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Correctly request de-interleaved data.
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Reuse buffer list.
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@nathanntg
nathanntg committed Nov 3, 2015
1 parent f1fb3e9 commit 729ba55
Showing 1 changed file with 71 additions and 43 deletions.
114 changes: 71 additions & 43 deletions SyllableDetector/AudioInterface.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -46,47 +46,29 @@ func processInput(inRefCon:UnsafeMutablePointer<Void>, actionFlags: UnsafeMutabl
// get audio in interface
let aii = unsafeBitCast(inRefCon, AudioInputInterface.self)

// build buffer
var buffer = AudioBuffer()
buffer.mDataByteSize = aii.inputFormat.mBytesPerFrame * frameCount
buffer.mNumberChannels = aii.inputFormat.mChannelsPerFrame
buffer.mData = UnsafeMutablePointer<Void>(aii.buffer)
// number of channels
let numberOfChannels = Int(aii.inputFormat.mChannelsPerFrame)

var bufferList = AudioBufferList()
bufferList.mNumberBuffers = 1
bufferList.mBuffers = buffer
// set buffer data size
for var channel = 0; channel < numberOfChannels; ++channel {
aii.bufferList[channel].mDataByteSize = aii.inputFormat.mBytesPerFrame * frameCount
}

// render input
let status = AudioUnitRender(aii.audioUnit, actionFlags, timeStamp, busNumber, frameCount, &bufferList)
let status = AudioUnitRender(aii.audioUnit, actionFlags, timeStamp, busNumber, frameCount, aii.bufferList.unsafeMutablePointer)

if noErr != status {
DLog("error rendering input \(status)")
return status
}

// data
let data = UnsafeMutablePointer<Float>(buffer.mData)

// number of channels
let maxi = Int(aii.inputFormat.mChannelsPerFrame)

// number of floats per channel
let frameLength = Int(frameCount)

// single channel? no interleaving
if maxi == 1 {
aii.delegate?.receiveAudioFrom(aii, fromChannel: 0, withData: data, ofLength: frameLength)
return 0
}
let frameCountAsInteger = Int(frameCount)

// multiple channels? de-interleave
var zero: Float = 0.0
for var i = 0; i < maxi; ++i {
// use vDSP to deinterleave
vDSP_vsadd(data + i, vDSP_Stride(maxi), &zero, aii.buffer2, 1, vDSP_Length(frameLength))


for var channel = 0; channel < numberOfChannels; ++channel {
// call delegate
aii.delegate?.receiveAudioFrom(aii, fromChannel: i, withData: aii.buffer2, ofLength: frameLength)
aii.delegate?.receiveAudioFrom(aii, fromChannel: channel, withData: UnsafeMutablePointer<Float>(aii.bufferList[channel].mData), ofLength: frameCountAsInteger)
}

return 0
Expand Down Expand Up @@ -255,6 +237,7 @@ class AudioOutputInterface: AudioInterface
let frameSize: Int

var outputFormat: AudioStreamBasicDescription = AudioStreamBasicDescription() // format of the actual audio hardware
var inputFormat: AudioStreamBasicDescription = AudioStreamBasicDescription() // format of the data read from the audio hardware

var outputHighFor = [Int]()

Expand Down Expand Up @@ -294,16 +277,34 @@ class AudioOutputInterface: AudioInterface
try checkError(AudioUnitGetProperty(audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, outputBus, &outputFormat, &size))

// print format information for debugging
DLog("OUT \(outputFormat)")
//DLog("OUT:OUT \(outputFormat)")

// check for expected format
guard outputFormat.mFormatID == kAudioFormatLinearPCM && outputFormat.mFramesPerPacket == 1 && outputFormat.mFormatFlags == kAudioFormatFlagsNativeFloatPacked else {
throw AudioInterfaceError.UnsupportedFormat
}

// set the audio format
// get the audio format
//size = UInt32(sizeof(AudioStreamBasicDescription))
//try checkError(AudioUnitSetProperty(audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, outputBus, &outputFormat, size))
//try checkError(AudioUnitGetProperty(audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, outputBus, &inputFormat, &size))
//DLog("OUT:INi \(inputFormat)")

// configure input format
inputFormat.mFormatID = kAudioFormatLinearPCM
inputFormat.mFormatFlags = kAudioFormatFlagsNativeFloatPacked | kLinearPCMFormatFlagIsNonInterleaved
inputFormat.mSampleRate = outputFormat.mSampleRate
inputFormat.mFramesPerPacket = 1
inputFormat.mBytesPerPacket = UInt32(sizeof(Float))
inputFormat.mBytesPerFrame = UInt32(sizeof(Float))
inputFormat.mChannelsPerFrame = outputFormat.mChannelsPerFrame
inputFormat.mBitsPerChannel = UInt32(8 * sizeof(Float))

// print format information for debugging
//DLog("OUT:IN \(inputFormat)")

// set the audio format
size = UInt32(sizeof(AudioStreamBasicDescription))
try checkError(AudioUnitSetProperty(audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, outputBus, &inputFormat, size))

// initiate output array
outputHighFor = [Int](count: Int(outputFormat.mChannelsPerFrame), repeatedValue: 0)
Expand Down Expand Up @@ -368,9 +369,9 @@ class AudioInputInterface: AudioInterface
weak var delegate: AudioInputInterfaceDelegate? = nil

var inputFormat: AudioStreamBasicDescription = AudioStreamBasicDescription()
var buffer = UnsafeMutablePointer<Float>()
var buffer2 = UnsafeMutablePointer<Float>() // used for de-interleaving data
var bufferLen: Int = 0
var outputFormat: AudioStreamBasicDescription = AudioStreamBasicDescription()

var bufferList: UnsafeMutableAudioBufferListPointer = UnsafeMutableAudioBufferListPointer(nil)

init(deviceID: AudioDeviceID, frameSize: Int = 64) {
self.deviceID = deviceID
Expand Down Expand Up @@ -419,26 +420,51 @@ class AudioInputInterface: AudioInterface
try checkError(AudioUnitGetProperty(audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, inputBus, &inputFormat, &size))

// print format information for debugging
DLog("IN \(inputFormat)")
//DLog("IN:IN \(inputFormat)")

// check for expected format
guard inputFormat.mFormatID == kAudioFormatLinearPCM && inputFormat.mFramesPerPacket == 1 && inputFormat.mFormatFlags == kAudioFormatFlagsNativeFloatPacked else {
throw AudioInterfaceError.UnsupportedFormat
}

// get the audio format
//size = UInt32(sizeof(AudioStreamBasicDescription))
//try checkError(AudioUnitGetProperty(audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, inputBus, &outputFormat, &size))
//DLog("IN:OUTi \(outputFormat)")

// configure output format
outputFormat.mFormatID = kAudioFormatLinearPCM
outputFormat.mFormatFlags = kAudioFormatFlagsNativeFloatPacked | kLinearPCMFormatFlagIsNonInterleaved
outputFormat.mSampleRate = inputFormat.mSampleRate
outputFormat.mFramesPerPacket = 1
outputFormat.mBytesPerPacket = UInt32(sizeof(Float))
outputFormat.mBytesPerFrame = UInt32(sizeof(Float))
outputFormat.mChannelsPerFrame = inputFormat.mChannelsPerFrame
outputFormat.mBitsPerChannel = UInt32(8 * sizeof(Float))

// print format information for debugging
//DLog("IN:OUT \(outputFormat)")

// set the audio format
size = UInt32(sizeof(AudioStreamBasicDescription))
try checkError(AudioUnitSetProperty(audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, inputBus, &inputFormat, size))
try checkError(AudioUnitSetProperty(audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, inputBus, &outputFormat, size))

// get maximum frame size
var maxFrameSize: UInt32 = 0
size = UInt32(sizeof(UInt32))
try checkError(AudioUnitGetProperty(audioUnit, kAudioUnitProperty_MaximumFramesPerSlice, kAudioUnitScope_Global, 0, &maxFrameSize, &size))

// create buffers
bufferLen = Int(maxFrameSize * inputFormat.mBytesPerPacket)
buffer = UnsafeMutablePointer<Float>.alloc(bufferLen)
buffer2 = UnsafeMutablePointer<Float>.alloc(bufferLen)
bufferList = AudioBufferList.allocate(maximumBuffers: Int(outputFormat.mChannelsPerFrame))
bufferList.count = Int(outputFormat.mChannelsPerFrame)
for var channel = 0; channel < Int(outputFormat.mChannelsPerFrame); ++channel {
// build buffer
var buffer = AudioBuffer()
buffer.mDataByteSize = outputFormat.mBytesPerFrame * maxFrameSize
buffer.mNumberChannels = 1 // since non-interleaved
buffer.mData = malloc(Int(outputFormat.mBytesPerFrame * maxFrameSize))
bufferList[channel] = buffer
}

// set frame size
var frameSize: UInt32 = UInt32(self.frameSize)
Expand All @@ -461,9 +487,11 @@ class AudioInputInterface: AudioInterface
}

// free buffer
if 0 < bufferLen {
buffer.dealloc(bufferLen)
bufferLen = 0
if nil != bufferList.unsafePointer {
for b in bufferList {
free(b.mData)
}
free(bufferList.unsafeMutablePointer)
}

// stop playback
Expand Down

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