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 */
56extern const uint8_t ff_log2_tab[256];
57
58extern const uint8_t av_reverse[256];
59
60static 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
76static 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 */
107static 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 */
119static 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 0-65535 range.
127 * @param a value to clip
128 * @return clipped value
129 */
130static inline av_const uint16_t av_clip_uint16(int a)
131{
132    if (a&(~0xFFFF)) return (-a)>>31;
133    else             return a;
134}
135
136/**
137 * Clips a signed integer value into the -32768,32767 range.
138 * @param a value to clip
139 * @return clipped value
140 */
141static inline av_const int16_t av_clip_int16(int a)
142{
143    if ((a+0x8000) & ~0xFFFF) return (a>>31) ^ 0x7FFF;
144    else                      return a;
145}
146
147/**
148 * Clips a signed 64-bit integer value into the -2147483648,2147483647 range.
149 * @param a value to clip
150 * @return clipped value
151 */
152static inline av_const int32_t av_clipl_int32(int64_t a)
153{
154    if ((a+0x80000000u) & ~UINT64_C(0xFFFFFFFF)) return (a>>63) ^ 0x7FFFFFFF;
155    else                                         return a;
156}
157
158/**
159 * Clips a float value into the amin-amax range.
160 * @param a value to clip
161 * @param amin minimum value of the clip range
162 * @param amax maximum value of the clip range
163 * @return clipped value
164 */
165static inline av_const float av_clipf(float a, float amin, float amax)
166{
167    if      (a < amin) return amin;
168    else if (a > amax) return amax;
169    else               return a;
170}
171
172/** Computes ceil(log2(x)).
173 * @param x value used to compute ceil(log2(x))
174 * @return computed ceiling of log2(x)
175 */
176static inline av_const int av_ceil_log2(int x)
177{
178    return av_log2((x - 1) << 1);
179}
180
181#define MKTAG(a,b,c,d) (a | (b << 8) | (c << 16) | (d << 24))
182#define MKBETAG(a,b,c,d) (d | (c << 8) | (b << 16) | (a << 24))
183
184/*!
185 * \def GET_UTF8(val, GET_BYTE, ERROR)
186 * Converts a UTF-8 character (up to 4 bytes long) to its 32-bit UCS-4 encoded form
187 * \param val is the output and should be of type uint32_t. It holds the converted
188 * UCS-4 character and should be a left value.
189 * \param GET_BYTE gets UTF-8 encoded bytes from any proper source. It can be
190 * a function or a statement whose return value or evaluated value is of type
191 * uint8_t. It will be executed up to 4 times for values in the valid UTF-8 range,
192 * and up to 7 times in the general case.
193 * \param ERROR action that should be taken when an invalid UTF-8 byte is returned
194 * from GET_BYTE. It should be a statement that jumps out of the macro,
195 * like exit(), goto, return, break, or continue.
196 */
197#define GET_UTF8(val, GET_BYTE, ERROR)\
198    val= GET_BYTE;\
199    {\
200        int ones= 7 - av_log2(val ^ 255);\
201        if(ones==1)\
202            ERROR\
203        val&= 127>>ones;\
204        while(--ones > 0){\
205            int tmp= GET_BYTE - 128;\
206            if(tmp>>6)\
207                ERROR\
208            val= (val<<6) + tmp;\
209        }\
210    }
211
212/*!
213 * \def GET_UTF16(val, GET_16BIT, ERROR)
214 * Converts a UTF-16 character (2 or 4 bytes) to its 32-bit UCS-4 encoded form
215 * \param val is the output and should be of type uint32_t. It holds the converted
216 * UCS-4 character and should be a left value.
217 * \param GET_16BIT gets two bytes of UTF-16 encoded data converted to native endianness.
218 * It can be a function or a statement whose return value or evaluated value is of type
219 * uint16_t. It will be executed up to 2 times.
220 * \param ERROR action that should be taken when an invalid UTF-16 surrogate is
221 * returned from GET_BYTE. It should be a statement that jumps out of the macro,
222 * like exit(), goto, return, break, or continue.
223 */
224#define GET_UTF16(val, GET_16BIT, ERROR)\
225    val = GET_16BIT;\
226    {\
227        unsigned int hi = val - 0xD800;\
228        if (hi < 0x800) {\
229            val = GET_16BIT - 0xDC00;\
230            if (val > 0x3FFU || hi > 0x3FFU)\
231                ERROR\
232            val += (hi<<10) + 0x10000;\
233        }\
234    }\
235
236/*!
237 * \def PUT_UTF8(val, tmp, PUT_BYTE)
238 * Converts a 32-bit Unicode character to its UTF-8 encoded form (up to 4 bytes long).
239 * \param val is an input-only argument and should be of type uint32_t. It holds
240 * a UCS-4 encoded Unicode character that is to be converted to UTF-8. If
241 * val is given as a function it is executed only once.
242 * \param tmp is a temporary variable and should be of type uint8_t. It
243 * represents an intermediate value during conversion that is to be
244 * output by PUT_BYTE.
245 * \param PUT_BYTE writes the converted UTF-8 bytes to any proper destination.
246 * It could be a function or a statement, and uses tmp as the input byte.
247 * For example, PUT_BYTE could be "*output++ = tmp;" PUT_BYTE will be
248 * executed up to 4 times for values in the valid UTF-8 range and up to
249 * 7 times in the general case, depending on the length of the converted
250 * Unicode character.
251 */
252#define PUT_UTF8(val, tmp, PUT_BYTE)\
253    {\
254        int bytes, shift;\
255        uint32_t in = val;\
256        if (in < 0x80) {\
257            tmp = in;\
258            PUT_BYTE\
259        } else {\
260            bytes = (av_log2(in) + 4) / 5;\
261            shift = (bytes - 1) * 6;\
262            tmp = (256 - (256 >> bytes)) | (in >> shift);\
263            PUT_BYTE\
264            while (shift >= 6) {\
265                shift -= 6;\
266                tmp = 0x80 | ((in >> shift) & 0x3f);\
267                PUT_BYTE\
268            }\
269        }\
270    }
271
272/*!
273 * \def PUT_UTF16(val, tmp, PUT_16BIT)
274 * Converts a 32-bit Unicode character to its UTF-16 encoded form (2 or 4 bytes).
275 * \param val is an input-only argument and should be of type uint32_t. It holds
276 * a UCS-4 encoded Unicode character that is to be converted to UTF-16. If
277 * val is given as a function it is executed only once.
278 * \param tmp is a temporary variable and should be of type uint16_t. It
279 * represents an intermediate value during conversion that is to be
280 * output by PUT_16BIT.
281 * \param PUT_16BIT writes the converted UTF-16 data to any proper destination
282 * in desired endianness. It could be a function or a statement, and uses tmp
283 * as the input byte.  For example, PUT_BYTE could be "*output++ = tmp;"
284 * PUT_BYTE will be executed 1 or 2 times depending on input character.
285 */
286#define PUT_UTF16(val, tmp, PUT_16BIT)\
287    {\
288        uint32_t in = val;\
289        if (in < 0x10000) {\
290            tmp = in;\
291            PUT_16BIT\
292        } else {\
293            tmp = 0xD800 | ((in - 0x10000) >> 10);\
294            PUT_16BIT\
295            tmp = 0xDC00 | ((in - 0x10000) & 0x3FF);\
296            PUT_16BIT\
297        }\
298    }\
299
300
301
302#include "mem.h"
303
304#ifdef HAVE_AV_CONFIG_H
305#    include "internal.h"
306#endif /* HAVE_AV_CONFIG_H */
307
308#endif /* AVUTIL_COMMON_H */
309