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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 "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() 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(_MSC_VER) && CONFIG_SHARED
66 # define av_export __declspec(dllimport)
67 #else
68 # define av_export
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 ignored \"-Wdeprecated-declarations\"")
80 # define FF_ENABLE_DEPRECATION_WARNINGS _Pragma("GCC diagnostic warning \"-Wdeprecated-declarations\"")
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 // Some broken preprocessors need a second expansion
95 // to be forced to tokenize __VA_ARGS__
96 #define E1(x) x
97 
98 /* Check if the hard coded offset of a struct member still matches reality.
99  * Induce a compilation failure if not.
100  */
101 #define AV_CHECK_OFFSET(s, m, o) struct check_##o { \
102  int x_##o[offsetof(s, m) == o? 1: -1]; \
103  }
104 
105 #define LOCAL_ALIGNED_A(a, t, v, s, o, ...) \
106  uint8_t la_##v[sizeof(t s o) + (a)]; \
107  t (*v) o = (void *)FFALIGN((uintptr_t)la_##v, a)
108 
109 #define LOCAL_ALIGNED_D(a, t, v, s, o, ...) \
110  DECLARE_ALIGNED(a, t, la_##v) s o; \
111  t (*v) o = la_##v
112 
113 #define LOCAL_ALIGNED(a, t, v, ...) E1(LOCAL_ALIGNED_A(a, t, v, __VA_ARGS__,,))
114 
115 #if HAVE_LOCAL_ALIGNED_8
116 # define LOCAL_ALIGNED_8(t, v, ...) E1(LOCAL_ALIGNED_D(8, t, v, __VA_ARGS__,,))
117 #else
118 # define LOCAL_ALIGNED_8(t, v, ...) LOCAL_ALIGNED(8, t, v, __VA_ARGS__)
119 #endif
120 
121 #if HAVE_LOCAL_ALIGNED_16
122 # define LOCAL_ALIGNED_16(t, v, ...) E1(LOCAL_ALIGNED_D(16, t, v, __VA_ARGS__,,))
123 #else
124 # define LOCAL_ALIGNED_16(t, v, ...) LOCAL_ALIGNED(16, t, v, __VA_ARGS__)
125 #endif
126 
127 #if HAVE_LOCAL_ALIGNED_32
128 # define LOCAL_ALIGNED_32(t, v, ...) E1(LOCAL_ALIGNED_D(32, t, v, __VA_ARGS__,,))
129 #else
130 # define LOCAL_ALIGNED_32(t, v, ...) LOCAL_ALIGNED(32, t, v, __VA_ARGS__)
131 #endif
132 
133 #define FF_ALLOC_OR_GOTO(ctx, p, size, label)\
134 {\
135  p = av_malloc(size);\
136  if (!(p) && (size) != 0) {\
137  av_log(ctx, AV_LOG_ERROR, "Cannot allocate memory.\n");\
138  goto label;\
139  }\
140 }
141 
142 #define FF_ALLOCZ_OR_GOTO(ctx, p, size, label)\
143 {\
144  p = av_mallocz(size);\
145  if (!(p) && (size) != 0) {\
146  av_log(ctx, AV_LOG_ERROR, "Cannot allocate memory.\n");\
147  goto label;\
148  }\
149 }
150 
151 #define FF_ALLOC_ARRAY_OR_GOTO(ctx, p, nelem, elsize, label)\
152 {\
153  p = av_malloc_array(nelem, elsize);\
154  if (!p) {\
155  av_log(ctx, AV_LOG_ERROR, "Cannot allocate memory.\n");\
156  goto label;\
157  }\
158 }
159 
160 #define FF_ALLOCZ_ARRAY_OR_GOTO(ctx, p, nelem, elsize, label)\
161 {\
162  p = av_mallocz_array(nelem, elsize);\
163  if (!p) {\
164  av_log(ctx, AV_LOG_ERROR, "Cannot allocate memory.\n");\
165  goto label;\
166  }\
167 }
168 
169 #include "libm.h"
170 
171 /**
172  * Return NULL if CONFIG_SMALL is true, otherwise the argument
173  * without modification. Used to disable the definition of strings
174  * (for example AVCodec long_names).
175  */
176 #if CONFIG_SMALL
177 # define NULL_IF_CONFIG_SMALL(x) NULL
178 #else
179 # define NULL_IF_CONFIG_SMALL(x) x
180 #endif
181 
182 /**
183  * Define a function with only the non-default version specified.
184  *
185  * On systems with ELF shared libraries, all symbols exported from
186  * FFmpeg libraries are tagged with the name and major version of the
187  * library to which they belong. If a function is moved from one
188  * library to another, a wrapper must be retained in the original
189  * location to preserve binary compatibility.
190  *
191  * Functions defined with this macro will never be used to resolve
192  * symbols by the build-time linker.
193  *
194  * @param type return type of function
195  * @param name name of function
196  * @param args argument list of function
197  * @param ver version tag to assign function
198  */
199 #if HAVE_SYMVER_ASM_LABEL
200 # define FF_SYMVER(type, name, args, ver) \
201  type ff_##name args __asm__ (EXTERN_PREFIX #name "@" ver); \
202  type ff_##name args
203 #elif HAVE_SYMVER_GNU_ASM
204 # define FF_SYMVER(type, name, args, ver) \
205  __asm__ (".symver ff_" #name "," EXTERN_PREFIX #name "@" ver); \
206  type ff_##name args; \
207  type ff_##name args
208 #endif
209 
210 /**
211  * Return NULL if a threading library has not been enabled.
212  * Used to disable threading functions in AVCodec definitions
213  * when not needed.
214  */
215 #if HAVE_THREADS
216 # define ONLY_IF_THREADS_ENABLED(x) x
217 #else
218 # define ONLY_IF_THREADS_ENABLED(x) NULL
219 #endif
220 
221 /**
222  * Log a generic warning message about a missing feature.
223  *
224  * @param[in] avc a pointer to an arbitrary struct of which the first
225  * field is a pointer to an AVClass struct
226  * @param[in] msg string containing the name of the missing feature
227  */
228 void avpriv_report_missing_feature(void *avc,
229  const char *msg, ...) av_printf_format(2, 3);
230 
231 /**
232  * Log a generic warning message about a missing feature.
233  * Additionally request that a sample showcasing the feature be uploaded.
234  *
235  * @param[in] avc a pointer to an arbitrary struct of which the first field is
236  * a pointer to an AVClass struct
237  * @param[in] msg string containing the name of the missing feature
238  */
239 void avpriv_request_sample(void *avc,
240  const char *msg, ...) av_printf_format(2, 3);
241 
242 #if HAVE_LIBC_MSVCRT
243 #include <crtversion.h>
244 #if defined(_VC_CRT_MAJOR_VERSION) && _VC_CRT_MAJOR_VERSION < 14
245 #pragma comment(linker, "/include:" EXTERN_PREFIX "avpriv_strtod")
246 #pragma comment(linker, "/include:" EXTERN_PREFIX "avpriv_snprintf")
247 #endif
248 
249 #define avpriv_open ff_open
250 #define avpriv_tempfile ff_tempfile
251 #define PTRDIFF_SPECIFIER "Id"
252 #define SIZE_SPECIFIER "Iu"
253 #else
254 #define PTRDIFF_SPECIFIER "td"
255 #define SIZE_SPECIFIER "zu"
256 #endif
257 
258 #ifdef DEBUG
259 # define ff_dlog(ctx, ...) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__)
260 #else
261 # define ff_dlog(ctx, ...) do { if (0) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
262 #endif
263 
264 // For debuging we use signed operations so overflows can be detected (by ubsan)
265 // For production we use unsigned so there are no undefined operations
266 #ifdef CHECKED
267 #define SUINT int
268 #define SUINT32 int32_t
269 #else
270 #define SUINT unsigned
271 #define SUINT32 uint32_t
272 #endif
273 
274 /**
275  * Clip and convert a double value into the long long amin-amax range.
276  * This function is needed because conversion of floating point to integers when
277  * it does not fit in the integer's representation does not necessarily saturate
278  * correctly (usually converted to a cvttsd2si on x86) which saturates numbers
279  * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined
280  * behavior, allowing this sort of mathematically bogus conversions. This provides
281  * a safe alternative that is slower obviously but assures safety and better
282  * mathematical behavior.
283  * @param a value to clip
284  * @param amin minimum value of the clip range
285  * @param amax maximum value of the clip range
286  * @return clipped value
287  */
288 static av_always_inline av_const int64_t ff_rint64_clip(double a, int64_t amin, int64_t amax)
289 {
290  int64_t res;
291 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
292  if (amin > amax) abort();
293 #endif
294  // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles
295  // do range checks first
296  if (a >= 9223372036854775808.0)
297  return amax;
298  if (a <= -9223372036854775808.0)
299  return amin;
300 
301  // safe to call llrint and clip accordingly
302  res = llrint(a);
303  if (res > amax)
304  return amax;
305  if (res < amin)
306  return amin;
307  return res;
308 }
309 
310 /**
311  * A wrapper for open() setting O_CLOEXEC.
312  */
314 int avpriv_open(const char *filename, int flags, ...);
315 
316 /**
317  * Wrapper to work around the lack of mkstemp() on mingw.
318  * Also, tries to create file in /tmp first, if possible.
319  * *prefix can be a character constant; *filename will be allocated internally.
320  * @return file descriptor of opened file (or negative value corresponding to an
321  * AVERROR code on error)
322  * and opened file name in **filename.
323  * @note On very old libcs it is necessary to set a secure umask before
324  * calling this, av_tempfile() can't call umask itself as it is used in
325  * libraries and could interfere with the calling application.
326  */
327 int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx);
328 
329 int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt);
330 
331 static av_always_inline av_const int avpriv_mirror(int x, int w)
332 {
333  if (!w)
334  return 0;
335 
336  while ((unsigned)x > (unsigned)w) {
337  x = -x;
338  if (x < 0)
339  x += 2 * w;
340  }
341  return x;
342 }
343 
344 void ff_check_pixfmt_descriptors(void);
345 
346 /**
347  * Set a dictionary value to an ISO-8601 compliant timestamp string.
348  *
349  * @param s AVFormatContext
350  * @param key metadata key
351  * @param timestamp unix timestamp in microseconds
352  * @return <0 on error
353  */
354 int avpriv_dict_set_timestamp(AVDictionary **dict, const char *key, int64_t timestamp);
355 
356 #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
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:288
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:106
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:331
#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:2470
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