create a separate WebMediaPlayer for URL derived from media stream

webkit/media/webmediaplayer_ms.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.
+
+// Delegate calls from WebCore::MediaPlayerPrivate to Chrome's media player

[scherkus (not reviewing), 2012/09/07 11:44:03]

move to class definition instead of top of file

[wjia(left Chromium), 2012/09/13 01:22:07]

Done.

+// when "src" is from media stream.
+//
+// WebMediaPlayerMS works with multiple objects, the most important ones are:
+//
+// VideoFrameProvider
+//   provides video frames for rendering.
+//
+// TODO(wjia): add AudioPlayer.
+// AudioPlayer
+//   plays audio streams.
+//
+// WebKit::WebMediaPlayerClient
+//   WebKit client of this media player object.
+//
+
+#ifndef WEBKIT_MEDIA_WEBMEDIAPLAYER_MS_H_
+#define WEBKIT_MEDIA_WEBMEDIAPLAYER_MS_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/message_loop.h"
+#include "googleurl/src/gurl.h"
+#include "skia/ext/platform_canvas.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebMediaPlayer.h"
+#include "webkit/media/skcanvas_video_renderer.h"
+
+namespace WebKit {
+class WebFrame;
+class WebMediaPlayerClient;
+}
+
+namespace media {
+class MediaLog;
+}
+
+namespace webkit_media {
+
+class MediaStreamClient;
+class VideoFrameProvider;
+class WebMediaPlayerDelegate;
+
+class WebMediaPlayerMS
+    : public WebKit::WebMediaPlayer,
+      public MessageLoop::DestructionObserver,
+      public base::SupportsWeakPtr<WebMediaPlayerMS> {
+ public:
+  // Construct a WebMediaPlayerMS with reference to the client, and
+  // a MediaStreamClient which provides VideoFrameProvider.
+  WebMediaPlayerMS(WebKit::WebFrame* frame,
+                   WebKit::WebMediaPlayerClient* client,
+                   base::WeakPtr<WebMediaPlayerDelegate> delegate,
+                   MediaStreamClient* media_stream_client,
+                   media::MediaLog* media_log);
+  virtual ~WebMediaPlayerMS();
+
+  virtual void load(const WebKit::WebURL& url, CORSMode cors_mode) OVERRIDE;
+  virtual void cancelLoad() OVERRIDE;
+
+  // Playback controls.
+  virtual void play() OVERRIDE;
+  virtual void pause() OVERRIDE;
+  virtual bool supportsFullscreen() const OVERRIDE;
+  virtual bool supportsSave() const OVERRIDE;
+  virtual void seek(float seconds) OVERRIDE;
+  virtual void setEndTime(float seconds) OVERRIDE;
+  virtual void setRate(float rate) OVERRIDE;
+  virtual void setVolume(float volume) OVERRIDE;
+  virtual void setVisible(bool visible) OVERRIDE;
+  virtual void setPreload(WebKit::WebMediaPlayer::Preload preload) OVERRIDE;
+  virtual bool totalBytesKnown() OVERRIDE;
+  virtual const WebKit::WebTimeRanges& buffered() OVERRIDE;
+  virtual float maxTimeSeekable() const OVERRIDE;
+
+  // Methods for painting.
+  virtual void setSize(const WebKit::WebSize& size) OVERRIDE;
+
+  virtual void paint(WebKit::WebCanvas* canvas,
+                     const WebKit::WebRect& rect,
+                     uint8_t alpha) OVERRIDE;
+
+  // True if the loaded media has a playable video/audio track.
+  virtual bool hasVideo() const OVERRIDE;
+  virtual bool hasAudio() const OVERRIDE;
+
+  // Dimensions of the video.
+  virtual WebKit::WebSize naturalSize() const OVERRIDE;
+
+  // Getters of playback state.
+  virtual bool paused() const OVERRIDE;
+  virtual bool seeking() const OVERRIDE;
+  virtual float duration() const OVERRIDE;
+  virtual float currentTime() const OVERRIDE;
+
+  // Get rate of loading the resource.
+  virtual int32 dataRate() const OVERRIDE;
+
+  // Internal states of loading and network.
+  virtual WebKit::WebMediaPlayer::NetworkState networkState() const OVERRIDE;
+  virtual WebKit::WebMediaPlayer::ReadyState readyState() const OVERRIDE;
+
+  virtual bool didLoadingProgress() const OVERRIDE;
+  virtual unsigned long long totalBytes() const OVERRIDE;
+
+  virtual bool hasSingleSecurityOrigin() const OVERRIDE;
+  virtual bool didPassCORSAccessCheck() const OVERRIDE;
+  virtual WebKit::WebMediaPlayer::MovieLoadType movieLoadType() const OVERRIDE;
+
+  virtual float mediaTimeForTimeValue(float timeValue) const OVERRIDE;
+
+  virtual unsigned decodedFrameCount() const OVERRIDE;
+  virtual unsigned droppedFrameCount() const OVERRIDE;
+  virtual unsigned audioDecodedByteCount() const OVERRIDE;
+  virtual unsigned videoDecodedByteCount() const OVERRIDE;
+
+  virtual WebKit::WebVideoFrame* getCurrentFrame() OVERRIDE;
+  virtual void putCurrentFrame(WebKit::WebVideoFrame* web_video_frame) OVERRIDE;
+
+  // As we are closing the tab or even the browser, |main_loop_| is destroyed
+  // even before this object gets destructed, so we need to know when
+  // |main_loop_| is being destroyed and we can stop posting repaint task
+  // to it.
+  virtual void WillDestroyCurrentMessageLoop() OVERRIDE;
+
+ private:
+  // The callback for VideoFrameProvider to signal a new frame is available.
+  void Repaint(const scoped_refptr<media::VideoFrame>& frame);

[scherkus (not reviewing), 2012/09/07 11:44:03]

how about OnFrameAvailable()?

Repaint() is a bit misleading

[wjia(left Chromium), 2012/09/13 01:22:07]

Done.

+  // Need repaint due to state change.
+  void RepaintInternal();
+
+  // The callback for source to report error.
+  void OnSourceError();

[scherkus (not reviewing), 2012/09/07 11:44:03]

this is a callback from VFP but the word "source" doesn't really tell me much
and neither does the comment

what is the "source" in this case? is there a better noun we can use to describe
where the error is coming from?

[wjia(left Chromium), 2012/09/13 01:22:07]

The "source" means the real module which creates the frames, not the
VideoFrameProvider which is just a relayer. For example, the webcam for
LocalVideoCapture, the network for RTCVideoRenderer. 

There could be many types of error from those "sources", e.g., webcam is
unplugged, device goes wrong, network is lost, etc. I might just call it
OnError() without "source". What do you think?

+
+  // Helpers that set the network/ready state and notifies the client if
+  // they've changed.
+  void SetNetworkState(WebKit::WebMediaPlayer::NetworkState state);
+  void SetReadyState(WebKit::WebMediaPlayer::ReadyState state);
+
+  // Destroy resources held.
+  void Destroy();
+
+  // Getter method to |client_|.
+  WebKit::WebMediaPlayerClient* GetClient();
+
+  // Lets V8 know that player uses extra resources not managed by V8.
+  void IncrementExternallyAllocatedMemory();
+
+  WebKit::WebFrame* frame_;
+
+  WebKit::WebMediaPlayer::NetworkState network_state_;
+  WebKit::WebMediaPlayer::ReadyState ready_state_;
+
+  WebKit::WebTimeRanges buffered_;
+
+  // Message loop for DCHECKs so methods calls executed in the correct thread.
+  MessageLoop* main_loop_;
+
+  WebKit::WebMediaPlayerClient* client_;
+
+  base::WeakPtr<WebMediaPlayerDelegate> delegate_;
+
+  MediaStreamClient* media_stream_client_;
+  scoped_refptr<VideoFrameProvider> video_frame_provider_;
+  bool video_frame_provider_started_;
+  bool paused_;
+  scoped_refptr<media::VideoFrame> current_frame_;
+  bool pending_repaint_;
+  bool got_first_frame_;
+  base::TimeDelta start_time_;
+  unsigned total_frame_count_;
+  unsigned dropped_frame_count_;
+  SkCanvasVideoRenderer video_renderer_;
+
+  scoped_refptr<media::MediaLog> media_log_;
+
+  // Since accelerated compositing status is only known after the first layout,
+  // we delay reporting it to UMA until that time.
+  bool accelerated_compositing_reported_;

[scherkus (not reviewing), 2012/09/07 11:44:03]

It looks like you copied code from WebMediaPlayerImpl that isn't applicable to
media streams

Can you make a pass to remove unneeded code/variables?

[wjia(left Chromium), 2012/09/13 01:22:07]

yes, this one is copied from WMPImpl. Removing this one. I thought this variable
is needed since it doesn't check any condition. 

Please let me know what else is not applicable here.

+
+  bool incremented_externally_allocated_memory_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerMS);
+};
+
+}  // namespace webkit_media
+
+#endif  // WEBKIT_MEDIA_WEBMEDIAPLAYER_MS_H_