diff options
Diffstat (limited to 'content/browser/renderer_host/media/audio_renderer_host.h')
| -rw-r--r-- | content/browser/renderer_host/media/audio_renderer_host.h | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/content/browser/renderer_host/media/audio_renderer_host.h b/content/browser/renderer_host/media/audio_renderer_host.h new file mode 100644 index 0000000..944857f --- /dev/null +++ b/content/browser/renderer_host/media/audio_renderer_host.h @@ -0,0 +1,222 @@ +// Copyright (c) 2011 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 and. +// +// 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 CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_RENDERER_HOST_H_ +#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_RENDERER_HOST_H_ +#pragma once + +#include <map> + +#include "base/gtest_prod_util.h" +#include "base/memory/ref_counted.h" +#include "base/memory/scoped_ptr.h" +#include "base/process.h" +#include "base/shared_memory.h" +#include "content/browser/browser_message_filter.h" +#include "content/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; +struct AudioParameters; + +class AudioRendererHost : public BrowserMessageFilter, + public media::AudioOutputController::EventHandler { + public: + typedef std::pair<int32, int> AudioEntryId; + + struct AudioEntry { + AudioEntry(); + ~AudioEntry(); + + // The AudioOutputController that manages the audio stream. + scoped_refptr<media::AudioOutputController> 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<media::AudioOutputController::SyncReader> reader; + + bool pending_buffer_request; + + // Set to true after we called Close() for the controller. + bool pending_close; + }; + + typedef std::map<AudioEntryId, AudioEntry*> AudioEntryMap; + + // Called from UI thread from the owner of this object. + AudioRendererHost(); + + + // BrowserMessageFilter implementation. + virtual void OnChannelClosing(); + virtual void OnDestruct() const; + virtual 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<AudioRendererHost>; + 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 AudioParameters& 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); + + // 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); + + // 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); + + // A map of id to audio sources. + AudioEntryMap audio_entries_; + + DISALLOW_COPY_AND_ASSIGN(AudioRendererHost); +}; + +#endif // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_RENDERER_HOST_H_ |