question about adjusted binary

[aa876433]

How adjusted binary actually works. I can't understand why can actually represent any code from 0 to 253 with just 8 bits - only the 4 codes from 254 to 257 take 9 bits.

Thanks.

[dbry]

Hi. I found the name "adjusted binary" somewhere, but I've also seen it called "phased-in" codes or "truncated binary" codes. They're exactly the same thing for encoding codes when there are not a power of two values to encode (i.e. 258). Here are a couple links that should help you understand it:

Truncated Binary Encoding
Phased-in codes

[aa876433]

Thanks