142 lines
4.5 KiB
C
142 lines
4.5 KiB
C
// 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);
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Alignment
|
|
|
|
#define WEBP_ALIGN_CST 31
|
|
#define WEBP_ALIGN(PTR) ((uintptr_t)((PTR) + WEBP_ALIGN_CST) & ~WEBP_ALIGN_CST)
|
|
|
|
//------------------------------------------------------------------------------
|
|
// 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);
|
|
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) {
|
|
unsigned long 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
|
|
|
|
//------------------------------------------------------------------------------
|
|
// 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);
|
|
|
|
//------------------------------------------------------------------------------
|
|
|
|
#ifdef __cplusplus
|
|
} // extern "C"
|
|
#endif
|
|
|
|
#endif /* WEBP_UTILS_UTILS_H_ */
|