1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
// Copyright 2012 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// Misc. common utility functions
//
// Authors: Skal (pascal.massimino@gmail.com)
// Urvang (urvang@google.com)
#ifndef WEBP_UTILS_UTILS_H_
#define WEBP_UTILS_UTILS_H_
#ifdef HAVE_CONFIG_H
#include "src/webp/config.h"
#endif
#include <assert.h>
#include <limits.h>
#include "src/dsp/dsp.h"
#include "src/webp/types.h"
#ifdef __cplusplus
extern "C" {
#endif
//------------------------------------------------------------------------------
// Memory allocation
// This is the maximum memory amount that libwebp will ever try to allocate.
#ifndef WEBP_MAX_ALLOCABLE_MEMORY
#if SIZE_MAX > (1ULL << 34)
#define WEBP_MAX_ALLOCABLE_MEMORY (1ULL << 34)
#else
// For 32-bit targets keep this below INT_MAX to avoid valgrind warnings.
#define WEBP_MAX_ALLOCABLE_MEMORY ((1ULL << 31) - (1 << 16))
#endif
#endif // WEBP_MAX_ALLOCABLE_MEMORY
static WEBP_INLINE int CheckSizeOverflow(uint64_t size) {
return size == (size_t)size;
}
// size-checking safe malloc/calloc: verify that the requested size is not too
// large, or return NULL. You don't need to call these for constructs like
// malloc(sizeof(foo)), but only if there's picture-dependent size involved
// somewhere (like: malloc(num_pixels * sizeof(*something))). That's why this
// safe malloc() borrows the signature from calloc(), pointing at the dangerous
// underlying multiply involved.
WEBP_EXTERN void* WebPSafeMalloc(uint64_t nmemb, size_t size);
// Note that WebPSafeCalloc() expects the second argument type to be 'size_t'
// in order to favor the "calloc(num_foo, sizeof(foo))" pattern.
WEBP_EXTERN void* WebPSafeCalloc(uint64_t nmemb, size_t size);
// Companion deallocation function to the above allocations.
WEBP_EXTERN void WebPSafeFree(void* const ptr);
//------------------------------------------------------------------------------
// Alignment
#define WEBP_ALIGN_CST 31
#define WEBP_ALIGN(PTR) (((uintptr_t)(PTR) + WEBP_ALIGN_CST) & ~WEBP_ALIGN_CST)
#include <string.h>
// memcpy() is the safe way of moving potentially unaligned 32b memory.
static WEBP_INLINE uint32_t WebPMemToUint32(const uint8_t* const ptr) {
uint32_t A;
memcpy(&A, ptr, sizeof(A));
return A;
}
static WEBP_INLINE void WebPUint32ToMem(uint8_t* const ptr, uint32_t val) {
memcpy(ptr, &val, sizeof(val));
}
//------------------------------------------------------------------------------
// Reading/writing data.
// Read 16, 24 or 32 bits stored in little-endian order.
static WEBP_INLINE int GetLE16(const uint8_t* const data) {
return (int)(data[0] << 0) | (data[1] << 8);
}
static WEBP_INLINE int GetLE24(const uint8_t* const data) {
return GetLE16(data) | (data[2] << 16);
}
static WEBP_INLINE uint32_t GetLE32(const uint8_t* const data) {
return GetLE16(data) | ((uint32_t)GetLE16(data + 2) << 16);
}
// Store 16, 24 or 32 bits in little-endian order.
static WEBP_INLINE void PutLE16(uint8_t* const data, int val) {
assert(val < (1 << 16));
data[0] = (val >> 0) & 0xff;
data[1] = (val >> 8) & 0xff;
}
static WEBP_INLINE void PutLE24(uint8_t* const data, int val) {
assert(val < (1 << 24));
PutLE16(data, val & 0xffff);
data[2] = (val >> 16) & 0xff;
}
static WEBP_INLINE void PutLE32(uint8_t* const data, uint32_t val) {
PutLE16(data, (int)(val & 0xffff));
PutLE16(data + 2, (int)(val >> 16));
}
// use GNU builtins where available.
#if defined(__GNUC__) && \
((__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || __GNUC__ >= 4)
// Returns (int)floor(log2(n)). n must be > 0.
static WEBP_INLINE int BitsLog2Floor(uint32_t n) {
return 31 ^ __builtin_clz(n);
}
// counts the number of trailing zero
static WEBP_INLINE int BitsCtz(uint32_t n) { return __builtin_ctz(n); }
#elif defined(_MSC_VER) && _MSC_VER > 1310 && \
(defined(_M_X64) || defined(_M_IX86))
#include <intrin.h>
#pragma intrinsic(_BitScanReverse)
#pragma intrinsic(_BitScanForward)
static WEBP_INLINE int BitsLog2Floor(uint32_t n) {
unsigned long first_set_bit; // NOLINT (runtime/int)
_BitScanReverse(&first_set_bit, n);
return first_set_bit;
}
static WEBP_INLINE int BitsCtz(uint32_t n) {
unsigned long first_set_bit; // NOLINT (runtime/int)
_BitScanForward(&first_set_bit, n);
return first_set_bit;
}
#else // default: use the (slow) C-version.
#define WEBP_HAVE_SLOW_CLZ_CTZ // signal that the Clz/Ctz function are slow
// Returns 31 ^ clz(n) = log2(n). This is the default C-implementation, either
// based on table or not. Can be used as fallback if clz() is not available.
#define WEBP_NEED_LOG_TABLE_8BIT
extern const uint8_t WebPLogTable8bit[256];
static WEBP_INLINE int WebPLog2FloorC(uint32_t n) {
int log_value = 0;
while (n >= 256) {
log_value += 8;
n >>= 8;
}
return log_value + WebPLogTable8bit[n];
}
static WEBP_INLINE int BitsLog2Floor(uint32_t n) { return WebPLog2FloorC(n); }
static WEBP_INLINE int BitsCtz(uint32_t n) {
int i;
for (i = 0; i < 32; ++i, n >>= 1) {
if (n & 1) return i;
}
return 32;
}
#endif
//------------------------------------------------------------------------------
// Pixel copying.
struct WebPPicture;
// Copy width x height pixels from 'src' to 'dst' honoring the strides.
WEBP_EXTERN void WebPCopyPlane(const uint8_t* src, int src_stride,
uint8_t* dst, int dst_stride,
int width, int height);
// Copy ARGB pixels from 'src' to 'dst' honoring strides. 'src' and 'dst' are
// assumed to be already allocated and using ARGB data.
WEBP_EXTERN void WebPCopyPixels(const struct WebPPicture* const src,
struct WebPPicture* const dst);
//------------------------------------------------------------------------------
// Unique colors.
// Returns count of unique colors in 'pic', assuming pic->use_argb is true.
// If the unique color count is more than MAX_PALETTE_SIZE, returns
// MAX_PALETTE_SIZE+1.
// If 'palette' is not NULL and number of unique colors is less than or equal to
// MAX_PALETTE_SIZE, also outputs the actual unique colors into 'palette'.
// Note: 'palette' is assumed to be an array already allocated with at least
// MAX_PALETTE_SIZE elements.
WEBP_EXTERN int WebPGetColorPalette(const struct WebPPicture* const pic,
uint32_t* const palette);
//------------------------------------------------------------------------------
#ifdef __cplusplus
} // extern "C"
#endif
#endif // WEBP_UTILS_UTILS_H_
|
