Haha-Yes/node_modules/m3u8stream/lib/m3u8-parser.js
2018-09-09 21:20:36 +02:00

67 lines
1.7 KiB
JavaScript

const Writable = require('stream').Writable;
/**
* A very simple m3u8 playlist file parser that detects tags and segments.
*
* @extends WritableStream
* @constructor
*/
module.exports = class m3u8Parser extends Writable {
constructor() {
super();
this._lastLine = '';
this._seq = 0;
this._nextItemDuration = null;
this.on('finish', () => {
this._parseLine(this._lastLine);
this.emit('end');
});
}
_parseLine(line) {
let match = line.match(/^#(EXT[A-Z0-9-]+)(?::(.*))?/);
if (match) {
// This is a tag.
const tag = match[1];
const value = match[2] || null;
switch (tag) {
case 'EXT-X-PROGRAM-DATE-TIME':
this.emit('starttime', new Date(value).getTime());
break;
case 'EXT-X-MEDIA-SEQUENCE':
this._seq = parseInt(value, 10);
break;
case 'EXTINF':
this._nextItemDuration =
Math.round(parseFloat(value.split(',')[0], 10) * 1000);
break;
case 'EXT-X-ENDLIST':
this.emit('endlist');
break;
}
} else if (!/^#/.test(line) && line.trim()) {
// This is a segment
this.emit('item', {
url: line.trim(),
seq: this._seq++,
duration: this._nextItemDuration,
});
}
}
_write(chunk, encoding, callback) {
let lines = chunk.toString('utf8').split('\n');
if (this._lastLine) { lines[0] = this._lastLine + lines[0]; }
lines.forEach((line, i) => {
if (i < lines.length - 1) {
this._parseLine(line);
} else {
// Save the last line in case it has been broken up.
this._lastLine = line;
}
});
callback();
}
};