bitjs/docs/bitjs.io.md

bitjs.io

This package includes stream objects for reading and writing binary data at the bit and byte level: BitStream, ByteStream.

BitStream

A bit stream is a way to read a variable number of bits from a series of bytes. This useful for parsing certain protocols (for example pkzip or rar algorithm). Note that the order of reading bits can go from least-to-most significant bit, or the reverse.

Least-to-Most Direction

const bstream = new BitStream(ab, false /* mtl */);
bstream.readBits(6); // (blue)  0b001011 = 11
bstream.readBits(5); // (red)   0b11001 = 25
bstream.readBits(8); // (green) 0b10000010 = 130

Most-to-Least Direction

const bstream = new BitStream(ab, true /* mtl */);
bstream.readBits(6); // (blue)  0b010010 = 18
bstream.readBits(5); // (red)   0b11000 = 24
bstream.readBits(8); // (green) 0b10110100 = 180