Browser-wide audio mirroring for TabCapture API

media/audio/virtual_audio_input_stream.h

+// 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_AUDIO_VIRTUAL_AUDIO_INPUT_STREAM_H_
+#define MEDIA_AUDIO_VIRTUAL_AUDIO_INPUT_STREAM_H_
+
+#include <map>
+#include <set>
+
+#include "base/cancelable_callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "media/audio/audio_io.h"
+#include "media/audio/audio_manager_base.h"
+#include "media/audio/audio_parameters.h"
+#include "media/base/audio_converter.h"
+
+namespace media {
+
+class VirtualAudioOutputStream;
+class LoopbackAudioConverter;
+
+class MEDIA_EXPORT VirtualAudioInputStream

[DaleCurtis, 2012/11/21 23:45:43]

Please provide a block class comment, method comments and then variable comments
where necessary. This class is really sparse at present.  See audio_converter.h
for an example.

[justinlin, 2012/11/26 20:19:20]

Done.

+    : public AudioInputStream {
+ public:
+  static VirtualAudioInputStream* MakeStream(AudioManagerBase* manager,
+                                             const AudioParameters& params);
+
+  virtual bool Open() OVERRIDE;

[DaleCurtis, 2012/11/21 23:45:43]

Comment what interface this is implementing.

[justinlin, 2012/11/26 20:19:20]

Done.

+  virtual void Start(AudioInputCallback* callback) OVERRIDE;
+  virtual void Stop() OVERRIDE;
+  virtual void Close() OVERRIDE;
+  virtual double GetMaxVolume() OVERRIDE;
+  virtual void SetVolume(double volume) OVERRIDE;
+  virtual double GetVolume() OVERRIDE;
+  virtual void SetAutomaticGainControl(bool enabled) OVERRIDE;
+  virtual bool GetAutomaticGainControl() OVERRIDE;
+
+  void AddOutputStream(
+      VirtualAudioOutputStream* stream, const AudioParameters& params);
+  void RemoveOutputStream(VirtualAudioOutputStream* stream);
+
+ private:
+  typedef std::map<AudioParameters, LoopbackAudioConverter*> AudioConvertersMap;
+  typedef std::map<AudioOutputStream*, AudioParameters> OutputStreamParams;
+
+  void DoCallback();
+
+  VirtualAudioInputStream(AudioManagerBase* manager,
+                       const AudioParameters& params);

[miu, 2012/11/22 00:53:50]

fix indent

[justinlin, 2012/11/26 20:19:20]

Done.

+
+  virtual ~VirtualAudioInputStream();
+
+  AudioManagerBase* audio_manager_;
+  AudioInputCallback* callback_;
+  scoped_array<uint8> buffer_;
+  int buffer_size_;
+  AudioParameters params_;
+  scoped_ptr<AudioBus> audio_bus_;
+  base::CancelableClosure on_more_data_cb_;
+  AudioConvertersMap converters_;
+  AudioConverter mixer_;
+  OutputStreamParams output_params_;
+
+  DISALLOW_COPY_AND_ASSIGN(VirtualAudioInputStream);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_AUDIO_FAKE_AUDIO_INPUT_STREAM_H_