import re
import subprocess


def get_video_real_duration(filename):
    ffmpeg_process = subprocess.Popen([
        "ffmpeg", "-hide_banner", "-i", filename, "-c", "copy", "-f", "null", "-"
    ], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    result = "0:0:0.0"
    for line in ffmpeg_process.stderr.readlines():
        match_result = re.findall("(?<= time=).+?(?= )", line.decode())
        if len(match_result) == 0:
            continue
        result = match_result.pop()
    return result