Convert FLV to MP4 with Python script (ffmpeg)

# coding: utf-8
"""
This script losslessly converts video files from FLV to MP4.
"""

__author__ = "Caleb Burns"
__version__ = "0.1"
__status__ = "Prototype"

import argparse
import os.path
import subprocess
import sys

def main(argv):
    parser = argparse.ArgumentParser(prog=argv[0], description=__doc__)
    parser.add_argument('flv', nargs='+', help="The FLV files to convert to MP4.")
    args = parser.parse_args(argv[1:])

    flvpaths = args.flv

    for flvpath in flvpaths:
        mp4path = os.path.splitext(flvpath)[0] + ".mp4"
        result = subprocess.call(['ffmpeg', '-i', flvpath, '-vcodec', 'copy', '-acodec', 'copy', mp4path])

if __name__ == '__main__':
    sys.exit(main(sys.argv))