如何连接调音台与AUGraph

我希望创建一个具有以下AudioUnits的AUGraph：如何连接调音台与AUGraph

1个* 440Hz的正弦波发生器
1个* 880HZ正弦波发生器
1 *混频器
1 *输出

如果我将正弦波发生器则调音台连接到我的调音台，到输出我没有得到任何声音。

如果我直接将正弦波发生器连接到输出，我确实听起来很可能是因为输出单元连接到正弦波发生器回调。

有什么我不知道这应该如何连接？

完整的代码示例，连接1 *加入1不工作，评论这些并运行连接2和联接2听到正弦波工作

// 
// main.c 
// TestAudioUnit 
// 
// Created by Chris Davis on 25/08/2013. 
// Copyright (c) 2013 Chris Davis. All rights reserved. 
// 

#include <CoreFoundation/CoreFoundation.h> 
#import <AudioToolbox/AudioToolbox.h> 

typedef struct MyAUGraphPlayer 
{ 
    AudioStreamBasicDescription streamFormat; 

    AUGraph graph; 
    AUNode output; 
    AUNode mixer; 
    AUNode sine; 
    AudioUnit audioUnits[3]; 


    AudioBufferList *inputBuffer; 


    Float64 firstInputSampleTime; 
    Float64 firstOutputSampleTime; 
    Float64 inToOutSampleTimeOffset; 
} MyAUGraphPlayer; 

OSStatus SineWaveRenderCallback(void * inRefCon, 
           AudioUnitRenderActionFlags * ioActionFlags, 
           const AudioTimeStamp * inTimeStamp, 
           UInt32 inBusNumber, 
           UInt32 inNumberFrames, 
           AudioBufferList * ioData) 
{ 
    // inRefCon is the context pointer we passed in earlier when setting the render callback 
    double currentPhase = *((double *)inRefCon); 
    // ioData is where we're supposed to put the audio samples we've created 
    Float32 * outputBuffer = (Float32 *)ioData->mBuffers[0].mData; 
    const double frequency = 880.0; 
    const double phaseStep = (frequency/44100.) * (M_PI * 2.); 

    for(int i = 0; i < inNumberFrames; i++) { 
     outputBuffer[i] = sin(currentPhase); 
     currentPhase += phaseStep; 
    } 

    // If we were doing stereo (or more), this would copy our sine wave samples 
    // to all of the remaining channels 
    for(int i = 1; i < ioData->mNumberBuffers; i++) { 
     memcpy(ioData->mBuffers[i].mData, outputBuffer, ioData->mBuffers[i].mDataByteSize); 
    } 

    // writing the current phase back to inRefCon so we can use it on the next call 
    *((double *)inRefCon) = currentPhase; 
    return noErr; 
} 


int main(int argc, const char * argv[]) 
{ 

    MyAUGraphPlayer *player = {0}; 
    MyAUGraphPlayer p = {0}; 
    player=&p; 

    NewAUGraph(&player->graph); 


    //Output 
    { 
    AudioComponentDescription description = { 
     .componentType = kAudioUnitType_Output, 
     .componentSubType = kAudioUnitSubType_DefaultOutput, 
     .componentManufacturer = kAudioUnitManufacturer_Apple 
    }; 
    AUGraphAddNode(player->graph, &description, &player->output); 
    AudioComponent comp = AudioComponentFindNext(NULL, &description); 
    AudioComponentInstanceNew(comp, &player->audioUnits[0]); 
    AudioUnitInitialize(player->audioUnits[0]); 
    AudioStreamBasicDescription ASBD = { 
     .mSampleRate  = 44100, 
     .mFormatID   = kAudioFormatLinearPCM, 
     .mFormatFlags  = kAudioFormatFlagsNativeFloatPacked, 
     .mChannelsPerFrame = 1, 
     .mFramesPerPacket = 1, 
     .mBitsPerChannel = sizeof(Float32) * 8, 
     .mBytesPerPacket = sizeof(Float32), 
     .mBytesPerFrame = sizeof(Float32) 
    }; 
    AudioUnitSetProperty(player->audioUnits[0], 
         kAudioUnitProperty_StreamFormat, 
         kAudioUnitScope_Global, 
         0, 
         &ASBD, 
         sizeof(ASBD)); 
    } 

    //Mixer 
    { 
     AudioComponentDescription description = { 
      .componentType = kAudioUnitType_Mixer, 
      .componentSubType = kAudioUnitSubType_StereoMixer, 
      .componentManufacturer = kAudioUnitManufacturer_Apple 
     }; 
     AUGraphAddNode(player->graph, &description, &player->mixer); 
     AudioComponent comp = AudioComponentFindNext(NULL, &description); 
     AudioComponentInstanceNew(comp, &player->audioUnits[1]); 
     AudioUnitInitialize(player->audioUnits[1]); 

    } 


    //Sine 
    { 
     AudioComponentDescription description = { 
      .componentType = kAudioUnitType_Generator, 
      .componentSubType = kAudioUnitSubType_ScheduledSoundPlayer, 
      .componentManufacturer = kAudioUnitManufacturer_Apple 
     }; 
     AUGraphAddNode(player->graph, &description, &player->sine); 
     AudioComponent comp = AudioComponentFindNext(NULL, &description); 
     AudioComponentInstanceNew(comp, &player->audioUnits[2]); 
     AudioUnitInitialize(player->audioUnits[2]); 

    } 



    //Connect 1 
    { 
     AURenderCallbackStruct callbackInfo = { 
      .inputProc  = SineWaveRenderCallback, 
      .inputProcRefCon = player 
     }; 

     AudioUnitSetProperty(player->audioUnits[1], 
             kAudioUnitProperty_SetRenderCallback, 
             kAudioUnitScope_Global, 
             0, 
             &callbackInfo, 
          sizeof(callbackInfo)); 

    } 

    //Joins 1 - sine to mixer to outout 
    { 
     AUGraphConnectNodeInput(player->graph, 
           player->sine, 
           0, 
           player->mixer, 
           0); 

     AUGraphConnectNodeInput(player->graph, 
           player->mixer, 
           0, 
           player->output, 
           0); 

    } 

    //connect 2 
    /*{ 
     AURenderCallbackStruct callbackInfo = { 
      .inputProc  = SineWaveRenderCallback, 
      .inputProcRefCon = player 
     }; 

     AudioUnitSetProperty(player->audioUnits[0], 
          kAudioUnitProperty_SetRenderCallback, 
          kAudioUnitScope_Global, 
          0, 
          &callbackInfo, 
          sizeof(callbackInfo)); 

    } 


    //Joins 2 - sine direct to output 
    { 
     AUGraphConnectNodeInput(player->graph, 
           player->sine, 
           0, 
           player->output, 
           0); 
    }*/ 

    AUGraphInitialize(player->graph); 
    player->firstOutputSampleTime = -1; 
    AudioOutputUnitStart(player->audioUnits[0]); 
    AUGraphStart(player->graph); 

    printf("enter key to stop\n"); 
    getchar(); 

    return 0; 
}

来源

2013-08-25 Chris

某些代码可能是？ – Larme

我已经为您添加了示例代码 – Chris

这与Apple示例代码中使用的是相同的吗？ – Larme

这段代码可以正常播放的正弦波，但是，在安装过程中，我从CoreAudio中收到很多错误：

// 
// main.c 
// TestAudioUnit 
// 
// Created by Chris Davis on 25/08/2013. 
// Copyright (c) 2013 Chris Davis. All rights reserved. 
// 

#include <CoreFoundation/CoreFoundation.h> 
#import <AudioToolbox/AudioToolbox.h> 

typedef struct MyAUGraphPlayer 
{ 
    AudioStreamBasicDescription streamFormat; 

    AUGraph graph; 
    AUNode output; 
    AUNode mixer; 
    AUNode sine; 
    AudioUnit audioUnits[3]; 


    AudioBufferList *inputBuffer; 


    Float64 firstInputSampleTime; 
    Float64 firstOutputSampleTime; 
    Float64 inToOutSampleTimeOffset; 
} MyAUGraphPlayer; 

OSStatus SineWaveRenderCallback(void * inRefCon, 
           AudioUnitRenderActionFlags * ioActionFlags, 
           const AudioTimeStamp * inTimeStamp, 
           UInt32 inBusNumber, 
           UInt32 inNumberFrames, 
           AudioBufferList * ioData) 
{ 
    // inRefCon is the context pointer we passed in earlier when setting the render callback 
    double currentPhase = *((double *)inRefCon); 
    // ioData is where we're supposed to put the audio samples we've created 
    Float32 * outputBuffer = (Float32 *)ioData->mBuffers[0].mData; 
    const double frequency = 880.0; 
    const double phaseStep = (frequency/44100.) * (M_PI * 2.); 

    for(int i = 0; i < inNumberFrames; i++) { 
     outputBuffer[i] = sin(currentPhase); 
     currentPhase += phaseStep; 
    } 

    // If we were doing stereo (or more), this would copy our sine wave samples 
    // to all of the remaining channels 
    for(int i = 1; i < ioData->mNumberBuffers; i++) { 
     memcpy(ioData->mBuffers[i].mData, outputBuffer, ioData->mBuffers[i].mDataByteSize); 
    } 

    // writing the current phase back to inRefCon so we can use it on the next call 
    *((double *)inRefCon) = currentPhase; 
    return noErr; 
} 


int main(int argc, const char * argv[]) 
{ 

    MyAUGraphPlayer *player = {0}; 
    MyAUGraphPlayer p = {0}; 
    player=&p; 

    NewAUGraph(&player->graph); 

    OSStatus result = 0; 

    AudioStreamBasicDescription ASBD = { 
     .mSampleRate  = 44100, 
     .mFormatID   = kAudioFormatLinearPCM, 
     .mFormatFlags  = kAudioFormatFlagsNativeFloatPacked, 
     .mChannelsPerFrame = 2, 
     .mFramesPerPacket = 1, 
     .mBitsPerChannel = sizeof(Float32) * 8, 
     .mBytesPerPacket = sizeof(Float32), 
     .mBytesPerFrame = sizeof(Float32) 
    }; 


    //Output 
    { 
     AudioComponentDescription description = { 
      .componentType = kAudioUnitType_Output, 
      .componentSubType = kAudioUnitSubType_DefaultOutput, 
      .componentManufacturer = kAudioUnitManufacturer_Apple 
     }; 
     result = AUGraphAddNode(player->graph, &description, &player->output); 
     printf("err: %d\n", result); 
     AudioComponent comp = AudioComponentFindNext(NULL, &description); 
     result = AudioComponentInstanceNew(comp, &player->audioUnits[0]); 
     printf("err: %d\n", result); 
     result = AudioUnitInitialize(player->audioUnits[0]); 
     printf("err: %d\n", result); 

    } 

    //Mixer 
    { 
     AudioComponentDescription description = { 
      .componentType = kAudioUnitType_Mixer, 
      .componentSubType = kAudioUnitSubType_StereoMixer, 
      .componentManufacturer = kAudioUnitManufacturer_Apple 
     }; 
     result = AUGraphAddNode(player->graph, &description, &player->mixer); 
     printf("err: %d\n", result); 
     AudioComponent comp = AudioComponentFindNext(NULL, &description); 
     result = AudioComponentInstanceNew(comp, &player->audioUnits[1]); 
     printf("err: %d\n", result); 


    } 


    //Sine 
    { 
     AudioComponentDescription description = { 
      .componentType = kAudioUnitType_Generator, 
      .componentSubType = kAudioUnitSubType_ScheduledSoundPlayer, 
      .componentManufacturer = kAudioUnitManufacturer_Apple 
     }; 
     result = AUGraphAddNode(player->graph, &description, &player->sine); 
     printf("err: %d\n", result); 
     AudioComponent comp = AudioComponentFindNext(NULL, &description); 
     result = AudioComponentInstanceNew(comp, &player->audioUnits[2]); 
     printf("err: %d\n", result); 
     result = AudioUnitInitialize(player->audioUnits[2]); 
     printf("err: %d\n", result); 

    } 




    result = AUGraphConnectNodeInput(player->graph, 
          player->sine, 
          0, 
          player->mixer, 
          0); 
    printf("err: %d\n", result); 

    result = AUGraphConnectNodeInput(player->graph, 
          player->mixer, 
          0, 
          player->output, 
          0); 
    printf("err: %d\n", result); 

    result = AUGraphOpen(player->graph); 
    printf("err: %d\n", result); 


    UInt32 numbuses = 1; 


    result = AudioUnitSetProperty(player->audioUnits[1], kAudioUnitProperty_ElementCount, kAudioUnitScope_Input, 0, &numbuses, sizeof(numbuses)); 
    printf("err: %d\n", result); 

    for (UInt32 i = 0; i <= numbuses; ++i) { 
     // setup render callback struct 
     AURenderCallbackStruct rcbs; 
     rcbs.inputProc = &SineWaveRenderCallback; 
     rcbs.inputProcRefCon = &player; 

     printf("set AUGraphSetNodeInputCallback\n"); 

     // set a callback for the specified node's specified input 
     result = AUGraphSetNodeInputCallback(player->graph, player->mixer, i, &rcbs); 
     printf("AUGraphSetNodeInputCallback err: %d\n", result); 

     printf("set input bus %d, client kAudioUnitProperty_StreamFormat\n", (unsigned int)i); 

     // set the input stream format, this is the format of the audio for mixer input 
     result = AudioUnitSetProperty(player->audioUnits[1], kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, i, &ASBD, sizeof(ASBD)); 
     printf("err: %d\n", result); 
    } 



    result = AudioUnitSetProperty(player->audioUnits[1], kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 0, &ASBD, sizeof(ASBD)); 
    printf("err: %d\n", result); 


    OSStatus status = AUGraphInitialize(player->graph); 
    printf("err: %d\n", status); 


    player->firstOutputSampleTime = -1; 
    AudioOutputUnitStart(player->audioUnits[0]); 
    AUGraphStart(player->graph); 

    printf("enter key to stop\n"); 
    getchar(); 

    return 0; 
}

来源

2013-08-26 20:29:33 Chris

如何连接调音台与AUGraph

回答

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