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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 #include <limits.h>
34 #include <stdint.h>
35 #include <stddef.h>
36 #include <assert.h>
37 #include "config.h"
38 #include "attributes.h"
39 #include "timer.h"
40 #include "cpu.h"
41 #include "dict.h"
42 
43 #if ARCH_X86
44 # include "x86/emms.h"
45 #endif
46 
47 #ifndef emms_c
48 # define emms_c()
49 #endif
50 
51 #ifndef attribute_align_arg
52 #if ARCH_X86_32 && AV_GCC_VERSION_AT_LEAST(4,2)
53 # define attribute_align_arg __attribute__((force_align_arg_pointer))
54 #else
55 # define attribute_align_arg
56 #endif
57 #endif
58 
59 #if defined(_MSC_VER) && CONFIG_SHARED
60 # define av_export __declspec(dllimport)
61 #else
62 # define av_export
63 #endif
64 
65 #ifndef INT_BIT
66 # define INT_BIT (CHAR_BIT * sizeof(int))
67 #endif
68 
69 // Some broken preprocessors need a second expansion
70 // to be forced to tokenize __VA_ARGS__
71 #define E1(x) x
72 
73 #define LOCAL_ALIGNED_A(a, t, v, s, o, ...) \
74  uint8_t la_##v[sizeof(t s o) + (a)]; \
75  t (*v) o = (void *)FFALIGN((uintptr_t)la_##v, a)
76 
77 #define LOCAL_ALIGNED_D(a, t, v, s, o, ...) \
78  DECLARE_ALIGNED(a, t, la_##v) s o; \
79  t (*v) o = la_##v
80 
81 #define LOCAL_ALIGNED(a, t, v, ...) E1(LOCAL_ALIGNED_A(a, t, v, __VA_ARGS__,,))
82 
83 #if HAVE_LOCAL_ALIGNED_8
84 # define LOCAL_ALIGNED_8(t, v, ...) E1(LOCAL_ALIGNED_D(8, t, v, __VA_ARGS__,,))
85 #else
86 # define LOCAL_ALIGNED_8(t, v, ...) LOCAL_ALIGNED(8, t, v, __VA_ARGS__)
87 #endif
88 
89 #if HAVE_LOCAL_ALIGNED_16
90 # define LOCAL_ALIGNED_16(t, v, ...) E1(LOCAL_ALIGNED_D(16, t, v, __VA_ARGS__,,))
91 #else
92 # define LOCAL_ALIGNED_16(t, v, ...) LOCAL_ALIGNED(16, t, v, __VA_ARGS__)
93 #endif
94 
95 #define FF_ALLOC_OR_GOTO(ctx, p, size, label)\
96 {\
97  p = av_malloc(size);\
98  if (p == NULL && (size) != 0) {\
99  av_log(ctx, AV_LOG_ERROR, "Cannot allocate memory.\n");\
100  goto label;\
101  }\
102 }
103 
104 #define FF_ALLOCZ_OR_GOTO(ctx, p, size, label)\
105 {\
106  p = av_mallocz(size);\
107  if (p == NULL && (size) != 0) {\
108  av_log(ctx, AV_LOG_ERROR, "Cannot allocate memory.\n");\
109  goto label;\
110  }\
111 }
112 
113 #include "libm.h"
114 
115 /**
116  * Return NULL if CONFIG_SMALL is true, otherwise the argument
117  * without modification. Used to disable the definition of strings
118  * (for example AVCodec long_names).
119  */
120 #if CONFIG_SMALL
121 # define NULL_IF_CONFIG_SMALL(x) NULL
122 #else
123 # define NULL_IF_CONFIG_SMALL(x) x
124 #endif
125 
126 /**
127  * Define a function with only the non-default version specified.
128  *
129  * On systems with ELF shared libraries, all symbols exported from
130  * FFmpeg libraries are tagged with the name and major version of the
131  * library to which they belong. If a function is moved from one
132  * library to another, a wrapper must be retained in the original
133  * location to preserve binary compatibility.
134  *
135  * Functions defined with this macro will never be used to resolve
136  * symbols by the build-time linker.
137  *
138  * @param type return type of function
139  * @param name name of function
140  * @param args argument list of function
141  * @param ver version tag to assign function
142  */
143 #if HAVE_SYMVER_ASM_LABEL
144 # define FF_SYMVER(type, name, args, ver) \
145  type ff_##name args __asm__ (EXTERN_PREFIX #name "@" ver); \
146  type ff_##name args
147 #elif HAVE_SYMVER_GNU_ASM
148 # define FF_SYMVER(type, name, args, ver) \
149  __asm__ (".symver ff_" #name "," EXTERN_PREFIX #name "@" ver); \
150  type ff_##name args; \
151  type ff_##name args
152 #endif
153 
154 /**
155  * Return NULL if a threading library has not been enabled.
156  * Used to disable threading functions in AVCodec definitions
157  * when not needed.
158  */
159 #if HAVE_THREADS
160 # define ONLY_IF_THREADS_ENABLED(x) x
161 #else
162 # define ONLY_IF_THREADS_ENABLED(x) NULL
163 #endif
164 
165 #endif /* AVUTIL_INTERNAL_H */