Chrome MediaStream VideoTrack implementation.

content/renderer/media/rtc_video_renderer.cc

Index: content/renderer/media/rtc_video_renderer.cc
diff --git a/content/renderer/media/rtc_video_renderer.cc b/content/renderer/media/rtc_video_renderer.cc
index 013fcad8dfb2e86994afc31872576ac71423f0a7..7d208b92b8ba7eb66d5afbe93449c47488a0cef4 100644
--- a/content/renderer/media/rtc_video_renderer.cc
+++ b/content/renderer/media/rtc_video_renderer.cc
@@ -11,6 +11,13 @@
 
 namespace content {
 
+// Empty method used for keeping a reference to the original media::VideoFrame
+// in RTCVideoRenderer::OnVideoFrame if a color conversion between I420 and
+// YV12 is needed.
+static void ReleaseOriginalFrame(
+    const scoped_refptr<media::VideoFrame>& frame) {
+}
+
 RTCVideoRenderer::RTCVideoRenderer(
     const blink::WebMediaStreamTrack& video_track,
     const base::Closure& error_cb,
@@ -88,8 +95,28 @@ void RTCVideoRenderer::OnVideoFrame(
                        TRACE_EVENT_SCOPE_THREAD,
                        "timestamp",
                        frame->GetTimestamp().InMilliseconds());
-  repaint_cb_.Run(frame);
   first_frame_rendered_ = true;
+
+  if (frame->format() != media::VideoFrame::I420) {
+    repaint_cb_.Run(frame);

[Ronghua Wu (Left Chromium), 2014/03/04 01:04:11]

what formats are expected here?

It seems YV12 will come here too.

[perkj_chrome, 2014/03/04 10:44:51]

That is correct. We need to special handle I420. See the added comment.

+    return;
+  }
+
+  scoped_refptr<media::VideoFrame> yuv_frame =

[Alpha Left Google, 2014/03/03 06:45:04]

A comment would help to explain what this is doing and why it is necessary.

[perkj_chrome, 2014/03/04 10:44:51]

Done.

+      media::VideoFrame::WrapExternalYuvData(
+          media::VideoFrame::YV12,
+          frame->coded_size(),
+          frame->visible_rect(),
+          frame->natural_size(),
+          frame->stride(media::VideoFrame::kYPlane),
+          frame->stride(media::VideoFrame::kUPlane),
+          frame->stride(media::VideoFrame::kVPlane),
+          frame->data(media::VideoFrame::kYPlane),
+          frame->data(media::VideoFrame::kUPlane),
+          frame->data(media::VideoFrame::kVPlane),
+          frame->GetTimestamp(),
+          base::Bind(&ReleaseOriginalFrame, frame));
+  repaint_cb_.Run(yuv_frame);
 }
 
 void RTCVideoRenderer::MaybeRenderSignalingFrame() {