// Copyright (c) 2010 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 (except Destroy()) happens // in 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 and // AddRef() is called to increase one ref count of this object. Owner of this // class should call Destroy() before decrementing the ref count to this object, // which essentially post a task of OnDestroyed() on IO thread. Inside // OnDestroyed(), audio output streams are destroyed and Release() is called // which may result in self-destruction. // // Here's an example of a typical IPC dialog for audio: // // Renderer AudioRendererHost // | | // | CreateStream > | // | < Created | // | | // | Play > | // | < Playing | time // | | // | < RequestAudioPacket | // | AudioPacketReady > | // | ... | // | < RequestAudioPacket | // | AudioPacketReady > | // | | // | ... | // | < RequestAudioPacket | // | AudioPacketReady > | // | ... | // | Pause > | // | < Paused | // | ... | // | Start > | // | < Started | // | ... | // | Close > | // v v // The above mode of operation uses relatively big buffers and has latencies // of 50 ms or more. There is a second mode of operation which is low latency. // For low latency audio, the picture above is modified by not having the // RequestAudioPacket and the AudioPacketReady messages, instead a SyncSocket // pair is used to signal buffer readiness without having to route messages // using the IO thread. #ifndef CHROME_BROWSER_RENDERER_HOST_AUDIO_RENDERER_HOST_H_ #define CHROME_BROWSER_RENDERER_HOST_AUDIO_RENDERER_HOST_H_ #pragma once #include #include "base/gtest_prod_util.h" #include "base/lock.h" #include "base/process.h" #include "base/ref_counted.h" #include "base/scoped_ptr.h" #include "base/shared_memory.h" #include "chrome/browser/browser_thread.h" #include "ipc/ipc_message.h" #include "media/audio/audio_io.h" #include "media/audio/audio_output_controller.h" #include "media/audio/simple_sources.h" class AudioManager; struct ViewHostMsg_Audio_CreateStream_Params; class AudioRendererHost : public base::RefCountedThreadSafe< AudioRendererHost, BrowserThread::DeleteOnIOThread>, public media::AudioOutputController::EventHandler { public: typedef std::pair AudioEntryId; struct AudioEntry { AudioEntry(); ~AudioEntry(); // The AudioOutputController that manages the audio stream. scoped_refptr controller; // Render view ID that requested the audio stream. int32 render_view_id; // The audio stream ID in the render view. 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 reader; bool pending_buffer_request; // Set to true after we called Close() for the controller. bool pending_close; }; typedef std::map AudioEntryMap; // Called from UI thread from the owner of this object. AudioRendererHost(); // Called from UI thread from the owner of this object to kick start // destruction of streams in IO thread. void Destroy(); ///////////////////////////////////////////////////////////////////////////// // The following public methods are called from ResourceMessageFilter in the // IO thread. // Event received when IPC channel is connected with the renderer process. void IPCChannelConnected(int process_id, base::ProcessHandle process_handle, IPC::Message::Sender* ipc_sender); // Event received when IPC channel is closing. void IPCChannelClosing(); // Returns true if the message is a audio related message and was processed. // If it was, message_was_ok will be false iff the message was corrupt. bool OnMessageReceived(const IPC::Message& message, bool* message_was_ok); ///////////////////////////////////////////////////////////////////////////// // AudioOutputController::EventHandler implementations. virtual void OnCreated(media::AudioOutputController* controller); virtual void OnPlaying(media::AudioOutputController* controller); virtual void OnPaused(media::AudioOutputController* controller); virtual void OnError(media::AudioOutputController* controller, int error_code); virtual void OnMoreData(media::AudioOutputController* controller, AudioBuffersState buffers_state); private: friend class AudioRendererHostTest; friend class BrowserThread; friend class DeleteTask; friend class MockAudioRendererHost; FRIEND_TEST_ALL_PREFIXES(AudioRendererHostTest, CreateMockStream); FRIEND_TEST_ALL_PREFIXES(AudioRendererHostTest, MockStreamDataConversation); virtual ~AudioRendererHost(); //////////////////////////////////////////////////////////////////////////// // Methods called on IO thread. // Returns true if the message is an audio related message and should be // handled by this class. bool IsAudioRendererHostMessage(const IPC::Message& message); // 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(const IPC::Message& msg, int stream_id, const ViewHostMsg_Audio_CreateStream_Params& params, bool low_latency); // Play the audio stream referenced by |stream_id|. void OnPlayStream(const IPC::Message& msg, int stream_id); // Pause the audio stream referenced by |stream_id|. void OnPauseStream(const IPC::Message& msg, int stream_id); // Discard all audio data in stream referenced by |stream_id|. void OnFlushStream(const IPC::Message& msg, int stream_id); // Close the audio stream referenced by |stream_id|. void OnCloseStream(const IPC::Message& msg, int stream_id); // Set the volume of the audio stream referenced by |stream_id|. void OnSetVolume(const IPC::Message& msg, int stream_id, double volume); // Get the volume of the audio stream referenced by |stream_id|. void OnGetVolume(const IPC::Message& msg, int stream_id); // Notify packet has been prepared for the audio stream. void OnNotifyPacketReady(const IPC::Message& msg, int stream_id, uint32 packet_size); // Release all acquired resources and decrease reference to this object. void DoDestroy(); // 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); // Request more data from the renderer. This method is used only in normal // latency mode. void DoRequestMoreData(media::AudioOutputController* controller, AudioBuffersState buffers_state); // Handle error coming from audio stream. void DoHandleError(media::AudioOutputController* controller, int error_code); // A helper method to send an IPC message to renderer process on IO thread. // This method is virtual for testing purpose. virtual void SendMessage(IPC::Message* message); // Send an error message to the renderer. void SendErrorMessage(int32 render_view_id, int32 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); // Called on the audio thread after the audio stream is closed. void OnStreamClosed(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 with a tuple of render view // id and stream id. Returns NULL if not found. AudioEntry* LookupById(int render_view_id, 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); int process_id_; base::ProcessHandle process_handle_; IPC::Message::Sender* ipc_sender_; // A map of id to audio sources. AudioEntryMap audio_entries_; DISALLOW_COPY_AND_ASSIGN(AudioRendererHost); }; #endif // CHROME_BROWSER_RENDERER_HOST_AUDIO_RENDERER_HOST_H_