SVB16

Svb16 compresses u16 values using 1-bit tags. Each value is stored in either 1 byte (values 0–255) or 2 bytes (values 256–65535). Eight tags share one control byte.

This is the codec used in the VBZ pipeline for Oxford Nanopore POD5 signal data.

Tag table

Example

#![allow(unused)]
fn main() {
use svb::u16::Svb16;

let values: Vec<u16> = vec![1, 300, 0, 65000];
let encoded = Svb16.encode(&values);
let decoded = Svb16.decode(&encoded, values.len()).unwrap();
assert_eq!(decoded, values);
}

Control stream layout

Tags are packed 8 per byte, LSB-first. For n values the control stream is ceil(n / 8) bytes.

control byte k  →  tags for values 8k+0 through 8k+7
bit 0  =  tag for value 8k+0
bit 1  =  tag for value 8k+1
...
bit 7  =  tag for value 8k+7