Implement "hole" video frame.

In order to support out-of-band compositing of protected video
content in Chrome, it is necessary to have a transparent hole in
Chrome's HTML rendering so that video playing "beneath" the HTML
elements can be seen through.
    
To accomplish the scenario stated above, define a "hole" video frame
which would clear the region where video would have been composited.
In CC, this is done by sending a transparent black SolidColorDrawQuad
with blending disabled.

Review URL: https://chromiumcodereview.appspot.com/12255032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@185841 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 61 insertions, 0 deletions

diff --git a/cc/video_layer_impl.cc b/cc/video_layer_impl.cc
index 8a624bfa..502ccc2 100644
--- a/cc/video_layer_impl.cc
+++ b/cc/video_layer_impl.cc
@@ -20,6 +20,10 @@
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/khronos/GLES2/gl2ext.h"
 
+#if defined(GOOGLE_TV)
+#include "cc/solid_color_draw_quad.h"
+#endif
+
 namespace cc {
 
 // static
@@ -89,6 +93,10 @@ static GLenum convertVFCFormatToGLenum(const media::VideoFrame& frame)
         return GL_LUMINANCE;
     case media::VideoFrame::NATIVE_TEXTURE:
         return frame.texture_target();
+#if defined(GOOGLE_TV)
+    case media::VideoFrame::HOLE:
+        return GL_INVALID_VALUE;
+#endif
     case media::VideoFrame::INVALID:
     case media::VideoFrame::RGB32:
     case media::VideoFrame::EMPTY:
@@ -108,6 +116,10 @@ size_t VideoLayerImpl::numPlanes() const
         return 1;
 
     switch (m_frame->format()) {
+#if defined(GOOGLE_TV)
+    case media::VideoFrame::HOLE:
+        return 0;
+#endif
     case media::VideoFrame::RGB32:
         return 1;
     case media::VideoFrame::YV12:
@@ -152,6 +164,11 @@ void VideoLayerImpl::willDrawInternal(ResourceProvider* resourceProvider)
     if (!m_frame)
         return;
 
+#if defined(GOOGLE_TV)
+    if (m_frame->format() == media::VideoFrame::HOLE)
+        return;
+#endif
+
     m_format = convertVFCFormatToGLenum(*m_frame);
 
     // If these fail, we'll have to add draw logic that handles offset bitmap/
@@ -215,6 +232,27 @@ void VideoLayerImpl::appendQuads(QuadSink& quadSink, AppendQuadsData& appendQuad
     const float texHeightScale =
         static_cast<float>(visibleRect.height()) / codedSize.height();
 
+#if defined(GOOGLE_TV)
+    // This block and other blocks wrapped around #if defined(GOOGLE_TV) is not
+    // maintained by the general compositor team. Please contact the following
+    // people instead:
+    //
+    // wonsik@chromium.org
+    // ycheo@chromium.org
+
+    if (m_frame->format() == media::VideoFrame::HOLE) {
+        scoped_ptr<SolidColorDrawQuad> solidColorDrawQuad =
+            SolidColorDrawQuad::Create();
+        // Create a solid color quad with transparent black and force no
+        // blending.
+        solidColorDrawQuad->SetAll(
+            sharedQuadState, quadRect, quadRect, quadRect, false,
+            SK_ColorTRANSPARENT);
+        quadSink.append(solidColorDrawQuad.PassAs<DrawQuad>(), appendQuadsData);
+        return;
+    }
+#endif
+
     switch (m_format) {
     case GL_LUMINANCE: {
         // YUV software decoder.
diff --git a/content/browser/renderer_host/media/video_capture_controller.cc b/content/browser/renderer_host/media/video_capture_controller.cc
index aad341d..9b3161b 100644
--- a/content/browser/renderer_host/media/video_capture_controller.cc
+++ b/content/browser/renderer_host/media/video_capture_controller.cc
@@ -465,6 +465,10 @@ void VideoCaptureController::OnIncomingCapturedVideoFrame(
 
   // Do color conversion from the camera format to I420.
   switch (frame->format()) {
+#if defined(GOOGLE_TV)
+    case media::VideoFrame::HOLE:
+      // Fall-through to NOTREACHED() block.
+#endif
     case media::VideoFrame::INVALID:
     case media::VideoFrame::YV16:
     case media::VideoFrame::EMPTY:
diff --git a/media/base/video_frame.cc b/media/base/video_frame.cc
index 71bdcf4..b5330bd 100644
--- a/media/base/video_frame.cc
+++ b/media/base/video_frame.cc
@@ -135,6 +135,17 @@ scoped_refptr<VideoFrame> VideoFrame::CreateBlackFrame(const gfx::Size& size) {
   return CreateColorFrame(size, kBlackY, kBlackUV, kBlackUV, kZero);
 }
 
+#if defined(GOOGLE_TV)
+// static
+scoped_refptr<VideoFrame> VideoFrame::CreateHoleFrame(
+    const gfx::Size& size) {
+  DCHECK(IsValidConfig(VideoFrame::HOLE, size, gfx::Rect(size), size));
+  scoped_refptr<VideoFrame> frame(new VideoFrame(
+      VideoFrame::HOLE, size, gfx::Rect(size), size, base::TimeDelta()));
+  return frame;
+}
+#endif
+
 static inline size_t RoundUp(size_t value, size_t alignment) {
   // Check that |alignment| is a power of 2.
   DCHECK((alignment + (alignment - 1)) == (alignment | (alignment - 1)));
diff --git a/media/base/video_frame.h b/media/base/video_frame.h
index 3483e91..07697c2 100644
--- a/media/base/video_frame.h
+++ b/media/base/video_frame.h
@@ -43,6 +43,9 @@ class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
     EMPTY = 9,  // An empty frame.
     I420 = 11,  // 12bpp YVU planar 1x1 Y, 2x2 UV samples.
     NATIVE_TEXTURE = 12,  // Native texture.  Pixel-format agnostic.
+#if defined(GOOGLE_TV)
+    HOLE = 13,  // Hole frame.
+#endif
   };
 
   // Creates a new frame in system memory with given parameters. Buffers for
@@ -125,6 +128,11 @@ class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
   // equivalent of RGB(0,0,0).
   static scoped_refptr<VideoFrame> CreateBlackFrame(const gfx::Size& size);
 
+#if defined(GOOGLE_TV)
+  // Allocates a hole frame.
+  static scoped_refptr<VideoFrame> CreateHoleFrame(const gfx::Size& size);
+#endif
+
   Format format() const { return format_; }
 
   const gfx::Size& coded_size() const { return coded_size_; }