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