iOS 音频采集 AudioBufferList转CMSampleBufferRef

@property (nonatomic,
assign) AudioComponent              component;

@property (nonatomic,
assign) AudioComponentInstance      componetInstance;

static OSStatus handleInputBuffer(void *inRefCon,

                                  AudioUnitRenderActionFlags *ioActionFlags,

                                  const
AudioTimeStamp *inTimeStamp,

                                  UInt32 inBusNumber,

                                  UInt32 inNumberFrames,

                                  AudioBufferList *ioData) {

    @autoreleasepool {

        <CLassName> *ref = (__bridge
<ClassName> *)inRefCon;

        

        AudioStreamBasicDescription asbd = [ref
asbd];

        

        CMSampleBufferRef buff =
NULL;

        

        CMFormatDescriptionRef format =
NULL;

        

        OSStatus status =
CMAudioFormatDescriptionCreate(kCFAllocatorDefault, &asbd,
0, NULL,
0, NULL, NULL, &format);

        if (status) {

            return status;

        }

        CMSampleTimingInfo timing = {
CMTimeMake(1,
48000),
kCMTimeZero, kCMTimeInvalid };

  

        status = CMSampleBufferCreate(kCFAllocatorDefault,
NULL, false,
NULL, NULL, format, (CMItemCount)inNumberFrames,
1, &timing, 0,
NULL, &buff);

        

        if (status) {
//失败

            return status;

        }

        

        AudioBuffer buffer;

        buffer.mData =
NULL;

        buffer.mDataByteSize =
0;

        buffer.mNumberChannels =
2;

        AudioBufferList buffers;

        buffers.mNumberBuffers =
1;

        buffers.mBuffers[0] = buffer;

        status = AudioUnitRender(ref.componetInstance,

                                          ioActionFlags,

                                          inTimeStamp,

                                          inBusNumber,

                                          inNumberFrames,

                                          &buffers);

        if (status) {

            return status;

        }

        status = CMSampleBufferSetDataBufferFromAudioBufferList(buff,
kCFAllocatorDefault,
kCFAllocatorDefault,
0, &buffers);

        

        if (!status) {

        }

        return status;

    }

}

- (AudioStreamBasicDescription)asbd

{

    AudioStreamBasicDescription desc = {0};

    desc.mSampleRate =
48000;

    

    desc.mFormatID =
kAudioFormatLinearPCM;

    desc.mFormatFlags =
kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;

    desc.mChannelsPerFrame =
2;

    desc.mFramesPerPacket =
1;

    desc.mBitsPerChannel =
16;

    desc.mBytesPerFrame = desc.mBitsPerChannel /
8 * desc.mChannelsPerFrame;

    desc.mBytesPerPacket = desc.mBytesPerFrame * desc.mFramesPerPacket;

    

    return desc;

}

- (void)initMicrophoneSource

{

    AVAuthorizationStatus status = [AVCaptureDevice
authorizationStatusForMediaType:AVMediaTypeAudio];

    if(status ==
AVAuthorizationStatusAuthorized){

        AVAudioSession *session = [AVAudioSession
sharedInstance];

        

        NSError *error =
nil;

        

        [session setCategory:AVAudioSessionCategoryPlayAndRecord
withOptions:AVAudioSessionCategoryOptionDefaultToSpeaker |
AVAudioSessionCategoryOptionMixWithOthers |
AVAudioSessionCategoryOptionAllowBluetooth error:nil];

        

        if (![session
setActive:YES
error:&error]) {

            NSString *log =
@"Failed to set audio session active.";

            NSLog(@"%@", log);

            return ;

        }

        

        AudioComponentDescription acd;

        acd.componentType =
kAudioUnitType_Output;

        acd.componentSubType =
kAudioUnitSubType_RemoteIO;

        acd.componentManufacturer =
kAudioUnitManufacturer_Apple;

        acd.componentFlags =
0;

        acd.componentFlagsMask =
0;

        

        self.component =
AudioComponentFindNext(NULL, &acd);

        

        OSStatus status =
noErr;

        status = AudioComponentInstanceNew(self.component,
&_componetInstance);

        

        if (noErr != status) {

            NSString *log =
@"Failed to new a audio component instance.";

            NSLog(@"%@", log);

            return ;

        }

        

        UInt32 flagOne =
1;

        

        AudioUnitSetProperty(self.componetInstance,
kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input,
1, &flagOne,
sizeof(flagOne));

        

        AudioStreamBasicDescription desc = [self
asbd];

        

        AudioUnitSetProperty(self.componetInstance,
kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output,
1, &desc,
sizeof(desc));

        

        

        AURenderCallbackStruct cb;

        cb.inputProcRefCon = (__bridge
void *)(self);

        cb.inputProc =
handleInputBuffer;

        

        AudioUnitSetProperty(self.componetInstance,
kAudioOutputUnitProperty_SetInputCallback,
kAudioUnitScope_Global, 1, &cb,
sizeof(cb));

        

        status = AudioUnitInitialize(self.componetInstance);

        

        if (noErr != status) {

            NSString *log =
@"Failed to init audio unit.";

            NSLog(@"%@", log);

        }

        

        AudioOutputUnitStart(self.componetInstance);

    }

    

}