Remove differ from ScreenCapturer implementations

webrtc/modules/desktop_capture/win/screen_capturer_win_magnifier.cc

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/modules/desktop_capture/win/screen_capturer_win_magnifier.h"
 
 #include <utility>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/timeutils.h"
 #include "webrtc/modules/desktop_capture/desktop_capture_options.h"
 #include "webrtc/modules/desktop_capture/desktop_frame.h"
 #include "webrtc/modules/desktop_capture/desktop_frame_win.h"
 #include "webrtc/modules/desktop_capture/desktop_region.h"
-#include "webrtc/modules/desktop_capture/differ.h"
 #include "webrtc/modules/desktop_capture/mouse_cursor.h"
 #include "webrtc/modules/desktop_capture/win/cursor.h"
 #include "webrtc/modules/desktop_capture/win/desktop.h"
 #include "webrtc/modules/desktop_capture/win/screen_capture_utils.h"
 #include "webrtc/system_wrappers/include/logging.h"
 
 namespace webrtc {
 
 // kMagnifierWindowClass has to be "Magnifier" according to the Magnification
 // API. The other strings can be anything.
@@ skipping 77 matching lines @@
   // CaptureImage may fail in some situations, e.g. windows8 metro mode. So
   // defer to the fallback capturer if magnifier capturer did not work.
   if (!CaptureImage(rect)) {
     LOG_F(LS_WARNING) << "Switching to the fallback screen capturer because "
                          "last capture attempt failed.";
     StartFallbackCapturer();
     fallback_capturer_->Capture(region);
     return;
   }
 
-  const DesktopFrame* current_frame = queue_.current_frame();
-  const DesktopFrame* last_frame = queue_.previous_frame();
-  DesktopRegion updated_region;
-  if (last_frame && last_frame->size().equals(current_frame->size())) {
-    // Make sure the differencer is set up correctly for these previous and
-    // current screens.
-    if (!differ_.get() || (differ_->width() != current_frame->size().width()) ||
-        (differ_->height() != current_frame->size().height()) ||
-        (differ_->bytes_per_row() != current_frame->stride())) {
-      differ_.reset(new Differ(current_frame->size().width(),
-                               current_frame->size().height(),
-                               DesktopFrame::kBytesPerPixel,
-                               current_frame->stride()));
-    }
-
-    // Calculate difference between the two last captured frames.
-    differ_->CalcDirtyRegion(
-        last_frame->data(), current_frame->data(), &updated_region);
-  } else {
-    updated_region.SetRect(DesktopRect::MakeSize(current_frame->size()));
-  }
-
   // Emit the current frame.
   std::unique_ptr<DesktopFrame> frame = queue_.current_frame()->Share();
   frame->set_dpi(DesktopVector(GetDeviceCaps(desktop_dc_, LOGPIXELSX),
                                GetDeviceCaps(desktop_dc_, LOGPIXELSY)));
-  frame->mutable_updated_region()->Swap(&updated_region);
+  // ScreenCapturerDifferWrapper will help to detect updated region if needed.

[Sergey Ulanov, 2016/09/22 18:25:08]

Same here. Add a comment in screen_capturer_win_magnifier.h

[Hzj_jie, 2016/09/22 21:01:34]

Done.

+  frame->mutable_updated_region()->SetRect(
+      DesktopRect::MakeSize(frame->size()));
   frame->set_capture_time_ms((rtc::TimeNanos() - capture_start_time_nanos) /
                              rtc::kNumNanosecsPerMillisec);
   callback_->OnCaptureResult(Result::SUCCESS, std::move(frame));
 }
 
 bool ScreenCapturerWinMagnifier::GetScreenList(ScreenList* screens) {
   return webrtc::GetScreenList(screens);
 }
 
 bool ScreenCapturerWinMagnifier::SelectScreen(ScreenId id) {
@@ skipping 246 matching lines @@
   RTC_DCHECK(fallback_capturer_);
   if (!fallback_capturer_started_) {
     fallback_capturer_started_ = true;
 
     fallback_capturer_->Start(callback_);
     fallback_capturer_->SelectScreen(current_screen_id_);
   }
 }
 
 }  // namespace webrtc