error in audio Unit code -remoteIO for iphone

Question

i have this code, in order to read buffer samples , but i get a strange mach-o linker error , Framework of audio unit couldnt loaded so i put the audioTollBox and coreAudio as i read. my code is :

#define kOutputBus 0
#define kInputBus 1
AudioComponentInstance audioUnit;



@implementation remoteIO


//callback function : 

    static OSStatus recordingCallback(void *inRefCon, 
                                      AudioUnitRenderActionFlags *ioActionFlags, 
                                      const AudioTimeStamp *inTimeStamp, 
                                      UInt32 inBusNumber, 
                                      UInt32 inNumberFrames, 
                                      AudioBufferList *ioData)
    {
        AudioBuffer buffer;

        buffer.mNumberChannels = 1;
        buffer.mDataByteSize = inNumberFrames * 2;
        NSLog(@"%ld",inNumberFrames);
        buffer.mData = malloc( inNumberFrames * 2 );


        AudioBufferList bufferList;
        bufferList.mNumberBuffers = 1;
        bufferList.mBuffers[0] = buffer;



        OSStatus status;
        status = AudioUnitRender(audioUnit, 
                                 ioActionFlags, 
                                 inTimeStamp, 
                                 inBusNumber, 
                                 inNumberFrames, 
                                 &bufferList);  
        checkStatus(status);                       //here is the warnning+error
        double *q = (double *)(&bufferList)->mBuffers[0].mData;
        for(int i=0; i < strlen((const char *)(&bufferList)->mBuffers[0].mData); i++)
        {

            NSLog(@"%f",q[i]); 
        }
    }

and the reading method :

-(void)startListeningWithFrequency:(float)freq;
{
    OSStatus status;

    AudioComponentDescription desc;
    desc.componentType = kAudioUnitType_Output;
    desc.componentSubType = kAudioUnitSubType_RemoteIO;
    desc.componentFlags = 0;
    desc.componentFlagsMask = 0;
    desc.componentManufacturer = kAudioUnitManufacturer_Apple;

    AudioComponent inputComponent = AudioComponentFindNext(NULL, &desc);
    status = AudioComponentInstanceNew( inputComponent, &audioUnit);
    checkStatus(status);

    UInt32 flag = 1;
    status = AudioUnitSetProperty(audioUnit, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input,kInputBus, &flag, sizeof(flag));
    checkStatus(status);

    AudioStreamBasicDescription audioFormat;
    audioFormat.mSampleRate         = 44100.00;//44100.00;
    audioFormat.mFormatID           = kAudioFormatLinearPCM;
    audioFormat.mFormatFlags        = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
    audioFormat.mFramesPerPacket    = 1;
    audioFormat.mChannelsPerFrame   = 1;
    audioFormat.mBitsPerChannel     = 16;
    audioFormat.mBytesPerPacket     = 2;
    audioFormat.mBytesPerFrame      = 2;

    status = AudioUnitSetProperty(audioUnit,
                                  kAudioUnitProperty_StreamFormat,
                                  kAudioUnitScope_Output,
                                  kInputBus,
                                  &audioFormat, 
                                  sizeof(audioFormat));
    checkStatus(status);

    checkStatus(status);
    AURenderCallbackStruct callbackStruct;
    callbackStruct.inputProc = recordingCallback;
    callbackStruct.inputProcRefCon = self;
    status = AudioUnitSetProperty(audioUnit, 
                                  kAudioOutputUnitProperty_SetInputCallback,
                                  kAudioUnitScope_Global,
                                  kInputBus, &callbackStruct, sizeof(callbackStruct));
    checkStatus(status);

    status = AudioOutputUnitStart(audioUnit);

}

and what i get is this error and warnning :

Undefined symbols for architecture i386:
  "_checkStatus", referenced from:
      _recordingCallback in remoteIO.o
      -[remoteIO startListeningWithFrequency:] in remoteIO.o
ld: symbol(s) not found for architecture i386
collect2: ld returned 1 exit status

whats wrong here, ? thanks.

please??? anyone ? i am losing my mind from this audio thing !!! i can see now that when i take out ALL THE CheckStatus(status) lines, i can compile it. what am i missing?? i have put all frameworks, why cant he recognize this checkStatus thing ??? — Curnelious, Jan 02 '12 at 12:29
i can see now that the word checkStatus is not mention in the whole apple doc, even once. not once. in any audio document, there is no function such as that . and in every audio guide, every post here ,everywhere, they all use this checkStatus(status) function, which wasnt declared by them .. what am i missing here ??? — Curnelious, Jan 02 '12 at 12:58

score 0 · Answer 1 · answered Jan 02 '12 at 19:48

0

You have to write your own checkStatus() function, as what it does (e.g. how it reports an error: dialog box, console output, analytics logging, crash dump, etc.), or whether is does anything at all other than return from the audio code, is specific to each app.

answered Jan 02 '12 at 19:48

hotpaw2

70,107
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i took it out from my code- no checkStatus, and it worked. but my question is, what are the number that i have to get from the samples? i get between -32700- +32700.. is that ok ? – Curnelious Jan 03 '12 at 08:58

error in audio Unit code -remoteIO for iphone

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