Merge 237531 "Fix DesktopCaptureDevice to handle inverted frames."

> Fix DesktopCaptureDevice to handle inverted frames.
> 
> Previously DesktopCaptureDevice was passing inverted frames to
> OnIncomingCapturedFrame() as is, and it would crash the browser.
> 
> BUG=306876
> 
> Review URL: https://codereview.chromium.org/77623002

TBR=sergeyu@chromium.org

Review URL: https://codereview.chromium.org/113453002

git-svn-id: svn://svn.chromium.org/chrome/branches/1700/src@240220 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 19 insertions, 3 deletions

diff --git a/content/browser/renderer_host/media/desktop_capture_device.cc b/content/browser/renderer_host/media/desktop_capture_device.cc
index 6303f21..5072841 100644
--- a/content/browser/renderer_host/media/desktop_capture_device.cc
+++ b/content/browser/renderer_host/media/desktop_capture_device.cc
@@ -180,11 +180,19 @@ void DesktopCaptureDevice::Core::OnCaptureCompleted(
   size_t output_bytes = output_size.width() * output_size.height() *
       webrtc::DesktopFrame::kBytesPerPixel;
   const uint8_t* output_data = NULL;
+  bool flip_vertically = false;
 
   if (frame->size().equals(output_size)) {
     // If the captured frame matches the output size, we can return the pixel
     // data directly, without scaling.
     output_data = frame->data();
+
+    // If the |frame| generated by the screen capturer is inverted then we need
+    // to adjust |output_data| to point at the beginning of the buffer instead
+    // of the first row.
+    flip_vertically = frame->stride() < 0;
+    if (flip_vertically)
+      output_data += frame->stride() * (frame->size().height() - 1);
   } else {
     // Otherwise we need to down-scale and/or letterbox to the target format.
 
@@ -212,7 +220,7 @@ void DesktopCaptureDevice::Core::OnCaptureCompleted(
 
   if (client_) {
     client_->OnIncomingCapturedFrame(output_data, output_bytes,
-                                     base::Time::Now(), 0, false, false);
+                                     base::Time::Now(), 0, flip_vertically, false);
   }
 }
 
diff --git a/content/browser/renderer_host/media/video_capture_controller.cc b/content/browser/renderer_host/media/video_capture_controller.cc
index 40e94bd..3c1b629 100644
--- a/content/browser/renderer_host/media/video_capture_controller.cc
+++ b/content/browser/renderer_host/media/video_capture_controller.cc
@@ -273,11 +273,19 @@ void VideoCaptureController::VideoCaptureDeviceClient::OnIncomingCapturedFrame(
   int destination_width = frame_info_.width;
   int destination_height = frame_info_.height;
   libyuv::FourCC origin_colorspace = libyuv::FOURCC_ANY;
+
+  // When rotating by 90 and 270 degrees swap |flip_horiz| and |flip_vert|
+  // because ConvertToI420() flips image before rotation, while
+  // OnIncomingCapturedFrame() interface assumes that rotation happens before
+  // flips.
+  if (rotation == 90 || rotation == 270)
+    std::swap(flip_horiz, flip_vert);
+
   // Assuming rotation happens first and flips next, we can consolidate both
   // vertical and horizontal flips together with rotation into two variables:
-  // new_rotation = (rotation + 180 * vertical_flip) modulo 360
+  // new_rotation = (rotation + 180 * horizontal_flip) modulo 360
   // new_vertical_flip = horizontal_flip XOR vertical_flip
-  int new_rotation_angle = (rotation + 180 * flip_vert) % 360;
+  int new_rotation_angle = (rotation + 180 * flip_horiz) % 360;
   libyuv::RotationMode rotation_mode = libyuv::kRotate0;
   if (new_rotation_angle == 90)
     rotation_mode = libyuv::kRotate90;