IPhone SDK (Beta 5) - AudioQueue Problem playing MP3

Question

Dear community,
i have a problem using the iPhone SDK (Beta 5). I want to playback a simple MP3-file. So i checked a lot of examples, read documentation and found a least the "AudioQueueTest" example. This is an simple example which is able to play MP3, WAV, ... from the command line. I ported the example to a simple application on the iPhone. Now the problem:
If i playback a WAV file in the iPhone simulator, everything works fine. If i want to playback an MP3 file, it doesn't work and i don't know why. I stepped through the debugger and found out that the application freezes at the command "AudioQueueNewOutput".
Do you have the same problem? What i am doing wrong? Is it no possible to create a background thread playing back a local MP3 file?
Thank you!

Answer 1

Did you get PCM recording on actual iPhone hardware? With Beta5, my PCM recording works fine in the simulator, but on the hardware, all the buffers I receive contain only 4 bytes of audio data!
Here's my source code - if anyone can spot anything wrong, I'd be enormously grateful!
#import "AudioAppDelegate.h"
#import "AudioViewController.h"
#import "AudioToolbox/AudioQueue.h"
#define BUFFER_CT 4
#define BUFFER_BYTES 8192
AudioQueueRef audioInQueue;
static void AudioInCallback(void* aqData,AudioQueueRef aq,AudioQueueBufferRef buffer,const AudioTimeStamp* startTime,UInt32 numPackets,const AudioStreamPacketDescription* desc)
OSStatus result;
printf("received %d bytes\n",buffer->mAudioDataByteSize);
result=AudioQueueEnqueueBuffer(audioInQueue,buffer,0,NULL);
if(result)
printf("AudioQueueEnqueueBuffer returned %d\n",result);
static void StartAudio(void)
OSStatus result;
AudioStreamBasicDescription format;
// 11KHz, 16-bit stereo
memset(&format,0,sizeof(format));
format.mSampleRate=11025;
format.mFormatFlags=kLinearPCMFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
format.mFormatID=kAudioFormatLinearPCM;
format.mBytesPerPacket=BUFFER_BYTES;
format.mBytesPerFrame=4;
format.mFramesPerPacket=format.mBytesPerPacket / format.mBytesPerFrame;
format.mChannelsPerFrame=2;
format.mBitsPerChannel=16;
result=AudioQueueNewInput(&format,AudioInCallback,NULL,CFRunLoopGetCurrent(),kC FRunLoopCommonModes,0,&audioInQueue);
printf("AudioQueueNewInput result was %d\n",result);
for(int i=0;i<BUFFER_CT;i++)
AudioQueueBufferRef buffer;
result=AudioQueueAllocateBuffer(audioInQueue,format.mBytesPerPacket,&buffer);
printf("AudioQueueAllocateBuffer result was %d\n",result);
result=AudioQueueEnqueueBuffer(audioInQueue,buffer,0,NULL);
printf("AudioQueueEnqueueBuffer to in result was %d\n",result);
Float32 gain=1.0;
AudioQueueSetParameter(audioInQueue,kAudioQueueParam_Volume,gain);
result=AudioQueueStart(audioInQueue,NULL);
printf("AudioQueueStart result was %d\n",result);
}