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在Mac OS X上,我尝试从用户选择的声卡获取音频流,并使用PCM缓冲区出来。AudioUnit,配置一个图形转换帧并将其发送到回调?
目前,我可以访问良好的设备,并使用AudioDeviceIOProc
获取硬件原生流描述的缓冲区。
现在我想用我的选定设备使用AUGraph
将我的缓冲区转换为自定义ASBD并在AURenderCallback
上得到它。
这里是我的设置代码(NSString* deviceUID and AudioStreamBasicDescription streamDescription
在参数被传递给我的设置功能):
// get the AudioDeviceID
AudioValueTranslation avt = {&deviceUID,
sizeof(deviceUID),
&_inDevice,
sizeof(_inDevice)};
UInt32 avt_len = sizeof(avt);
osstat = AudioHardwareGetProperty(kAudioHardwarePropertyDeviceForUID, &avt_len, &avt);
osstat = NewAUGraph(&_inputGraph);
AudioComponentDescription streamConverterDesc;
streamConverterDesc.componentType = kAudioUnitType_FormatConverter;
streamConverterDesc.componentSubType = kAudioUnitSubType_AUConverter;
streamConverterDesc.componentManufacturer = kAudioUnitManufacturer_Apple;
streamConverterDesc.componentFlags = streamConverterDesc.componentFlagsMask = 0;
AUNode streamConverterNode;
osstat = AUGraphAddNode(_inputGraph, &streamConverterDesc, &streamConverterNode);
AudioUnit streamConverterUnit;
osstat = AUGraphNodeInfo(_inputGraph, streamConverterNode, NULL, &streamConverterUnit);
osstat = AudioUnitSetProperty(streamConverterUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 0, &streamDescription, sizeof(streamDescription));
osstat = AudioUnitSetProperty(streamConverterUnit, kAudioOutputUnitProperty_CurrentDevice, kAudioUnitScope_Global, 0, &_inDevice, sizeof(_inDevice));
AudioComponentDescription streamReaderDesc;
streamReaderDesc.componentType = kAudioUnitType_Output;
streamReaderDesc.componentSubType = kAudioUnitSubType_GenericOutput;
streamReaderDesc.componentManufacturer = kAudioUnitManufacturer_Apple;
streamReaderDesc.componentFlags = streamReaderDesc.componentFlagsMask = 0;
AUNode streamReaderNode;
osstat = AUGraphAddNode(_inputGraph, &streamReaderDesc, &streamReaderNode);
AudioUnit streamReaderUnit;
osstat = AUGraphNodeInfo(_inputGraph, streamReaderNode, NULL, &streamReaderUnit);
AURenderCallbackStruct callback;
callback.inputProc = EIRenderCallback;
callback.inputProcRefCon = self;
osstat = AudioUnitSetProperty(streamReaderUnit, kAudioOutputUnitProperty_SetInputCallback, kAudioUnitScope_Output, 0, &callback, sizeof(callback));
osstat = AudioUnitSetProperty(streamReaderUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 0, &streamDescription, sizeof(streamDescription));
osstat = AUGraphConnectNodeInput(_inputGraph, streamConverterNode, 1, streamReaderNode, 0);
osstat = AUGraphOpen(_inputGraph);
osstat = AUGraphInitialize(_inputGraph);
我开始我的AUGraph
后。
其实我在AudioUnitSetProperty
和streamConverterUnit
上得到了错误-50。
我想有一个反馈,从人们习惯了CoreAudio
,这个设置流程是好的吗?为什么这个错误-50,我应该怎么做才能完成一个工作设置?
最好的问候, 约恩