Concat .mp4 files, using ffmpeg and python

concat-mp4.py

# Output in same dir as script

import os
import tkinter as tk
from tkinter import ttk
from tkinter import filedialog as fd
from tkinter.messagebox import showinfo, askokcancel

def concat():

    filetypes = (
        ('Video files', '.ts .mp4'),
    )

    files = fd.askopenfilenames(
        title='Open files',
        initialdir=os.getcwd(),
        filetypes=filetypes
    )

    if (len(files)<1):
        return

    output_name = name.get("1.0", "end-1c") or files[0] + '.output.mp4'
    if not output_name.endswith(".mp4"):
        output_name +='.mp4'


    is_ok = askokcancel(
        title='Please Check the order!',
        message=f"{files} --> {output_name}"
    )

    if not is_ok:
        return

    # .mp4 -> .ts, (ignoring already .ts files)
    temp_files = list(files)
    for i, file in enumerate(files):
        if file.endswith(".ts"):
            continue

        temp_files[i] = temp_files[i].replace('.mp4', '.ts')
        os.system(f'''ffmpeg -i "{file}" -c copy -bsf:v h264_mp4toannexb -f mpegts "{temp_files[i]}"''')

    # concating all the .ts files created
    os.system(f'''ffmpeg -i "concat:{"|".join(temp_files)}" -c copy -bsf:a aac_adtstoasc "{output_name}"''')

    showinfo(
        title='Done!',
        message=output_name
    )

    # deleting all the .ts and .mp4 files except output
    for i in {*files, *temp_files}:
        os.remove(i)

    exit()


if __name__=="__main__":
  # create the root window
  root = tk.Tk()
  root.title('Concat MP4')
  root.resizable(False, False)
  root.geometry('300x150')

  # open button
  open_button = ttk.Button(
      root,
      text='Select Files',
      command=concat
  )

  # text box
  name = tk.Text(root)

  # place on tk
  open_button.pack(expand=True)
  name.pack()

  # start GUI
  root.mainloop()