Audio corruption on the device

Question

I am working on an mp3 streaming app with CBR data. Using CBR (Constant Bitrate) makes setup of the audio buffers really easy, vs. VBR that requires setting up packet size data for each packet. Well, if I pretend that my streams are VBR, things generally "work" although the code is more complicated than it needs to be. If I use the CBR approach (read X bytes, shove X bytes to AudioQueueEnqueueBuffer(, magically play music..) it works great on the simulator. However, it fails on the device. I get audio corruption, little glitches ever second or two, typical of trying to play incomplete mp3 packets.
Has anyone else observed this and know if this is a known issue?

Answer 1

In your Code a important part is to set up the AudioStreamBasicDescription structure.
Channels: Stereo = 2 or Mono = 1.
Format: MP3 [There is format setting that will set this value something like AudioStreamFormat ... ]
Sample Rate: What ever your sample rate is. If its wrong the mp3 will sound chipmunky
When reading the file from disk use AudioFileReadPackets to get the amount of packets. For the buffersize you'll need there is a function AudioQueueGetProperty which once the AudioQueue has been opened you can get the maximum size for the buffer.
Mike.