content/browser/renderer_host/media/web_contents_audio_input_stream.h

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4 //
   5 // An AudioInputStream which provides a loop-back of all audio output generated
   6 // by the RenderView associated with a WebContents instance.  The single stream
   7 // of data is produced by format-converting and mixing all audio output from a
   8 // RenderView.  In other words, WebContentsAudioInputStream provides tab-level
   9 // audio mirroring.
  10 //
  11 // The implementation observes a WebContents instance (which represents a
  12 // browser tab) so that it can track the replacement of RenderViews due to
  13 // navigation, crash/reload, etc. events; and take appropriate actions to
  14 // provide a seamless, uninterrupted mirroring experience.
  15
  16 #ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_WEB_CONTENTS_AUDIO_INPUT_STREAM_H_
  17 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_WEB_CONTENTS_AUDIO_INPUT_STREAM_H_
  18
  19 #include <string>
  20
  21 #include "base/memory/ref_counted.h"
  22 #include "content/common/content_export.h"
  23 #include "media/audio/audio_io.h"
  24
  25 namespace base {
  26 class MessageLoopProxy;
  27 }
  28
  29 namespace media {
  30 class AudioParameters;
  31 class VirtualAudioInputStream;
  32 }
  33
  34 namespace content {
  35
  36 class AudioMirroringManager;
  37 class WebContentsTracker;
  38
  39 class CONTENT_EXPORT WebContentsAudioInputStream
  40     : NON_EXPORTED_BASE(public media::AudioInputStream) {
  41  public:
  42   // media::AudioInputStream implementation
  43   virtual bool Open() OVERRIDE;
  44   virtual void Start(AudioInputCallback* callback) OVERRIDE;
  45   virtual void Stop() OVERRIDE;
  46   virtual void Close() OVERRIDE;
  47   virtual double GetMaxVolume() OVERRIDE;
  48   virtual void SetVolume(double volume) OVERRIDE;
  49   virtual double GetVolume() OVERRIDE;
  50   virtual void SetAutomaticGainControl(bool enabled) OVERRIDE;
  51   virtual bool GetAutomaticGainControl() OVERRIDE;
  52
  53   // Create a new audio mirroring session, or return NULL on error.  |device_id|
  54   // should be in the format accepted by
  55   // WebContentsCaptureUtil::ExtractTabCaptureTarget().  The caller must
  56   // guarantee Close() is called on the returned object so that it may
  57   // self-destruct.
  58   // |worker_loop| is the loop on which AudioInputCallback methods are called
  59   // and may or may not be the single thread that invokes the AudioInputStream
  60   // methods.
  61   static WebContentsAudioInputStream* Create(
  62       const std::string& device_id,
  63       const media::AudioParameters& params,
  64       const scoped_refptr<base::MessageLoopProxy>& worker_loop,
  65       AudioMirroringManager* audio_mirroring_manager);
  66
  67  private:
  68   friend class WebContentsAudioInputStreamTest;
  69
  70   // Maintain most state and functionality in an internal ref-counted
  71   // implementation class.  This object must outlive a call to Close(), until
  72   // the shutdown tasks running on other threads complete: The
  73   // AudioMirroringManager on the IO thread, the WebContentsTracker on the UI
  74   // thread, and the VirtualAudioOuputStreams on the audio thread.
  75   class Impl;
  76
  77   WebContentsAudioInputStream(
  78       int render_process_id, int render_view_id,
  79       AudioMirroringManager* mirroring_manager,
  80       const scoped_refptr<WebContentsTracker>& tracker,
  81       media::VirtualAudioInputStream* mixer_stream);
  82
  83   virtual ~WebContentsAudioInputStream();
  84
  85   scoped_refptr<Impl> impl_;
  86
  87   DISALLOW_COPY_AND_ASSIGN(WebContentsAudioInputStream);
  88 };
  89
  90 }  // namespace content
  91
  92 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_WEB_CONTENTS_AUDIO_INPUT_STREAM_H_