1/*
2 *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include "webrtc/modules/desktop_capture/differ_block.h"
12
13#include <string.h>
14
15#include "build/build_config.h"
16#include "webrtc/modules/desktop_capture/differ_block_sse2.h"
17#include "webrtc/system_wrappers/interface/cpu_features_wrapper.h"
18
19namespace webrtc {
20
21int BlockDifference_C(const uint8_t* image1,
22                      const uint8_t* image2,
23                      int stride) {
24  int width_bytes = kBlockSize * kBytesPerPixel;
25
26  for (int y = 0; y < kBlockSize; y++) {
27    if (memcmp(image1, image2, width_bytes) != 0)
28      return 1;
29    image1 += stride;
30    image2 += stride;
31  }
32  return 0;
33}
34
35int BlockDifference(const uint8_t* image1, const uint8_t* image2, int stride) {
36  static int (*diff_proc)(const uint8_t*, const uint8_t*, int) = NULL;
37
38  if (!diff_proc) {
39#if defined(ARCH_CPU_ARM_FAMILY) || defined(ARCH_CPU_MIPS_FAMILY)
40    // For ARM and MIPS processors, always use C version.
41    // TODO(hclam): Implement a NEON version.
42    diff_proc = &BlockDifference_C;
43#else
44    bool have_sse2 = WebRtc_GetCPUInfo(kSSE2) != 0;
45    // For x86 processors, check if SSE2 is supported.
46    if (have_sse2 && kBlockSize == 32) {
47      diff_proc = &BlockDifference_SSE2_W32;
48    } else if (have_sse2 && kBlockSize == 16) {
49      diff_proc = &BlockDifference_SSE2_W16;
50    } else {
51      diff_proc = &BlockDifference_C;
52    }
53#endif
54  }
55
56  return diff_proc(image1, image2, stride);
57}
58
59}  // namespace webrtc
60