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 "webrtc/typedefs.h"
16 #include "webrtc/modules/desktop_capture/differ_block_sse2.h"
17 #include "webrtc/system_wrappers/include/cpu_features_wrapper.h"
18
19 namespace webrtc {
20
BlockDifference_C(const uint8_t * image1,const uint8_t * image2,int stride)21 bool 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 true;
29 image1 += stride;
30 image2 += stride;
31 }
32 return false;
33 }
34
BlockDifference(const uint8_t * image1,const uint8_t * image2,int stride)35 bool BlockDifference(const uint8_t* image1,
36 const uint8_t* image2,
37 int stride) {
38 static bool (*diff_proc)(const uint8_t*, const uint8_t*, int) = NULL;
39
40 if (!diff_proc) {
41 #if defined(WEBRTC_ARCH_ARM_FAMILY) || defined(WEBRTC_ARCH_MIPS_FAMILY)
42 // For ARM and MIPS processors, always use C version.
43 // TODO(hclam): Implement a NEON version.
44 diff_proc = &BlockDifference_C;
45 #else
46 bool have_sse2 = WebRtc_GetCPUInfo(kSSE2) != 0;
47 // For x86 processors, check if SSE2 is supported.
48 if (have_sse2 && kBlockSize == 32) {
49 diff_proc = &BlockDifference_SSE2_W32;
50 } else if (have_sse2 && kBlockSize == 16) {
51 diff_proc = &BlockDifference_SSE2_W16;
52 } else {
53 diff_proc = &BlockDifference_C;
54 }
55 #endif
56 }
57
58 return diff_proc(image1, image2, stride);
59 }
60
61 } // namespace webrtc
62