MuteSource Audio During Full Screen Cast

media/audio/win/audio_low_latency_input_win.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.
 //
 // Implementation of AudioInputStream for Windows using Windows Core Audio
 // WASAPI for low latency capturing.
 //
 // Overview of operation:
 //
 // - An object of WASAPIAudioInputStream is created by the AudioManager
@@ skipping 40 matching lines @@
 //   interface to control the master volume level of an audio endpoint device.
 //   This implementation is using the ISimpleAudioVolume interface.
 //   MSDN states that "In rare cases, a specialized audio application might
 //   require the use of the IAudioEndpointVolume".
 //
 #ifndef MEDIA_AUDIO_WIN_AUDIO_LOW_LATENCY_INPUT_WIN_H_
 #define MEDIA_AUDIO_WIN_AUDIO_LOW_LATENCY_INPUT_WIN_H_
 
 #include <Audioclient.h>
 #include <MMDeviceAPI.h>
+#include <endpointvolume.h>
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/threading/platform_thread.h"
@@ skipping 118 matching lines @@
   // The IAudioCaptureClient interface enables a client to read input data
   // from a capture endpoint buffer.
   base::win::ScopedComPtr<IAudioCaptureClient> audio_capture_client_;
 
   // The ISimpleAudioVolume interface enables a client to control the
   // master volume level of an audio session.
   // The volume-level is a value in the range 0.0 to 1.0.
   // This interface does only work with shared-mode streams.
   base::win::ScopedComPtr<ISimpleAudioVolume> simple_audio_volume_;
 
+  // The IAudioEndpointVolume allows a client to control the volume level of
+  // the whole system.
+  base::win::ScopedComPtr<IAudioEndpointVolume> system_audio_volume_;
+
   // The audio engine will signal this event each time a buffer has been
   // recorded.
   base::win::ScopedHandle audio_samples_ready_event_;
 
   // This event will be signaled when capturing shall stop.
   base::win::ScopedHandle stop_capture_event_;
 
   // Extra audio bus used for storage of deinterleaved data for the OnData
   // callback.
   std::unique_ptr<media::AudioBus> audio_bus_;
 
+  // Never set it through external API. Only used when |device_id_| ==
+  // kLoopbackWithMuteDeviceId.
+  // True, if we have muted the system audio for the stream capturing, and
+  // indicate we need to unmute the system audio when stopping capturing.

[henrika (OOO until Aug 14), 2016/07/26 10:04:25]

..and indicates that we need to...

[qiangchen, 2016/07/26 16:53:02]

Done.

+  bool mute_done_;
+
   DISALLOW_COPY_AND_ASSIGN(WASAPIAudioInputStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_WIN_AUDIO_LOW_LATENCY_INPUT_WIN_H_