I'm using the Audio Unit Framework to develop a VOIP app on mac os x. There are two audio unit in my program , one is the input-only AUHAL ,the other is the default output unit.
I use the input-only AUHAL to capture audio. When the sample rate is 44.1khz , in the AUHAL's callback , the value of inNumberFrames is 512 which means my program will get 512 frames audio data from each call AudioUnitRender. And the value of inNumberFrames in the default output unit's callback is also 512.In this case , every things is fine.
But when I change the sample rate(8khz) both on the input-only AUHAL and default output unit , my program isn't working properly.
Because in the output unit's callback , the value of inNumberFrames became 93 which means the output device need 93 frames audio data from each call , but the value of inNumberFrames remain 512 in the AUHAL's callback. The number of frames didn't match between the AUHAL and the output unit .
I can change the AUHAL I/O buffer size manual by using AudioUnitSetProperty and slove this problem by using a simple formula with a little error . But I want to know if there are some method to make the AUHAL adjust its I/O buffer size automatic just like the default output unit do ？
Thanks & regard
