Handle Alpha channel in Canvas capture

content/renderer/pepper/pepper_video_source_host.cc

 // Copyright (c) 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/pepper/pepper_video_source_host.h"
 
 #include <string.h>
 
 #include "base/bind.h"
 #include "base/numerics/safe_conversions.h"
 #include "content/public/renderer/renderer_ppapi_host.h"
 #include "content/renderer/media/video_track_to_pepper_adapter.h"
 #include "content/renderer/pepper/ppb_image_data_impl.h"
 #include "content/renderer/render_thread_impl.h"
+#include "media/base/video_util.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/host/dispatch_host_message.h"
 #include "ppapi/host/ppapi_host.h"
 #include "ppapi/proxy/host_dispatcher.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/ppb_image_data_proxy.h"
 #include "ppapi/shared_impl/scoped_pp_resource.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_image_data_api.h"
 #include "third_party/libyuv/include/libyuv/convert.h"
@@ skipping 23 matching lines @@
   base::ThreadChecker thread_checker_;
 };
 
 PepperVideoSourceHost::FrameReceiver::FrameReceiver(
     const base::WeakPtr<PepperVideoSourceHost>& host)
     : host_(host) {}
 
 PepperVideoSourceHost::FrameReceiver::~FrameReceiver() {}
 
 void PepperVideoSourceHost::FrameReceiver::GotFrame(
-    const scoped_refptr<media::VideoFrame>& frame) {
+    const scoped_refptr<media::VideoFrame>& video_frame) {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (!host_)
     return;
+
+  if (!(video_frame->format() == media::PIXEL_FORMAT_I420 ||
+        video_frame->format() == media::PIXEL_FORMAT_YV12A)) {
+    NOTREACHED();
+    return;
+  }
+  scoped_refptr<media::VideoFrame> frame = video_frame;
+  // Drop alpha channel since we do not support it yet.
+  if (frame->format() == media::PIXEL_FORMAT_YV12A)
+    frame = media::WrapAsI420VideoFrame(video_frame);
+
   // Hold a reference to the new frame and release the previous.
   host_->last_frame_ = frame;
   if (host_->get_frame_pending_)
     host_->SendGetFrameReply();
 }
 
 PepperVideoSourceHost::PepperVideoSourceHost(RendererPpapiHost* host,
                                              PP_Instance instance,
                                              PP_Resource resource)
     : ResourceHost(host->GetPpapiHost(), instance, resource),
@@ skipping 230 matching lines @@
   if (frame_source_.get() && !stream_url_.empty())
     frame_source_->Close(frame_receiver_.get());
 
   frame_source_.reset(NULL);
   stream_url_.clear();
 
   shared_image_ = NULL;
 }
 
 }  // namespace content