Method for concatenating .ts video pieces using FFmpeg concat command

VideoDownloaderUtil.java

 private void executeFFMPEG(String outputFilePath, String ffmpegInputFileNames) {
        System.out.println("\nExecuting ffmpeg with output path = " + outputFilePath + "\n");
        System.out.println("Input ffmpegInputFileNames character length >> " + ffmpegInputFileNames.length());
        // Build ffmpeg tool command and execute
        // ffmpeg will concat all our *.ts files and produce a single output video file
        ProcessBuilder processBuilder = new ProcessBuilder();
        String commandStr = "ffmpeg -i \"concat:" + ffmpegInputFileNames + "\" -c copy " + outputFilePath;
        // Run this on Windows, cmd, /c = terminate after this run
        processBuilder.command("cmd.exe", "/c", commandStr);
        processBuilder.redirectErrorStream(true);

        try {
            System.out.println("Executing command - " + commandStr);
            Process process = processBuilder.start();

            // Let's read and print the ffmpeg's output
            BufferedReader r = new BufferedReader(new InputStreamReader(process.getInputStream()));
            String line;
            while (true) {
                line = r.readLine();
                if (line == null) {
                    break;
                }
                System.out.println(line);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
    }