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

media/mojo/services/mojo_renderer_service.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_SERVICE_H_
+#define MEDIA_MOJO_SERVICES_MOJO_RENDERER_SERVICE_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "media/base/audio_decoder_config.h"
+#include "media/base/audio_hardware_config.h"
+#include "media/base/buffering_state.h"
+#include "media/base/pipeline_status.h"
+#include "media/mojo/interfaces/media_renderer.mojom.h"
+#include "mojo/public/cpp/bindings/interface_impl.h"
+
+namespace mojo {
+class ApplicationConnection;
+}
+
+namespace media {
+
+class AudioRenderer;
+class MojoDemuxerStreamAdapter;
+
+// A mojo::MediaRenderer implementation that uses media::AudioRenderer to
+// decode and render audio to a sink obtained from the ApplicationConnection.
+class MojoRendererService : public mojo::InterfaceImpl<mojo::MediaRenderer> {
+ public:
+  // |connection| is a pointer to the connection back to our embedder. The
+  // embedder should have configured it (via ConfigureOutgoingConnection) to
+  // allow |this| to connect to a sink that will receive decoded data ready
+  // for playback.
+  explicit MojoRendererService(mojo::ApplicationConnection* connection);
+  virtual ~MojoRendererService();
+
+  // mojo::MediaRenderer implementation.
+  virtual void Initialize(mojo::DemuxerStreamPtr stream,
+                          const mojo::Callback<void()>& callback) MOJO_OVERRIDE;
+  virtual void Flush(const mojo::Callback<void()>& callback) MOJO_OVERRIDE;
+  virtual void StartPlayingFrom(int64_t time_delta_usec) MOJO_OVERRIDE;
+  virtual void SetPlaybackRate(float playback_rate) MOJO_OVERRIDE;
+  virtual void SetVolume(float volume) MOJO_OVERRIDE;
+
+ private:
+  // Called when the MojoDemuxerStreamAdapter is ready to go (has a config,
+  // pipe handle, etc) and can be handed off to a renderer for use.
+  void OnStreamReady();
+
+  // Called when |audio_renderer_| initialization has completed.
+  void OnAudioRendererInitializeDone(PipelineStatus status);
+
+  // Callback executed by filters to update statistics.
+  void OnUpdateStatistics(const PipelineStatistics& stats);
+
+  // Callback executed by audio renderer to update clock time.
+  void OnAudioTimeUpdate(base::TimeDelta time, base::TimeDelta max_time);
+
+  // Callback executed by audio renderer when buffering state changes.
+  // TODO(tim): Need old and new.
+  void OnBufferingStateChanged(BufferingState new_buffering_state);
+
+  // Callback executed when a renderer has ended.
+  void OnAudioRendererEnded();
+
+  // Callback executed when a runtime error happens.
+  void OnError(PipelineStatus error);
+
+  scoped_ptr<MojoDemuxerStreamAdapter> stream_;
+  scoped_ptr<AudioRenderer> audio_renderer_;
+
+  mojo::Callback<void()> init_cb_;
+
+  // TODO(tim): Figure out how to set up hardware config.
+  // NOTE: AudioRendererImpl stores a const& to the config we pass in (hmm..).
+  // Hence stack-allocating one and passing it to Initialize results in
+  // undefined badness (e.g, hangs trying to acquire config_lock_);
+  media::AudioHardwareConfig hardware_config_;
+
+  base::WeakPtrFactory<MojoRendererService> weak_factory_;
+  base::WeakPtr<MojoRendererService> weak_this_;
+  DISALLOW_COPY_AND_ASSIGN(MojoRendererService);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_MOJO_SERVICES_MOJO_RENDERER_SERVICE_H_