dave-irvine / packbits

An implementation of the PackBits algorithm.

packbits

An implementation of the PackBits algorithm.

Installation

npm install packbits

Usage

var packbits = require('packbits');

Encode or decode a string of hex bytes with or without separating spaces.

encode

packbits.encode('AA AA AA 80 00 2A AA AA AA AA 80 00 2A 22 AA AA AA AA AA AA AA AA AA AA');
//-> FEAA0280002AFDAA0380002A22F7AA

decode

packbits.decode('FE AA 02 80 00 2A FD AA 03 80 00 2A 22 F7 AA');
//-> AAAAAA80002AAAAAAAAA80002A22AAAAAAAAAAAAAAAAAAAA

Examples

See examples/ directory

packbits's Issues

bytesToHex is missing?

Hi,
I'm using the packbits module currently and found that bytesToHex didn't define in encode.js, is there really missing or just misunderstanding?

this implementation is not lossles

example

var packbits = require('../');

function code(p){
var out = packbits.encode(p);
var out2 = packbits.decode(out);
console.log(${p} enc=> ${out} dec=> ${out2});

}

for( var i=0;i<=255;i++){
var ar = new Uint8Array(1);
ar[0] = i;
code(Buffer.from(ar).toString('hex'));
}

output :

.
.
.
36 enc=> 0054 dec=> 54
37 enc=> 0055 dec=> 55
.
.
.
fe enc=> 0054 dec=> 54
ff enc=> 0055 dec=> 55