/* *  Copyright 2012 The LibYuv Project Authors. All rights reserved. * *  Use of this source code is governed by a BSD-style license *  that can be found in the LICENSE 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. */ #include "libyuv/basic_types.h" #include "libyuv/compare_row.h" #ifdef __cplusplusnamespace libyuv {extern "C" {#endif #if ORIGINAL_OPTuint32_t HammingDistance_C1(const uint8_t* src_a,                            const uint8_t* src_b,                            int count) {  uint32_t diff = 0u;   int i;  for (i = 0; i < count; ++i) {    int x = src_a[i] ^ src_b[i];    if (x & 1)      ++diff;    if (x & 2)      ++diff;    if (x & 4)      ++diff;    if (x & 8)      ++diff;    if (x & 16)      ++diff;    if (x & 32)      ++diff;    if (x & 64)      ++diff;    if (x & 128)      ++diff;  }  return diff;}#endif // Hakmem method for hamming distance.uint32_t HammingDistance_C(const uint8_t* src_a,                           const uint8_t* src_b,                           int count) {  uint32_t diff = 0u;   int i;  for (i = 0; i < count - 3; i += 4) {    uint32_t x = *((const uint32_t*)src_a) ^ *((const uint32_t*)src_b);    uint32_t u = x - ((x >> 1) & 0x55555555);    u = ((u >> 2) & 0x33333333) + (u & 0x33333333);    diff += ((((u + (u >> 4)) & 0x0f0f0f0f) * 0x01010101) >> 24);    src_a += 4;    src_b += 4;  }   for (; i < count; ++i) {    uint32_t x = *src_a ^ *src_b;    uint32_t u = x - ((x >> 1) & 0x55);    u = ((u >> 2) & 0x33) + (u & 0x33);    diff += (u + (u >> 4)) & 0x0f;    src_a += 1;    src_b += 1;  }   return diff;} uint32_t SumSquareError_C(const uint8_t* src_a,                          const uint8_t* src_b,                          int count) {  uint32_t sse = 0u;  int i;  for (i = 0; i < count; ++i) {    int diff = src_a[i] - src_b[i];    sse += (uint32_t)(diff * diff);  }  return sse;} // hash seed of 5381 recommended.// Internal C version of HashDjb2 with int sized count for efficiency.uint32_t HashDjb2_C(const uint8_t* src, int count, uint32_t seed) {  uint32_t hash = seed;  int i;  for (i = 0; i < count; ++i) {    hash += (hash << 5) + src[i];  }  return hash;} #ifdef __cplusplus}  // extern "C"}  // namespace libyuv#endif