8

我有个问题 ;）

我想从麦克风录制音频并将其写入具有扩展音频文件服务的文件系统，并播放录制的东西。如果我只使用带有两个回调的 remoteIO，一个用于读取，一个用于写入，它可以工作。

对于 Volumen Control，我想使用 MultiChannelMixer 和 AUGraph。可以用同一个混音器和RemoteIO实现回放和录音吗？

我认为它必须看起来像这样：

RemotIO Input   ->        -> Write Callback
                    Mixer
RemoteIO Output <-        <- Read Callback

我创建了两个 AUNode（RemoteIO 和 MultiChannelMixer），我必须如何设置回调和连接，一个回调从麦克风传递 AudioData，另一个从文件读取数据并且两条路径都通过混音器？

读写不是问题，只是节点的配置！

…以及 CAShow 的输出：

AudioUnitGraph 0x8AEE000:
  Member Nodes:
    node 1: 'aumx' 'mcmx' 'appl', instance 0x865a510 O I
    node 2: 'auou' 'rioc' 'appl', instance 0x865d0a0 O I
  Connections:
    node   1 bus   0 => node   2 bus   0  [ 2 ch,  44100 Hz, 'lpcm' (0x0000000C) 16-bit little-endian signed integer]
    node   2 bus   1 => node   1 bus   1  [ 2 ch,  44100 Hz, 'lpcm' (0x0000000C) 16-bit little-endian signed integer]
  Input Callbacks:
    {0x4150, 0x7573340} => node   2 bus   1  [2 ch, 44100 Hz]
    {0x4330, 0x7573340} => node   1 bus   0  [2 ch, 44100 Hz]
  CurrentState:
    mLastUpdateError=0, eventsToProcess=F, isRunning=F

这是设置代码：

    OSStatus setupErr = noErr;

AudioComponentDescription mixerDescription;
AudioComponentDescription ioDescription;

// the AUNodes
AUNode mixerNode;
AUNode ioNode;

// the graph
setupErr = NewAUGraph(&_graph);
NSAssert(setupErr == noErr, @"Couldn't create graph");

// the mixer
mixerDescription.componentFlags = 0;
mixerDescription.componentFlagsMask = 0;
mixerDescription.componentType = kAudioUnitType_Mixer;
mixerDescription.componentSubType = kAudioUnitSubType_MultiChannelMixer;
mixerDescription.componentManufacturer = kAudioUnitManufacturer_Apple;

// the io 
ioDescription.componentFlags = 0;
ioDescription.componentFlagsMask = 0;
ioDescription.componentType = kAudioUnitType_Output;
ioDescription.componentSubType = kAudioUnitSubType_RemoteIO;
ioDescription.componentManufacturer = kAudioUnitManufacturer_Apple;

// add mixer Node
setupErr = AUGraphAddNode(self.graph, &mixerDescription, &mixerNode);
NSAssert(setupErr == noErr, @"Couldn't create master mixer");

// add io Node
setupErr = AUGraphAddNode(self.graph, &ioDescription, &ioNode);
NSAssert(setupErr == noErr, @"Couldn't create io node");

// open Graph
setupErr = AUGraphOpen(self.graph);
NSAssert(setupErr == noErr, @"Couldn't open graph");

// get the mixer info
setupErr = AUGraphNodeInfo(self.graph, mixerNode, &mixerDescription, &_mixer);
NSAssert(setupErr == noErr, @"Couldn't get master mixer info");

// get the io info
setupErr = AUGraphNodeInfo(self.graph, ioNode, &ioDescription, &_io);
NSAssert(setupErr == noErr, @"Couldn't get io Node info");

// enable io input
UInt32 enableFlag = 1;
setupErr = AudioUnitSetProperty(self.io, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input, kInputBus, &enableFlag, sizeof(enableFlag));
NSAssert(setupErr == noErr, @"Couldn't enable io input");

// set up the mixers input callbacks
AURenderCallbackStruct outputCallbackStruct;
outputCallbackStruct.inputProc = outputCallback;
outputCallbackStruct.inputProcRefCon = self;

AURenderCallbackStruct inputCallbackStruct;
inputCallbackStruct.inputProc = inputCallback;
inputCallbackStruct.inputProcRefCon = self;

setupErr = AUGraphConnectNodeInput(self.graph, mixerNode, 0, ioNode, 0);
NSAssert(setupErr == noErr, @"Couldn't connect mixer output to io output");
setupErr = AUGraphConnectNodeInput(self.graph, ioNode, 1, mixerNode, 1);
NSAssert(setupErr == noErr, @"Couldn't connect io input to mixer input");

// set output Callback
setupErr = AUGraphSetNodeInputCallback(self.graph, ioNode, 1, &outputCallbackStruct);
NSAssert(setupErr == noErr, @"Error setting io output callback");

// set input Callback
setupErr = AUGraphSetNodeInputCallback(self.graph, mixerNode, 0, &inputCallbackStruct);
NSAssert(setupErr == noErr, @"Error setting mixer input callback");

// describe format
AudioStreamBasicDescription audioFormat = {0};
audioFormat.mSampleRate                 = 44100.00;
audioFormat.mFormatID                   = kAudioFormatLinearPCM;
audioFormat.mFormatFlags                = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
audioFormat.mFramesPerPacket            = 1;
audioFormat.mChannelsPerFrame           = 2;
audioFormat.mBitsPerChannel             = 16;
audioFormat.mBytesPerPacket             = 4;
audioFormat.mBytesPerFrame              = 4;

// set the rio input properties
setupErr = AudioUnitSetProperty(self.io, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, kOutputBus, &audioFormat, sizeof(audioFormat));
NSAssert(setupErr == noErr, @"Error setting RIO input property");

// set the rio output properties
setupErr = AudioUnitSetProperty(self.io, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, kInputBus, &audioFormat, sizeof(audioFormat));
NSAssert(setupErr == noErr, @"Error setting RIO output property");

// set the master fader output properties
setupErr = AudioUnitSetProperty(self.mixer, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Global, kOutputBus, &audioFormat, sizeof(audioFormat));
NSAssert(setupErr == noErr, @"Error setting master output property");

// set the master fader input properties
setupErr = AudioUnitSetProperty(self.mixer, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Global, kOutputBus, &audioFormat, sizeof(audioFormat));
NSAssert(setupErr == noErr, @"Error setting master input1 property");

// initialize Graph
setupErr = AUGraphInitialize(self.graph);
NSAssert(setupErr == noErr, @"Error initializing graph - error code");

CAShow(self.graph);

// start Graph
setupErr = AUGraphStart(self.graph);
NSAssert(setupErr == noErr, @"Error starting graph. - error code");

我希望你能理解我的问题:) 谢谢..

更新： 还有一些东西来描述我的问题！

录音：RemoteIO InputScope Bus 0 -> Mixer Input Bus 0 -> Mixer Output Bus 0 -> Write Callback -> 文件播放：File -> Read Callback -> Mixer Input Bus 1 -> Mixer Output Bus 0 -> RemoteIO OutputScope Bus 1

连接计划

4

1 回答 1

7

您需要创建具有三个节点（单元）的 AUGraph：

  1. 文件播放器 (kAudioUnitSubType_AudioFilePlayer)
  2. 远程IO
  3. 混合器

像这样连接它们：

AUGraphConnectNodeInput(m_graph, m_player, 0, m_mixerNode, 0); // player -> mixer
AUGraphConnectNodeInput(m_graph, m_mixerNode, 0, m_rioNode, 0); // mixer -> output
AUGraphConnectNodeInput(m_graph, m_rioNode, 1, m_mixerNode, 1); // input -> mixer

在 RIO 上启用输入：

UInt32 enable = 1;
AudioUnitSetProperty(m_rioUnit, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input, 1, &enable, sizeof(UInt32));

获取混音器输出格式并将其设置为扩展音频文件的客户端格式：

AudioStreamBasicDescription mixerASBD;
UInt32 prop = sizeof(mixerASBD);
AudioUnitGetProperty(m_mixerUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 0, &mixerASBD, &prop);
ExtAudioFileSetProperty(extAudioFile, kExtAudioFileProperty_ClientDataFormat, sizeof(mixerASBD), &mixerASBD);

定义渲染回调：

static OSStatus mixerCallBack(void *inRefCon, AudioUnitRenderActionFlags *ioActionFlags, const AudioTimeStamp * inTimeStamp, UInt32 inBusNumber,UInt32 inNumberFrames, AudioBufferList *ioData) {
    if ((*ioActionFlags) & kAudioUnitRenderAction_PostRender)
        return (ExtAudioFileWrite(extAudioFile, inNumberFrames, ioData));

    return noErr;
}

为混音器的输出数据添加回调：

AudioUnitAddRenderNotify(m_mixerUnit, mixerCallBack, NULL);

就这样。您需要将音频文件安排到 FilePlayer 单元进行播放。

于 2012-11-18T21:21:20.060 回答