I think you could just have a different code for each given index and all the symbols seen until that point. This seems to do something similar: https://en.wik

I think you could just have a different code for each given index and all the symbols seen until that point. This seems to do something similar: https://en.wikipedia.org/wiki/Context-adaptive_binary_arithmetic_coding https://en.wikipedia.org/wiki/Context-adaptive_binary_arithm...