AudioQueue: Can't read raw data in AudioFileReadPackets

I'm working on a DSP related iOS app. Part of the work is to copy audio data from outBuffer ->mAudioData to an user-specified array for data processing. The read method is like this:

OSStatus result = AudioFileReadPackets(myInfo->mAudioFile,      // The audio file from which packets of audio data are to be read.
                                       false,                   // Set to true to cache the data. Otherwise, set to false.
                                       &numBytes,               // On output, a pointer to the number of bytes actually returned.
                                       myInfo->mPacketDescs,    // A pointer to an array of packet descriptions that have been allocated.
                                       m开发者_Python百科yInfo->mCurrentPacket,  // The packet index of the first packet you want to be returned.
                                       &nPackets,               // On input, a pointer to the number of packets to read. On output, the number of packets actually read.                                           
                                       outBuffer->mAudioData); // A pointer to user-allocated memory.

This process is successful. But when I'm trying to read data from outBuffer->mAudioData, there is always an error saying invalid conversion from 'void* const' to 'SInt16*':

outBuffer->mAudioDataByteSize = numBytes;       
SInt16 *testBuffer = outBuffer->mAudioData; //Read data from buffer... Error!

for (int i=0; i<numBytes; i++)
{
    UInt16 currentData = testBuffer[i];
    printf("Current data in testbuffer is %d", currentData);
}

I have gone through several related questions like THIS and THIS, seems theirs are working... I also tried to replace outBuffer->mAudioData to testBuffer in AudioFileReadPackets(), but the testBuffer turns out to be an empty array.

So is it the right approach? Is there any other way to read the raw data to an int/float array?

Or more generally, how to access an void constant pointer and perform read/write operation to it? (Yeah my C++ is not that strong...)

Any help will be appreciated :-)

Cheers, Manca

I just put a cast in front and it seemed to work:

SInt16* frames = (SInt16*)inBuffer->mAudioData;