Files
SingularityViewer/indra/plugins/webkit/mac_volume_catcher.cpp
2011-06-10 00:31:51 +02:00

269 lines
7.8 KiB
C++

/**
* @file mac_volume_catcher.cpp
* @brief A Mac OS X specific hack to control the volume level of all audio channels opened by a process.
*
* @cond
* $LicenseInfo:firstyear=2010&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
* @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 = 0.0; // 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.
}