VideoCapture: Remove deep frame copy in the border to libJingle

media/base/video_frame.cc

Index: media/base/video_frame.cc
diff --git a/media/base/video_frame.cc b/media/base/video_frame.cc
index 5f0d7282c6e01aedfe0861ee90e55e2cb319b7c1..33b00549db270bf5fc9a2d311e6b02414409f23c 100644
--- a/media/base/video_frame.cc
+++ b/media/base/video_frame.cc
@@ -27,6 +27,12 @@ static inline size_t RoundUp(size_t value, size_t alignment) {
   return ((value + (alignment - 1)) & ~(alignment - 1));
 }
 
+static inline size_t RoundDown(size_t value, size_t alignment) {
+  // Check that |alignment| is a power of 2.
+  DCHECK((alignment + (alignment - 1)) == (alignment | (alignment - 1)));
+  return value & ~(alignment - 1);
+}
+
 // Rounds up |coded_size| if necessary for |format|.
 static gfx::Size AdjustCodedSize(VideoFrame::Format format,
                                  const gfx::Size& coded_size) {
@@ -881,11 +887,40 @@ int VideoFrame::rows(size_t plane) const {
   return Rows(plane, format_, coded_size_.height());
 }
 
-uint8* VideoFrame::data(size_t plane) const {
+const uint8* VideoFrame::data(size_t plane) const {
   DCHECK(IsValidPlane(plane, format_));
   return data_[plane];
 }
 
+uint8* VideoFrame::data(size_t plane) {
+  DCHECK(IsValidPlane(plane, format_));
+  return data_[plane];
+}
+
+const uint8* VideoFrame::visible_data(size_t plane) const {
+  DCHECK(IsValidPlane(plane, format_));
+  const uint8* coded_data = data(plane);
+  const int coded_stride = stride(plane);
+  const int offset_x = RoundDown(visible_rect_.x(), 2);
+  const int offset_y = RoundDown(visible_rect_.y(), 2);
+  switch (plane) {
+    case kYPlane:
+    case kAPlane:
+      return coded_data + offset_y * coded_stride + offset_x;
+    case kUPlane:
+    case kVPlane:
+      return coded_data + offset_y / 2 * coded_stride + offset_x / 2;
+    default:
+      NOTIMPLEMENTED();
+      return NULL;
+  }
+}
+
+uint8* VideoFrame::visible_data(size_t plane) {
+  return const_cast<uint8*>(
+      static_cast<const VideoFrame*>(this)->visible_data(plane));
+}
+
 const gpu::MailboxHolder* VideoFrame::mailbox_holder() const {
   DCHECK_EQ(format_, NATIVE_TEXTURE);
   return mailbox_holder_.get();