boost mode in classifier

[williamfzc]

• no need for checking each frames of stable ranges actually about what it is
• be optional

[williamfzc]

much more effective than what I though ...

before: 16.52203392982483 s after: 0.7159671783447266 s

nearly 20x faster

video:

• 4s total
• 60 fps
• 5 stages