Adding experimental exclusive-mode streaming to WASAPIAudioOutputStream

media/audio/win/audio_manager_win.cc

 // 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.
 
 #include "media/audio/audio_io.h"
 
 #include <windows.h>
 #include <objbase.h>  // This has to be before initguid.h
 #include <initguid.h>
 #include <mmsystem.h>
 #include <setupapi.h>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "media/audio/audio_util.h"
 #include "media/audio/win/audio_low_latency_input_win.h"
 #include "media/audio/win/audio_low_latency_output_win.h"
 #include "media/audio/win/audio_manager_win.h"
 #include "media/audio/win/device_enumeration_win.h"
 #include "media/audio/win/wavein_input_win.h"
 #include "media/audio/win/waveout_output_win.h"
 #include "media/base/limits.h"
+#include "media/base/media_switches.h"
 
 // Libraries required for the SetupAPI and Wbem APIs used here.
 #pragma comment(lib, "setupapi.lib")
 
 // The following are defined in various DDK headers, and we (re)define them
 // here to avoid adding the DDK as a chrome dependency.
 #define DRV_QUERYDEVICEINTERFACE 0x80c
 #define DRVM_MAPPER_PREFERRED_GET 0x2015
 #define DRV_QUERYDEVICEINTERFACESIZE 0x80d
 DEFINE_GUID(AM_KSCATEGORY_AUDIO, 0x6994ad04, 0x93ef, 0x11d0,
@@ skipping 223 matching lines @@
     return NULL;
 
   AudioOutputStream* stream = NULL;
   if (!media::IsWASAPISupported()) {
     // Fall back to Windows Wave implementation on Windows XP or lower.
     DVLOG(1) << "Using WaveOut since WASAPI requires at least Vista.";
     stream = new PCMWaveOutAudioOutputStream(this, params, 2, WAVE_MAPPER);
   } else {
     // TODO(henrika): improve possibility to specify audio endpoint.
     // Use the default device (same as for Wave) for now to be compatible.
-    stream = new WASAPIAudioOutputStream(this, params, eConsole);
+    const CommandLine* cmd_line = CommandLine::ForCurrentProcess();
+    if (cmd_line->HasSwitch(switches::kEnableExclusiveMode)) {
+      // Experiemental mode; use with care.
+      stream = new WASAPIAudioOutputStream(
+          this, params, eConsole, AUDCLNT_SHAREMODE_EXCLUSIVE);
+    } else {
+      // Shared mode streaming is the default mode.
+      stream = new WASAPIAudioOutputStream(
+          this, params, eConsole, AUDCLNT_SHAREMODE_SHARED);
+    }
   }
 
   return stream;
 }
 
 // Factory for the implementations of AudioInputStream for AUDIO_PCM_LINEAR
 // mode.
 AudioInputStream* AudioManagerWin::MakeLinearInputStream(
     const AudioParameters& params, const std::string& device_id) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
@@ skipping 34 matching lines @@
   return new PCMWaveInAudioInputStream(this, params, kNumInputBuffers,
                                        xp_device_id);
 }
 
 /// static
 AudioManager* CreateAudioManager() {
   return new AudioManagerWin();
 }
 
 }  // namespace media