  0: [0- 0]: ctl
  4: [0- 0]: hardware dependent
  8: [0- 0]: raw midi
 19: [0- 3]: digital audio playback
 26: [0- 2]: digital audio capture
 25: [0- 1]: digital audio capture
 16: [0- 0]: digital audio playback
 24: [0- 0]: digital audio capture
 33:       : timer
