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internal.h
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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 "mem.h"
47 #include "pixfmt.h"
48 #include "version.h"
49 
50 #if ARCH_X86
51 # include "x86/emms.h"
52 #endif
53 
54 #ifndef emms_c
55 # define emms_c() while(0)
56 #endif
57 
58 #ifndef attribute_align_arg
59 #if ARCH_X86_32 && AV_GCC_VERSION_AT_LEAST(4,2)
60 # define attribute_align_arg __attribute__((force_align_arg_pointer))
61 #else
62 # define attribute_align_arg
63 #endif
64 #endif
65 
66 #if defined(_WIN32) && CONFIG_SHARED && !defined(BUILDING_avutil)
67 # define av_export_avutil __declspec(dllimport)
68 #else
69 # define av_export_avutil
70 #endif
71 
72 #if HAVE_PRAGMA_DEPRECATED
73 # if defined(__ICL) || defined (__INTEL_COMPILER)
74 # define FF_DISABLE_DEPRECATION_WARNINGS __pragma(warning(push)) __pragma(warning(disable:1478))
75 # define FF_ENABLE_DEPRECATION_WARNINGS __pragma(warning(pop))
76 # elif defined(_MSC_VER)
77 # define FF_DISABLE_DEPRECATION_WARNINGS __pragma(warning(push)) __pragma(warning(disable:4996))
78 # define FF_ENABLE_DEPRECATION_WARNINGS __pragma(warning(pop))
79 # else
80 # define FF_DISABLE_DEPRECATION_WARNINGS _Pragma("GCC diagnostic push") _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
81 # define FF_ENABLE_DEPRECATION_WARNINGS _Pragma("GCC diagnostic pop")
82 # endif
83 #else
84 # define FF_DISABLE_DEPRECATION_WARNINGS
85 # define FF_ENABLE_DEPRECATION_WARNINGS
86 #endif
87 
88 
89 #define FF_MEMORY_POISON 0x2a
90 
91 #define MAKE_ACCESSORS(str, name, type, field) \
92  type av_##name##_get_##field(const str *s) { return s->field; } \
93  void av_##name##_set_##field(str *s, type v) { s->field = v; }
94 
95 // Some broken preprocessors need a second expansion
96 // to be forced to tokenize __VA_ARGS__
97 #define E1(x) x
98 
99 /* Check if the hard coded offset of a struct member still matches reality.
100  * Induce a compilation failure if not.
101  */
102 #define AV_CHECK_OFFSET(s, m, o) struct check_##o { \
103  int x_##o[offsetof(s, m) == o? 1: -1]; \
104  }
105 
106 #define LOCAL_ALIGNED_A(a, t, v, s, o, ...) \
107  uint8_t la_##v[sizeof(t s o) + (a)]; \
108  t (*v) o = (void *)FFALIGN((uintptr_t)la_##v, a)
109 
110 #define LOCAL_ALIGNED_D(a, t, v, s, o, ...) \
111  DECLARE_ALIGNED(a, t, la_##v) s o; \
112  t (*v) o = la_##v
113 
114 #define LOCAL_ALIGNED(a, t, v, ...) LOCAL_ALIGNED_##a(t, v, __VA_ARGS__)
115 
116 #if HAVE_LOCAL_ALIGNED
117 # define LOCAL_ALIGNED_4(t, v, ...) E1(LOCAL_ALIGNED_D(4, t, v, __VA_ARGS__,,))
118 #else
119 # define LOCAL_ALIGNED_4(t, v, ...) E1(LOCAL_ALIGNED_A(4, t, v, __VA_ARGS__,,))
120 #endif
121 
122 #if HAVE_LOCAL_ALIGNED
123 # define LOCAL_ALIGNED_8(t, v, ...) E1(LOCAL_ALIGNED_D(8, t, v, __VA_ARGS__,,))
124 #else
125 # define LOCAL_ALIGNED_8(t, v, ...) E1(LOCAL_ALIGNED_A(8, t, v, __VA_ARGS__,,))
126 #endif
127 
128 #if HAVE_LOCAL_ALIGNED
129 # define LOCAL_ALIGNED_16(t, v, ...) E1(LOCAL_ALIGNED_D(16, t, v, __VA_ARGS__,,))
130 #else
131 # define LOCAL_ALIGNED_16(t, v, ...) E1(LOCAL_ALIGNED_A(16, t, v, __VA_ARGS__,,))
132 #endif
133 
134 #if HAVE_LOCAL_ALIGNED
135 # define LOCAL_ALIGNED_32(t, v, ...) E1(LOCAL_ALIGNED_D(32, t, v, __VA_ARGS__,,))
136 #else
137 # define LOCAL_ALIGNED_32(t, v, ...) E1(LOCAL_ALIGNED_A(32, t, v, __VA_ARGS__,,))
138 #endif
139 
140 #define FF_ALLOC_OR_GOTO(ctx, p, size, label)\
141 {\
142  p = av_malloc(size);\
143  if (!(p) && (size) != 0) {\
144  av_log(ctx, AV_LOG_ERROR, "Cannot allocate memory.\n");\
145  goto label;\
146  }\
147 }
148 
149 #define FF_ALLOCZ_OR_GOTO(ctx, p, size, label)\
150 {\
151  p = av_mallocz(size);\
152  if (!(p) && (size) != 0) {\
153  av_log(ctx, AV_LOG_ERROR, "Cannot allocate memory.\n");\
154  goto label;\
155  }\
156 }
157 
158 #define FF_ALLOC_ARRAY_OR_GOTO(ctx, p, nelem, elsize, label)\
159 {\
160  p = av_malloc_array(nelem, elsize);\
161  if (!p) {\
162  av_log(ctx, AV_LOG_ERROR, "Cannot allocate memory.\n");\
163  goto label;\
164  }\
165 }
166 
167 #define FF_ALLOCZ_ARRAY_OR_GOTO(ctx, p, nelem, elsize, label)\
168 {\
169  p = av_mallocz_array(nelem, elsize);\
170  if (!p) {\
171  av_log(ctx, AV_LOG_ERROR, "Cannot allocate memory.\n");\
172  goto label;\
173  }\
174 }
175 
176 #include "libm.h"
177 
178 /**
179  * Return NULL if CONFIG_SMALL is true, otherwise the argument
180  * without modification. Used to disable the definition of strings
181  * (for example AVCodec long_names).
182  */
183 #if CONFIG_SMALL
184 # define NULL_IF_CONFIG_SMALL(x) NULL
185 #else
186 # define NULL_IF_CONFIG_SMALL(x) x
187 #endif
188 
189 /**
190  * Define a function with only the non-default version specified.
191  *
192  * On systems with ELF shared libraries, all symbols exported from
193  * FFmpeg libraries are tagged with the name and major version of the
194  * library to which they belong. If a function is moved from one
195  * library to another, a wrapper must be retained in the original
196  * location to preserve binary compatibility.
197  *
198  * Functions defined with this macro will never be used to resolve
199  * symbols by the build-time linker.
200  *
201  * @param type return type of function
202  * @param name name of function
203  * @param args argument list of function
204  * @param ver version tag to assign function
205  */
206 #if HAVE_SYMVER_ASM_LABEL
207 # define FF_SYMVER(type, name, args, ver) \
208  type ff_##name args __asm__ (EXTERN_PREFIX #name "@" ver); \
209  type ff_##name args
210 #elif HAVE_SYMVER_GNU_ASM
211 # define FF_SYMVER(type, name, args, ver) \
212  __asm__ (".symver ff_" #name "," EXTERN_PREFIX #name "@" ver); \
213  type ff_##name args; \
214  type ff_##name args
215 #endif
216 
217 /**
218  * Return NULL if a threading library has not been enabled.
219  * Used to disable threading functions in AVCodec definitions
220  * when not needed.
221  */
222 #if HAVE_THREADS
223 # define ONLY_IF_THREADS_ENABLED(x) x
224 #else
225 # define ONLY_IF_THREADS_ENABLED(x) NULL
226 #endif
227 
228 /**
229  * Log a generic warning message about a missing feature.
230  *
231  * @param[in] avc a pointer to an arbitrary struct of which the first
232  * field is a pointer to an AVClass struct
233  * @param[in] msg string containing the name of the missing feature
234  */
235 void avpriv_report_missing_feature(void *avc,
236  const char *msg, ...) av_printf_format(2, 3);
237 
238 /**
239  * Log a generic warning message about a missing feature.
240  * Additionally request that a sample showcasing the feature be uploaded.
241  *
242  * @param[in] avc a pointer to an arbitrary struct of which the first field is
243  * a pointer to an AVClass struct
244  * @param[in] msg string containing the name of the missing feature
245  */
246 void avpriv_request_sample(void *avc,
247  const char *msg, ...) av_printf_format(2, 3);
248 
249 #if HAVE_LIBC_MSVCRT
250 #include <crtversion.h>
251 #if defined(_VC_CRT_MAJOR_VERSION) && _VC_CRT_MAJOR_VERSION < 14
252 #pragma comment(linker, "/include:" EXTERN_PREFIX "avpriv_strtod")
253 #pragma comment(linker, "/include:" EXTERN_PREFIX "avpriv_snprintf")
254 #endif
255 
256 #define avpriv_open ff_open
257 #define avpriv_tempfile ff_tempfile
258 #define PTRDIFF_SPECIFIER "Id"
259 #define SIZE_SPECIFIER "Iu"
260 #else
261 #define PTRDIFF_SPECIFIER "td"
262 #define SIZE_SPECIFIER "zu"
263 #endif
264 
265 #ifdef DEBUG
266 # define ff_dlog(ctx, ...) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__)
267 #else
268 # define ff_dlog(ctx, ...) do { if (0) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
269 #endif
270 
271 // For debuging we use signed operations so overflows can be detected (by ubsan)
272 // For production we use unsigned so there are no undefined operations
273 #ifdef CHECKED
274 #define SUINT int
275 #define SUINT32 int32_t
276 #else
277 #define SUINT unsigned
278 #define SUINT32 uint32_t
279 #endif
280 
281 /**
282  * Clip and convert a double value into the long long amin-amax range.
283  * This function is needed because conversion of floating point to integers when
284  * it does not fit in the integer's representation does not necessarily saturate
285  * correctly (usually converted to a cvttsd2si on x86) which saturates numbers
286  * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined
287  * behavior, allowing this sort of mathematically bogus conversions. This provides
288  * a safe alternative that is slower obviously but assures safety and better
289  * mathematical behavior.
290  * @param a value to clip
291  * @param amin minimum value of the clip range
292  * @param amax maximum value of the clip range
293  * @return clipped value
294  */
295 static av_always_inline av_const int64_t ff_rint64_clip(double a, int64_t amin, int64_t amax)
296 {
297  int64_t res;
298 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
299  if (amin > amax) abort();
300 #endif
301  // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles
302  // do range checks first
303  if (a >= 9223372036854775808.0)
304  return amax;
305  if (a <= -9223372036854775808.0)
306  return amin;
307 
308  // safe to call llrint and clip accordingly
309  res = llrint(a);
310  if (res > amax)
311  return amax;
312  if (res < amin)
313  return amin;
314  return res;
315 }
316 
317 /**
318  * A wrapper for open() setting O_CLOEXEC.
319  */
321 int avpriv_open(const char *filename, int flags, ...);
322 
323 /**
324  * Wrapper to work around the lack of mkstemp() on mingw.
325  * Also, tries to create file in /tmp first, if possible.
326  * *prefix can be a character constant; *filename will be allocated internally.
327  * @return file descriptor of opened file (or negative value corresponding to an
328  * AVERROR code on error)
329  * and opened file name in **filename.
330  * @note On very old libcs it is necessary to set a secure umask before
331  * calling this, av_tempfile() can't call umask itself as it is used in
332  * libraries and could interfere with the calling application.
333  */
334 int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx);
335 
336 int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt);
337 
338 static av_always_inline av_const int avpriv_mirror(int x, int w)
339 {
340  if (!w)
341  return 0;
342 
343  while ((unsigned)x > (unsigned)w) {
344  x = -x;
345  if (x < 0)
346  x += 2 * w;
347  }
348  return x;
349 }
350 
351 void ff_check_pixfmt_descriptors(void);
352 
353 /**
354  * Set a dictionary value to an ISO-8601 compliant timestamp string.
355  *
356  * @param s AVFormatContext
357  * @param key metadata key
358  * @param timestamp unix timestamp in microseconds
359  * @return <0 on error
360  */
361 int avpriv_dict_set_timestamp(AVDictionary **dict, const char *key, int64_t timestamp);
362 
363 #endif /* AVUTIL_INTERNAL_H */
#define av_const
Definition: attributes.h:76
av_warn_unused_result int avpriv_open(const char *filename, int flags,...)
A wrapper for open() setting O_CLOEXEC.
Definition: file_open.c:66
static enum AVPixelFormat pix_fmt
Memory handling functions.
static av_always_inline av_const int64_t ff_rint64_clip(double a, int64_t amin, int64_t amax)
Clip and convert a double value into the long long amin-amax range.
Definition: internal.h:295
const char * key
Macro definitions for various function/variable attributes.
Public dictionary API.
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
static int flags
Definition: log.c:57
high precision timer, useful to profile code
Utility Preprocessor macros.
int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx)
Wrapper to work around the lack of mkstemp() on mingw.
Definition: file_open.c:110
Libavutil version macros.
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:155
int avpriv_dict_set_timestamp(AVDictionary **dict, const char *key, int64_t timestamp)
Set a dictionary value to an ISO-8601 compliant timestamp string.
Definition: dict.c:258
static av_always_inline av_const int avpriv_mirror(int x, int w)
Definition: internal.h:338
#define llrint(x)
Definition: libm.h:394
Replacements for frequently missing libm functions.
void avpriv_report_missing_feature(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
#define av_warn_unused_result
Definition: attributes.h:56
void ff_check_pixfmt_descriptors(void)
Definition: pixdesc.c:2418
pixel format definitions
int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt)
Definition: imgutils.c:152
#define av_always_inline
Definition: attributes.h:39
AVPixelFormat
Pixel format.
Definition: pixfmt.h:60