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 "modules/desktop_capture/differ_block.h"
12
13 #include <string.h>
14
15 #include "rtc_base/system/arch.h"
16 #include "system_wrappers/include/cpu_features_wrapper.h"
17
18 // This needs to be after rtc_base/system/arch.h which defines
19 // architecture macros.
20 #if defined(WEBRTC_ARCH_X86_FAMILY)
21 #include "modules/desktop_capture/differ_vector_sse2.h"
22 #endif
23
24 namespace webrtc {
25
26 namespace {
27
VectorDifference_C(const uint8_t * image1,const uint8_t * image2)28 bool VectorDifference_C(const uint8_t* image1, const uint8_t* image2) {
29 return memcmp(image1, image2, kBlockSize * kBytesPerPixel) != 0;
30 }
31
32 } // namespace
33
VectorDifference(const uint8_t * image1,const uint8_t * image2)34 bool VectorDifference(const uint8_t* image1, const uint8_t* image2) {
35 static bool (*diff_proc)(const uint8_t*, const uint8_t*) = nullptr;
36
37 if (!diff_proc) {
38 #if defined(WEBRTC_ARCH_X86_FAMILY)
39 bool have_sse2 = GetCPUInfo(kSSE2) != 0;
40 // For x86 processors, check if SSE2 is supported.
41 if (have_sse2 && kBlockSize == 32) {
42 diff_proc = &VectorDifference_SSE2_W32;
43 } else if (have_sse2 && kBlockSize == 16) {
44 diff_proc = &VectorDifference_SSE2_W16;
45 } else {
46 diff_proc = &VectorDifference_C;
47 }
48 #else
49 // For other processors, always use C version.
50 // TODO(hclam): Implement a NEON version.
51 diff_proc = &VectorDifference_C;
52 #endif
53 }
54
55 return diff_proc(image1, image2);
56 }
57
BlockDifference(const uint8_t * image1,const uint8_t * image2,int height,int stride)58 bool BlockDifference(const uint8_t* image1,
59 const uint8_t* image2,
60 int height,
61 int stride) {
62 for (int i = 0; i < height; i++) {
63 if (VectorDifference(image1, image2)) {
64 return true;
65 }
66 image1 += stride;
67 image2 += stride;
68 }
69 return false;
70 }
71
BlockDifference(const uint8_t * image1,const uint8_t * image2,int stride)72 bool BlockDifference(const uint8_t* image1, const uint8_t* image2, int stride) {
73 return BlockDifference(image1, image2, kBlockSize, stride);
74 }
75
76 } // namespace webrtc
77