static int tdav_consumer_audiounit_prepare(tmedia_consumer_t* self, const tmedia_codec_t* codec)
{
    tdav_consumer_audiounit_t* consumer = (tdav_consumer_audiounit_t*)self;
    
    if (!consumer || !codec || !codec->plugin) {
        TSK_DEBUG_ERROR("Invalid parameter");
        return -1;
    }
    
    // Initialize the decoder parameters without allocating AudioUnit resourses
    TMEDIA_CONSUMER(consumer)->audio.ptime = TMEDIA_CODEC_PTIME_AUDIO_DECODING(codec);
    TMEDIA_CONSUMER(consumer)->audio.in.channels = TMEDIA_CODEC_CHANNELS_AUDIO_DECODING(codec);
    TMEDIA_CONSUMER(consumer)->audio.in.rate = TMEDIA_CODEC_RATE_DECODING(codec);
    
    TSK_DEBUG_INFO("AudioUnit consumer prepared (ptime=%d, channels=%d, rate=%d)",
                   (int)TMEDIA_CONSUMER(consumer)->audio.ptime,
                   (int)TMEDIA_CONSUMER(consumer)->audio.in.channels,
                   (int)TMEDIA_CONSUMER(consumer)->audio.in.rate);
    return 0;
}
static int tdav_consumer_audiounit_prepare(tmedia_consumer_t* self, const tmedia_codec_t* codec)
{
	static UInt32 flagOne = 1;
	AudioStreamBasicDescription audioFormat;
#define kOutputBus  0
	
	tdav_consumer_audiounit_t* consumer = (tdav_consumer_audiounit_t*)self;
	OSStatus status = noErr;
	
	if(!consumer || !codec || !codec->plugin){
		TSK_DEBUG_ERROR("Invalid parameter");
		return -1;
	}
	if(!consumer->audioUnitHandle){
		if(!(consumer->audioUnitHandle = tdav_audiounit_handle_create(TMEDIA_CONSUMER(consumer)->session_id))){
			TSK_DEBUG_ERROR("Failed to get audio unit instance for session with id=%lld", TMEDIA_CONSUMER(consumer)->session_id);
			return -3;
		}
	}

	// enable
	status = AudioUnitSetProperty(tdav_audiounit_handle_get_instance(consumer->audioUnitHandle), 
								  kAudioOutputUnitProperty_EnableIO, 
								  kAudioUnitScope_Output, 
								  kOutputBus,
								  &flagOne, 
								  sizeof(flagOne));
	if(status){
		TSK_DEBUG_ERROR("AudioUnitSetProperty(kAudioOutputUnitProperty_EnableIO) failed with status=%d", (int32_t)status);
		return -4;
	}
	else {
		
#if !TARGET_OS_IPHONE // strange: TARGET_OS_MAC is equal to '1' on Smulator
		UInt32 param;
		
		// disable input
		param = 0;
		status = AudioUnitSetProperty(tdav_audiounit_handle_get_instance(consumer->audioUnitHandle), kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input, 1, &param, sizeof(UInt32));
		if(status != noErr){
			TSK_DEBUG_ERROR("AudioUnitSetProperty(kAudioOutputUnitProperty_EnableIO) failed with status=%ld", (signed long)status);
			return -4;
		}
		
		// set default audio device
		param = sizeof(AudioDeviceID);
		AudioDeviceID outputDeviceID;
		status = AudioHardwareGetProperty(kAudioHardwarePropertyDefaultOutputDevice, &param, &outputDeviceID);
		if(status != noErr){
			TSK_DEBUG_ERROR("AudioHardwareGetProperty(kAudioHardwarePropertyDefaultOutputDevice) failed with status=%ld", (signed long)status);
			return -4;
		}
		
		// set the current device to the default input unit
		status = AudioUnitSetProperty(tdav_audiounit_handle_get_instance(consumer->audioUnitHandle), 
									  kAudioOutputUnitProperty_CurrentDevice, 
									  kAudioUnitScope_Global, 
									  0, 
									  &outputDeviceID, 
									  sizeof(AudioDeviceID));
		if(status != noErr){
			TSK_DEBUG_ERROR("AudioUnitSetProperty(kAudioOutputUnitProperty_CurrentDevice) failed with status=%ld", (signed long)status);
			return -4;
		}
		
#endif

		TMEDIA_CONSUMER(consumer)->audio.ptime = TMEDIA_CODEC_PTIME_AUDIO_DECODING(codec);
		TMEDIA_CONSUMER(consumer)->audio.in.channels = TMEDIA_CODEC_CHANNELS_AUDIO_DECODING(codec);
		TMEDIA_CONSUMER(consumer)->audio.in.rate = TMEDIA_CODEC_RATE_DECODING(codec);
        
        TSK_DEBUG_INFO("AudioUnit consumer: in.channels=%d, out.channles=%d, in.rate=%d, out.rate=%d, ptime=%d",
                       TMEDIA_CONSUMER(consumer)->audio.in.channels,
                       TMEDIA_CONSUMER(consumer)->audio.out.channels,
                       TMEDIA_CONSUMER(consumer)->audio.in.rate,
                       TMEDIA_CONSUMER(consumer)->audio.out.rate,
                       TMEDIA_CONSUMER(consumer)->audio.ptime);
		
		audioFormat.mSampleRate = TMEDIA_CONSUMER(consumer)->audio.out.rate ? TMEDIA_CONSUMER(consumer)->audio.out.rate : TMEDIA_CONSUMER(consumer)->audio.in.rate;
		audioFormat.mFormatID = kAudioFormatLinearPCM;
		audioFormat.mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
		audioFormat.mChannelsPerFrame = TMEDIA_CONSUMER(consumer)->audio.in.channels;
		audioFormat.mFramesPerPacket = 1;
		audioFormat.mBitsPerChannel = TMEDIA_CONSUMER(consumer)->audio.bits_per_sample;
		audioFormat.mBytesPerPacket = audioFormat.mBitsPerChannel / 8 * audioFormat.mChannelsPerFrame;
		audioFormat.mBytesPerFrame = audioFormat.mBytesPerPacket;
		audioFormat.mReserved = 0;
		status = AudioUnitSetProperty(tdav_audiounit_handle_get_instance(consumer->audioUnitHandle), 
									  kAudioUnitProperty_StreamFormat, 
									  kAudioUnitScope_Input, 
									  kOutputBus, 
									  &audioFormat, 
									  sizeof(audioFormat));
		
		if(status){
			TSK_DEBUG_ERROR("AudioUnitSetProperty(kAudioUnitProperty_StreamFormat) failed with status=%ld", (signed long)status);
			return -5;
		}
		else {
			// configure
			if(tdav_audiounit_handle_configure(consumer->audioUnitHandle, tsk_true, TMEDIA_CONSUMER(consumer)->audio.ptime, &audioFormat)){
				TSK_DEBUG_ERROR("tdav_audiounit_handle_set_rate(%d) failed", TMEDIA_CONSUMER(consumer)->audio.out.rate);
				return -4;
			}
			
			// set callback function
			AURenderCallbackStruct callback;
			callback.inputProc = __handle_output_buffer;
			callback.inputProcRefCon = consumer;
			status = AudioUnitSetProperty(tdav_audiounit_handle_get_instance(consumer->audioUnitHandle), 
										  kAudioUnitProperty_SetRenderCallback, 
										  kAudioUnitScope_Input, 
										  kOutputBus,
										  &callback, 
										  sizeof(callback));
			if(status){
				TSK_DEBUG_ERROR("AudioUnitSetProperty(kAudioOutputUnitProperty_SetInputCallback) failed with status=%ld", (signed long)status);
				return -6;
			}
		}
	}
	
	// allocate the chunck buffer and create the ring
	consumer->ring.chunck.size = (TMEDIA_CONSUMER(consumer)->audio.ptime * audioFormat.mSampleRate * audioFormat.mBytesPerFrame) / 1000;
	consumer->ring.size = kRingPacketCount * consumer->ring.chunck.size;
	if(!(consumer->ring.chunck.buffer = tsk_realloc(consumer->ring.chunck.buffer, consumer->ring.chunck.size))){
		TSK_DEBUG_ERROR("Failed to allocate new buffer");
		return -7;
	}
	if(!consumer->ring.buffer){
		consumer->ring.buffer = speex_buffer_init(consumer->ring.size);
	}
	else {
		int ret;
		if((ret = speex_buffer_resize(consumer->ring.buffer, consumer->ring.size)) < 0){
			TSK_DEBUG_ERROR("speex_buffer_resize(%d) failed with error code=%d", consumer->ring.size, ret);
			return ret;
		}
	}
	if(!consumer->ring.buffer){
		TSK_DEBUG_ERROR("Failed to create a new ring buffer with size = %d", consumer->ring.size);
		return -8;
	}
	if(!consumer->ring.mutex && !(consumer->ring.mutex = tsk_mutex_create_2(tsk_false))){
		TSK_DEBUG_ERROR("Failed to create mutex");
		return -9;
	}

	// set maximum frames per slice as buffer size
	//UInt32 numFrames = (UInt32)consumer->ring.chunck.size;
	//status = AudioUnitSetProperty(tdav_audiounit_handle_get_instance(consumer->audioUnitHandle), 
	//							  kAudioUnitProperty_MaximumFramesPerSlice,
	//							  kAudioUnitScope_Global, 
	//							  0, 
	//							  &numFrames, 
	//							  sizeof(numFrames));
	//if(status){
	//	TSK_DEBUG_ERROR("AudioUnitSetProperty(kAudioUnitProperty_MaximumFramesPerSlice, %u) failed with status=%d", (unsigned)numFrames, (int32_t)status);
	//	return -6;
	//}
	
	TSK_DEBUG_INFO("AudioUnit consumer prepared");
    return tdav_audiounit_handle_signal_consumer_prepared(consumer->audioUnitHandle);
}
int tdav_consumer_audioqueue_prepare(tmedia_consumer_t* self, const tmedia_codec_t* codec)
{
    OSStatus ret;
	tsk_size_t i;
	tdav_consumer_audioqueue_t* consumer = (tdav_consumer_audioqueue_t*)self;
	
	if(!consumer || !codec && codec->plugin){
		TSK_DEBUG_ERROR("Invalid parameter");
		return -1;
	}

	TMEDIA_CONSUMER(consumer)->audio.ptime = TMEDIA_CODEC_PTIME_AUDIO_DECODING(codec);
	TMEDIA_CONSUMER(consumer)->audio.in.channels = TMEDIA_CODEC_CHANNELS_AUDIO_DECODING(codec);
	TMEDIA_CONSUMER(consumer)->audio.in.rate = TMEDIA_CODEC_RATE_DECODING(codec);
	/* codec should have ptime */
	
	// Set audio category
#if TARGET_OS_IPHONE
	UInt32 category = kAudioSessionCategory_PlayAndRecord; 
	AudioSessionSetProperty(kAudioSessionProperty_AudioCategory, sizeof(category), &category);
#endif
	
    // Create the audio stream description
    AudioStreamBasicDescription *description = &(consumer->description);
    description->mSampleRate = TMEDIA_CONSUMER(consumer)->audio.out.rate ? TMEDIA_CONSUMER(consumer)->audio.out.rate : TMEDIA_CONSUMER(consumer)->audio.in.rate;
    description->mFormatID = kAudioFormatLinearPCM;
    description->mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
    description->mChannelsPerFrame = TMEDIA_CONSUMER(consumer)->audio.in.channels;
    description->mFramesPerPacket = 1;
    description->mBitsPerChannel = TMEDIA_CONSUMER(consumer)->audio.bits_per_sample;
    description->mBytesPerPacket = description->mBitsPerChannel / 8 * description->mChannelsPerFrame;
    description->mBytesPerFrame = description->mBytesPerPacket;
    description->mReserved = 0;
    
    int packetperbuffer = 1000 / TMEDIA_CONSUMER(consumer)->audio.ptime;
    consumer->buffer_size = description->mSampleRate * description->mBytesPerFrame / packetperbuffer;
    
    // Create the playback audio queue
    ret = AudioQueueNewOutput(&(consumer->description),
                              __handle_output_buffer,
                              consumer,
                              NULL, 
                              NULL,
                              0,
                              &(consumer->queue));
    
    for(i = 0; i < CoreAudioPlayBuffers; i++) {
        // Create the buffer for the queue
        ret = AudioQueueAllocateBuffer(consumer->queue, consumer->buffer_size, &(consumer->buffers[i]));
        if (ret) {
            break;
        }
        
        // Clear the data
        memset(consumer->buffers[i]->mAudioData, 0, consumer->buffer_size);
        consumer->buffers[i]->mAudioDataByteSize = consumer->buffer_size;
        
        // Enqueue the buffer
        ret = AudioQueueEnqueueBuffer(consumer->queue, consumer->buffers[i], 0, NULL);
        if (ret) {
            break;
        }
    }
	
	return ret;
}