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