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Diffstat (limited to 'src/main/jni/libwebp/utils/utils.h')
-rw-r--r-- | src/main/jni/libwebp/utils/utils.h | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/src/main/jni/libwebp/utils/utils.h b/src/main/jni/libwebp/utils/utils.h new file mode 100644 index 000000000..f2c498a9d --- /dev/null +++ b/src/main/jni/libwebp/utils/utils.h @@ -0,0 +1,121 @@ +// 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_ + +#include <assert.h> + +#include "../webp/types.h" + +#ifdef __cplusplus +extern "C" { +#endif + +//------------------------------------------------------------------------------ +// Memory allocation + +// This is the maximum memory amount that libwebp will ever try to allocate. +#define WEBP_MAX_ALLOCABLE_MEMORY (1ULL << 40) + +// 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); + +//------------------------------------------------------------------------------ +// 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 (uint32_t)GetLE16(data) | (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); + data[1] = (val >> 8); +} + +static WEBP_INLINE void PutLE24(uint8_t* const data, int val) { + assert(val < (1 << 24)); + PutLE16(data, val & 0xffff); + data[2] = (val >> 16); +} + +static WEBP_INLINE void PutLE32(uint8_t* const data, uint32_t val) { + PutLE16(data, (int)(val & 0xffff)); + PutLE16(data + 2, (int)(val >> 16)); +} + +// Returns (int)floor(log2(n)). n must be > 0. +// use GNU builtins where available. +#if defined(__GNUC__) && \ + ((__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || __GNUC__ >= 4) +static WEBP_INLINE int BitsLog2Floor(uint32_t n) { + return 31 ^ __builtin_clz(n); +} +#elif defined(_MSC_VER) && _MSC_VER > 1310 && \ + (defined(_M_X64) || defined(_M_IX86)) +#include <intrin.h> +#pragma intrinsic(_BitScanReverse) + +static WEBP_INLINE int BitsLog2Floor(uint32_t n) { + uint32_t first_set_bit; + _BitScanReverse(&first_set_bit, n); + return first_set_bit; +} +#else +static WEBP_INLINE int BitsLog2Floor(uint32_t n) { + int log = 0; + uint32_t value = n; + int i; + + for (i = 4; i >= 0; --i) { + const int shift = (1 << i); + const uint32_t x = value >> shift; + if (x != 0) { + value = x; + log += shift; + } + } + return log; +} +#endif + +//------------------------------------------------------------------------------ + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif /* WEBP_UTILS_UTILS_H_ */ |