FFmpeg
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() do {} 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_TYPED_ARRAY(p, nelem) (p = av_malloc_array(nelem, sizeof(*p)))
141 #define FF_ALLOCZ_TYPED_ARRAY(p, nelem) (p = av_mallocz_array(nelem, sizeof(*p)))
142 
143 #include "libm.h"
144 
145 /**
146  * Return NULL if CONFIG_SMALL is true, otherwise the argument
147  * without modification. Used to disable the definition of strings
148  * (for example AVCodec long_names).
149  */
150 #if CONFIG_SMALL
151 # define NULL_IF_CONFIG_SMALL(x) NULL
152 #else
153 # define NULL_IF_CONFIG_SMALL(x) x
154 #endif
155 
156 /**
157  * Define a function with only the non-default version specified.
158  *
159  * On systems with ELF shared libraries, all symbols exported from
160  * FFmpeg libraries are tagged with the name and major version of the
161  * library to which they belong. If a function is moved from one
162  * library to another, a wrapper must be retained in the original
163  * location to preserve binary compatibility.
164  *
165  * Functions defined with this macro will never be used to resolve
166  * symbols by the build-time linker.
167  *
168  * @param type return type of function
169  * @param name name of function
170  * @param args argument list of function
171  * @param ver version tag to assign function
172  */
173 #if HAVE_SYMVER_ASM_LABEL
174 # define FF_SYMVER(type, name, args, ver) \
175  type ff_##name args __asm__ (EXTERN_PREFIX #name "@" ver); \
176  type ff_##name args
177 #elif HAVE_SYMVER_GNU_ASM
178 # define FF_SYMVER(type, name, args, ver) \
179  __asm__ (".symver ff_" #name "," EXTERN_PREFIX #name "@" ver); \
180  type ff_##name args; \
181  type ff_##name args
182 #endif
183 
184 /**
185  * Return NULL if a threading library has not been enabled.
186  * Used to disable threading functions in AVCodec definitions
187  * when not needed.
188  */
189 #if HAVE_THREADS
190 # define ONLY_IF_THREADS_ENABLED(x) x
191 #else
192 # define ONLY_IF_THREADS_ENABLED(x) NULL
193 #endif
194 
195 /**
196  * Log a generic warning message about a missing feature.
197  *
198  * @param[in] avc a pointer to an arbitrary struct of which the first
199  * field is a pointer to an AVClass struct
200  * @param[in] msg string containing the name of the missing feature
201  */
202 void avpriv_report_missing_feature(void *avc,
203  const char *msg, ...) av_printf_format(2, 3);
204 
205 /**
206  * Log a generic warning message about a missing feature.
207  * Additionally request that a sample showcasing the feature be uploaded.
208  *
209  * @param[in] avc a pointer to an arbitrary struct of which the first field is
210  * a pointer to an AVClass struct
211  * @param[in] msg string containing the name of the missing feature
212  */
213 void avpriv_request_sample(void *avc,
214  const char *msg, ...) av_printf_format(2, 3);
215 
216 #if HAVE_LIBC_MSVCRT
217 #include <crtversion.h>
218 #if defined(_VC_CRT_MAJOR_VERSION) && _VC_CRT_MAJOR_VERSION < 14
219 #pragma comment(linker, "/include:" EXTERN_PREFIX "avpriv_strtod")
220 #pragma comment(linker, "/include:" EXTERN_PREFIX "avpriv_snprintf")
221 #endif
222 
223 #define avpriv_open ff_open
224 #define avpriv_tempfile ff_tempfile
225 #define PTRDIFF_SPECIFIER "Id"
226 #define SIZE_SPECIFIER "Iu"
227 #else
228 #define PTRDIFF_SPECIFIER "td"
229 #define SIZE_SPECIFIER "zu"
230 #endif
231 
232 #ifdef DEBUG
233 # define ff_dlog(ctx, ...) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__)
234 #else
235 # define ff_dlog(ctx, ...) do { if (0) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
236 #endif
237 
238 // For debuging we use signed operations so overflows can be detected (by ubsan)
239 // For production we use unsigned so there are no undefined operations
240 #ifdef CHECKED
241 #define SUINT int
242 #define SUINT32 int32_t
243 #else
244 #define SUINT unsigned
245 #define SUINT32 uint32_t
246 #endif
247 
248 /**
249  * Clip and convert a double value into the long long amin-amax range.
250  * This function is needed because conversion of floating point to integers when
251  * it does not fit in the integer's representation does not necessarily saturate
252  * correctly (usually converted to a cvttsd2si on x86) which saturates numbers
253  * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined
254  * behavior, allowing this sort of mathematically bogus conversions. This provides
255  * a safe alternative that is slower obviously but assures safety and better
256  * mathematical behavior.
257  * @param a value to clip
258  * @param amin minimum value of the clip range
259  * @param amax maximum value of the clip range
260  * @return clipped value
261  */
262 static av_always_inline av_const int64_t ff_rint64_clip(double a, int64_t amin, int64_t amax)
263 {
264  int64_t res;
265 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
266  if (amin > amax) abort();
267 #endif
268  // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles
269  // do range checks first
270  if (a >= 9223372036854775808.0)
271  return amax;
272  if (a <= -9223372036854775808.0)
273  return amin;
274 
275  // safe to call llrint and clip accordingly
276  res = llrint(a);
277  if (res > amax)
278  return amax;
279  if (res < amin)
280  return amin;
281  return res;
282 }
283 
284 /**
285  * A wrapper for open() setting O_CLOEXEC.
286  */
288 int avpriv_open(const char *filename, int flags, ...);
289 
290 /**
291  * Wrapper to work around the lack of mkstemp() on mingw.
292  * Also, tries to create file in /tmp first, if possible.
293  * *prefix can be a character constant; *filename will be allocated internally.
294  * @return file descriptor of opened file (or negative value corresponding to an
295  * AVERROR code on error)
296  * and opened file name in **filename.
297  * @note On very old libcs it is necessary to set a secure umask before
298  * calling this, av_tempfile() can't call umask itself as it is used in
299  * libraries and could interfere with the calling application.
300  */
301 int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx);
302 
303 int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt);
304 
305 static av_always_inline av_const int avpriv_mirror(int x, int w)
306 {
307  if (!w)
308  return 0;
309 
310  while ((unsigned)x > (unsigned)w) {
311  x = -x;
312  if (x < 0)
313  x += 2 * w;
314  }
315  return x;
316 }
317 
318 void ff_check_pixfmt_descriptors(void);
319 
320 /**
321  * Set a dictionary value to an ISO-8601 compliant timestamp string.
322  *
323  * @param dict pointer to a pointer to a dictionary struct. If *dict is NULL
324  * a dictionary struct is allocated and put in *dict.
325  * @param key metadata key
326  * @param timestamp unix timestamp in microseconds
327  * @return <0 on error
328  */
329 int avpriv_dict_set_timestamp(AVDictionary **dict, const char *key, int64_t timestamp);
330 
331 // Helper macro for AV_PIX_FMT_FLAG_PSEUDOPAL deprecation. Code inside FFmpeg
332 // should always use FF_PSEUDOPAL. Once the public API flag gets removed, all
333 // code using it is dead code.
334 #if FF_API_PSEUDOPAL
335 #define FF_PSEUDOPAL AV_PIX_FMT_FLAG_PSEUDOPAL
336 #else
337 #define FF_PSEUDOPAL 0
338 #endif
339 
340 #endif /* AVUTIL_INTERNAL_H */
#define av_const
Definition: attributes.h:82
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:262
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
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.
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:161
uint8_t w
Definition: llviddspenc.c:38
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:305
#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 flags(name, subs,...)
Definition: cbs_av1.c:560
#define av_warn_unused_result
Definition: attributes.h:62
void ff_check_pixfmt_descriptors(void)
Definition: pixdesc.c:2628
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:45
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64