44
#else
45
#    define AV_GCC_VERSION_AT_LEAST(x,y) 0
46
#endif
47

    
48
#ifndef av_always_inline
49
#if AV_GCC_VERSION_AT_LEAST(3,1)
50
#    define av_always_inline __attribute__((always_inline)) inline
51
#else
52
#    define av_always_inline inline
53
#endif
54
#endif
55

    
56
#ifndef av_noinline
57
#if AV_GCC_VERSION_AT_LEAST(3,1)
58
#    define av_noinline __attribute__((noinline))
59
#else
60
#    define av_noinline
61
#endif
62
#endif
63

    
64
#ifndef av_pure
65
#if AV_GCC_VERSION_AT_LEAST(3,1)
66
#    define av_pure __attribute__((pure))
67
#else
68
#    define av_pure
69
#endif
70
#endif
71

    
72
#ifndef av_const
73
#if AV_GCC_VERSION_AT_LEAST(2,6)
74
#    define av_const __attribute__((const))
75
#else
76
#    define av_const
77
#endif
78
#endif
79

    
80
#ifndef av_cold
81
#if (!defined(__ICC) || __ICC > 1110) && AV_GCC_VERSION_AT_LEAST(4,3)
82
#    define av_cold __attribute__((cold))
83
#else
84
#    define av_cold
85
#endif
86
#endif
87

    
88
#ifndef av_flatten
89
#if (!defined(__ICC) || __ICC > 1110) && AV_GCC_VERSION_AT_LEAST(4,1)
90
#    define av_flatten __attribute__((flatten))
91
#else
92
#    define av_flatten
93
#endif
94
#endif
95

    
96
#ifndef attribute_deprecated
97
#if AV_GCC_VERSION_AT_LEAST(3,1)
98
#    define attribute_deprecated __attribute__((deprecated))
99
#else
100
#    define attribute_deprecated
101
#endif
102
#endif
103

    
104
#ifndef av_unused
105
#if defined(__GNUC__)
106
#    define av_unused __attribute__((unused))
107
#else
108
#    define av_unused
109
#endif
110
#endif
111

    
112
#ifndef av_uninit
113
#if defined(__GNUC__) && !defined(__ICC)
114
#    define av_uninit(x) x=x
115
#else
116
#    define av_uninit(x) x
117
#endif
118
#endif
119

    
120
//rounded division & shift
121
#define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
122
/* assume b>0 */
123
#define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
124
#define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
125
#define FFSIGN(a) ((a) > 0 ? 1 : -1)
126

    
127
#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
128
#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
129
#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
130
#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
131

    
132
#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
133
#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
134
#define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
135

    
136
/* misc math functions */
137
extern const uint8_t ff_log2_tab[256];
138

    
139
extern const uint8_t av_reverse[256];
140

    
141
static inline av_const int av_log2(unsigned int v)
142
{
143
    int n = 0;
144
    if (v & 0xffff0000) {
145
        v >>= 16;
146
        n += 16;
147
    }
148
    if (v & 0xff00) {
149
        v >>= 8;
150
        n += 8;
151
    }
152
    n += ff_log2_tab[v];
153

    
154
    return n;
155
}
156

    
157
static inline av_const int av_log2_16bit(unsigned int v)
158
{
159
    int n = 0;
160
    if (v & 0xff00) {
161
        v >>= 8;
162
        n += 8;
163
    }
164
    n += ff_log2_tab[v];
165

    
166
    return n;
167
}
168

    
169
/**
170
 * Clips a signed integer value into the amin-amax range.
171
 * @param a value to clip
172
 * @param amin minimum value of the clip range
173
 * @param amax maximum value of the clip range
174
 * @return clipped value
175
 */
176
static inline av_const int av_clip(int a, int amin, int amax)
177
{
178
    if      (a < amin) return amin;
179
    else if (a > amax) return amax;
180
    else               return a;
181
}
182

    
183
/**
184
 * Clips a signed integer value into the 0-255 range.
185
 * @param a value to clip
186
 * @return clipped value
187
 */
188
static inline av_const uint8_t av_clip_uint8(int a)
189
{
190
    if (a&(~255)) return (-a)>>31;
191
    else          return a;
192
}
193

    
194
/**
195
 * Clips a signed integer value into the 0-65535 range.
196
 * @param a value to clip
197
 * @return clipped value
198
 */
199
static inline av_const uint16_t av_clip_uint16(int a)
200
{
201
    if (a&(~65535)) return (-a)>>31;
202
    else            return a;
203
}
204

    
205
/**
206
 * Clips a signed integer value into the -32768,32767 range.
207
 * @param a value to clip
208
 * @return clipped value
209
 */
210
static inline av_const int16_t av_clip_int16(int a)
211
{
212
    if ((a+32768) & ~65535) return (a>>31) ^ 32767;
213
    else                    return a;
214
}
215

    
216
/**
217
 * Clips a float value into the amin-amax range.
218
 * @param a value to clip
219
 * @param amin minimum value of the clip range
220
 * @param amax maximum value of the clip range
221
 * @return clipped value
222
 */
223
static inline av_const float av_clipf(float a, float amin, float amax)
224
{
225
    if      (a < amin) return amin;
226
    else if (a > amax) return amax;
227
    else               return a;
228
}
229

    
230
/** Computes ceil(log2(x)).
231
 * @param x value used to compute ceil(log2(x))
232
 * @return computed ceiling of log2(x)
233
 */
234
static inline av_const int av_ceil_log2(int x)
235
{
236
    return av_log2((x - 1) << 1);
237
}
238

    
239
#define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))
240
#define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24))
241

    
242
/*!
243
 * \def GET_UTF8(val, GET_BYTE, ERROR)
244
 * Converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
245
 * \param val is the output and should be of type uint32_t. It holds the converted
246
 * UCS-4 character and should be a left value.
247
 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
248
 * a function or a statement whose return value or evaluated value is of type
249
 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
250
 * and up to 7 times in the general case.
251
 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
252
 * from GET_BYTE. It should be a statement that jumps out of the macro,
253
 * like exit(), goto, return, break, or continue.
254
 */
255
#define GET_UTF8(val, GET_BYTE, ERROR)\
256
    val= GET_BYTE;\
257
    {\
258
        int ones= 7 - av_log2(val ^ 255);\
259
        if(ones==1)\
260
            ERROR\
261
        val&= 127>>ones;\
262
        while(--ones > 0){\
263
            int tmp= GET_BYTE - 128;\
264
            if(tmp>>6)\
265
                ERROR\
266
            val= (val<<6) + tmp;\
267
        }\
268
    }
269

    
270
/*!
271
 * \def GET_UTF16(val, GET_16BIT, ERROR)
272
 * Converts a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form
273
 * \param val is the output and should be of type uint32_t. It holds the converted
274
 * UCS-4 character and should be a left value.
275
 * \param GET_16BIT gets two bytes of UTF-16 encoded data converted to native endianness.
276
 * It can be a function or a statement whose return value or evaluated value is of type
277
 * uint16_t. It will be executed up to 2 times.
278
 * \param ERROR action that should be taken when an invalid UTF-16 surrogate is
279
 * returned from GET_BYTE. It should be a statement that jumps out of the macro,
280
 * like exit(), goto, return, break, or continue.
281
 */
282
#define GET_UTF16(val, GET_16BIT, ERROR)\
283
    val = GET_16BIT;\
284
    {\
285
        unsigned int hi = val - 0xD800;\
286
        if (hi < 0x800) {\
287
            val = GET_16BIT - 0xDC00;\
288
            if (val > 0x3FFU || hi > 0x3FFU)\
289
                ERROR\
290
            val += (hi<<10) + 0x10000;\
291
        }\
292
    }\
293

    
294
/*!
295
 * \def PUT_UTF8(val, tmp, PUT_BYTE)
296
 * Converts a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
297
 * \param val is an input-only argument and should be of type uint32_t. It holds
298
 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
299
 * val is given as a function it is executed only once.
300
 * \param tmp is a temporary variable and should be of type uint8_t. It
301
 * represents an intermediate value during conversion that is to be
302
 * output by PUT_BYTE.
303
 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
304
 * It could be a function or a statement, and uses tmp as the input byte.
305
 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
306
 * executed up to 4 times for values in the valid UTF-8 range and up to
307
 * 7 times in the general case, depending on the length of the converted
308
 * Unicode character.
309
 */
310
#define PUT_UTF8(val, tmp, PUT_BYTE)\
311
    {\
312
        int bytes, shift;\
313
        uint32_t in = val;\
314
        if (in < 0x80) {\
315
            tmp = in;\
316
            PUT_BYTE\
317
        } else {\
318
            bytes = (av_log2(in) + 4) / 5;\
319
            shift = (bytes - 1) * 6;\
320
            tmp = (256 - (256 >> bytes)) | (in >> shift);\
321
            PUT_BYTE\
322
            while (shift >= 6) {\
323
                shift -= 6;\
324
                tmp = 0x80 | ((in >> shift) & 0x3f);\
325
                PUT_BYTE\
326
            }\
327
        }\
328
    }
329

    
330
#include "mem.h"
331

    
332
#ifdef HAVE_AV_CONFIG_H
333
#    include "internal.h"
334
#endif /* HAVE_AV_CONFIG_H */
335

    
336
#endif /* AVUTIL_COMMON_H */