MuteSource Audio During Full Screen Cast

media/audio/win/audio_low_latency_input_win.cc

Index: media/audio/win/audio_low_latency_input_win.cc
diff --git a/media/audio/win/audio_low_latency_input_win.cc b/media/audio/win/audio_low_latency_input_win.cc
index 949d681945f058919e25758b9509bfb3aaa295b9..f1af6494b3da68f052ca17555330034ff23fccf6 100644
--- a/media/audio/win/audio_low_latency_input_win.cc
+++ b/media/audio/win/audio_low_latency_input_win.cc
@@ -4,6 +4,7 @@
 
 #include "media/audio/win/audio_low_latency_input_win.h"
 
+#include <endpointvolume.h>
 #include <memory>
 
 #include "base/logging.h"
@@ -165,6 +166,13 @@ void WASAPIAudioInputStream::Stop() {
   if (!started_)
     return;
 
+  if (device_id_ == AudioDeviceDescription::kLoopbackWithMuteDeviceId) {
+    IAudioEndpointVolume* pVolume = NULL;
+    HRESULT hr =
+        endpoint_device_->Activate(__uuidof(IAudioEndpointVolume), CLSCTX_ALL,
+                                   NULL, reinterpret_cast<void**>(&pVolume));
+    hr = pVolume->SetMute(false, NULL);
+  }
   // Stops periodic AGC microphone measurements.
   StopAgc();
 
@@ -471,6 +479,16 @@ HRESULT WASAPIAudioInputStream::SetCaptureDevice() {
   } else if (device_id_ == AudioDeviceDescription::kCommunicationsDeviceId) {
     hr = enumerator->GetDefaultAudioEndpoint(eCapture, eCommunications,
                                              endpoint_device_.Receive());
+  } else if (device_id_ == AudioDeviceDescription::kLoopbackWithMuteDeviceId) {
+    // Capture the default playback stream.
+    hr = enumerator->GetDefaultAudioEndpoint(eRender, eConsole,
+                                             endpoint_device_.Receive());
+
+    IAudioEndpointVolume* pVolume = NULL;
+    HRESULT hr2 =
+        endpoint_device_->Activate(__uuidof(IAudioEndpointVolume), CLSCTX_ALL,
+                                   NULL, reinterpret_cast<void**>(&pVolume));
+    hr2 = pVolume->SetMute(true, NULL);
   } else if (device_id_ == AudioDeviceDescription::kLoopbackInputDeviceId) {
     // Capture the default playback stream.
     hr = enumerator->GetDefaultAudioEndpoint(eRender, eConsole,
@@ -572,7 +590,8 @@ HRESULT WASAPIAudioInputStream::InitializeAudioEngine() {
   // Use event-driven mode only fo regular input devices. For loopback the
   // EVENTCALLBACK flag is specified when intializing
   // |audio_render_client_for_loopback_|.
-  if (device_id_ == AudioDeviceDescription::kLoopbackInputDeviceId) {
+  if (device_id_ == AudioDeviceDescription::kLoopbackInputDeviceId ||
+      device_id_ == AudioDeviceDescription::kLoopbackWithMuteDeviceId) {
     flags = AUDCLNT_STREAMFLAGS_LOOPBACK | AUDCLNT_STREAMFLAGS_NOPERSIST;
   } else {
     flags = AUDCLNT_STREAMFLAGS_EVENTCALLBACK | AUDCLNT_STREAMFLAGS_NOPERSIST;
@@ -646,7 +665,8 @@ HRESULT WASAPIAudioInputStream::InitializeAudioEngine() {
   //   samples from the capture endpoint buffer.
   //
   // http://msdn.microsoft.com/en-us/library/windows/desktop/dd316551(v=vs.85).aspx
-  if (device_id_ == AudioDeviceDescription::kLoopbackInputDeviceId) {
+  if (device_id_ == AudioDeviceDescription::kLoopbackInputDeviceId ||
+      device_id_ == AudioDeviceDescription::kLoopbackWithMuteDeviceId) {
     hr = endpoint_device_->Activate(
         __uuidof(IAudioClient), CLSCTX_INPROC_SERVER, NULL,
         audio_render_client_for_loopback_.ReceiveVoid());