Combines .ts video files from a directory or multiple directories into .mp4 files using ffmpeg.

ts-merge.js

#!/usr/bin/env node

/**
 * @example node ts-merge.js ./videos output_folder
 */

const { execSync } = require("child_process");
const { readdirSync, writeFileSync, existsSync, mkdirSync } = require("fs");
const { join } = require("path");

const [, , inputPath, outputPath] = process.argv;

/**
 * Combines .ts video files from a directory into a single .mp4 output file using ffmpeg.
 * @param {string} inputPath - Path to the directory containing .ts files.
 * @param {string} outputPath - Path to the output .mp4 file.
 */
function combineTSFiles(inputPath, outputPath) {
  const ls = readdirSync(inputPath);
  const tsFiles = ls.filter((e) => e.match(/\.ts$/));
  const inputTxt = tsFiles
    .map((file) => `file '${inputPath}/${file}'`)
    .join("\n");
  writeFileSync(join(__dirname, "input.txt"), inputTxt);
  const ffmpegArgs = [
    "-f",
    "concat",
    "-safe",
    "0",
    "-i",
    "input.txt",
    "-c",
    "copy",
    outputPath,
  ];
  const cmd = `ffmpeg ${ffmpegArgs.join(" ")}`;
  const stdout = execSync(cmd);
  console.log(stdout.toString());
}

/**
 * Combines .ts video files from a directory or multiple directories into .mp4 files.
 * If the inputPath contains .ts files directly, it combines them into a single .mp4.
 * If the inputPath contains subdirectories, it processes each subdirectory separately,
 * combining their .ts files into individual .mp4 files with matching folder names.
 * @param {string} inputPath - Path to the directory or directories containing .ts files.
 * @param {string} outputPath - Path to the directory where the .mp4 files will be saved.
 */
function combineTSFolders(inputPath, outputPath) {
  const ls = readdirSync(inputPath);
  console.log(ls);
  if (ls.find((e) => e.match(/\.ts$/))) {
    combineTSFiles(inputPath);
  } else {
    if (!existsSync(outputPath)) {
      mkdirSync(outputPath, { recursive: true });
    }
    for (const folder of ls) {
      combineTSFiles(
        join(inputPath, folder),
        join(outputPath, `${folder}.mp4`)
      );
    }
  }
}

combineTSFolders(inputPath, outputPath);