Browsing Occitan (post 1500) translation

On a 2.93 gHz iMac i7, I get these rates with -delay 0:

detail 3:  invisible
detail 4:  barely visible
detail 5:  1000+ fps, looks like noise at -delay 0, ok at -delay 20000
detail 8:  ~700+ fps
detail 9:  ~400 fps
detail 10: ~300 fps
detail 11: ~100 fps
detail 12:  ~50 fps
detail 13:  ~17 fps
detail 14:   ~8 fps
detail 15:   ~2 fps

With the default -delay, CPU load only starts causing the frame rate
to drop below 30 fps detail 12 or higher.

#### -color [random]