media: Optimize HW Video to 2D Canvas copy.

cc/resources/media/skcanvas_video_renderer.h

+// Copyright (c) 2012 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.
+
+#ifndef CC_RESOURCES_MEDIA_SKCANVAS_VIDEO_RENDERER_H_
+#define CC_RESOURCES_MEDIA_SKCANVAS_VIDEO_RENDERER_H_
+
+#include "base/time/time.h"
+#include "cc/base/cc_export.h"
+#include "cc/output/context_provider.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/gfx/rect.h"
+
+class SkCanvas;
+
+namespace media {
+class VideoFrame;
+}
+
+namespace cc {
+
+// Handles rendering of VideoFrames to SkCanvases, doing any necessary YUV
+// conversion and caching of resulting RGB bitmaps.
+class CC_EXPORT SkCanvasVideoRenderer {
+ public:
+  SkCanvasVideoRenderer();
+  ~SkCanvasVideoRenderer();
+
+  // Paints |video_frame| on |canvas|, scaling the result to fit dimensions
+  // specified by |dest_rect|.
+  //
+  // Black will be painted on |canvas| if |video_frame| is null.
+  void Paint(media::VideoFrame* video_frame,
+             SkCanvas* canvas,
+             const gfx::RectF& dest_rect,
+             uint8 alpha,
+             ContextProvider* context_provider);
+
+  static void CopyVideoFrameToTexture(gpu::gles2::GLES2Interface* gl,
+                                      media::VideoFrame* video_frame,
+                                      unsigned int texture,
+                                      unsigned int level,
+                                      unsigned int internal_format,
+                                      unsigned int type,
+                                      bool premultiply_alpha,
+                                      bool flip_y);
+
+ private:
+  void CleanUpTemporaryBuffers();
+
+  // An RGB bitmap and corresponding timestamp of the previously converted
+  // video frame data.
+  SkBitmap last_frame_;
+  base::TimeDelta last_frame_timestamp_;
+  // It's possible to be used by accelerated client and non-accelerated client.
+  SkBitmap accelerated_last_frame_;
+  base::TimeDelta accelerated_last_frame_timestamp_;
+
+  DISALLOW_COPY_AND_ASSIGN(SkCanvasVideoRenderer);
+};
+
+}  // namespace cc
+
+#endif  // CC_RESOURCES_MEDIA_SKCANVAS_VIDEO_RENDERER_H_