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diff --git a/indra/media_plugins/webkit/mac_volume_catcher.cpp b/indra/media_plugins/webkit/mac_volume_catcher.cpp
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+++ b/indra/media_plugins/webkit/mac_volume_catcher.cpp
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+/** 
+ * @file dummy_volume_catcher.cpp
+ * @brief A Mac OS X specific hack to control the volume level of all audio channels opened by a process.
+ *
+ * @cond
+ * $LicenseInfo:firstyear=2010&license=viewergpl$
+ *
+ * Copyright (c) 2010, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlife.com/developers/opensource/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at http://secondlife.com/developers/opensource/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ * @endcond
+ */
+
+/**************************************************************************************************************
+	This code works by using CaptureComponent to capture the "Default Output" audio component
+	(kAudioUnitType_Output/kAudioUnitSubType_DefaultOutput) and delegating all calls to the original component.
+	It does this just to keep track of all instances of the default output component, so that it can set the
+	kHALOutputParam_Volume parameter on all of them to adjust the output volume.
+**************************************************************************************************************/
+
+#include "volume_catcher.h"
+
+#include <Carbon/Carbon.h>
+#include <QuickTime/QuickTime.h>
+#include <AudioUnit/AudioUnit.h>
+
+struct VolumeCatcherStorage;
+
+class VolumeCatcherImpl
+{
+public:
+
+	void setVolume(F32 volume);
+	void setPan(F32 pan);
+	
+	void setInstanceVolume(VolumeCatcherStorage *instance);
+	
+	std::list<VolumeCatcherStorage*> mComponentInstances;
+	Component mOriginalDefaultOutput;
+	Component mVolumeAdjuster;
+	
+	static VolumeCatcherImpl *getInstance();
+private:
+	// This is a singleton class -- both callers and the component implementation should use getInstance() to find the instance.
+	VolumeCatcherImpl();
+	static VolumeCatcherImpl *sInstance;
+	
+	// The singlar instance of this class is expected to last until the process exits.
+	// To ensure this, we declare the destructor here but never define it, so any code which attempts to destroy the instance will not link.
+	~VolumeCatcherImpl();	
+	
+	F32 mVolume;
+	F32 mPan;
+};
+
+VolumeCatcherImpl *VolumeCatcherImpl::sInstance = NULL;;
+
+struct VolumeCatcherStorage
+{
+	ComponentInstance self;
+	ComponentInstance delegate;
+};
+
+static ComponentResult volume_catcher_component_entry(ComponentParameters *cp, Handle componentStorage);
+static ComponentResult volume_catcher_component_open(VolumeCatcherStorage *storage, ComponentInstance self);
+static ComponentResult volume_catcher_component_close(VolumeCatcherStorage *storage, ComponentInstance self);
+
+VolumeCatcherImpl *VolumeCatcherImpl::getInstance()
+{
+	if(!sInstance)
+	{
+		sInstance = new VolumeCatcherImpl;
+	}
+	
+	return sInstance;
+}
+
+VolumeCatcherImpl::VolumeCatcherImpl()
+{
+	mVolume = 1.0;	// default to full volume
+	mPan = 0.5;		// and center pan
+		
+	ComponentDescription desc;
+	desc.componentType = kAudioUnitType_Output;
+	desc.componentSubType = kAudioUnitSubType_DefaultOutput;
+	desc.componentManufacturer = kAudioUnitManufacturer_Apple;
+	desc.componentFlags = 0;
+	desc.componentFlagsMask = 0;
+	
+	// Find the original default output component
+	mOriginalDefaultOutput = FindNextComponent(NULL, &desc);
+
+	// Register our own output component with the same parameters
+	mVolumeAdjuster = RegisterComponent(&desc, NewComponentRoutineUPP(volume_catcher_component_entry), 0, NULL, NULL, NULL);
+
+	// Capture the original component, so we always get found instead.
+	CaptureComponent(mOriginalDefaultOutput, mVolumeAdjuster);
+
+}
+
+static ComponentResult volume_catcher_component_entry(ComponentParameters *cp, Handle componentStorage)
+{
+	ComponentResult result = badComponentSelector;
+	VolumeCatcherStorage *storage = (VolumeCatcherStorage*)componentStorage;
+	
+	switch(cp->what)
+	{
+		case kComponentOpenSelect:
+//			std::cerr << "kComponentOpenSelect" << std::endl;
+			result = CallComponentFunctionWithStorageProcInfo((Handle)storage, cp, (ProcPtr)volume_catcher_component_open, uppCallComponentOpenProcInfo);
+		break;
+
+		case kComponentCloseSelect:
+//			std::cerr << "kComponentCloseSelect" << std::endl;
+			result = CallComponentFunctionWithStorageProcInfo((Handle)storage, cp, (ProcPtr)volume_catcher_component_close, uppCallComponentCloseProcInfo);
+			// CallComponentFunctionWithStorageProcInfo
+		break;
+		
+		default:
+//			std::cerr << "Delegating selector: " << cp->what << " to component instance " << storage->delegate << std::endl;
+			result = DelegateComponentCall(cp, storage->delegate);
+		break;
+	}
+	
+	return result;
+}
+
+static ComponentResult volume_catcher_component_open(VolumeCatcherStorage *storage, ComponentInstance self)
+{
+	ComponentResult result = noErr;
+	VolumeCatcherImpl *impl = VolumeCatcherImpl::getInstance();	
+	
+	storage = new VolumeCatcherStorage;
+
+	storage->self = self;
+	storage->delegate = NULL;
+
+	result = OpenAComponent(impl->mOriginalDefaultOutput, &(storage->delegate));
+	
+	if(result != noErr)
+	{
+//		std::cerr << "OpenAComponent result = " << result << ", component ref = " << storage->delegate << std::endl;
+		
+		// If we failed to open the delagate component, our open is going to fail.  Clean things up.
+		delete storage;
+	}
+	else
+	{
+		// Success -- set up this component's storage
+		SetComponentInstanceStorage(self, (Handle)storage);
+
+		// add this instance to the global list
+		impl->mComponentInstances.push_back(storage);	
+		
+		// and set up the initial volume
+		impl->setInstanceVolume(storage);
+	}
+
+	return result;
+}
+
+static ComponentResult volume_catcher_component_close(VolumeCatcherStorage *storage, ComponentInstance self)
+{
+	ComponentResult result = noErr;
+	
+	if(storage)
+	{
+		if(storage->delegate)
+		{
+			CloseComponent(storage->delegate);
+			storage->delegate = NULL;
+		}
+		
+		VolumeCatcherImpl *impl = VolumeCatcherImpl::getInstance();	
+		impl->mComponentInstances.remove(storage);
+		delete[] storage;
+	}
+		
+	return result;
+}
+
+void VolumeCatcherImpl::setVolume(F32 volume)
+{
+	VolumeCatcherImpl *impl = VolumeCatcherImpl::getInstance();	
+	impl->mVolume = volume;
+	
+	// Iterate through all known instances, setting the volume on each.
+	for(std::list<VolumeCatcherStorage*>::iterator iter = mComponentInstances.begin(); iter != mComponentInstances.end(); ++iter)
+	{
+		impl->setInstanceVolume(*iter);
+	}
+}
+
+void VolumeCatcherImpl::setPan(F32 pan)
+{
+	VolumeCatcherImpl *impl = VolumeCatcherImpl::getInstance();	
+	impl->mPan = pan;
+	
+	// TODO: implement this.
+	// This will probably require adding a "panner" audio unit to the chain somehow.
+	// There's also a "3d mixer" component that we might be able to use...
+}
+
+void VolumeCatcherImpl::setInstanceVolume(VolumeCatcherStorage *instance)
+{
+//	std::cerr << "Setting volume on component instance: " << (instance->delegate) << " to " << mVolume << std::endl;
+	
+	OSStatus err = noErr;
+	
+	if(instance && instance->delegate)
+	{
+		err = AudioUnitSetParameter(
+				instance->delegate, 
+				kHALOutputParam_Volume, 
+				kAudioUnitScope_Global,
+				0, 
+				mVolume, 
+				0);
+	}
+	
+	if(err)
+	{
+//		std::cerr << "    AudioUnitSetParameter returned " << err << std::endl;
+	}
+}
+
+/////////////////////////////////////////////////////
+
+VolumeCatcher::VolumeCatcher()
+{
+	pimpl = VolumeCatcherImpl::getInstance();
+}
+
+VolumeCatcher::~VolumeCatcher()
+{
+	// Let the instance persist until exit.
+}
+
+void VolumeCatcher::setVolume(F32 volume)
+{
+	pimpl->setVolume(volume);
+}
+
+void VolumeCatcher::setPan(F32 pan)
+{
+	pimpl->setPan(pan);
+}
+
+void VolumeCatcher::pump()
+{
+	// No periodic tasks are necessary for this implementation.
+}
+