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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 API header
24  */
25 
26 #ifndef AVUTIL_INTERNAL_H
27 #define AVUTIL_INTERNAL_H
28 
29 #if !defined(DEBUG) && !defined(NDEBUG)
30 #    define NDEBUG
31 #endif
32 
33 // This can be enabled to allow detection of additional integer overflows with ubsan
34 //#define CHECKED
35 
36 #include <limits.h>
37 #include <stdint.h>
38 #include <stddef.h>
39 #include <assert.h>
40 #include "config.h"
41 #include "attributes.h"
42 #include "timer.h"
43 #include "cpu.h"
44 #include "dict.h"
45 #include "macros.h"
46 #include "pixfmt.h"
47 #include "version.h"
48 
49 #if ARCH_X86
50 #   include "x86/emms.h"
51 #endif
52 
53 #ifndef emms_c
54 #   define emms_c() do {} while(0)
55 #endif
56 
57 #ifndef attribute_align_arg
58 #if ARCH_X86_32 && AV_GCC_VERSION_AT_LEAST(4,2)
59 #    define attribute_align_arg __attribute__((force_align_arg_pointer))
60 #else
61 #    define attribute_align_arg
62 #endif
63 #endif
64 
65 #if defined(_WIN32) && CONFIG_SHARED && !defined(BUILDING_avutil)
66 #    define av_export_avutil __declspec(dllimport)
67 #else
68 #    define av_export_avutil
69 #endif
70 
71 #if HAVE_PRAGMA_DEPRECATED
72 #    if defined(__ICL) || defined (__INTEL_COMPILER)
73 #        define FF_DISABLE_DEPRECATION_WARNINGS __pragma(warning(push)) __pragma(warning(disable:1478))
74 #        define FF_ENABLE_DEPRECATION_WARNINGS  __pragma(warning(pop))
75 #    elif defined(_MSC_VER)
76 #        define FF_DISABLE_DEPRECATION_WARNINGS __pragma(warning(push)) __pragma(warning(disable:4996))
77 #        define FF_ENABLE_DEPRECATION_WARNINGS  __pragma(warning(pop))
78 #    else
79 #        define FF_DISABLE_DEPRECATION_WARNINGS _Pragma("GCC diagnostic push") _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
80 #        define FF_ENABLE_DEPRECATION_WARNINGS  _Pragma("GCC diagnostic pop")
81 #    endif
82 #else
83 #    define FF_DISABLE_DEPRECATION_WARNINGS
84 #    define FF_ENABLE_DEPRECATION_WARNINGS
85 #endif
86 
87 
88 #define FF_MEMORY_POISON 0x2a
89 
90 #define MAKE_ACCESSORS(str, name, type, field) \
91     type av_##name##_get_##field(const str *s) { return s->field; } \
92     void av_##name##_set_##field(str *s, type v) { s->field = v; }
93 
94 /* Check if the hard coded offset of a struct member still matches reality.
95  * Induce a compilation failure if not.
96  */
97 #define AV_CHECK_OFFSET(s, m, o) struct check_##o {    \
98         int x_##o[offsetof(s, m) == o? 1: -1];         \
99     }
100 
101 
102 #define FF_ALLOC_TYPED_ARRAY(p, nelem)  (p = av_malloc_array(nelem, sizeof(*p)))
103 #define FF_ALLOCZ_TYPED_ARRAY(p, nelem) (p = av_mallocz_array(nelem, sizeof(*p)))
104 
105 #define FF_PTR_ADD(ptr, off) ((off) ? (ptr) + (off) : (ptr))
106 
107 #include "libm.h"
108 
109 /**
110  * Return NULL if CONFIG_SMALL is true, otherwise the argument
111  * without modification. Used to disable the definition of strings
112  * (for example AVCodec long_names).
113  */
114 #if CONFIG_SMALL
115 #   define NULL_IF_CONFIG_SMALL(x) NULL
116 #else
117 #   define NULL_IF_CONFIG_SMALL(x) x
118 #endif
119 
120 /**
121  * Define a function with only the non-default version specified.
122  *
123  * On systems with ELF shared libraries, all symbols exported from
124  * FFmpeg libraries are tagged with the name and major version of the
125  * library to which they belong.  If a function is moved from one
126  * library to another, a wrapper must be retained in the original
127  * location to preserve binary compatibility.
128  *
129  * Functions defined with this macro will never be used to resolve
130  * symbols by the build-time linker.
131  *
132  * @param type return type of function
133  * @param name name of function
134  * @param args argument list of function
135  * @param ver  version tag to assign function
136  */
137 #if HAVE_SYMVER_ASM_LABEL
138 #   define FF_SYMVER(type, name, args, ver)                     \
139     type ff_##name args __asm__ (EXTERN_PREFIX #name "@" ver);  \
140     type ff_##name args
141 #elif HAVE_SYMVER_GNU_ASM
142 #   define FF_SYMVER(type, name, args, ver)                             \
143     __asm__ (".symver ff_" #name "," EXTERN_PREFIX #name "@" ver);      \
144     type ff_##name args;                                                \
145     type ff_##name args
146 #endif
147 
148 /**
149  * Return NULL if a threading library has not been enabled.
150  * Used to disable threading functions in AVCodec definitions
151  * when not needed.
152  */
153 #if HAVE_THREADS
154 #   define ONLY_IF_THREADS_ENABLED(x) x
155 #else
156 #   define ONLY_IF_THREADS_ENABLED(x) NULL
157 #endif
158 
159 /**
160  * Log a generic warning message about a missing feature.
161  *
162  * @param[in] avc a pointer to an arbitrary struct of which the first
163  *                field is a pointer to an AVClass struct
164  * @param[in] msg string containing the name of the missing feature
165  */
166 void avpriv_report_missing_feature(void *avc,
167                                    const char *msg, ...) av_printf_format(2, 3);
168 
169 /**
170  * Log a generic warning message about a missing feature.
171  * Additionally request that a sample showcasing the feature be uploaded.
172  *
173  * @param[in] avc a pointer to an arbitrary struct of which the first field is
174  *                a pointer to an AVClass struct
175  * @param[in] msg string containing the name of the missing feature
176  */
177 void avpriv_request_sample(void *avc,
178                            const char *msg, ...) av_printf_format(2, 3);
179 
180 #if HAVE_LIBC_MSVCRT
181 #include <crtversion.h>
182 #if defined(_VC_CRT_MAJOR_VERSION) && _VC_CRT_MAJOR_VERSION < 14
183 #pragma comment(linker, "/include:" EXTERN_PREFIX "avpriv_strtod")
184 #pragma comment(linker, "/include:" EXTERN_PREFIX "avpriv_snprintf")
185 #endif
186 
187 #define avpriv_open ff_open
188 #define avpriv_tempfile ff_tempfile
189 #define PTRDIFF_SPECIFIER "Id"
190 #define SIZE_SPECIFIER "Iu"
191 #else
192 #define PTRDIFF_SPECIFIER "td"
193 #define SIZE_SPECIFIER "zu"
194 #endif
195 
196 #ifdef DEBUG
197 #   define ff_dlog(ctx, ...) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__)
198 #else
199 #   define ff_dlog(ctx, ...) do { if (0) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
200 #endif
201 
202 // For debuging we use signed operations so overflows can be detected (by ubsan)
203 // For production we use unsigned so there are no undefined operations
204 #ifdef CHECKED
205 #define SUINT   int
206 #define SUINT32 int32_t
207 #else
208 #define SUINT   unsigned
209 #define SUINT32 uint32_t
210 #endif
211 
212 /**
213  * Clip and convert a double value into the long long amin-amax range.
214  * This function is needed because conversion of floating point to integers when
215  * it does not fit in the integer's representation does not necessarily saturate
216  * correctly (usually converted to a cvttsd2si on x86) which saturates numbers
217  * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined
218  * behavior, allowing this sort of mathematically bogus conversions. This provides
219  * a safe alternative that is slower obviously but assures safety and better
220  * mathematical behavior.
221  * @param a value to clip
222  * @param amin minimum value of the clip range
223  * @param amax maximum value of the clip range
224  * @return clipped value
225  */
ff_rint64_clip(double a,int64_t amin,int64_t amax)226 static av_always_inline av_const int64_t ff_rint64_clip(double a, int64_t amin, int64_t amax)
227 {
228     int64_t res;
229 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
230     if (amin > amax) abort();
231 #endif
232     // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles
233     // do range checks first
234     if (a >=  9223372036854775808.0)
235         return amax;
236     if (a <= -9223372036854775808.0)
237         return amin;
238 
239     // safe to call llrint and clip accordingly
240     res = llrint(a);
241     if (res > amax)
242         return amax;
243     if (res < amin)
244         return amin;
245     return res;
246 }
247 
248 /**
249  * A wrapper for open() setting O_CLOEXEC.
250  */
251 av_warn_unused_result
252 int avpriv_open(const char *filename, int flags, ...);
253 
254 /**
255  * Wrapper to work around the lack of mkstemp() on mingw.
256  * Also, tries to create file in /tmp first, if possible.
257  * *prefix can be a character constant; *filename will be allocated internally.
258  * @return file descriptor of opened file (or negative value corresponding to an
259  * AVERROR code on error)
260  * and opened file name in **filename.
261  * @note On very old libcs it is necessary to set a secure umask before
262  *       calling this, av_tempfile() can't call umask itself as it is used in
263  *       libraries and could interfere with the calling application.
264  */
265 int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx);
266 
267 int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt);
268 
avpriv_mirror(int x,int w)269 static av_always_inline av_const int avpriv_mirror(int x, int w)
270 {
271     if (!w)
272         return 0;
273 
274     while ((unsigned)x > (unsigned)w) {
275         x = -x;
276         if (x < 0)
277             x += 2 * w;
278     }
279     return x;
280 }
281 
282 void ff_check_pixfmt_descriptors(void);
283 
284 /**
285  * Set a dictionary value to an ISO-8601 compliant timestamp string.
286  *
287  * @param dict pointer to a pointer to a dictionary struct. If *dict is NULL
288  *             a dictionary struct is allocated and put in *dict.
289  * @param key metadata key
290  * @param timestamp unix timestamp in microseconds
291  * @return <0 on error
292  */
293 int avpriv_dict_set_timestamp(AVDictionary **dict, const char *key, int64_t timestamp);
294 
295 // Helper macro for AV_PIX_FMT_FLAG_PSEUDOPAL deprecation. Code inside FFmpeg
296 // should always use FF_PSEUDOPAL. Once the public API flag gets removed, all
297 // code using it is dead code.
298 #if FF_API_PSEUDOPAL
299 #define FF_PSEUDOPAL AV_PIX_FMT_FLAG_PSEUDOPAL
300 #else
301 #define FF_PSEUDOPAL 0
302 #endif
303 
304 // Temporary typedef to simplify porting all AVBufferRef users to size_t
305 #if FF_API_BUFFER_SIZE_T
306 typedef int buffer_size_t;
307 #else
308 typedef size_t buffer_size_t;
309 #endif
310 
311 #endif /* AVUTIL_INTERNAL_H */
312