node-sstv

A Slow-Scan Television (SSTV) encoder for node.js.

var fs = require('fs'),
    Speaker = require('speaker'), // npm install speaker
    SSTV = require('./index.js');

function play(pcm) { speaker.write(pcm); }

function onRead(err, data) {
	if (err !== null) {
		console.log(err);
		return;
    }
	for (var m in SSTV.Modes) {
		new SSTV.Encoder().encode(SSTV.Modes[m], data, play);
	}
}

var speaker = new Speaker({ channels : 1, bitDepth : 16, sampleRate : 44100 });
fs.readFile('/path/to/some/picture.png', onRead);

####SSTV.Encoder

Produces a Buffer of PCM audio data based on a Buffer of PNG, JPEG, or BMP image data (eg. as read from a file).

#####Methods

• encode(mode, picture [, callback])
  • mode is one of the properties of SSTV.Modes (see below).
  • picture is a Buffer containing the image data (see example above).
  • Optional function callback will receive one argument, a Buffer containing PCM audio data.

#####Events

• data
  • The data event is fired once the image has been encoded as audio. Listener will receive one argument, a Buffer containing PCM audio data.

####SSTV.Modes

Mode identifiers for use with SSTV.Encoder.encode(mode, picture).

Additional modes can be added if anybody wants them. I've implemented a variety of "popular", "fast", or interesting ones to start with.

#####Properties

• ROBOT_BW_8
• ROBOT_BW_12
• ROBOT_COLOR_36
• ROBOT_COLOR_72
• MARTIN_1
• MARTIN_2
• SCOTTIE_1
• SCOTTIE_2
• SCOTTIE_DX
• FAX480