stcformat

A parser for ZX Spectrum Soundtracker (.stc) files

Installation

npm install stcformat

Usage

This package exports a function readSTC which accepts a buffer containing the binary data of the .stc file, and returns the data as a structured JSON-like object.

const fs = require("fs");
const { readSTC } = require('stcformat');

const buf = fs.readFileSync('myfile.stc'));
const stc = readSTC(buf);

The returned object contains the following items:

• tempo - the song tempo, in frames per row
• length - the number of positions in the song
• samples - an array of sample objects
• positions - an array of positions, where each position is a two-element array of pattern number and transposition value
• ornaments - an array of ornament objects
• patterns - an array of pattern objects

Sample objects consist of the items:

• repeat - the offset from which the sample will be repeated after reaching the end of the sample
• repeatLength - the length of the repeating section
• volumes - an array of 32 integers from 0 to 15, giving the volume over time
• noiseLevels - an array of 32 integers from 0 to 31, giving the noise periods over time
• toneMasks - an array of 32 booleans indicating the frames on which the tone generator is masked
• noiseMasks - an array of 32 booleans indicating the frames on which the noise generator is masked
• tones - an array of 32 integers giving the pitch offsets over time

Ornament objects consist of a single item tones, an array of 32 integers giving the semitone offsets over time.

Pattern objects consist of the items:

• length - the number of rows in the pattern
• channels - an array of 3 items, giving the note data for each channel. Each channel is an array of rows, where each row is a four-element array consisting of:
  • Note name as a string, e.g. "C-4" or "F#4"
  • Sample number
  • Effect number (8-14 to select an envelope, 15 for an ornament)
  • Effect parameter (envelope period or ornament number)