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 (at) gmail.com) 13 // Urvang (urvang (at) google.com) 14 15 #ifndef WEBP_UTILS_UTILS_H_ 16 #define WEBP_UTILS_UTILS_H_ 17 18 #include <assert.h> 19 20 #include "webp/types.h" 21 22 #if defined(__cplusplus) || defined(c_plusplus) 23 extern "C" { 24 #endif 25 26 //------------------------------------------------------------------------------ 27 // Memory allocation 28 29 // This is the maximum memory amount that libwebp will ever try to allocate. 30 #define WEBP_MAX_ALLOCABLE_MEMORY (1ULL << 40) 31 32 // size-checking safe malloc/calloc: verify that the requested size is not too 33 // large, or return NULL. You don't need to call these for constructs like 34 // malloc(sizeof(foo)), but only if there's picture-dependent size involved 35 // somewhere (like: malloc(num_pixels * sizeof(*something))). That's why this 36 // safe malloc() borrows the signature from calloc(), pointing at the dangerous 37 // underlying multiply involved. 38 void* WebPSafeMalloc(uint64_t nmemb, size_t size); 39 // Note that WebPSafeCalloc() expects the second argument type to be 'size_t' 40 // in order to favor the "calloc(num_foo, sizeof(foo))" pattern. 41 void* WebPSafeCalloc(uint64_t nmemb, size_t size); 42 43 //------------------------------------------------------------------------------ 44 // Reading/writing data. 45 46 // Read 16, 24 or 32 bits stored in little-endian order. 47 static WEBP_INLINE int GetLE16(const uint8_t* const data) { 48 return (int)(data[0] << 0) | (data[1] << 8); 49 } 50 51 static WEBP_INLINE int GetLE24(const uint8_t* const data) { 52 return GetLE16(data) | (data[2] << 16); 53 } 54 55 static WEBP_INLINE uint32_t GetLE32(const uint8_t* const data) { 56 return (uint32_t)GetLE16(data) | (GetLE16(data + 2) << 16); 57 } 58 59 // Store 16, 24 or 32 bits in little-endian order. 60 static WEBP_INLINE void PutLE16(uint8_t* const data, int val) { 61 assert(val < (1 << 16)); 62 data[0] = (val >> 0); 63 data[1] = (val >> 8); 64 } 65 66 static WEBP_INLINE void PutLE24(uint8_t* const data, int val) { 67 assert(val < (1 << 24)); 68 PutLE16(data, val & 0xffff); 69 data[2] = (val >> 16); 70 } 71 72 static WEBP_INLINE void PutLE32(uint8_t* const data, uint32_t val) { 73 PutLE16(data, (int)(val & 0xffff)); 74 PutLE16(data + 2, (int)(val >> 16)); 75 } 76 77 //------------------------------------------------------------------------------ 78 79 #if defined(__cplusplus) || defined(c_plusplus) 80 } // extern "C" 81 #endif 82 83 #endif /* WEBP_UTILS_UTILS_H_ */ 84
