Statistics
| Branch: | Revision:

ffmpeg / libavutil / common.h @ 45a1b86a

History | View | Annotate | Download (9.51 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
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
#include "attributes.h"
38

    
39
//rounded division & shift
40
#define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
41
/* assume b>0 */
42
#define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b))
43
#define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
44
#define FFSIGN(a) ((a) > 0 ? 1 : -1)
45

    
46
#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
47
#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
48
#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
49
#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
50

    
51
#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
52
#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
53
#define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
54

    
55
/* misc math functions */
56
extern const uint8_t ff_log2_tab[256];
57

    
58
extern const uint8_t av_reverse[256];
59

    
60
static inline av_const int av_log2_c(unsigned int v)
61
{
62
    int n = 0;
63
    if (v & 0xffff0000) {
64
        v >>= 16;
65
        n += 16;
66
    }
67
    if (v & 0xff00) {
68
        v >>= 8;
69
        n += 8;
70
    }
71
    n += ff_log2_tab[v];
72

    
73
    return n;
74
}
75

    
76
static inline av_const int av_log2_16bit_c(unsigned int v)
77
{
78
    int n = 0;
79
    if (v & 0xff00) {
80
        v >>= 8;
81
        n += 8;
82
    }
83
    n += ff_log2_tab[v];
84

    
85
    return n;
86
}
87

    
88
#ifdef HAVE_AV_CONFIG_H
89
#   include "config.h"
90
#   include "intmath.h"
91
#endif
92

    
93
#ifndef av_log2
94
#   define av_log2       av_log2_c
95
#endif
96
#ifndef av_log2_16bit
97
#   define av_log2_16bit av_log2_16bit_c
98
#endif
99

    
100
/**
101
 * Clips a signed integer value into the amin-amax range.
102
 * @param a value to clip
103
 * @param amin minimum value of the clip range
104
 * @param amax maximum value of the clip range
105
 * @return clipped value
106
 */
107
static inline av_const int av_clip(int a, int amin, int amax)
108
{
109
    if      (a < amin) return amin;
110
    else if (a > amax) return amax;
111
    else               return a;
112
}
113

    
114
/**
115
 * Clips a signed integer value into the 0-255 range.
116
 * @param a value to clip
117
 * @return clipped value
118
 */
119
static inline av_const uint8_t av_clip_uint8(int a)
120
{
121
    if (a&(~0xFF)) return (-a)>>31;
122
    else           return a;
123
}
124

    
125
/**
126
 * Clips a signed integer value into the -128,127 range.
127
 * @param a value to clip
128
 * @return clipped value
129
 */
130
static inline av_const int8_t av_clip_int8(int a)
131
{
132
    if ((a+0x80) & ~0xFF) return (a>>31) ^ 0x7F;
133
    else                  return a;
134
}
135

    
136
/**
137
 * Clips a signed integer value into the 0-65535 range.
138
 * @param a value to clip
139
 * @return clipped value
140
 */
141
static inline av_const uint16_t av_clip_uint16(int a)
142
{
143
    if (a&(~0xFFFF)) return (-a)>>31;
144
    else             return a;
145
}
146

    
147
/**
148
 * Clips a signed integer value into the -32768,32767 range.
149
 * @param a value to clip
150
 * @return clipped value
151
 */
152
static inline av_const int16_t av_clip_int16(int a)
153
{
154
    if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
155
    else                      return a;
156
}
157

    
158
/**
159
 * Clips a signed 64-bit integer value into the -2147483648,2147483647 range.
160
 * @param a value to clip
161
 * @return clipped value
162
 */
163
static inline av_const int32_t av_clipl_int32(int64_t a)
164
{
165
    if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;
166
    else                                         return a;
167
}
168

    
169
/**
170
 * Clips a float 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 float av_clipf(float a, float amin, float amax)
177
{
178
    if      (a < amin) return amin;
179
    else if (a > amax) return amax;
180
    else               return a;
181
}
182

    
183
/** Computes ceil(log2(x)).
184
 * @param x value used to compute ceil(log2(x))
185
 * @return computed ceiling of log2(x)
186
 */
187
static inline av_const int av_ceil_log2(int x)
188
{
189
    return av_log2((x - 1) << 1);
190
}
191

    
192
#define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((d) << 24))
193
#define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((a) << 24))
194

    
195
/*!
196
 * \def GET_UTF8(val, GET_BYTE, ERROR)
197
 * Converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
198
 * \param val is the output and should be of type uint32_t. It holds the converted
199
 * UCS-4 character and should be a left value.
200
 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
201
 * a function or a statement whose return value or evaluated value is of type
202
 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
203
 * and up to 7 times in the general case.
204
 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
205
 * from GET_BYTE. It should be a statement that jumps out of the macro,
206
 * like exit(), goto, return, break, or continue.
207
 */
208
#define GET_UTF8(val, GET_BYTE, ERROR)\
209
    val= GET_BYTE;\
210
    {\
211
        int ones= 7 - av_log2(val ^ 255);\
212
        if(ones==1)\
213
            ERROR\
214
        val&= 127>>ones;\
215
        while(--ones > 0){\
216
            int tmp= GET_BYTE - 128;\
217
            if(tmp>>6)\
218
                ERROR\
219
            val= (val<<6) + tmp;\
220
        }\
221
    }
222

    
223
/*!
224
 * \def GET_UTF16(val, GET_16BIT, ERROR)
225
 * Converts a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form
226
 * \param val is the output and should be of type uint32_t. It holds the converted
227
 * UCS-4 character and should be a left value.
228
 * \param GET_16BIT gets two bytes of UTF-16 encoded data converted to native endianness.
229
 * It can be a function or a statement whose return value or evaluated value is of type
230
 * uint16_t. It will be executed up to 2 times.
231
 * \param ERROR action that should be taken when an invalid UTF-16 surrogate is
232
 * returned from GET_BYTE. It should be a statement that jumps out of the macro,
233
 * like exit(), goto, return, break, or continue.
234
 */
235
#define GET_UTF16(val, GET_16BIT, ERROR)\
236
    val = GET_16BIT;\
237
    {\
238
        unsigned int hi = val - 0xD800;\
239
        if (hi < 0x800) {\
240
            val = GET_16BIT - 0xDC00;\
241
            if (val > 0x3FFU || hi > 0x3FFU)\
242
                ERROR\
243
            val += (hi<<10) + 0x10000;\
244
        }\
245
    }\
246

    
247
/*!
248
 * \def PUT_UTF8(val, tmp, PUT_BYTE)
249
 * Converts a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
250
 * \param val is an input-only argument and should be of type uint32_t. It holds
251
 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
252
 * val is given as a function it is executed only once.
253
 * \param tmp is a temporary variable and should be of type uint8_t. It
254
 * represents an intermediate value during conversion that is to be
255
 * output by PUT_BYTE.
256
 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
257
 * It could be a function or a statement, and uses tmp as the input byte.
258
 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
259
 * executed up to 4 times for values in the valid UTF-8 range and up to
260
 * 7 times in the general case, depending on the length of the converted
261
 * Unicode character.
262
 */
263
#define PUT_UTF8(val, tmp, PUT_BYTE)\
264
    {\
265
        int bytes, shift;\
266
        uint32_t in = val;\
267
        if (in < 0x80) {\
268
            tmp = in;\
269
            PUT_BYTE\
270
        } else {\
271
            bytes = (av_log2(in) + 4) / 5;\
272
            shift = (bytes - 1) * 6;\
273
            tmp = (256 - (256 >> bytes)) | (in >> shift);\
274
            PUT_BYTE\
275
            while (shift >= 6) {\
276
                shift -= 6;\
277
                tmp = 0x80 | ((in >> shift) & 0x3f);\
278
                PUT_BYTE\
279
            }\
280
        }\
281
    }
282

    
283
/*!
284
 * \def PUT_UTF16(val, tmp, PUT_16BIT)
285
 * Converts a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
286
 * \param val is an input-only argument and should be of type uint32_t. It holds
287
 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
288
 * val is given as a function it is executed only once.
289
 * \param tmp is a temporary variable and should be of type uint16_t. It
290
 * represents an intermediate value during conversion that is to be
291
 * output by PUT_16BIT.
292
 * \param PUT_16BIT writes the converted UTF-16 data to any proper destination
293
 * in desired endianness. It could be a function or a statement, and uses tmp
294
 * as the input byte.  For example, PUT_BYTE could be "*output++ = tmp;"
295
 * PUT_BYTE will be executed 1 or 2 times depending on input character.
296
 */
297
#define PUT_UTF16(val, tmp, PUT_16BIT)\
298
    {\
299
        uint32_t in = val;\
300
        if (in < 0x10000) {\
301
            tmp = in;\
302
            PUT_16BIT\
303
        } else {\
304
            tmp = 0xD800 | ((in - 0x10000) >> 10);\
305
            PUT_16BIT\
306
            tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
307
            PUT_16BIT\
308
        }\
309
    }\
310

    
311

    
312

    
313
#include "mem.h"
314

    
315
#ifdef HAVE_AV_CONFIG_H
316
#    include "internal.h"
317
#endif /* HAVE_AV_CONFIG_H */
318

    
319
#endif /* AVUTIL_COMMON_H */