Python 2.7 mediainfo --inform outputs full info rather than one string
Question: Using the following in powershell produces the expected output of
`01:22:02:03`:

    
    
     MediaInfo --Language=raw --Full --Inform="Video;%Duration/String4%" filename
    

My following python 2.7 script always gives the full mediainfo output with
every piece of metadata, not just the Duration String that I specified.. I've
tried escaping the semi colons but it has no effect. What am I doing wrong?

    
    
    import sys
    import subprocess
    filename = sys.argv[1]
    test = subprocess.check_output(['MediaInfo', '--Language=raw', '--Full', '--inform="Video;%Duration/String4%"', filename])
    print test
    


Answer: Lose the double-quotes in the `--Inform` argument. I can reproduce your
problem with this code:

    
    
    import subprocess
    
    args =  [
        'mediainfo',
        '--Language=raw',
        '--Full',
        '--inform="Video;%Duration/String4%"',
        'tests/reference.mp4'
    ]
    
    bad_output = subprocess.check_output(args)
    line_count_bad = len(bad_output.splitlines())
    
    args[3] = args[3].replace('"', '')
    
    good_output = subprocess.check_output(args)
    line_count_good = len(good_output.splitlines())
    
    print(line_count_bad, line_count_good, sep='\t')
    print(good_output)
    

The output is:

    
    
    204 1
    b'00:00:07:08\n'
    

