1// Copyright 2012 Google Inc. All Rights Reserved. 2// 3// This code is licensed under the same terms as WebM: 4// Software License Agreement: http://www.webmproject.org/license/software/ 5// Additional IP Rights Grant: http://www.webmproject.org/license/additional/ 6// ----------------------------------------------------------------------------- 7// 8// Misc. common utility functions 9// 10// Authors: Skal (pascal.massimino@gmail.com) 11// Urvang (urvang@google.com) 12 13#ifndef WEBP_UTILS_UTILS_H_ 14#define WEBP_UTILS_UTILS_H_ 15 16#include <assert.h> 17 18#include "webp/types.h" 19 20#if defined(__cplusplus) || defined(c_plusplus) 21extern "C" { 22#endif 23 24//------------------------------------------------------------------------------ 25// Memory allocation 26 27// This is the maximum memory amount that libwebp will ever try to allocate. 28#define WEBP_MAX_ALLOCABLE_MEMORY (1ULL << 40) 29 30// size-checking safe malloc/calloc: verify that the requested size is not too 31// large, or return NULL. You don't need to call these for constructs like 32// malloc(sizeof(foo)), but only if there's picture-dependent size involved 33// somewhere (like: malloc(num_pixels * sizeof(*something))). That's why this 34// safe malloc() borrows the signature from calloc(), pointing at the dangerous 35// underlying multiply involved. 36void* WebPSafeMalloc(uint64_t nmemb, size_t size); 37// Note that WebPSafeCalloc() expects the second argument type to be 'size_t' 38// in order to favor the "calloc(num_foo, sizeof(foo))" pattern. 39void* WebPSafeCalloc(uint64_t nmemb, size_t size); 40 41//------------------------------------------------------------------------------ 42// Reading/writing data. 43 44// Read 16, 24 or 32 bits stored in little-endian order. 45static WEBP_INLINE int GetLE16(const uint8_t* const data) { 46 return (int)(data[0] << 0) | (data[1] << 8); 47} 48 49static WEBP_INLINE int GetLE24(const uint8_t* const data) { 50 return GetLE16(data) | (data[2] << 16); 51} 52 53static WEBP_INLINE uint32_t GetLE32(const uint8_t* const data) { 54 return (uint32_t)GetLE16(data) | (GetLE16(data + 2) << 16); 55} 56 57// Store 16, 24 or 32 bits in little-endian order. 58static WEBP_INLINE void PutLE16(uint8_t* const data, int val) { 59 assert(val < (1 << 16)); 60 data[0] = (val >> 0); 61 data[1] = (val >> 8); 62} 63 64static WEBP_INLINE void PutLE24(uint8_t* const data, int val) { 65 assert(val < (1 << 24)); 66 PutLE16(data, val & 0xffff); 67 data[2] = (val >> 16); 68} 69 70static WEBP_INLINE void PutLE32(uint8_t* const data, uint32_t val) { 71 PutLE16(data, (int)(val & 0xffff)); 72 PutLE16(data + 2, (int)(val >> 16)); 73} 74 75//------------------------------------------------------------------------------ 76 77#if defined(__cplusplus) || defined(c_plusplus) 78} // extern "C" 79#endif 80 81#endif /* WEBP_UTILS_UTILS_H_ */ 82