在我的应用程序中,我正在渲染回调中进行音频处理(仅输入,不输出)。 这里是我初始化音频:iOS在渲染回调处理之前添加音频效果?
-(void) initAudio {
OSStatus status;
NewAUGraph(&graph);
AudioComponentDescription desc;
desc.componentType = kAudioUnitType_Output;
desc.componentSubType = kAudioUnitSubType_RemoteIO;
desc.componentFlags = 0;
desc.componentFlagsMask = 0;
desc.componentManufacturer = kAudioUnitManufacturer_Apple;
AUNode ioNode;
status = AUGraphAddNode(graph, &desc, &ioNode);
checkStatus(status, "At adding node");
AUGraphOpen(graph);
AUGraphNodeInfo(graph, ioNode, NULL, &audioUnit);
//Enable IO for recording
UInt32 enableInput = 1;
status = AudioUnitSetProperty(audioUnit,
kAudioOutputUnitProperty_EnableIO,
kAudioUnitScope_Input,
kInputBus,
&enableInput,
sizeof(enableInput));
checkStatus(status, "At setting property for input");
//Disable playback
UInt32 enableOutput = 0;
status = AudioUnitSetProperty(audioUnit,
kAudioOutputUnitProperty_EnableIO,
kAudioUnitScope_Output,
kOutputBus,
&enableOutput,
sizeof(enableOutput));
checkStatus(status, "At setting property for input");
// ASBD
AudioStreamBasicDescription audioFormatIn;
audioFormatIn.mSampleRate = SampleRate;
audioFormatIn.mFormatID = kAudioFormatLinearPCM;
audioFormatIn.mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
audioFormatIn.mFramesPerPacket = 1;
audioFormatIn.mChannelsPerFrame = 1;
audioFormatIn.mBitsPerChannel = 16;//sizeof(AudioSampleType) * 8;
audioFormatIn.mBytesPerPacket = 2 * audioFormatIn.mChannelsPerFrame;
audioFormatIn.mBytesPerFrame = 2 * audioFormatIn.mChannelsPerFrame;
//Apply format
status = AudioUnitSetProperty(audioUnit,
kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Output,
kInputBus,
&audioFormatIn,
sizeof(audioFormatIn));
checkStatus(status,"At setting property for AudioStreamBasicDescription for input");
//Set up input callback
AURenderCallbackStruct callbackStruct;
callbackStruct.inputProc = recordingCallback;
callbackStruct.inputProcRefCon = (__bridge void *)self;
status = AudioUnitSetProperty(audioUnit,
kAudioOutputUnitProperty_SetInputCallback,
kAudioUnitScope_Global,
kInputBus,
&callbackStruct,
sizeof(callbackStruct));
checkStatus(status,"At setting property for recording callback");
// Disable buffer allocation for the recorder
UInt32 flag = 0;
status = AudioUnitSetProperty(audioUnit,
kAudioUnitProperty_ShouldAllocateBuffer,
kAudioUnitScope_Output,
kInputBus,
&flag,
sizeof(flag));
checkStatus(status, "At set property should allocate buffer");
// Allocate own buffers
tempBuffer.mNumberChannels = 1;
tempBuffer.mDataByteSize = 1024 * 2;
tempBuffer.mData = malloc(1024 * 2);
status = AUGraphInitialize(graph);
checkStatus(status,"At AUGraph Initalize");
}
现在,我想在渲染回调处理之前增加一个高通滤波器或带通滤波器的输入音频。所以我觉得我应该增加这样的:
desc.componentType = kAudioUnitType_Effect;
desc.componentSubType = kAudioUnitSubType_BandPassFilter;
desc.componentFlags = 0;
desc.componentFlagsMask = 0;
desc.componentManufacturer = kAudioUnitManufacturer_Apple;
,但我没能创造/正确连接节点,使这项工作... 感谢您的帮助!
您的渲染链条是否在没有带通的情况下工作? – dave234
@Dave我曾经使用过经典的音频单元初始化,但是我开始转向AUGraph,即使我不确定自己做的是否正确,我上面的代码似乎也能正常工作。 – jcr