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 19 namespace webrtc { 20 21 int 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 35 int 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
