static void OpenAudioFile(CFURLRef sourceURL) {

ExtAudioFileRef xafref = 0;

// open source file
int result = ExtAudioFileOpenURL(sourceURL, &xafref);
if (result || !xafref) {
printf("ExtAudioFileOpenURL result %d %08X %4.4s\n", result, result,
(char*)&result);
return;
}

// get the file data format, this represents the file's actual data format
CAStreamBasicDescription clientFormat;
UInt32 propSize = sizeof(clientFormat);

result = ExtAudioFileGetProperty(xafref,
kExtAudioFileProperty_FileDataFormat, &propSize, &clientFormat);
if (result) {
printf("ExtAudioFileGetProperty kExtAudioFileProperty_FileDataFormat
result %d %08X %4.4s\n", result, result, (char*)&result);
return;
}

// set the client format to be what we want back
clientFormat.mSampleRate = 44100.0;
clientFormat.SetAUCanonical(2, false);

propSize = sizeof(clientFormat);
result = ExtAudioFileSetProperty(xafref,
kExtAudioFileProperty_ClientDataFormat, propSize, &clientFormat);
if (result) {
printf("ExtAudioFileSetProperty
kExtAudioFileProperty_ClientDataFormat %d %08X %4.4s\n", result,
result, (char*)&result);
return;
}

// get the file's length in sample frames
UInt64 numFrames = 0;
propSize = sizeof(numFrames);
result = ExtAudioFileGetProperty(xafref,
kExtAudioFileProperty_FileLengthFrames, &propSize, &numFrames);
if (result) {
printf("ExtAudioFileGetProperty
kExtAudioFileProperty_FileLengthFrames result %d %08X %4.4s\n",
result, result, (char*)&result);
return;
}

UInt32 numFrames32 = (UInt32)(numFrames);

UInt32 samples = numFrames32 * clientFormat.mChannelsPerFrame;

AudioBufferList* bufList = (AudioBufferList*)calloc(1,
sizeof(AudioBufferList) + 2 * sizeof(AudioBuffer));
bufList->mNumberBuffers = 2;
bufList->mBuffers[0].mNumberChannels = 1;
bufList->mBuffers[0].mDataByteSize = samples * sizeof(AudioUnitSampleType);
bufList->mBuffers[0].mData = (AudioUnitSampleType
*)malloc(sizeof(AudioUnitSampleType) * 4096);

bufList->mBuffers[1].mNumberChannels = 1;
bufList->mBuffers[1].mDataByteSize = samples * sizeof(AudioUnitSampleType);
bufList->mBuffers[1].mData = (AudioUnitSampleType
*)malloc(sizeof(AudioUnitSampleType) * 4096);

UInt32 numPacketsRead = 0;

//read up till the end of the file
while (numPacketsRead + 4096 < numFrames32){
UInt32 packetstoRead = 4096;
result = ExtAudioFileRead(xafref, &packetstoRead, bufList);
numPacketsRead += packetstoRead;
}

UInt32 remainingPackets = numFrames32 - numPacketsRead;

//read the remaining packets
result = ExtAudioFileRead(xafref, &remainingPackets, bufList);

//reset the file
SInt64 position = 0;
result = ExtAudioFileSeek(xafref, position);

//check the position
SInt64 outFrameOffset = 0;
result = ExtAudioFileTell (xafref, &outFrameOffset);
printf("offset after reset %d\n", outFrameOffset);

//now start reading from the start of the file : THIS Should read
4096 packets, but it does not!
UInt32 packetstoRead = 4096;
result = ExtAudioFileRead(xafref, &packetstoRead, bufList);

result = ExtAudioFileTell (xafref, &outFrameOffset);
printf("offset after read %d\n", outFrameOffset);
}