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// 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.
// AudioRendererHost serves audio related requests from AudioRenderer which
// lives inside the render process and provide access to audio hardware.
// This class is owned by BrowserRenderProcessHost, and instantiated on UI
// thread, but all other operations and method calls happen on IO thread, so we
// need to be extra careful about the lifetime of this object. AudioManager is a
// singleton and created in IO thread, audio output streams are also created in
// the IO thread, so we need to destroy them also in IO thread. After this class
// is created, a task of OnInitialized() is posted on IO thread in which
// singleton of AudioManager is created.
// Here's an example of a typical IPC dialog for audio:
// Renderer AudioRendererHost
// | |
// | CreateStream > |
// | < NotifyStreamCreated |
// | |
// | PlayStream > |
// | < NotifyStreamStateChanged | kAudioStreamPlaying
// | |
// | PauseStream > |
// | < NotifyStreamStateChanged | kAudioStreamPaused
// | |
// | PlayStream > |
// | < NotifyStreamStateChanged | kAudioStreamPlaying
// | ... |
// | CloseStream > |
// v v
// A SyncSocket pair is used to signal buffer readiness between processes.
#pragma once
#include <map>
#include "base/gtest_prod_util.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/message_loop_helpers.h"
#include "base/process.h"
#include "base/shared_memory.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_message_filter.h"
#include "content/public/browser/browser_thread.h"
#include "media/audio/audio_io.h"
#include "media/audio/audio_output_controller.h"
#include "media/audio/simple_sources.h"
class AudioManager;
class AudioParameters;
namespace content {
class MediaObserver;
class ResourceContext;
} // namespace content
class CONTENT_EXPORT AudioRendererHost
: public content::BrowserMessageFilter,
public media::AudioOutputController::EventHandler {
struct AudioEntry {
// The AudioOutputController that manages the audio stream.
scoped_refptr<media::AudioOutputController> controller;
// The audio stream ID.
int stream_id;
// Shared memory for transmission of the audio data.
base::SharedMemory shared_memory;
// The synchronous reader to be used by the controller. We have the
// ownership of the reader.
scoped_ptr<media::AudioOutputController::SyncReader> reader;
// Set to true after we called Close() for the controller.
bool pending_close;
typedef std::map<int, AudioEntry*> AudioEntryMap;
// Called from UI thread from the owner of this object.
AudioRendererHost(AudioManager* audio_manager,
content::MediaObserver* media_observer);
// content::BrowserMessageFilter implementation.
virtual void OnChannelClosing() OVERRIDE;
virtual void OnDestruct() const OVERRIDE;
virtual bool OnMessageReceived(const IPC::Message& message,
bool* message_was_ok) OVERRIDE;
// AudioOutputController::EventHandler implementations.
virtual void OnCreated(media::AudioOutputController* controller) OVERRIDE;
virtual void OnPlaying(media::AudioOutputController* controller) OVERRIDE;
virtual void OnPaused(media::AudioOutputController* controller) OVERRIDE;
virtual void OnError(media::AudioOutputController* controller,
int error_code) OVERRIDE;
friend class AudioRendererHostTest;
friend class content::BrowserThread;
friend class base::DeleteHelper<AudioRendererHost>;
friend class MockAudioRendererHost;
FRIEND_TEST_ALL_PREFIXES(AudioRendererHostTest, CreateMockStream);
FRIEND_TEST_ALL_PREFIXES(AudioRendererHostTest, MockStreamDataConversation);
virtual ~AudioRendererHost();
// Methods called on IO thread ----------------------------------------------
// Audio related IPC message handlers.
// Creates an audio output stream with the specified format. If this call is
// successful this object would keep an internal entry of the stream for the
// required properties.
void OnCreateStream(int stream_id, const AudioParameters& params);
// Play the audio stream referenced by |stream_id|.
void OnPlayStream(int stream_id);
// Pause the audio stream referenced by |stream_id|.
void OnPauseStream(int stream_id);
// Discard all audio data in stream referenced by |stream_id|.
void OnFlushStream(int stream_id);
// Close the audio stream referenced by |stream_id|.
void OnCloseStream(int stream_id);
// Set the volume of the audio stream referenced by |stream_id|.
void OnSetVolume(int stream_id, double volume);
// Complete the process of creating an audio stream. This will set up the
// shared memory or shared socket in low latency mode.
void DoCompleteCreation(media::AudioOutputController* controller);
// Send a state change message to the renderer.
void DoSendPlayingMessage(media::AudioOutputController* controller);
void DoSendPausedMessage(media::AudioOutputController* controller);
// Handle error coming from audio stream.
void DoHandleError(media::AudioOutputController* controller, int error_code);
// Send an error message to the renderer.
void SendErrorMessage(int stream_id);
// Delete all audio entry and all audio streams
void DeleteEntries();
// Closes the stream. The stream is then deleted in DeleteEntry() after it
// is closed.
void CloseAndDeleteStream(AudioEntry* entry);
// Delete an audio entry and close the related audio stream.
void DeleteEntry(AudioEntry* entry);
// Delete audio entry and close the related audio stream due to an error,
// and error message is send to the renderer.
void DeleteEntryOnError(AudioEntry* entry);
// A helper method to look up a AudioEntry identified by |stream_id|.
// Returns NULL if not found.
AudioEntry* LookupById(int stream_id);
// Search for a AudioEntry having the reference to |controller|.
// This method is used to look up an AudioEntry after a controller
// event is received.
AudioEntry* LookupByController(media::AudioOutputController* controller);
// A map of stream IDs to audio sources.
AudioEntryMap audio_entries_;
AudioManager* audio_manager_;
content::MediaObserver* media_observer_;
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