I'm trying to use the dynamic processor and a bunch of filters to compress a specific frequency band within the spotify method connectOutputBus but when i mix the nodes in the kAudioUnitSubType_MultiChannelMixer only the sound of the first added node comes out.
obs: i actually use filters on sourceNodeCopy to remove the freqs that will be compressed on the souceNode but to keep things short i omitted them.
Here's the code:
override func connectOutputBus(_ sourceOutputBusNumber: UInt32, ofNode sourceNode: AUNode, toInputBus destinationInputBusNumber: UInt32, ofNode destinationNode: AUNode, in graph: AUGraph!) throws {
let sourceNodeCopy = sourceNode //original node without the harsh freq
//create a filter for the harsh frequencies
var filterDescription = AudioComponentDescription()
filterDescription.componentType = kAudioUnitType_Effect
filterDescription.componentSubType = kAudioUnitSubType_BandPassFilter
filterDescription.componentManufacturer = kAudioUnitManufacturer_Apple
filterDescription.componentFlags = 0
filterDescription.componentFlagsMask = 0
AUGraphAddNode(graph, &filterDescription, &filterNode!) // Add the filter node
AUGraphNodeInfo(graph, filterNode!, nil, &filterUnit!) // Get the Audio Unit from the node
AudioUnitInitialize(filterUnit!) // Initialize the audio unit
// Set filter params
AudioUnitSetParameter(filterUnit!, kBandpassParam_CenterFrequency, kAudioUnitScope_Global, 0, 10038, 0)
//create a processor to compress the frequency
var dynamicProcessorDescription = AudioComponentDescription()
dynamicProcessorDescription.componentType = kAudioUnitType_Effect
dynamicProcessorDescription.componentSubType = kAudioUnitSubType_DynamicsProcessor
dynamicProcessorDescription.componentManufacturer = kAudioUnitManufacturer_Apple
dynamicProcessorDescription.componentFlags = 0
dynamicProcessorDescription.componentFlagsMask = 0
// Add the dynamic processor node
AUGraphAddNode(graph, &dynamicProcessorDescription, &dynamicProcessorNode)
AUGraphNodeInfo(graph, dynamicProcessorNode, nil, &dynamicProcessorUnit)
AudioUnitInitialize(dynamicProcessorUnit!)
// Set compressor params
AudioUnitSetParameter(dynamicProcessorUnit!, kDynamicsProcessorParam_Threshold, kAudioUnitScope_Global, 0, -35, 0)
AudioUnitSetParameter(dynamicProcessorUnit!, kDynamicsProcessorParam_AttackTime, kAudioUnitScope_Global, 0, 0.02, 0)
AudioUnitSetParameter(dynamicProcessorUnit!, kDynamicsProcessorParam_ReleaseTime, kAudioUnitScope_Global, 0, 0.04, 0)
AudioUnitSetParameter(dynamicProcessorUnit!, kDynamicsProcessorParam_HeadRoom, kAudioUnitScope_Global, 0, 0, 0)
//mixer
var mixerDescription = AudioComponentDescription()
mixerDescription.componentType = kAudioUnitType_Mixer
mixerDescription.componentSubType = kAudioUnitSubType_MultiChannelMixer
mixerDescription.componentManufacturer = kAudioUnitManufacturer_Apple
mixerDescription.componentFlags = 0
mixerDescription.componentFlagsMask = 0
AUGraphAddNode(graph, &mixerDescription, &audioEffectsController.mixerNode)
AUGraphNodeInfo(graph, audioEffectsController.mixerNode, nil,
&audioEffectsController.mixerUnit)
AudioUnitInitialize(audioEffectsController.mixerUnit!)
AudioUnitSetParameter(mixerUnit!, kMultiChannelMixerParam_Volume, kAudioUnitScope_Input, 0, 1.0, 0);
AudioUnitSetParameter(mixerUnit!, kMultiChannelMixerParam_Volume, kAudioUnitScope_Output, 0, 1.0, 0);
//connect the nodes
AUGraphConnectNodeInput(graph, sourceNode, sourceOutputBusNumber, filterNode, 0)
AUGraphConnectNodeInput(graph, filterNode, sourceOutputBusNumber, dynamicProcessorNode, 0)
AUGraphConnectNodeInput(graph, sourceNodeCopy, sourceOutputBusNumber, mixerNode, 0)
AUGraphConnectNodeInput(graph, fiterNode, sourceOutputBusNumber, mixerNode, 0)
//connect the mixer to the output
AUGraphConnectNodeInput(graph, audioEffectsController.mixerNode, 0, destinationNode, destinationInputBusNumber)
In your code you connect the node like this
AUGraphConnectNodeInput(graph, sourceNodeCopy, sourceOutputBusNumber, mixerNode, 0)
AUGraphConnectNodeInput(graph, fiterNode, sourceOutputBusNumber, mixerNode, 0)
If you do this, you will connect sourceNodeCopy and filterNode to the same input (0) of the MixerNode. But only one can be connected...
You should try this instead
AUGraphConnectNodeInput(graph, sourceNodeCopy, sourceOutputBusNumber, mixerNode, 0)
AUGraphConnectNodeInput(graph, fiterNode, sourceOutputBusNumber, mixerNode, 1)