Question

I created custom callback for mixing sounds in real time for a timing music application using ExtAudioFile.

OSStatus MyAURenderCallack (
   void                        *inRefCon,
   AudioUnitRenderActionFlags  *ioActionFlags,
   const AudioTimeStamp        *inTimeStamp,
   UInt32                      inBusNumber,
   UInt32                      inNumberFrames,
   AudioBufferList             *ioData
);

I need to change the time every single callback is called.

I’m checking how many ticks each new callback is called with …

soundStructPointerArray[inBusNumber].callTime=mach_absolute_time()-soundStructPointerArray[inBusNumber].last;
soundStructPointerArray[inBusNumber].last=mach_absolute_time();

In the simulator i get aprox … 11595773

I need to change this time to be more quick. Anyone know how I could do it?

Answer 1

You can use the audio session property kAudioSessionProperty_PreferredHardwareIOBufferDuration to request more frequent audio unit buffer callbacks.