xref: /third_party/ffmpeg/libavutil/internal.h (revision cabdff1a)
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 <stdio.h>
41#include "config.h"
42#include "attributes.h"
43#include "timer.h"
44#include "dict.h"
45#include "macros.h"
46#include "pixfmt.h"
47
48#if ARCH_X86
49#   include "x86/emms.h"
50#endif
51
52#ifndef emms_c
53#   define emms_c() do {} while(0)
54#endif
55
56#ifndef attribute_align_arg
57#if ARCH_X86_32 && AV_GCC_VERSION_AT_LEAST(4,2)
58#    define attribute_align_arg __attribute__((force_align_arg_pointer))
59#else
60#    define attribute_align_arg
61#endif
62#endif
63
64#if defined(_WIN32) && CONFIG_SHARED && !defined(BUILDING_avutil)
65#    define av_export_avutil __declspec(dllimport)
66#else
67#    define av_export_avutil
68#endif
69
70#if HAVE_PRAGMA_DEPRECATED
71#    if defined(__ICL) || defined (__INTEL_COMPILER)
72#        define FF_DISABLE_DEPRECATION_WARNINGS __pragma(warning(push)) __pragma(warning(disable:1478))
73#        define FF_ENABLE_DEPRECATION_WARNINGS  __pragma(warning(pop))
74#    elif defined(_MSC_VER)
75#        define FF_DISABLE_DEPRECATION_WARNINGS __pragma(warning(push)) __pragma(warning(disable:4996))
76#        define FF_ENABLE_DEPRECATION_WARNINGS  __pragma(warning(pop))
77#    else
78#        define FF_DISABLE_DEPRECATION_WARNINGS _Pragma("GCC diagnostic push") _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
79#        define FF_ENABLE_DEPRECATION_WARNINGS  _Pragma("GCC diagnostic pop")
80#    endif
81#else
82#    define FF_DISABLE_DEPRECATION_WARNINGS
83#    define FF_ENABLE_DEPRECATION_WARNINGS
84#endif
85
86
87#define FF_MEMORY_POISON 0x2a
88
89/* Check if the hard coded offset of a struct member still matches reality.
90 * Induce a compilation failure if not.
91 */
92#define AV_CHECK_OFFSET(s, m, o) struct check_##o {    \
93        int x_##o[offsetof(s, m) == o? 1: -1];         \
94    }
95
96
97#define FF_ALLOC_TYPED_ARRAY(p, nelem)  (p = av_malloc_array(nelem, sizeof(*p)))
98#define FF_ALLOCZ_TYPED_ARRAY(p, nelem) (p = av_calloc(nelem, sizeof(*p)))
99
100#define FF_PTR_ADD(ptr, off) ((off) ? (ptr) + (off) : (ptr))
101
102/**
103 * Access a field in a structure by its offset.
104 */
105#define FF_FIELD_AT(type, off, obj) (*(type *)((char *)&(obj) + (off)))
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 */
166void 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 */
177void 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_fopen_utf8 ff_fopen_utf8
188#define avpriv_open ff_open
189#define avpriv_tempfile ff_tempfile
190
191#define PTRDIFF_SPECIFIER "Id"
192#define SIZE_SPECIFIER "Iu"
193#else
194#define PTRDIFF_SPECIFIER "td"
195#define SIZE_SPECIFIER "zu"
196#endif
197
198#ifdef DEBUG
199#   define ff_dlog(ctx, ...) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__)
200#else
201#   define ff_dlog(ctx, ...) do { if (0) av_log(ctx, AV_LOG_DEBUG, __VA_ARGS__); } while (0)
202#endif
203
204#ifdef TRACE
205#   define ff_tlog(ctx, ...) av_log(ctx, AV_LOG_TRACE, __VA_ARGS__)
206#else
207#   define ff_tlog(ctx, ...) do { } while(0)
208#endif
209
210// For debuging we use signed operations so overflows can be detected (by ubsan)
211// For production we use unsigned so there are no undefined operations
212#ifdef CHECKED
213#define SUINT   int
214#define SUINT32 int32_t
215#else
216#define SUINT   unsigned
217#define SUINT32 uint32_t
218#endif
219
220/**
221 * Clip and convert a double value into the long long amin-amax range.
222 * This function is needed because conversion of floating point to integers when
223 * it does not fit in the integer's representation does not necessarily saturate
224 * correctly (usually converted to a cvttsd2si on x86) which saturates numbers
225 * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined
226 * behavior, allowing this sort of mathematically bogus conversions. This provides
227 * a safe alternative that is slower obviously but assures safety and better
228 * mathematical behavior.
229 * @param a value to clip
230 * @param amin minimum value of the clip range
231 * @param amax maximum value of the clip range
232 * @return clipped value
233 */
234static av_always_inline av_const int64_t ff_rint64_clip(double a, int64_t amin, int64_t amax)
235{
236    int64_t res;
237#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
238    if (amin > amax) abort();
239#endif
240    // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles
241    // do range checks first
242    if (a >=  9223372036854775808.0)
243        return amax;
244    if (a <= -9223372036854775808.0)
245        return amin;
246
247    // safe to call llrint and clip accordingly
248    res = llrint(a);
249    if (res > amax)
250        return amax;
251    if (res < amin)
252        return amin;
253    return res;
254}
255
256/**
257 * A wrapper for open() setting O_CLOEXEC.
258 */
259av_warn_unused_result
260int avpriv_open(const char *filename, int flags, ...);
261
262/**
263 * Open a file using a UTF-8 filename.
264 */
265FILE *avpriv_fopen_utf8(const char *path, const char *mode);
266
267/**
268 * Wrapper to work around the lack of mkstemp() on mingw.
269 * Also, tries to create file in /tmp first, if possible.
270 * *prefix can be a character constant; *filename will be allocated internally.
271 * @return file descriptor of opened file (or negative value corresponding to an
272 * AVERROR code on error)
273 * and opened file name in **filename.
274 * @note On very old libcs it is necessary to set a secure umask before
275 *       calling this, av_tempfile() can't call umask itself as it is used in
276 *       libraries and could interfere with the calling application.
277 */
278int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx);
279
280int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt);
281
282static av_always_inline av_const int avpriv_mirror(int x, int w)
283{
284    if (!w)
285        return 0;
286
287    while ((unsigned)x > (unsigned)w) {
288        x = -x;
289        if (x < 0)
290            x += 2 * w;
291    }
292    return x;
293}
294
295void ff_check_pixfmt_descriptors(void);
296
297/**
298 * Set a dictionary value to an ISO-8601 compliant timestamp string.
299 *
300 * @param dict pointer to a pointer to a dictionary struct. If *dict is NULL
301 *             a dictionary struct is allocated and put in *dict.
302 * @param key metadata key
303 * @param timestamp unix timestamp in microseconds
304 * @return <0 on error
305 */
306int avpriv_dict_set_timestamp(AVDictionary **dict, const char *key, int64_t timestamp);
307
308#endif /* AVUTIL_INTERNAL_H */
309