CarryLessRangeCoder 1.0.2

Python implementation of carry-less range coder

Both static and dynamic encoding can be used.

Install

$ pip install CarryLessRangeCoder

Examples

from collections import Counter
import carryless_rangecoder as rc
from io import BytesIO

data = list(map(ord, 'qawsedrftgyhujikolp;'))
count = [1] * 256
for i, c in Counter(data).items():
    count[i] += c
count_cum = [0] * 256
for i in range(1, 256):
    count_cum[i] = count[i] + count_cum[i - 1]

out = BytesIO()
# Encode
with rc.Encoder(out) as enc:  # or enc.finish()
    for index in data:
        enc.encode(count, count_cum, index)
# Decode
decoded = []
with rc.Decode(out) as dec:  # or dec.start()
    for _ in range(len(data)):
        decoded.append(dec.decode(count, count_cum))

assert decoded == data