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-rw-r--r-- | media/libwebp/src/utils/utils.h | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/media/libwebp/src/utils/utils.h b/media/libwebp/src/utils/utils.h new file mode 100644 index 0000000000..ef04f108fe --- /dev/null +++ b/media/libwebp/src/utils/utils.h @@ -0,0 +1,200 @@ +// 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_ |