# code

import youtube_dl

vlink = input("Please enter a link: ")

selectedformat = input("Download Audio or Video? (A/V): ")


if selectedformat == "A" or selectedformat == "a":

    ydl_opts = {  # a dictionary which contains the settings for downloading
        'format': 'bestaudio/best',
        'postprocessors': [{
            'key': 'FFmpegExtractAudio',
            'preferredcodec': 'mp3',
            'preferredquality': '192',
        }]
    }

    with youtube_dl.YoutubeDL(ydl_opts) as ydl:
        ydl.download([vlink])

    print('Download successful!')

else:

    ydl_opts = {
        'format': 'bestvideo/best',
        }

    with youtube_dl.YoutubeDL(ydl_opts) as ydl:
        ydl.download([vlink])

    print('Download successful!')

# error

youtube_dl.utils.DownloadError: ERROR: ffprobe/avprobe and ffmpeg/avconv not found. Please install one.