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_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 #define FF_PTR_ADD(ptr, off) ((off) ? (ptr) + (off) : (ptr))
177 
178 #include "libm.h"
179 
180 /**
181  * Return NULL if CONFIG_SMALL is true, otherwise the argument
182  * without modification. Used to disable the definition of strings
183  * (for example AVCodec long_names).
184  */
185 #if CONFIG_SMALL
186 # define NULL_IF_CONFIG_SMALL(x) NULL
187 #else
188 # define NULL_IF_CONFIG_SMALL(x) x
189 #endif
190 
191 /**
192  * Define a function with only the non-default version specified.
193  *
194  * On systems with ELF shared libraries, all symbols exported from
195  * FFmpeg libraries are tagged with the name and major version of the
196  * library to which they belong. If a function is moved from one
197  * library to another, a wrapper must be retained in the original
198  * location to preserve binary compatibility.
199  *
200  * Functions defined with this macro will never be used to resolve
201  * symbols by the build-time linker.
202  *
203  * @param type return type of function
204  * @param name name of function
205  * @param args argument list of function
206  * @param ver version tag to assign function
207  */
208 #if HAVE_SYMVER_ASM_LABEL
209 # define FF_SYMVER(type, name, args, ver) \
210  type ff_##name args __asm__ (EXTERN_PREFIX #name "@" ver); \
211  type ff_##name args
212 #elif HAVE_SYMVER_GNU_ASM
213 # define FF_SYMVER(type, name, args, ver) \
214  __asm__ (".symver ff_" #name "," EXTERN_PREFIX #name "@" ver); \
215  type ff_##name args; \
216  type ff_##name args
217 #endif
218 
219 /**
220  * Return NULL if a threading library has not been enabled.
221  * Used to disable threading functions in AVCodec definitions
222  * when not needed.
223  */
224 #if HAVE_THREADS
225 # define ONLY_IF_THREADS_ENABLED(x) x
226 #else
227 # define ONLY_IF_THREADS_ENABLED(x) NULL
228 #endif
229 
230 /**
231  * Log a generic warning message about a missing feature.
232  *
233  * @param[in] avc a pointer to an arbitrary struct of which the first
234  * field is a pointer to an AVClass struct
235  * @param[in] msg string containing the name of the missing feature
236  */
237 void avpriv_report_missing_feature(void *avc,
238  const char *msg, ...) av_printf_format(2, 3);
239 
240 /**
241  * Log a generic warning message about a missing feature.
242  * Additionally request that a sample showcasing the feature be uploaded.
243  *
244  * @param[in] avc a pointer to an arbitrary struct of which the first field is
245  * a pointer to an AVClass struct
246  * @param[in] msg string containing the name of the missing feature
247  */
248 void avpriv_request_sample(void *avc,
249  const char *msg, ...) av_printf_format(2, 3);
250 
251 #if HAVE_LIBC_MSVCRT
252 #include <crtversion.h>
253 #if defined(_VC_CRT_MAJOR_VERSION) && _VC_CRT_MAJOR_VERSION < 14
254 #pragma comment(linker, "/include:" EXTERN_PREFIX "avpriv_strtod")
255 #pragma comment(linker, "/include:" EXTERN_PREFIX "avpriv_snprintf")
256 #endif
257 
258 #define avpriv_open ff_open
259 #define avpriv_tempfile ff_tempfile
260 #define PTRDIFF_SPECIFIER "Id"
261 #define SIZE_SPECIFIER "Iu"
262 #else
263 #define PTRDIFF_SPECIFIER "td"
264 #define SIZE_SPECIFIER "zu"
265 #endif
266 
267 #ifdef DEBUG
268 # define ff_dlog(ctx, ...) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__)
269 #else
270 # define ff_dlog(ctx, ...) do { if (0) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
271 #endif
272 
273 // For debuging we use signed operations so overflows can be detected (by ubsan)
274 // For production we use unsigned so there are no undefined operations
275 #ifdef CHECKED
276 #define SUINT int
277 #define SUINT32 int32_t
278 #else
279 #define SUINT unsigned
280 #define SUINT32 uint32_t
281 #endif
282 
283 /**
284  * Clip and convert a double value into the long long amin-amax range.
285  * This function is needed because conversion of floating point to integers when
286  * it does not fit in the integer's representation does not necessarily saturate
287  * correctly (usually converted to a cvttsd2si on x86) which saturates numbers
288  * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined
289  * behavior, allowing this sort of mathematically bogus conversions. This provides
290  * a safe alternative that is slower obviously but assures safety and better
291  * mathematical behavior.
292  * @param a value to clip
293  * @param amin minimum value of the clip range
294  * @param amax maximum value of the clip range
295  * @return clipped value
296  */
297 static av_always_inline av_const int64_t ff_rint64_clip(double a, int64_t amin, int64_t amax)
298 {
299  int64_t res;
300 #if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
301  if (amin > amax) abort();
302 #endif
303  // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles
304  // do range checks first
305  if (a >= 9223372036854775808.0)
306  return amax;
307  if (a <= -9223372036854775808.0)
308  return amin;
309 
310  // safe to call llrint and clip accordingly
311  res = llrint(a);
312  if (res > amax)
313  return amax;
314  if (res < amin)
315  return amin;
316  return res;
317 }
318 
319 /**
320  * A wrapper for open() setting O_CLOEXEC.
321  */
323 int avpriv_open(const char *filename, int flags, ...);
324 
325 /**
326  * Wrapper to work around the lack of mkstemp() on mingw.
327  * Also, tries to create file in /tmp first, if possible.
328  * *prefix can be a character constant; *filename will be allocated internally.
329  * @return file descriptor of opened file (or negative value corresponding to an
330  * AVERROR code on error)
331  * and opened file name in **filename.
332  * @note On very old libcs it is necessary to set a secure umask before
333  * calling this, av_tempfile() can't call umask itself as it is used in
334  * libraries and could interfere with the calling application.
335  */
336 int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx);
337 
338 int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt);
339 
340 static av_always_inline av_const int avpriv_mirror(int x, int w)
341 {
342  if (!w)
343  return 0;
344 
345  while ((unsigned)x > (unsigned)w) {
346  x = -x;
347  if (x < 0)
348  x += 2 * w;
349  }
350  return x;
351 }
352 
353 void ff_check_pixfmt_descriptors(void);
354 
355 /**
356  * Set a dictionary value to an ISO-8601 compliant timestamp string.
357  *
358  * @param s AVFormatContext
359  * @param key metadata key
360  * @param timestamp unix timestamp in microseconds
361  * @return <0 on error
362  */
363 int avpriv_dict_set_timestamp(AVDictionary **dict, const char *key, int64_t timestamp);
364 
365 // Helper macro for AV_PIX_FMT_FLAG_PSEUDOPAL deprecation. Code inside FFmpeg
366 // should always use FF_PSEUDOPAL. Once the public API flag gets removed, all
367 // code using it is dead code.
368 #if FF_API_PSEUDOPAL
369 #define FF_PSEUDOPAL AV_PIX_FMT_FLAG_PSEUDOPAL
370 #else
371 #define FF_PSEUDOPAL 0
372 #endif
373 
374 #endif /* AVUTIL_INTERNAL_H */
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
libm.h
avpriv_set_systematic_pal2
int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt)
Definition: imgutils.c:152
w
uint8_t w
Definition: llviddspenc.c:38
av_const
#define av_const
Definition: attributes.h:78
AVDictionary
Definition: dict.c:30
macros.h
avpriv_tempfile
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
limits.h
pix_fmt
static enum AVPixelFormat pix_fmt
Definition: demuxing_decoding.c:40
avpriv_request_sample
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
key
const char * key
Definition: hwcontext_opencl.c:168
av_printf_format
#define av_printf_format(fmtpos, attrpos)
Definition: attributes.h:155
timer.h
avpriv_mirror
static av_always_inline av_const int avpriv_mirror(int x, int w)
Definition: internal.h:340
cpu.h
avpriv_report_missing_feature
void avpriv_report_missing_feature(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
a
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:41
avpriv_dict_set_timestamp
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
attributes.h
ff_check_pixfmt_descriptors
void ff_check_pixfmt_descriptors(void)
Definition: pixdesc.c:2577
av_warn_unused_result
#define av_warn_unused_result
Definition: attributes.h:58
emms.h
av_always_inline
#define av_always_inline
Definition: attributes.h:43
version.h
pixfmt.h
dict.h
config.h
mem.h
llrint
#define llrint(x)
Definition: libm.h:394
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:565
ff_rint64_clip
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:297
avpriv_open
av_warn_unused_result int avpriv_open(const char *filename, int flags,...)
A wrapper for open() setting O_CLOEXEC.
Definition: file_open.c:66