DirectX based screen capturer logic

webrtc/modules/desktop_capture/desktop_frame_win.cc

Index: webrtc/modules/desktop_capture/desktop_frame_win.cc
diff --git a/webrtc/modules/desktop_capture/desktop_frame_win.cc b/webrtc/modules/desktop_capture/desktop_frame_win.cc
index f139fb5cddf2bb7ea2b71a668fddb940b23441c0..ec0f198445c9cc9ebbc49f171971bb182ab8e2c8 100644
--- a/webrtc/modules/desktop_capture/desktop_frame_win.cc
+++ b/webrtc/modules/desktop_capture/desktop_frame_win.cc
@@ -16,6 +16,16 @@
 
 namespace webrtc {
 
+using Microsoft::WRL::ComPtr;
+
+namespace {
+
+int CalculateStrideFromDesktopSize(DesktopSize size) {
+  return size.width() * DesktopFrame::kBytesPerPixel;
+}
+
+}  // namespace
+
 DesktopFrameWin::DesktopFrameWin(DesktopSize size,
                                  int stride,
                                  uint8_t* data,
@@ -34,7 +44,7 @@ DesktopFrameWin* DesktopFrameWin::Create(
     DesktopSize size,
     SharedMemoryFactory* shared_memory_factory,
     HDC hdc) {
-  int bytes_per_row = size.width() * kBytesPerPixel;
+  int bytes_per_row = CalculateStrideFromDesktopSize(size);
   int buffer_size = bytes_per_row * size.height();
 
   // Describe a device independent bitmap (DIB) that is the size of the desktop.
@@ -42,9 +52,9 @@ DesktopFrameWin* DesktopFrameWin::Create(
   bmi.bmiHeader.biHeight = -size.height();
   bmi.bmiHeader.biWidth = size.width();
   bmi.bmiHeader.biPlanes = 1;
-  bmi.bmiHeader.biBitCount = DesktopFrameWin::kBytesPerPixel * 8;
+  bmi.bmiHeader.biBitCount = DesktopFrame::kBytesPerPixel * 8;
   bmi.bmiHeader.biSize = sizeof(bmi.bmiHeader);
-  bmi.bmiHeader.biSizeImage = bytes_per_row * size.height();
+  bmi.bmiHeader.biSizeImage = buffer_size;
 
   std::unique_ptr<SharedMemory> shared_memory;
   HANDLE section_handle = nullptr;
@@ -67,4 +77,21 @@ DesktopFrameWin* DesktopFrameWin::Create(
                              std::move(shared_memory), bitmap);
 }
 
+DesktopFrameWinDXGI::~DesktopFrameWinDXGI() {}
+
+DesktopFrameWinDXGI::DesktopFrameWinDXGI(DesktopSize size,
+                                         ComPtr<IDXGISurface> surface,
+                                         DXGI_MAPPED_RECT rect) :

[Sergey Ulanov, 2016/03/31 18:41:15]

Do you really need to pass this parameter? It can be mapped from surface. Maybe
add DesktopFrameWinDXGI::Create() which maps the surface and then creates 
DesktopFrameWinDXGI, similar to DesktopFrameWin.

[Hzj_jie, 2016/04/05 23:15:17]

Yes, I can move the logic in ScreenCapturerWinDirectX::ProcessFrame into a
Create function.

+    DesktopFrame(size,
+                 CalculateStrideFromDesktopSize(size),

[Sergey Ulanov, 2016/03/31 18:41:15]

 DXGI_MAPPED_RECT  contains pitch field. Use it here?

[Hzj_jie, 2016/04/05 23:15:17]

Done.

+                 rect.pBits,
+                 nullptr),
+    surface_(surface) {}
+
+DesktopFrameWinDXGI::DesktopFrameWinDXGI(DesktopSize size) :
+    DesktopFrame(size,
+                 0,
+                 nullptr,
+                 nullptr) {}
+
 }  // namespace webrtc