/*

    File:       CoreAudioUtils.c

    Description: Utility functions for building a simple AUGraph

                 to play buffers of audio data.

    Originally introduced at WWDC 2005 at Session 201:

        "Harnessing the Audio Capabilities of QuickTime 7" 

    Copyright:   © Copyright 2004, 2005 Apple Computer, Inc.

             All rights reserved.

    Disclaimer: IMPORTANT:  This Apple software is supplied to you by

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    following terms, and your use, installation, modification or

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    Inc. may be used to endorse or promote products derived from the Apple

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    as expressly stated in this notice, no other rights or licenses, express

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    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.

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*/

#include "CoreAudioUtils.h"

// Return a ComponentDescription for a default output device AU

static void ConfigureOutputDescription(ComponentDescription *inOutputDesc)

{

    inOutputDesc->componentType = kAudioUnitType_Output;

    inOutputDesc->componentSubType = kAudioUnitSubType_DefaultOutput;

    inOutputDesc->componentManufacturer = kAudioUnitManufacturer_Apple;

    inOutputDesc->componentFlags = 0;

    inOutputDesc->componentFlagsMask = 0;

}

// Set the stream format on the output device AU.

// This only needs to set the input scope, since the output describes the audio hw settings.

static OSStatus SetOutputUnitStreamFormat(AudioUnit outputUnit, AudioStreamBasicDescription *asbd)

{

    return (AudioUnitSetProperty(outputUnit, kAudioUnitProperty_StreamFormat,

                                kAudioUnitScope_Input, 0, asbd, sizeof(AudioStreamBasicDescription)));

}

// Set the channel layout on the output device AU.

// This only needs to set the input scope, since the output describes the audio hw settings.

// Setting the channel layout here helps route channels properly, but note that the OutputAU

// does not do channel mixdown.

static OSStatus SetOutputUnitChannelLayout(AudioUnit outputUnit, QTPropertyValuePtr layoutProperty, UInt32 size)

{

    return (AudioUnitSetProperty(outputUnit, kAudioUnitProperty_AudioChannelLayout,

                                 kAudioUnitScope_Input,0, layoutProperty, size));

}

// Return a ComponentDescription for a ScheduledSoundPlayer AU

static void ConfigureScheduledPlayerDescription(ComponentDescription *inPlayerDesc)

{

    inPlayerDesc->componentType = kAudioUnitType_Generator;

    inPlayerDesc->componentSubType = kAudioUnitSubType_ScheduledSoundPlayer;

    inPlayerDesc->componentManufacturer = kAudioUnitManufacturer_Apple;

    inPlayerDesc->componentFlags = 0;

    inPlayerDesc->componentFlagsMask = 0;

}

//////////

//

// ConfigureEffectDescription

//

// Fills a ComponentDescription structure to describe a Audio Unit effect component.

// In this case, the effect component specified is the reverb effect.

// 

//////////

static void ConfigureReverbEffectDescription(ComponentDescription *inEffectDesc)

{

    inEffectDesc->componentType = kAudioUnitType_Effect;

    inEffectDesc->componentSubType = kAudioUnitSubType_MatrixReverb;

    inEffectDesc->componentManufacturer = kAudioUnitManufacturer_Apple;

    inEffectDesc->componentFlags = 0;

    inEffectDesc->componentFlagsMask = 0;

}

//////////

//

// SetPlayerUnitStreamFormat

//

// Set the stream format on the ScheduledSoundPlayer AU.

// This only needs to set the output scope, since the unit doesn't have an input scope.

// 

//////////

static OSStatus SetPlayerUnitStreamFormat(AudioUnit playerUnit, AudioStreamBasicDescription *asbd)

{

    return (AudioUnitSetProperty(playerUnit, kAudioUnitProperty_StreamFormat,

                                 kAudioUnitScope_Output, 0, asbd, sizeof(AudioStreamBasicDescription)));

}

//////////

//

// SetPlayerUnitStreamFormat

//

// Set the stream format on the Effect AU.

// 

//////////

static OSStatus SetEffectUnitStreamFormat(AudioUnit effectUnit, AudioStreamBasicDescription *asbd)

{

    OSStatus status = noErr;

    status = AudioUnitSetProperty(effectUnit, kAudioUnitProperty_StreamFormat,

                                kAudioUnitScope_Input, 0, asbd, sizeof(AudioStreamBasicDescription));

    require(status == noErr, bail);

    status = AudioUnitSetProperty(effectUnit, kAudioUnitProperty_StreamFormat,

                                kAudioUnitScope_Output, 0, asbd, sizeof(AudioStreamBasicDescription));

bail:

    return status;

}

//////////

//

// SetReverbEffectParams

//

// Set the PreDelay and ModulationRate parameters for the Reverb Effect.

// 

//////////

OSStatus SetReverbEffectParams(AudioUnit audioUnit)

{

    Float32 preDelay = 0.01;

    OSStatus status = AudioUnitSetParameter(    audioUnit,

                                                kReverbParam_PreDelay,

                                                kAudioUnitScope_Input,

                                                0,

                                                preDelay,

                                                0);

    require(status == noErr, bail);

    Float32 modulationRate = 1.7;

    status = AudioUnitSetParameter( audioUnit,

                                    kReverbParam_ModulationRate,

                                    kAudioUnitScope_Input,

                                    0,

                                    modulationRate,

                                    0);

bail:

    return status;

}

//////////

//

// BuildAUGraphPlayer

//

// Build a simple AUGraph containing a Default Output AU sourced by a ScheduledSoundPlayer AU.

// This allows us to schedule (from any thread) buffers of audio data to play automatically.

// 

//////////

OSStatus BuildAUGraphPlayer(AudioChannelLayout *layout, UInt32 layoutSize,

                            AudioStreamBasicDescription *asbd,

                            AUGraphPlayerRef *graphUnit, AudioUnit *thePlayerUnit)

{

    OSStatus err = noErr;

    // Create a new AUGraph

    *graphUnit = nil;

    err = NewAUGraph(graphUnit);

    require(err == noErr, bail);    

    // Add an output unit, and a scheduled sound player unit

    // Configure the two units.  

    ComponentDescription    output_desc, player_desc;

    ConfigureOutputDescription(&output_desc);

    ConfigureScheduledPlayerDescription(&player_desc);

    // Create new nodes inside our AUGraph for the output unit

    // and the AUScheduledSoundPlayer unit.

    AUNode outputNode, playerNode;

    err = AUGraphNewNode(*graphUnit, &output_desc, 0, NULL, &outputNode);

    require(err == noErr, bail);    

    err = AUGraphNewNode(*graphUnit, &player_desc, 0, NULL, &playerNode);

    require(err == noErr, bail);    

    // Connect the two graph nodes together and specify the way inputs are ordered.

    // The player node will route its output to the output node

    // connect the player to the output unit. 

    err = AUGraphConnectNodeInput(*graphUnit, playerNode, 0, outputNode, 0);

    require(err == noErr, bail);    

    // Open the graph: Instantiates every Audio Unit in the graph.

    err = AUGraphOpen(*graphUnit);

    require(err == noErr, bail);    

    // Get the output unit & the player unit from their respective nodes    

    AudioUnit theOutputUnit;

    err = AUGraphGetNodeInfo(*graphUnit, outputNode, NULL, NULL, NULL, &theOutputUnit);

    require(err == noErr, bail);    

    err = AUGraphGetNodeInfo(*graphUnit, playerNode, NULL, NULL, NULL, thePlayerUnit);

    require(err == noErr, bail);    

    // Configure stream formats of the output and player to the specified format

    err = SetOutputUnitStreamFormat(theOutputUnit, asbd);

    require(err == noErr, bail);    

    err = SetPlayerUnitStreamFormat(*thePlayerUnit, asbd);

    require(err == noErr, bail);    

    // Get the extraction channel layout and map the output device

    err = SetOutputUnitChannelLayout(theOutputUnit, layout, layoutSize);

    require(err == noErr, bail);    

    // Initialize the graph

    err = AUGraphInitialize(*graphUnit);

bail:

    if (err && (*graphUnit != nil))

    {

        AUGraphClose(*graphUnit);

    }

    return (err);       

}

//////////

//

// BuildAUGraphPlayerWithEffect

//

// Build a simple AUGraph containing a Default Output AU sourced by an Effect AU which in turn is

// sourced by a ScheduledSoundPlayer AU.

// This allows us to schedule (from any thread) buffers of audio data to play automatically.

// 

//////////

OSStatus BuildAUGraphPlayerWithEffect(AudioChannelLayout *layout, UInt32 layoutSize,

                                        AudioStreamBasicDescription *asbd,

                                        AUGraphPlayerRef *graphUnit, AudioUnit *thePlayerUnit,

                                        AudioUnit *theEffectUnit)

{

    OSStatus err = noErr;

    // Create a new AUGraph

    *graphUnit = nil;

    err = NewAUGraph(graphUnit);

    require(err == noErr, bail);    

    // Add an output unit, a scheduled sound player unit and

    // an effect unit.

    // Configure the three units.  

    ComponentDescription output_desc, player_desc, effect_desc;

    ConfigureOutputDescription(&output_desc);

    ConfigureScheduledPlayerDescription(&player_desc);

    ConfigureReverbEffectDescription(&effect_desc);

    // Create new nodes inside our AUGraph for the output unit,

    // the AUScheduledSoundPlayer unit and the Effect unit.

    AUNode outputNode, playerNode, effectNode;

    err = AUGraphNewNode(*graphUnit, &output_desc, 0, NULL, &outputNode);

    require(err == noErr, bail);

    err = AUGraphNewNode(*graphUnit, &effect_desc, 0, NULL, &effectNode);

    require(err == noErr, bail);

    err = AUGraphNewNode(*graphUnit, &player_desc, 0, NULL, &playerNode);

    require(err == noErr, bail);

    // Connect the three graph nodes together and specify the way inputs are ordered.

    // The player node will route its output to the effect node which will route its

    // output to the output node

    err = AUGraphConnectNodeInput(*graphUnit, playerNode, 0, effectNode, 0);

    require(err == noErr, bail);

    err = AUGraphConnectNodeInput(*graphUnit, effectNode, 0, outputNode, 0);

    require(err == noErr, bail);

    // Open the graph: Instantiates every Audio Unit in the graph.

    err = AUGraphOpen(*graphUnit);

    require(err == noErr, bail);    

    // Get the output, player and effect units from their respective nodes  

    AudioUnit theOutputUnit;

    err = AUGraphGetNodeInfo(*graphUnit, outputNode, NULL, NULL, NULL, &theOutputUnit);

    require(err == noErr, bail);    

    err = AUGraphGetNodeInfo(*graphUnit, playerNode, NULL, NULL, NULL, thePlayerUnit);

    require(err == noErr, bail);    

    err = AUGraphGetNodeInfo(*graphUnit, effectNode, NULL, NULL, NULL, theEffectUnit);

    require(err == noErr, bail);

    // Configure stream formats of the output, player and effect to the specified format

    err = SetOutputUnitStreamFormat(theOutputUnit, asbd);

    require(err == noErr, bail);    

    err = SetPlayerUnitStreamFormat(*thePlayerUnit, asbd);

    require(err == noErr, bail);    

    err = SetEffectUnitStreamFormat(*theEffectUnit, asbd);

    require(err == noErr, bail);

    // Get the extraction channel layout and map the output device

    err = SetOutputUnitChannelLayout(theOutputUnit, layout, layoutSize);

    require(err == noErr, bail);    

    // Initialize the graph

    err = AUGraphInitialize(*graphUnit);

    require(err == noErr, bail);    

    // adjust some of the effect parameters

    err = SetReverbEffectParams(*theEffectUnit);

bail:

    if (err && (*graphUnit != nil))

    {

        AUGraphClose(*graphUnit);

    }

    return (err);       

}

//////////

//

// StartAUGraphPlayer

//

// Start the player graph running.

// 

//////////

OSStatus StartAUGraphPlayer(AUGraphPlayerRef graphUnit)

{

    OSStatus    err = noErr;

    UInt32      numNodes;

    AudioUnit   playerUnit = nil;

    // Start the AUGraph

    err = AUGraphStart(graphUnit);

    require(err == noErr, bail);    

    // Locate the AUScheduledSoundPlayer that we need to start.

    // It was added last, so its node number is the node count.

    err = AUGraphGetNodeCount(graphUnit, &numNodes);

    if (!err)

    {

        err = AUGraphGetNodeInfo(graphUnit, numNodes, nil, nil, nil, &playerUnit);

    }

    require(err == noErr, bail);    

    require(playerUnit != nil, bail);   

    // Start playback of the scheduledPlayer unit by setting its start time.

    AudioTimeStamp theTimeStamp = {0};

    theTimeStamp.mFlags = kAudioTimeStampSampleTimeValid;

    theTimeStamp.mSampleTime = -1.;     // start now

    err = AudioUnitSetProperty(playerUnit,

                                kAudioUnitProperty_ScheduleStartTimeStamp, kAudioUnitScope_Global, 0,

                                &theTimeStamp, sizeof(theTimeStamp));

bail:

    return (err);

}

//////////

//

// StopAUGraphPlayer

//

//////////

void StopAUGraphPlayer(AUGraphPlayerRef graphUnit)

{

    if (graphUnit != nil) 

    {   

        (void) AUGraphStop(graphUnit);

        (void) AUGraphUninitialize(graphUnit);

    }

}

//////////

//

// CloseAUGraphPlayer

//

//////////

void CloseAUGraphPlayer(AUGraphPlayerRef graphUnit)

{

    if (graphUnit != nil) 

    {   

        StopAUGraphPlayer(graphUnit);

        (void) AUGraphClose(graphUnit);

    }

}