code: def pack_LR(self,left_out,right_out):
          
          for i in range(0,self.frame_length*2):
              if i % 2:
                  self.out[i] = right_out[(int)(i/2)]
              else:
                  self.out[i] = left_out[(int)(i/2)]
          return self.out
docs: Packs separate left and right channel data into one array to output
          and returns the output.
  
          Parameters
          ----------
          left_out : left channel array of samples going to output
          right_out : right channel array of samples going to output
  
          Returns
          -------
          out : packed left and right channel array of samples