AudioQueueを使ってPCMを再生

gistfile1.m

NSData *recordedPcm;

AVAudioPlayer *player;
AudioQueueRef audioQueue;
AudioQueueBufferRef audioQueueBuffers;

// Queue/Buffer への追加は playPCM での1回しかしないため、コールバックでは何もしない (必要があればここで追加)
static void AQOutputCallback(void *userData, AudioQueueRef audioQueueRef, AudioQueueBufferRef audioQueueBufferRef) {
    return;
}

-(void)playPCM:(NSData *)data queue:(AudioQueueRef)outQ buffer:(AudioQueueBufferRef)outQB {
    outQB->mAudioDataByteSize = (UInt32)data.length;
    UInt8 *audioData = (UInt8 *)outQB->mAudioData;
    for(int i = 0; i < data.length; i++) {
        audioData[i] = ((UInt8 *)data.bytes)[i];
    }
    
    AudioQueueEnqueueBuffer(outQ, outQB, 0, NULL);
}

- (BOOL)startPlaying:(NSData *)data {
    NSLog(@"%@", NSStringFromSelector(_cmd));

    [self stopPlaying];
    
    NSError *error = nil;
    OSStatus status;
    
    AudioStreamBasicDescription desc; // NOTE: fill this
    
    status = AudioQueueNewOutput(&desc, AQOutputCallback, (__bridge void *)(self), nil, nil, 0, &audioQueue);
    if (status != noErr) {
        NSLog(@"AudioQueueNewOutput() ret=%ld", (long int)status);
    }
    
    status = AudioQueueAllocateBuffer(audioQueue, (UInt32)recordedPcm.length, &audioQueueBuffers);
    if (status != noErr) {
        NSLog(@"AudioQueueAllocateBuffer() ret=%ld", (long int)status);
    }
    
    AudioQueueStart(audioQueue, NULL);
    [self playPCM:recordedPcm queue:audioQueue buffer:audioQueueBuffers];

    if(error) {
        return FALSE;
    }
    
    self.buttonPlayingStart.enabled = NO;
    self.buttonPlayingStop.enabled = YES;
    return TRUE;
}

// 再生終了
- (void)stopPlaying {
    NSLog(@"%@", NSStringFromSelector(_cmd));
    
    AudioQueueStop(audioQueue, YES);

    self.buttonPlayingStart.enabled = YES;
    self.buttonPlayingStop.enabled = NO;

    player = nil;
}