media: scaffolding and plumbing for MojoRenderer{Impl, Service}

media/mojo/services/mojo_renderer_impl.h

+// Copyright 2014 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 MEDIA_MOJO_SERVICES_MOJO_RENDERER_IMPL_H_
+#define MEDIA_MOJO_SERVICES_MOJO_RENDERER_IMPL_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "media/base/renderer.h"
+#include "media/mojo/interfaces/media_renderer.mojom.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}
+
+namespace mojo {
+class ServiceProvider;
+}
+
+namespace media {
+class DemuxerStreamProvider;
+
+// A media::Renderer that proxies to a mojo::MediaRenderer. That
+// mojo::MediaRenderer proxies back to the MojoRendererImpl via the
+// mojo::MediaRendererClient interface.
+//
+// MojoRendererImpl implements media::Renderer for use as either an audio
+// or video renderer.
+//
+// TODO(tim): Only audio is currently supported. http://crbug.com/410451.
+class MojoRendererImpl : public Renderer, public mojo::MediaRendererClient {
+ public:
+  // |task_runner| is the TaskRunner on which all methods are invoked.
+  // |demuxer_stream_provider| provides encoded streams for decoding and
+  //     rendering.
+  // |audio_renderer_provider| is a ServiceProvider from a connected
+  //     Application that is hosting a mojo::MediaRenderer.
+  MojoRendererImpl(
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+      DemuxerStreamProvider* demuxer_stream_provider,
+      mojo::ServiceProvider* audio_renderer_provider);
+  virtual ~MojoRendererImpl();
+
+  // Renderer implementation.
+  virtual void Initialize(const base::Closure& init_cb,
+                          const StatisticsCB& statistics_cb,
+                          const base::Closure& ended_cb,
+                          const PipelineStatusCB& error_cb,
+                          const BufferingStateCB& buffering_state_cb) OVERRIDE;
+  virtual void Flush(const base::Closure& flush_cb) OVERRIDE;
+  virtual void StartPlayingFrom(base::TimeDelta time) OVERRIDE;
+  virtual void SetPlaybackRate(float playback_rate) OVERRIDE;
+  virtual void SetVolume(float volume) OVERRIDE;
+  virtual base::TimeDelta GetMediaTime() OVERRIDE;
+  virtual bool HasAudio() OVERRIDE;
+  virtual bool HasVideo() OVERRIDE;
+  virtual void SetCdm(MediaKeys* cdm) OVERRIDE;
+
+  // mojo::MediaRendererClient implementation.
+  virtual void OnTimeUpdate(int64_t time_usec,
+                            int64_t max_time_usec) MOJO_OVERRIDE;
+  virtual void OnBufferingStateChange(mojo::BufferingState state) MOJO_OVERRIDE;
+  virtual void OnEnded() MOJO_OVERRIDE;
+  virtual void OnError() MOJO_OVERRIDE;
+
+ private:
+  // Called when |remote_audio_renderer_| has finished initializing.
+  void OnInitialized();
+
+  // Task runner used to execute pipeline tasks.
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
+  DemuxerStreamProvider* demuxer_stream_provider_;
+  mojo::MediaRendererPtr remote_audio_renderer_;
+
+  // Callbacks passed to Initialize() that we forward messages from
+  // |remote_audio_renderer_| through.
+  base::Closure init_cb_;
+  base::Closure ended_cb_;
+  PipelineStatusCB error_cb_;
+  BufferingStateCB buffering_state_cb_;
+
+  base::WeakPtrFactory<MojoRendererImpl> weak_factory_;
+  DISALLOW_COPY_AND_ASSIGN(MojoRendererImpl);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_MOJO_SERVICES_MOJO_RENDERER_IMPL_H_