如何將效果應用到麥克風輸入？（iOS核心音頻和音頻圖）

Question

我想在iOS5上開發能夠獲取聲音並對其施加效果（高通濾波器，延遲等）並從揚聲器輸出的應用程序。

我嘗試了RemoteIO（輸入）->效果-> RemoteIO（輸出），但是沒有用。

AudioComponentDescription   cd;
cd.componentType            = kAudioUnitType_Output;
cd.componentSubType         = kAudioUnitSubType_RemoteIO;
cd.componentManufacturer    = kAudioUnitManufacturer_Apple;
cd.componentFlags           = 0;
cd.componentFlagsMask       = 0;

AUGraphAddNode(self.auGraph, &cd, &remoteIONode);
AUGraphNodeInfo(self.auGraph, remoteIONode, NULL, &remoteIOUnit);

UInt32  flag = 1;
AudioUnitSetProperty(remoteIOUnit, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input, 1, &flag, sizeof(flag));

AudioStreamBasicDescription audioFormat = [self auCanonicalASBDSampleRate:44100.0 channel:1];
AudioUnitSetProperty(remoteIOUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 1, &audioFormat, sizeof(AudioStreamBasicDescription));
AudioUnitSetProperty(remoteIOUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 0, &audioFormat, sizeof(AudioStreamBasicDescription));  


AudioComponentDescription cd_e;

cd_e.componentSubType = kAudioUnitSubType_LowPassFilter;
cd_e.componentSubType = kAudioUnitSubType_Reverb2;
cd_e.componentFlags = 0;
cd_e.componentFlagsMask = 0;
cd_e.componentManufacturer = kAudioUnitManufacturer_Apple;
AUGraphAddNode(self.auGraph, &cd_e, &effectNode);
AUGraphNodeInfo(self.auGraph, effectNode, NULL, &effectUnit);

AudioUnitSetProperty(effectUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Global, 0, &audioFormat, sizeof(AudioStreamBasicDescription));    


 AudioUnitSetParameter(effectUnit, kAudioUnitScope_Global, 0, kLowPassParam_CutoffFrequency, 10.f, 0);
 AudioUnitSetParameter(effectUnit, kAudioUnitScope_Global, 0, kLowPassParam_Resonance, 10, 0);

AUGraphConnectNodeInput(self.auGraph, remoteIONode, 1, effectNode, 0);
AUGraphConnectNodeInput(self.auGraph, effectNode, 0, remoteIONode, 0);

AUGraphInitialize(localGraph);

但是，如果AUGraphConnectNodeInput設置為below，我會聽到揚聲器的聲音。

AUGraphConnectNodeInput(self.auGraph, remoteIONode, 1, remoteIONode, 0);

我該怎么做？

Answer 1

我寫了一個教程，詳細說明如何做到實時處理和記錄來自麥克風在iOS上，但從那時起，我已經發現的樂趣普魯卡因 ，這是iOS上做效果處理的更簡單的方法。 這比處理AURemoteGraph和類似的東西容易得多。