mpegts-demuxer/lib/MpegTsDemuxer.js

Demuxes an MPEG Transport Stream into elementary packets.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.MpegTsDemuxer = void 0;

var _stream = require("stream");

var _constants = require("./constants");

var _classes = require("./classes");

var _utils = require("./utils");

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

class MpegTsDemuxer extends _stream.Transform {
  constructor() {
    super({
      readableObjectMode: true,
      flush: callback => {
        this.finalize();
        callback();
      },
      transform: (chunk, encoding, callback) => {
        this.process(chunk);
        callback();
      }
    });

    _defineProperty(this, "pids", new Map());

    _defineProperty(this, "pmt", new _classes.Pmt());

    _defineProperty(this, "unprocessed", Buffer.alloc(0));

    _defineProperty(this, "cb", p => {
      this.push(p);
    });
  }

  process(chunk) {
    const {
      pmt,
      pids,
      cb
    } = this; // Add the chunk to the unprocessed data

    this.unprocessed = Buffer.concat([this.unprocessed, chunk]);
    const mem = (0, _utils.getSafeDataView)(this.unprocessed); // Loop through all the data

    let ptr = 0;

    while (this.unprocessed.length - ptr >= _constants.PACKET_LEN) {
      // Demux packet will return the number of bytes it has analyzed, or zero if a full
      // packet was consumed
      const consumedBytes = (0, _utils.demuxPacket)(pmt, mem, ptr, pids, cb, false) || _constants.PACKET_LEN;

      ptr += consumedBytes;
    }

    this.unprocessed = this.unprocessed.slice(ptr);
  }

  finalize() {
    const {
      pids,
      cb
    } = this;
    pids.forEach(s => {
      const packet = s.finalize();
      if (packet) cb(packet);
    });
  }

}

exports.MpegTsDemuxer = MpegTsDemuxer;