finding stragtegies for testing audio modules

[hems]

1. Testing the impulse response of an audio module

• the desired output is stored in a wave file of table
• a unit test would start a recording into a buffer~
• sending a click~ to the module
• recording for a given time
• comparing the desired wave file with the content of the test buffer~

1. How to compare?

   • Simple sample to sample comparison between desired wave form and test buffer

     \* danger if test recording has a starting delay 
     \* what happens if the general gain of the test buffer recoding differs fro the desired recording?  
     

   • Normalized cross correlation between desired wave form and test buffer

     * output would be 1 if the test response would be similar but shifted in the buffer~
     * the lag output of the cross correlation shows the delay

   see more on the original redmine issue http://redmine.jamoma.org/issues/366