关于使用音频队列录音的问题

问题是这样的，在模拟器上调试，回调函数里面能有音频数据，但是用IPAD2调试，队列里面的音频数据的长度是0.下面是代码：#import "PcmRecorder.h"
#pragma  -
#pragma  recorder call back
static void MyInputBufferHandler( void * inUserData,
                                    AudioQueueRef inAQ,
                                    AudioQueueBufferRef inBuffer,
                                    const AudioTimeStamp * inStartTime,
                                    UInt32 inNumPackets,
                                    const AudioStreamPacketDescription* inPacketDesc)
{
   
    //拿到一帧的数据
    unsigned int buf_length = inBuffer->mAudioDataByteSize;
    void * buf = inBuffer->mAudioData;
    if(buf_length == 0)
    {
        AudioQueueEnqueueBuffer(inAQ, inBuffer, 0, nil);
        NSLog(@"recording fail!!");
        return;
    }
    
    //AudioQueueEnqueueBuffer(inAQ, inBuffer, 0, nil);
    NSLog(@"AudioRecordAQInputCallback");
    
    PcmRecorder *recorder = (PcmRecorder *)inUserData;
    [recorder setRecordData:buf length:buf_length];
    
    //[recorder stopRecord]; //播完一帧就不播了
}@implementation PcmRecorder- (id)init
{
    self = [super init];
    if (self) {
        synlock = [[NSLock alloc] init];
    }
    return self;
}-(void)initAudio
{
    ///设置音频参数
    audioDescription.mSampleRate = 44100;//采样率
audioDescription.mFormatID = kAudioFormatLinearPCM;
audioDescription.mFormatFlags =kLinearPCMFormatFlagIsBigEndian| kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagIsPacked;
    audioDescription.mChannelsPerFrame = 1;///单声道
    audioDescription.mFramesPerPacket = 1;//每一个packet一侦数据
    audioDescription.mBitsPerChannel = 8;//每个采样点16bit量化
    audioDescription.mBytesPerFrame = (audioDescription.mBitsPerChannel/8) * audioDescription.mChannelsPerFrame;
    audioDescription.mBytesPerPacket = audioDescription.mBytesPerFrame ;
    ///创建一个新的从audioqueue到硬件层的通道
    // AudioQueueNewOutput(&audioDescription, AudioPlayerAQInputCallback, self, CFRunLoopGetCurrent(), kCFRunLoopCommonModes, 0, &audioQueue);///使用当前线程播
   // AudioQueueNewOutput(&audioDescription, AudioPlayerAQInputCallback, self, nil, nil, 0, &audioQueue);//使用player的内部线程播
    AudioQueueNewInput(&audioDescription, MyInputBufferHandler, self, nil, kCFRunLoopCommonModes, 0, &audioQueue);
////添加buffer区
    //for(int i=0;i<QUEUE_BUFFER_SIZE;i++)
    //{
        //int result =  AudioQueueAllocateBuffer(audioQueue, 44100*2, &audioQueueBuffers[i]);///创建buffer区，MIN_SIZE_PER_FRAME为每一侦所需要的最小的大小，该大小应该比每次往buffer里写的最大的一次还大
//NSLog(@"AudioQueueAllocateBuffer i = %d,result = %d",i,result);
    //}
}
-(void) record
{
    [synlock lock];
    int ret = 0;
    [self initAudio];   
    NSLog(@"recording start");
    for(int i=0;i<QUEUE_BUFFER_SIZE;i++)
    {
        //[self readPCMAndPlay:audioQueue buffer:audioQueueBuffers[i]];
        ret = AudioQueueAllocateBuffer(audioQueue, 44100, &audioQueueBuffers[i]);
        NSLog(@"ret = %d", ret);
        ret = AudioQueueEnqueueBuffer(audioQueue, audioQueueBuffers[i], 0, nil);
        NSLog(@"ret = %d", ret);    }
    ret = AudioQueueStart(audioQueue, nil);
    NSLog(@"ret = %d", ret);    [synlock unlock];
}-(void) stopRecord
{
    AudioQueueStop(audioQueue, YES);
    AudioQueueDispose(audioQueue, YES);
}-(void) setRecordData:(Byte*)pcm_data_buf length:(unsigned int)buf_length
{
    recordData = [NSData dataWithBytes:pcm_data_buf length:buf_length];
    //pcmDataBuffer = pcm_data_buf;
    //bufLength = buf_length;
}-(void) setBufLength:(unsigned int ) len
{
    bufLength = len;
}
-(NSData*) getRecordData
{
    return recordData;
}
@end