WIP - Add EME

media/remoting/remoting_renderer_controller.h

+// Copyright 2016 The Chromium Authors. All rights reserved.

[miu, 2016/10/25 04:21:26]

Since remoting_renderer_controller.h/.cc are modifications of the [now deleted]
remoting_controller.h/.cc, consider uploading your next patch set with a lower
similarity (maybe `git cl upload --similarity=20` would work?) so that these new
files show up as a diff from the old files.

[xjz, 2016/10/26 22:00:26]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MEDIA_REMOTING_REMOTING_RENDERER_CONTROLLER_H_
+#define MEDIA_REMOTING_REMOTING_RENDERER_CONTROLLER_H_
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+#include "media/base/media_observer.h"
+#include "media/remoting/remoting_source_impl.h"
+
+namespace media {
+struct PipelineMetadata;
+}
+
+namespace media {
+
+// This class:
+// 1) Implements the RemotingSourceImpl::Client;
+// 2) Monitors player events as a MediaObserver;
+// 3) May trigger the switch of the media renderer between local playback
+// and remoting.
+class RemotingRendererController final : public RemotingSourceImpl::Client,
+                                         public MediaObserver {
+ public:
+  explicit RemotingRendererController(
+      scoped_refptr<RemotingSourceImpl> remoting_source);
+  ~RemotingRendererController() override;
+
+  // RemotingSourceImpl::Client implemenations.
+  void OnStarted(bool success) override;
+  void OnSessionStateChanged() override;
+
+  // MediaObserver implementations.
+  void OnEnteredFullscreen() override;
+  void OnExitedFullscreen() override;
+  void OnSetCdm(CdmContext* cdm_context) override;
+  void OnMetadataChanged(const PipelineMetadata& metadata) override;
+
+  using SwitchRendererCallback = base::Callback<void()>;

[miu, 2016/10/25 04:21:26]

This is the same as base::Closure, so consider removing this typedef and just
using base::Closure.

[xjz, 2016/10/26 22:00:26]

Done.

+  void SetSwitchRendererCallback(const SwitchRendererCallback& cb);
+
+  base::WeakPtr<RemotingRendererController> GetWeakPtr() {
+    return weak_factory_.GetWeakPtr();
+  }
+
+  // Used to query whether to create Media Remoting Renderer.

[miu, 2016/10/25 04:21:26]

To help those unfamiliar with this code: s/Used to query/Used by
RemotingRendererFactory to query/

[xjz, 2016/10/26 22:00:26]

Done.

+  bool IsRemoting() const;
+
+  // Used to query whether the remoting session is permanently terminated.

[miu, 2016/10/25 04:21:26]

ditto: (Used by RemotingRendererFactory)

[xjz, 2016/10/26 22:00:26]

Done.

+  bool IsTerminated() const;
+
+ private:
+  bool IsVideoCodecSupported();
+  bool IsAudioCodecSupported();
+
+  // Helper to decide whether to enter or leave Remoting mode.
+  bool ShouldBeRemoting();
+
+  // Determines whether to enter or leave Remoting mode and switches if
+  // necessary.
+  void UpdateAndMaybeSwitch();
+
+  // Indicates if this media element or its ancestor enters full screen.

[miu, 2016/10/25 04:21:26]

s/if/whether/

and

s/enters/is in/

[xjz, 2016/10/26 22:00:26]

Done.

+  bool is_fullscreen_ = false;
+
+  // Indicates whether to switch to remoting.
+  bool should_be_remoting_ = false;

[miu, 2016/10/25 04:21:26]

naming: Based on the way this variable is used, it seems like it should be named
|remote_rendering_started_|. (and to avoid confusion between this variable and
the ShouldBeRemoting() helper method)

[xjz, 2016/10/26 22:00:26]

Done.

+
+  // Indicates whether remoting session can be started.
+  bool can_start_remoting_ = false;
+
+  // Indicates whether audio or video is encrypted.
+  bool is_encrypted_ = false;
+
+  // Current audio/video config.
+  VideoDecoderConfig video_decoder_config_;
+  AudioDecoderConfig audio_decoder_config_;
+  bool has_audio_ = false;
+  bool has_video_ = false;
+
+  // The callback to switch the media renderer.
+  SwitchRendererCallback switch_renderer_cb_;
+
+  // This will be replaced by the remoting source in RemotingCdmController

[miu, 2016/10/25 04:21:26]

For clarification: "This is initially the RemotingSourceImpl passed to the ctor,
and might be replaced with a different instance later if OnSetCdm() is called."

[xjz, 2016/10/26 22:00:26]

Done.

+  // when OnSetCdm() is called.
+  scoped_refptr<RemotingSourceImpl> remoting_source_;
+
+  // This is used to check all the methods are called on the current thread in
+  // debug builds.
+  base::ThreadChecker thread_checker_;
+
+  base::WeakPtrFactory<RemotingRendererController> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(RemotingRendererController);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_REMOTING_REMOTING_RENDERER_CONTROLLER_H_