禁用 AudioUnit AGC 失败
Posted
技术标签:
【中文标题】禁用 AudioUnit AGC 失败【英文标题】:Disabling AudioUnit AGC fails 【发布时间】:2020-07-13 21:20:54 【问题描述】:我正在尝试禁用 AGC 并绕过 AudioUnit 的语音过滤器,但它无法设置这两个属性:
private func setupAudioUnit()
var componentDesc:AudioComponentDescription = AudioComponentDescription(
componentType: OSType(kAudioUnitType_Output),
componentSubType: OSType(kAudioUnitSubType_RemoteIO), // Always this for ios.
componentManufacturer: OSType(kAudioUnitManufacturer_Apple),
componentFlags: 0,
componentFlagsMask: 0)
var osErr: OSStatus = 0
// Get an audio component matching our description.
let component: AudioComponent! = AudioComponentFindNext(nil, &componentDesc)
assert(component != nil, "Couldn't find a default component")
// Create an instance of the AudioUnit
var tempAudioUnit: AudioUnit?
osErr = AudioComponentInstanceNew(component, &tempAudioUnit)
self.audioUnit = tempAudioUnit
assert(osErr == noErr, "*** AudioComponentInstanceNew err \(osErr)")
// Enable I/O for input.
var one: UInt32 = 1
var off: UInt32 = 0
osErr = AudioUnitSetProperty(audioUnit,
kAudioOutputUnitProperty_EnableIO,
kAudioUnitScope_Input,
inputBus,
&one,
UInt32(MemoryLayout<UInt32>.size))
/// Bypass Voice Processing
osErr = AudioUnitSetProperty(audioUnit,
kAUVoiceIOProperty_BypassVoiceProcessing,
kAudioUnitScope_Global,
inputBus,
&one,
UInt32(MemoryLayout<UInt32>.size))
print("AudioUnitSetProperty returned code:\(osErr)")
/// Disable AGC
osErr = AudioUnitSetProperty(audioUnit,
kAUVoiceIOProperty_VoiceProcessingEnableAGC,
kAudioUnitScope_Global,
inputBus,
&off,
UInt32(MemoryLayout<UInt32>.size))
print("AudioUnitSetProperty returned code:\(osErr)")
assert(osErr == noErr, "*** AudioUnitSetProperty err \(osErr)")
// Set format to 32 bit, floating point, linear PCM
var streamFormatDesc:AudioStreamBasicDescription = AudioStreamBasicDescription(
mSampleRate: Double(sampleRate),
mFormatID: kAudioFormatLinearPCM,
mFormatFlags: kAudioFormatFlagsNativeFloatPacked | kAudioFormatFlagIsNonInterleaved, // floating point data - docs say this is fastest
mBytesPerPacket: 4,
mFramesPerPacket: 1,
mBytesPerFrame: 4,
mChannelsPerFrame: UInt32(self.numberOfChannels),
mBitsPerChannel: 4 * 8,
mReserved: 0
)
// Set format for input and output busses
osErr = AudioUnitSetProperty(audioUnit,
kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Input, outputBus,
&streamFormatDesc,
UInt32(MemoryLayout<AudioStreamBasicDescription>.size))
assert(osErr == noErr, "*** AudioUnitSetProperty err \(osErr)")
osErr = AudioUnitSetProperty(audioUnit,
kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Output,
inputBus,
&streamFormatDesc,
UInt32(MemoryLayout<AudioStreamBasicDescription>.size))
assert(osErr == noErr, "*** AudioUnitSetProperty err \(osErr)")
// Set up our callback.
var inputCallbackStruct = AURenderCallbackStruct(inputProc: recordingCallback, inputProcRefCon: UnsafeMutableRawPointer(Unmanaged.passUnretained(self).toOpaque()))
osErr = AudioUnitSetProperty(audioUnit,
AudioUnitPropertyID(kAudioOutputUnitProperty_SetInputCallback),
AudioUnitScope(kAudioUnitScope_Global),
inputBus,
&inputCallbackStruct,
UInt32(MemoryLayout<AURenderCallbackStruct>.size))
assert(osErr == noErr, "*** AudioUnitSetProperty err \(osErr)")
// Ask CoreAudio to allocate buffers for us on render. (This is true by default but just to be explicit about it...)
osErr = AudioUnitSetProperty(audioUnit,
AudioUnitPropertyID(kAudioUnitProperty_ShouldAllocateBuffer),
AudioUnitScope(kAudioUnitScope_Output),
inputBus,
&one,
UInt32(MemoryLayout<UInt32>.size))
assert(osErr == noErr, "*** AudioUnitSetProperty err \(osErr)")
在这里我得到无效的属性响应:
/// Bypass Voice Processing
osErr = AudioUnitSetProperty(audioUnit,
kAUVoiceIOProperty_BypassVoiceProcessing,
kAudioUnitScope_Global,
inputBus,
&one,
UInt32(MemoryLayout<UInt32>.size))
print("AudioUnitSetProperty returned code:\(osErr)")
// AudioUnitSetProperty returned code:-10879
/// Disable AGC
osErr = AudioUnitSetProperty(audioUnit,
kAUVoiceIOProperty_VoiceProcessingEnableAGC,
kAudioUnitScope_Global,
inputBus,
&off,
UInt32(MemoryLayout<UInt32>.size))
print("AudioUnitSetProperty returned code:\(osErr)")
// AudioUnitSetProperty returned code:-10879
我做错了吗?
【问题讨论】:
【参考方案1】:我没有在 iOS 上使用过 CoreAudio,也没有使用过语音处理 AU,但看起来问题出在您指定的子类型上。
有问题的属性似乎特定于kAudioUnitSubType_VoiceProcessingIO
的子类型,但您正在实例化子类型kAudioUnitSubType_RemoteIO
。如果您使用前一个子类型,那么属性应该是有效的。
【讨论】:
以上是关于禁用 AudioUnit AGC 失败的主要内容,如果未能解决你的问题,请参考以下文章