Break down the webrtc code and AudioInputDevice into a WebRtcAudioCapturer.

This capturer contains a source (AudioInputDevice) and a sink (WebRtcAudioDeviceImpl) by default. What it does is to get data from AudioInputDevice via CaptureCallback::Capture() callback,
and forward the data to WebRtcAudioDeviceImpl.

The source can be over written by API:
SetCapturerSource(media::AudioCapturerSource* source)

This capture currently only support one sink (WebRtcAudioDeviceImpl), but this can be extended to multiple sinks for the future.

Design doc: https://docs.google.com/a/google.com/document/d/1FmiXtk1pxFlAw_CWwbfG-EQ4Syi4vpnZm6GWMyJ1UfU/edit

BUG=157306
TEST=manual test

Review URL: https://codereview.chromium.org/11231003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@167387 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 96 insertions, 56 deletions

diff --git a/media/audio/audio_input_device.cc b/media/audio/audio_input_device.cc
index e457787..a60d60d 100644
--- a/media/audio/audio_input_device.cc
+++ b/media/audio/audio_input_device.cc
@@ -13,9 +13,6 @@
 
 namespace media {
 
-AudioInputDevice::CaptureCallback::~CaptureCallback() {}
-AudioInputDevice::CaptureEventHandler::~CaptureEventHandler() {}
-
 // Takes care of invoking the capture callback on the audio thread.
 // An instance of this class is created for each capture stream in
 // OnLowLatencyCreated().
diff --git a/media/audio/audio_input_device.h b/media/audio/audio_input_device.h
index ddb2535..edefdf1 100644
--- a/media/audio/audio_input_device.h
+++ b/media/audio/audio_input_device.h
@@ -72,6 +72,7 @@
 #include "media/audio/audio_input_ipc.h"
 #include "media/audio/audio_parameters.h"
 #include "media/audio/scoped_loop_observer.h"
+#include "media/base/audio_capturer_source.h"
 #include "media/base/media_export.h"
 
 namespace media {
@@ -82,63 +83,22 @@ namespace media {
 // OnCaptureStopped etc.) and ensure that we can deliver these notifications
 // to any clients using this class.
 class MEDIA_EXPORT AudioInputDevice
-    : NON_EXPORTED_BASE(public AudioInputIPCDelegate),
-      NON_EXPORTED_BASE(public ScopedLoopObserver),
-      public base::RefCountedThreadSafe<AudioInputDevice> {
+    : NON_EXPORTED_BASE(public AudioCapturerSource),
+      NON_EXPORTED_BASE(public AudioInputIPCDelegate),
+      NON_EXPORTED_BASE(public ScopedLoopObserver) {
  public:
-  class MEDIA_EXPORT CaptureCallback {
-   public:
-    virtual void Capture(AudioBus* audio_bus,
-                         int audio_delay_milliseconds,
-                         double volume) = 0;
-    virtual void OnCaptureError() = 0;
-   protected:
-    virtual ~CaptureCallback();
-  };
-
-  class MEDIA_EXPORT CaptureEventHandler {
-   public:
-    // Notification to the client that the device with the specific |device_id|
-    // has been started.
-    // This callback is triggered as a result of StartDevice().
-    virtual void OnDeviceStarted(const std::string& device_id) = 0;
-
-    // Notification to the client that the device has been stopped.
-    virtual void OnDeviceStopped() = 0;
-
-   protected:
-    virtual ~CaptureEventHandler();
-  };
-
   AudioInputDevice(AudioInputIPC* ipc,
                    const scoped_refptr<base::MessageLoopProxy>& io_loop);
 
-  // Initializes the AudioInputDevice.  This method must be called before
-  // any other methods can be used.
-  void Initialize(const AudioParameters& params,
-                  CaptureCallback* callback,
-                  CaptureEventHandler* event_handler);
-
-  // Specify the |session_id| to query which device to use.
-  // Start() will use the second sequence if this method is called before.
-  void SetDevice(int session_id);
-
-  // Starts audio capturing.
-  // TODO(henrika): add support for notification when recording has started.
-  void Start();
-
-  // Stops audio capturing.
-  // TODO(henrika): add support for notification when recording has stopped.
-  void Stop();
-
-  // Sets the capture volume scaling, with range [0.0, 1.0] inclusive.
-  // Returns |true| on success.
-  void SetVolume(double volume);
-
-  // Sets the Automatic Gain Control state to on or off.
-  // This method must be called before Start(). It will not have any effect
-  // if it is called while capturing has already started.
-  void SetAutomaticGainControl(bool enabled);
+  // AudioCapturerSource implementation.
+  virtual void Initialize(const AudioParameters& params,
+                          CaptureCallback* callback,
+                          CaptureEventHandler* event_handler) OVERRIDE;
+  virtual void Start() OVERRIDE;
+  virtual void Stop() OVERRIDE;
+  virtual void SetVolume(double volume) OVERRIDE;
+  virtual void SetDevice(int session_id) OVERRIDE;
+  virtual void SetAutomaticGainControl(bool enabled) OVERRIDE;
 
  protected:
   // Methods called on IO thread ----------------------------------------------
diff --git a/media/base/audio_capturer_source.h b/media/base/audio_capturer_source.h
new file mode 100644
index 0000000..7611025
--- /dev/null
+++ b/media/base/audio_capturer_source.h
@@ -0,0 +1,81 @@
+// 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.
+
+#ifndef MEDIA_BASE_AUDIO_CAPTURER_SOURCE_H_
+#define MEDIA_BASE_AUDIO_CAPTURER_SOURCE_H_
+
+#include <vector>
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "media/audio/audio_parameters.h"
+#include "media/base/audio_bus.h"
+#include "media/base/media_export.h"
+
+namespace media {
+
+// AudioCapturerSource is an interface representing the source for
+// captured audio.  An implementation will periodically call Capture() on a
+// callback object.
+class AudioCapturerSource
+    : public base::RefCountedThreadSafe<media::AudioCapturerSource> {
+ public:
+  class CaptureCallback {
+   public:
+    // Callback to deliver the captured data from the OS.
+    virtual void Capture(AudioBus* audio_source,
+                         int audio_delay_milliseconds,
+                         double volume) = 0;
+
+    // Signals an error has occurred.
+    virtual void OnCaptureError() = 0;
+
+   protected:
+    virtual ~CaptureCallback() {}
+  };
+
+  class CaptureEventHandler {
+   public:
+    // Notification to the client that the device with the specific |device_id|
+    // has been started.
+    virtual void OnDeviceStarted(const std::string& device_id) = 0;
+
+    // Notification to the client that the device has been stopped.
+    virtual void OnDeviceStopped() = 0;
+
+   protected:
+    virtual ~CaptureEventHandler() {}
+  };
+
+  // Sets information about the audio stream format and the device
+  // to be used. It must be called before any of the other methods.
+  // TODO(xians): Add |device_id| to this Initialize() function.
+  virtual void Initialize(const AudioParameters& params,
+                          CaptureCallback* callback,
+                          CaptureEventHandler* event_handler) = 0;
+
+  // Starts the audio recording.
+  virtual void Start() = 0;
+
+  // Stops the audio recording. This API is synchronous, and no more data
+  // callback will be passed to the client after it is being called.
+  virtual void Stop() = 0;
+
+  // Sets the capture volume, with range [0.0, 1.0] inclusive.
+  virtual void SetVolume(double volume) = 0;
+
+  // Specifies the |session_id| to query which device to use.
+  // TODO(xians): Change the interface to SetDevice(const std::string&).
+  virtual void SetDevice(int session_id) = 0;
+
+  // Enables or disables the WebRtc AGC control.
+  virtual void SetAutomaticGainControl(bool enable) = 0;
+
+ protected:
+  friend class base::RefCountedThreadSafe<AudioCapturerSource>;
+  virtual ~AudioCapturerSource() {}
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_AUDIO_CAPTURER_SOURCE_H_
diff --git a/media/media.gyp b/media/media.gyp
index 9fb5f37..b0c2bdf 100644
--- a/media/media.gyp
+++ b/media/media.gyp
@@ -158,6 +158,7 @@
         'base/android/cookie_getter.h',
         'base/android/media_player_bridge_manager.cc',
         'base/android/media_player_bridge_manager.h',
+        'base/audio_capturer_source.h',
         'base/audio_decoder.cc',
         'base/audio_decoder.h',
         'base/audio_decoder_config.cc',
@@ -168,6 +169,7 @@
         'base/audio_pull_fifo.h',
         'base/audio_renderer.cc',
         'base/audio_renderer.h',
+        'base/audio_renderer_sink.h',
         'base/audio_renderer_mixer.cc',
         'base/audio_renderer_mixer.h',
         'base/audio_renderer_mixer_input.cc',