summaryrefslogtreecommitdiffstats
path: root/media/libvpx/libvpx/third_party/libyuv/source/compare_common.cc
diff options
context:
space:
mode:
Diffstat (limited to 'media/libvpx/libvpx/third_party/libyuv/source/compare_common.cc')
-rw-r--r--media/libvpx/libvpx/third_party/libyuv/source/compare_common.cc104
1 files changed, 104 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/third_party/libyuv/source/compare_common.cc b/media/libvpx/libvpx/third_party/libyuv/source/compare_common.cc
new file mode 100644
index 0000000000..d4b170ad98
--- /dev/null
+++ b/media/libvpx/libvpx/third_party/libyuv/source/compare_common.cc
@@ -0,0 +1,104 @@
+/*
+ * 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 __cplusplus
+namespace libyuv {
+extern "C" {
+#endif
+
+#if ORIGINAL_OPT
+uint32_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