我是Core Audio的新手,所以我可能看不到明显的东西... 我的目标是处理先前录制的音频信号。但是,这些信号应该先过滤。我不需要播放任何音频。我只需要记录并处理它。核心音频:在非remoteIO单元上的kAudioOutputUnitProperty_SetInputCallback
My图表看起来像这样: RemoteIO - > HighPassFilter - >回调(处理音频)
,我把它像这样:
LBAudioDetectiveGetDefaultFormat(&detective->streamFormat);
// Create new AUGraph
OSStatus error = NewAUGraph(&detective->graph);
LBErrorCheck(error);
// Initialize AUNodes
AudioComponentDescription rioCD = {0};
rioCD.componentType = kAudioUnitType_Output;
rioCD.componentSubType = kAudioUnitSubType_RemoteIO;
rioCD.componentManufacturer = kAudioUnitManufacturer_Apple;
AUNode rioNode;
error = AUGraphAddNode(detective->graph, &rioCD, &rioNode);
LBErrorCheck(error);
AudioComponentDescription filterCD = {0};
filterCD.componentType = kAudioUnitType_Effect;
filterCD.componentSubType = kAudioUnitSubType_HighPassFilter;
filterCD.componentManufacturer = kAudioUnitManufacturer_Apple;
AUNode filterNode;
error = AUGraphAddNode(detective->graph, &filterCD, &filterNode);
LBErrorCheck(error);
// Open the graph so I can modify the AudioUnits
error = AUGraphOpen(detective->graph);
// Adapt rioUnit
error = AUGraphNodeInfo(detective->graph, rioNode, NULL, &detective->rioUnit);
LBErrorCheck(error);
UInt32 onFlag = 1;
AudioUnitElement bus1 = 1;
UInt32 propertySize = sizeof(UInt32);
error = AudioUnitSetProperty(detective->rioUnit, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input, bus1, &onFlag, propertySize);
LBErrorCheck(error);
propertySize = sizeof(AudioStreamBasicDescription);
error = AudioUnitSetProperty(detective->rioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, bus1, &detective->streamFormat, propertySize);
LBErrorCheck(error);
// Adapt filterUnit
error = AUGraphNodeInfo(detective->graph, filterNode, NULL, &detective->filterUnit);
LBErrorCheck(error);
AURenderCallbackStruct callback = {0};
callback.inputProc = _LBAudioDetectiveFilterOutput;
callback.inputProcRefCon = detective;
propertySize = sizeof(AURenderCallbackStruct);
error = AudioUnitSetProperty(detective->filterUnit, kAudioOutputUnitProperty_SetInputCallback, kAudioUnitScope_Global, 0, &callback, propertySize);
LBErrorCheck(error);
// Connect the two units
AudioUnitElement bus0 = 0;
error = AUGraphConnectNodeInput(detective->graph, rioNode, bus1, filterNode, bus0);
LBErrorCheck(error);
AUGraphInitialize(detective->graph);
我的代码失败,出现错误 - 10879当我尝试设置回调。我假设过滤器音频单元不支持此属性。 那我该如何获得录制的声音呢?据我所知,第二个通用输出单元是不允许的。
感谢您提前RemoteIO音频单元,但在RemoteIO回调(过滤单元或输入总线代替),拉的帮助
嗯,这是一个聪明的做法,但不会再调用输入回调。我确实需要连接哪些巴士。我使用filterUnit的总线0连接了rioUnit的总线1。回调结构在输出范围的rioUnit的总线1上配置。回调被调用,但它不包含'ioData-> mBuffers [0] .mData'中的任何数据' – lbrndnr 2013-04-22 19:40:03