/*

*   File:       SampleUSBAudioPlugin.cpp

*

*   Contains:   com_MySoftwareCompany_driver_SampleUSBAudioPlugin Implementation

*

*           A simple USB audio plug-in that performs a lowpass filtering operation on audio streamed

*           through the Griffin iMic. The target SampleUSBAudioPlugin.kext must be copied to the 

*           /System/Library/Extensions folder of the boot volume by an administrator using a 

*           command like (from the project folder):

*

*           sudo cp -rf ./build/SampleUSBAudioPlugin.kext /System/Library/Extensions

*

*           Then you must notify the operating system that the contents of the kernel extension directory has 

*           changed by "touching the directory":

*

*           sudo touch /System/Library/Extensions

*

*           Restart the system.

* 

*           After restarting the system, the plug-in should automatically load when the device

*           specified in the Info.plist is plugged in. Plug-in logging can be observed by viewing 

*           the system log using Console in /Applications/Utilities.

*           

*   

*   Version:    1.0

*

*   Created:    11-23-2004

*

*   © Copyright 2004-2013 Apple Computer, Inc. All rights reserved.

*

*   Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc. ("Apple") in

*               consideration of your agreement to the following terms, and your use, installation, modification

*               or redistribution of this Apple software constitutes acceptance of these terms.  If you do

*               not agree with these terms, please do not use, install, modify or redistribute this Apple

*               software.

*

*               In consideration of your agreement to abide by the following terms, and subject to these terms,

*               Apple grants you a personal, non-exclusive license, under Apple's copyrights in this

*               original Apple software (the "Apple Software"), to use, reproduce, modify and redistribute the

*               Apple Software, with or without modifications, in source and/or binary forms; provided that if you

*               redistribute the Apple Software in its entirety and without modifications, you must retain this

*               notice and the following text and disclaimers in all such redistributions of the Apple Software.

*               Neither the name, trademarks, service marks or logos of Apple Computer, Inc. may be used to

*               endorse or promote products derived from the Apple Software without specific prior written

*               permission from Apple.  Except as expressly stated in this notice, no other rights or

*               licenses, express or implied, are granted by Apple herein, including but not limited to any

*               patent rights that may be infringed by your derivative works or by other works in which the

*               Apple Software may be incorporated.

*

*               The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO WARRANTIES, EXPRESS OR

*               IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY

*               AND FITNESS FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE

*               OR IN COMBINATION WITH YOUR PRODUCTS.

*

*               IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL

*               DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS

*               OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE,

*               REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER

*               UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN

*               IF APPLE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*

*/

#include <IOKit/IOLib.h>

#include "SampleUSBAudioPlugin.h"

#define super AppleUSBAudioPlugin

OSDefineMetaClassAndStructors (com_MySoftwareCompany_driver_SampleUSBAudioPlugin, AppleUSBAudioPlugin);

// AppleUSBAudioPlugin methods

/*****************************************************

*

* com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginInit (IOService * provider, UInt16 vendorID, UInt16 productID)

*

* Purpose:  

*

* Inputs:   provider   -  AppleUSBAudioEngine object associated with device

*           vendorID   -  idVendor

*           productID  -  idProduct

*

* Returns:  IOReturn  result -  (0 == no error)

*/

IOReturn com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginInit (IOService * provider, UInt16 vendorID, UInt16 productID) 

{

    IOReturn                result;

    //IOUSBDevRequest       myRequest;

    // Init our superclass first

    result = super::pluginInit (provider, vendorID, productID);

#warning   Change the idVendor & idProduct here (and in Info.plist) to match the audio device you want to use! 

    // Double check that we're loaded on the device that we want to be;

    if (vendorID != 0x077D || productID != 0x07AF)

    {

        //NOTE: Avoid logging this type of information (idVendor, idProduct) in a released product

        //The plug-in should fail silently, if the incorrect (idVendor, idProduct) is given.

        //Only log this type of information during development!

        //IOLog ("vendorID = %u, productID = %u", vendorID, productID);

        return kIOReturnNoDevice;

    }

    if (result == kIOReturnSuccess) 

    {

        // Do our one time initialization

        IOLog ("com_MySoftwareCompany_driver_SampleUSBAudioPlugin initialized successfully\n");

        /* Just initialize to some random values to verify that pluginSetFormat is working.

           These values should be overwritten by the device's actual format when pluginSetFormat is called. */

        mSampleRate = 44101;

        mNumChannels = 3;

        setProcessingParameters (&mParamStruct, mSampleRate, mNumChannels);

    }

    return result;

}

/*****************************************************

*

* com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginStart ()

*

* Purpose:  Start processing audio

*

* Inputs:   (void)

*

* Returns:  IOReturn  result -  (0 == no error)

*/

IOReturn com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginStart () 

{

    IOReturn                result;

    // Start our superclass first

    result = super::pluginStart ();

    if (result == kIOReturnSuccess) 

    {

        // Do our every time initialization

        resetProcessingState (&mStateStruct);

        IOLog ("com_MySoftwareCompany_driver_SampleUSBAudioPlugin starting.\n");

    }

    return result;

}

/*****************************************************

*

* com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginReset ()

*

* Purpose:  Reset processing parameters and state.

*

* Inputs:   (void)

*

* Returns:  IOReturn  result -  (0 == no error)

*/

IOReturn com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginReset () 

{

    IOReturn                result;

    IOLog ("com_MySoftwareCompany_driver_SampleUSBAudioPlugin resetting...\n");

    // Reset the plugin's state

    setProcessingParameters (&mParamStruct, mSampleRate, mNumChannels);

    resetProcessingState (&mStateStruct);

    // No need to call super::pluginReset

    result = kIOReturnSuccess;

    return result;

}

/*****************************************************

*

* com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginSetFormat(const IOAudioStreamFormat * const newFormat, const IOAudioSampleRate * const newSampleRate)

*

* Purpose:  Changes the current audio stream format

*

* Inputs:   newFormat - new audio stream format

*           newSampleRate- new sample rate

*

* Returns:  IOReturn  result -  (0 == no error)

*/

IOReturn com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginSetFormat (const IOAudioStreamFormat * const newFormat, const IOAudioSampleRate * const newSampleRate) 

{

    IOReturn                result;

    IOLog ("com_MySoftwareCompany_driver_SampleUSBAudioPlugin changing format\n");

    // If parameters depend on sample rate or number of channels (or other format info), update them here

    if (NULL != newSampleRate) 

    {

        mSampleRate = newSampleRate->whole;

    }

    if (NULL != newFormat) 

    {

        mNumChannels = newFormat->fNumChannels;

    }

    setProcessingParameters (&mParamStruct, mSampleRate, mNumChannels);

    IOLog ("mSampleRate = %u, mNumChannels = %u\n", (unsigned int)mSampleRate, (unsigned int)mNumChannels);

    // No need to call super::pluginProcess

    result = kIOReturnSuccess;

    return result;

} 

/*****************************************************

*

* com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginProcess (float * mixBuf, UInt32 numSampleFrames, UInt32 numChannels) 

*

* Purpose:  Calls processSamples() (low pass filter) to process audio data

*

* Inputs:   mixBuf - pointer to the mixed buffer samples

*           numSampleFrames - number of sample frames in mixed buffer

*           numChannels - number of channels that are interleaved in the mixed buffer

*

* Returns:  IOReturn  result -  (kIOReturnSuccess == no error)

*/

IOReturn com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginProcess (float * mixBuf, UInt32 numSampleFrames, UInt32 numChannels) 

{

    IOReturn                result;

    // Do our data processing methods

    if (    (mSampleRate == 44100)

         && (mNumChannels <= 2))

    {

        processSamples (mixBuf, numSampleFrames, numChannels, &mParamStruct, &mStateStruct);

    }

    // No need to call super::pluginProcess

    result = kIOReturnSuccess;

    return result;

}

/*****************************************************

*

* com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginStop ()

*

* Purpose:  Start processing audio

*

* Inputs:   (void)

*

* Returns:  IOReturn  result -  (0 == no error)

*/

IOReturn com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginStop () 

{

    IOReturn                result;

    // Do our stop work first, then call super

    IOLog ("com_MySoftwareCompany_driver_SampleUSBAudioPlugin stopping.\n");

    pluginReset ();

    result = super::pluginStop ();

    return result;

}

/*****************************************************

 *

 * com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginProcessInput (float * destBuf, UInt32 numSampleFrames, UInt32 numChannels) 

 *

 * Purpose:  Calls processSamples() (low pass filter) to process audio data

 *

 * Inputs:   destBuf - pointer to the input & destination buffer samples

 *          numSampleFrames - number of sample frames in mixed buffer

 *          numChannels - number of channels that are interleaved in the mixed buffer

 *

 * Returns:  IOReturn  result -  (kIOReturnSuccess == no error)

 */

IOReturn com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginProcessInput (float * destBuf, UInt32 numSampleFrames, UInt32 numChannels) 

{

    // Do our data processing methods

    if (    (mSampleRate == 44100)

        && (mNumChannels <= 2))

    {

        processSamples (destBuf, numSampleFrames, numChannels, &mParamStruct, &mStateStruct);

    }

    return kIOReturnSuccess;

}

/*****************************************************

 *

 * com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginSetDirection (IOAudioStreamDirection direction) 

 *

 * Purpose:  Process audio data

 *

 * Inputs:   direction - Direction of audio stream, either input or output.

 *          numSampleFrames - number of sample frames in mixed buffer

 *          numChannels - number of channels that are interleaved in the mixed buffer

 *

 * Returns:  IOReturn  result -  (kIOReturnSuccess == no error)

 */

IOReturn com_MySoftwareCompany_driver_SampleUSBAudioPlugin::pluginSetDirection (IOAudioStreamDirection direction) 

{

    IOLog ("com_MySoftwareCompany_driver_SampleUSBAudioPlugin set direction - %u\n", (unsigned int)direction);

    mDirection = direction;

    return kIOReturnSuccess;

}