postProcess.js

const { spawn } = require("child_process");
const path = require('path');

var isWin = process.platform === "win32";

const CHRONOSENSE_ROOT_DIR = path.join(path.resolve(__dirname), '../');
const FFMPEG_DIR = path.join(CHRONOSENSE_ROOT_DIR, 'ffmpeg');

process.on('message', (msg) => {
    let pp = null;
    // console.log('Message from parent:', msg);
    dirName = msg.dirName;
    fileName = msg.fileName;
    pp = new postProcesser(dirName, fileName)
    pp.postProcessVideoFile();
    pp = null;
});

class postProcesser {
    #c = null;
    #dirName = null;
    #fileName = null;
    constructor(dirName, fileName){
        this.#dirName = dirName;
        this.#fileName = fileName;
    }
    postProcessVideoFile() {
        if (isWin) {
            // process.send("isWin true");
            this.#c = spawn(path.join(FFMPEG_DIR,"ffmpeg.exe"), [
                "-i",
                path.join(this.#dirName, "raw", this.#fileName),
                path.join(this.#dirName, this.#fileName.substring(0, this.#fileName.length - 5).concat(".mp4"))
            ], {detached: true});
            process.send({ pid: this.#c.pid, child_state: "processing" });
        }
        else {
            // process.send("isWin false");
            this.#c = spawn("ffmpeg", [
                "-i",
                '"'+path.join(this.#dirName, "raw", this.#fileName)+'"',
                '"'+path.join(this.#dirName, this.#fileName.substring(0, this.#fileName.length - 5).concat(".mp4"))+'"'
            ], {detached: true, shell: true, PATH: process.env.PATH});
            process.send({ pid: this.#c.pid, child_state: "processing" });
        }

        // this.#c.stdout.on('data', (data) => {
        //     process.send(`stdout: ${data}`);
        // });
        
        // this.#c.stderr.on('data', (data) => {
        //     process.send(`stderr: ${data}`);
        // });
          
        // this.#c.on('close', () => {
        //     process.send({ pid: this.#c.pid, child_state: "done" });
        // });
    }
}