Remove differ from ScreenCapturer implementations

webrtc/modules/desktop_capture/win/screen_capturer_win_gdi.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_gdi.h"
 
 #include <assert.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 {
 
 namespace {
 
@@ skipping 45 matching lines @@
   RTC_DCHECK(!queue_.current_frame() || !queue_.current_frame()->IsShared());
 
   // Make sure the GDI capture resources are up-to-date.
   PrepareCaptureResources();
 
   if (!CaptureImage()) {
     callback_->OnCaptureResult(Result::ERROR_TEMPORARY, nullptr);
     return;
   }
 
-  const DesktopFrame* current_frame = queue_.current_frame();
-  const DesktopFrame* last_frame = queue_.previous_frame();
-  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.
-    DesktopRegion region;
-    differ_->CalcDirtyRegion(last_frame->data(), current_frame->data(),
-                             &region);
-    helper_.InvalidateRegion(region);
-  } else {
-    // No previous frame is available, or the screen is resized. Invalidate the
-    // whole screen.
-    helper_.InvalidateScreen(current_frame->size());
-  }
-
-  helper_.set_size_most_recent(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()->Clear();
-  helper_.TakeInvalidRegion(frame->mutable_updated_region());
+  // ScreenCapturerDifferWrapper will help to detect updated region if needed.

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

I suggest adding a comment in screen_capturer_win_gdi.h saying that this class
doesn't detect updated_region() and that ScreenCapturerDifferWrapper should be
used if that functionality is necessary. Then this comment can be removed.

[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 ScreenCapturerWinGdi::GetScreenList(ScreenList* screens) {
   return webrtc::GetScreenList(screens);
 }
 
@@ skipping 71 matching lines @@
     if (!desktop_dc_)
       abort();
     memory_dc_ = CreateCompatibleDC(desktop_dc_);
     if (!memory_dc_)
       abort();
 
     desktop_dc_rect_ = screen_rect;
 
     // Make sure the frame buffers will be reallocated.
     queue_.Reset();
-
-    helper_.ClearInvalidRegion();
   }
 }
 
 bool ScreenCapturerWinGdi::CaptureImage() {
   DesktopRect screen_rect =
       GetScreenRect(current_screen_id_, current_device_key_);
   if (screen_rect.is_empty())
     return false;
 
   DesktopSize size = screen_rect.size();
@@ skipping 23 matching lines @@
            SRCCOPY | CAPTUREBLT);
 
     // Select back the previously selected object to that the device contect
     // could be destroyed independently of the bitmap if needed.
     SelectObject(memory_dc_, previous_object);
   }
   return true;
 }
 
 }  // namespace webrtc