Is there any high level Audio Queue Record Service Library for iOS?

Question

I'm trying to develop an application which about VOIP,

is there any high level audio queue service library for iOS ?

because I'm not very good at for working on extension filename ".mm",

using an open source would be a better option.

or someone could give me some hints for how to fetch the buffer from AudioQueueBufferRef ?

the ideal way is like a delegate :

- (void)audioRecorderDidReceivedBuffer:(Buffer) {
    do something for other operations
}

Update I found an article which about Using RemoteIO audio unit

maybe the input callback is what I need.

Overvier

Identify the audio component (kAudioUnitType_Output/ kAudioUnitSubType_RemoteIO/ kAudioUnitManufacturerApple)

Use AudioComponentFindNext(NULL, &descriptionOfAudioComponent) to obtain the AudioComponent, which is like the factory with which you obtain the audio unit

Use AudioComponentInstanceNew(ourComponent, &audioUnit) to make an instance of the audio unit

Enable IO for recording and possibly playback with AudioUnitSetProperty

Describe the audio format in an AudioStreamBasicDescription structure, and apply the format using AudioUnitSetProperty

Provide a callback for recording, and possibly playback, again using AudioUnitSetProperty

Allocate some buffers

Initialise the audio unit

Start the audio unit

Rejoice

// Enable IO for recording
UInt32 flag = 1;
status = AudioUnitSetProperty(audioUnit, 
                              kAudioOutputUnitProperty_EnableIO, 
                              kAudioUnitScope_Input, 
                              kInputBus,
                              &flag, 
                              sizeof(flag));



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



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

// TODO: Use inRefCon to access our interface object to do stuff
// Then, use inNumberFrames to figure out how much data is available, and make
// that much space available in buffers in an AudioBufferList.

AudioBufferList *bufferList; // <- Fill this up with buffers (you will want to malloc it, as it's a dynamic-length list)

// Then:
// Obtain recorded samples

OSStatus status;

status = AudioUnitRender([audioInterface audioUnit], 
                         ioActionFlags, 
                         inTimeStamp, 
                         inBusNumber, 
                         inNumberFrames, 
                         bufferList);
checkStatus(status);

// Now, we have the samples we just read sitting in buffers in bufferList
DoStuffWithTheRecordedAudio(bufferList);
return noErr;
}

PatrickSCLin PatrickSCLin · Accepted Answer · 2012-11-26T16:30:45

Here is the method that how to fetch Audio Buffer from recording

( reference from: http://atastypixel.com/blog/using-remoteio-audio-unit/ )

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

    // TODO: Use inRefCon to access our interface object to do stuff
    // Then, use inNumberFrames to figure out how much data is available, and make
    // that much space available in buffers in an AudioBufferList.

    AudioBufferList *bufferList; // <- Fill this up with buffers (you will want to malloc it, as it's a dynamic-length list)

    // Then:
    // Obtain recorded samples

    OSStatus status;

    status = AudioUnitRender([audioInterface audioUnit], 
                             ioActionFlags, 
                             inTimeStamp, 
                             inBusNumber, 
                             inNumberFrames, 
                             bufferList);
    checkStatus(status);

    // Now, we have the samples we just read sitting in buffers in bufferList
    DoStuffWithTheRecordedAudio(bufferList);
    return noErr;
}

Is there any high level Audio Queue Record Service Library for iOS?

1 Answers