Handle Alpha channel in Canvas capture

content/renderer/media/canvas_capture_handler_unittest.cc

 // Copyright 2015 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 "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/thread_task_runner_handle.h"
 #include "content/child/child_process.h"
 #include "content/renderer/media/canvas_capture_handler.h"
 #include "content/renderer/media/media_stream_video_capturer_source.h"
 #include "media/base/limits.h"
 #include "skia/ext/refptr.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
 #include "third_party/WebKit/public/web/WebHeap.h"
 
 using ::testing::_;
 using ::testing::InSequence;
 using ::testing::Mock;
 using ::testing::SaveArg;
 using ::testing::Test;
 
 namespace content {
 
+namespace {
+
 static const int kTestCanvasCaptureWidth = 320;
 static const int kTestCanvasCaptureHeight = 240;
 static const double kTestCanvasCaptureFramesPerSecond = 55.5;
 
 static const int kTestCanvasCaptureFrameWidth = 2;
 static const int kTestCanvasCaptureFrameHeight = 2;
 static const int kTestCanvasCaptureFrameErrorTolerance = 2;
+static const int kTestAlphaValue = 175;
 
 ACTION_P(RunClosure, closure) {
   closure.Run();
 }
 
+}  // namespace
+
 class CanvasCaptureHandlerTest : public Test {
  public:
   CanvasCaptureHandlerTest() {}
 
   void SetUp() override {
     canvas_capture_handler_.reset(
         CanvasCaptureHandler::CreateCanvasCaptureHandler(
             blink::WebSize(kTestCanvasCaptureWidth, kTestCanvasCaptureHeight),
             kTestCanvasCaptureFramesPerSecond, message_loop_.task_runner(),
             &track_));
@@ skipping 23 matching lines @@
   }
 
   MOCK_METHOD1(DoOnRunning, void(bool));
   void OnRunning(bool state) { DoOnRunning(state); }
 
   // Verify returned frames.
   static skia::RefPtr<SkImage> GenerateTestImage() {
     SkBitmap testBitmap;
     testBitmap.allocN32Pixels(kTestCanvasCaptureFrameWidth,
                               kTestCanvasCaptureFrameHeight);
-    testBitmap.eraseColor(SK_ColorBLUE);
+    testBitmap.eraseARGB(kTestAlphaValue, 30, 60, 200);
     return skia::AdoptRef(SkImage::NewFromBitmap(testBitmap));
   }
 
   void OnVerifyDeliveredFrame(
       const scoped_refptr<media::VideoFrame>& video_frame,
       base::TimeTicks estimated_capture_time) {
-    EXPECT_EQ(media::PIXEL_FORMAT_I420, video_frame->format());
+    EXPECT_EQ(media::PIXEL_FORMAT_YV12A, video_frame->format());
     const gfx::Size& size = video_frame->coded_size();
     EXPECT_EQ(kTestCanvasCaptureFrameWidth, size.width());
     EXPECT_EQ(kTestCanvasCaptureFrameHeight, size.height());
-    const uint8_t* y_plane = video_frame->data(0);
-    EXPECT_NEAR(41, y_plane[0], kTestCanvasCaptureFrameErrorTolerance);
-    const uint8_t* u_plane = video_frame->data(1);
-    EXPECT_NEAR(239, u_plane[0], kTestCanvasCaptureFrameErrorTolerance);
-    const uint8_t* v_plane = video_frame->data(2);
-    EXPECT_NEAR(110, v_plane[0], kTestCanvasCaptureFrameErrorTolerance);
+    const uint8_t* y_plane = video_frame->data(media::VideoFrame::kYPlane);
+    EXPECT_NEAR(74, y_plane[0], kTestCanvasCaptureFrameErrorTolerance);
+    const uint8_t* u_plane = video_frame->data(media::VideoFrame::kUPlane);
+    EXPECT_NEAR(193, u_plane[0], kTestCanvasCaptureFrameErrorTolerance);
+    const uint8_t* v_plane = video_frame->data(media::VideoFrame::kVPlane);
+    EXPECT_NEAR(105, v_plane[0], kTestCanvasCaptureFrameErrorTolerance);
+    const uint8_t* a_plane = video_frame->data(media::VideoFrame::kAPlane);
+    EXPECT_EQ(kTestAlphaValue, a_plane[0]);
   }
 
   blink::WebMediaStreamTrack track_;
   // The Class under test. Needs to be scoped_ptr to force its destruction.
   scoped_ptr<CanvasCaptureHandler> canvas_capture_handler_;
 
  protected:
   media::VideoCapturerSource* GetVideoCapturerSource(
       MediaStreamVideoCapturerSource* ms_source) {
     return ms_source->source_.get();
@@ skipping 83 matching lines @@
   media::VideoCapturerSource* source =
       GetVideoCapturerSource(static_cast<MediaStreamVideoCapturerSource*>(
           track_.source().extraData()));
   EXPECT_TRUE(source != nullptr);
   EXPECT_TRUE(canvas_capture_handler_->needsNewFrame());
   source->StopCapture();
   EXPECT_FALSE(canvas_capture_handler_->needsNewFrame());
 }
 
 }  // namespace content