Rotation into Video Layer + Content Transform

content/renderer/media/webmediaplayer_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/webmediaplayer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 #include <vector>
@@ skipping 522 matching lines @@
 
   // TODO(scherkus): Clarify paint() API contract to better understand when and
   // why it's being called. For example, today paint() is called when:
   //   - We haven't reached HAVE_CURRENT_DATA and need to paint black
   //   - We're painting to a canvas
   // See http://crbug.com/341225 http://crbug.com/342621 for details.
   scoped_refptr<media::VideoFrame> video_frame =
       GetCurrentFrameFromCompositor();
 
   gfx::Rect gfx_rect(rect);
+
+  if (pipeline_metadata_.video_rotation == media::VIDEO_ROTATION_90 ||
+      pipeline_metadata_.video_rotation == media::VIDEO_ROTATION_270)
+    gfx_rect.set_size(

[enne (OOO), 2014/07/21 22:37:14]

Whoa, how does this do the right thing? Does the caller of this function know
that the frame is painted differently?

[suderman, 2014/07/21 23:12:12]

This is to maintain Canvas's current behavior. As blink is now provided the
rotated dimensions (for 90 and 270 degree rotations) this Paint is provided
incorrect dimensions of the frame. If this correction isn't performed frames
become stretched/squished. 

There is a future CL (https://codereview.chromium.org/402133005/) that corrects
this behavior however I wanted to minimize the contents of this CL.

+        gfx::Size(gfx_rect.size().height(), gfx_rect.size().width()));
+
   skcanvas_video_renderer_.Paint(video_frame.get(), canvas, gfx_rect, alpha);
 }
 
 bool WebMediaPlayerImpl::hasSingleSecurityOrigin() const {
   if (data_source_)
     return data_source_->HasSingleOrigin();
   return true;
 }
 
 bool WebMediaPlayerImpl::didPassCORSAccessCheck() const {
@@ skipping 410 matching lines @@
 
   pipeline_metadata_ = metadata;
 
   UMA_HISTOGRAM_ENUMERATION("Media.VideoRotation",
                             metadata.video_rotation,
                             media::VIDEO_ROTATION_MAX + 1);
   SetReadyState(WebMediaPlayer::ReadyStateHaveMetadata);
 
   if (hasVideo()) {
     DCHECK(!video_weblayer_);
-    video_weblayer_.reset(
-        new WebLayerImpl(cc::VideoLayer::Create(compositor_)));
+    scoped_refptr<cc::VideoLayer> layer = cc::VideoLayer::Create(compositor_);
+    layer->set_video_rotation(pipeline_metadata_.video_rotation);
+
+    if (pipeline_metadata_.video_rotation == media::VIDEO_ROTATION_90 ||
+        pipeline_metadata_.video_rotation == media::VIDEO_ROTATION_270) {
+      gfx::Size size = pipeline_metadata_.natural_size;
+      pipeline_metadata_.natural_size = gfx::Size(size.height(), size.width());
+    }
+
+    video_weblayer_.reset(new WebLayerImpl(layer));

[enne (OOO), 2014/07/21 22:37:14]

Can you just set the transform here on the web layer instead of much later in
the pipeline in VideoLayerImpl?

[suderman, 2014/07/21 23:12:12]

In order to correctly rotate the video layer it must be translated post rotation
(to correctly center the image). To perform this rotation we need the scale of
the frame that blink computes which isn't available at this point.

[enne (OOO), 2014/07/21 23:42:49]

And I guess Blink doesn't know at layout time that this is a video so it can't
do anything special there, either.  So, maybe cc really is the only place where
both of these pieces of information are known.  Hmm.

     video_weblayer_->setOpaque(opaque_);
     client_->setWebLayer(video_weblayer_.get());
   }
 
   // TODO(scherkus): This should be handled by HTMLMediaElement and controls
   // should know when to invalidate themselves http://crbug.com/337015
   InvalidateOnMainThread();
 }
 
 void WebMediaPlayerImpl::OnPipelineBufferingStateChanged(
@@ skipping 376 matching lines @@
   compositor_task_runner_->PostTask(FROM_HERE,
                                     base::Bind(&GetCurrentFrameAndSignal,
                                                base::Unretained(compositor_),
                                                &video_frame,
                                                &event));
   event.Wait();
   return video_frame;
 }
 
 }  // namespace content