Add audiofile.has_video()

[hagenw]

Add audiofile.has_video() to check if a given media file contains video.

In audbcards we need to inspect media files if they contain video or not. One approach is to use mediainfo for this. As audiofile relies already on mediainfo, I thought it would be a good fit to integrate that function here.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.0%. Comparing base (a8a130b) to head (5d83477).

Additional details and impacted files

Files	Coverage Δ
audiofile/__init__.py	100.0% <100.0%> (ø)
audiofile/core/info.py	100.0% <100.0%> (ø)

[schruefer]

Hey, thanks for the update! I think it's a great extension.

My only question is how we should handle it if a file does not exist.

If we have an non-existing ["wav", "flac", "mp3", "ogg"] file we get an result

>>> has_video('no_file.wav')
False

whereas it raises an Error for all other datatypes.

>>> has_video('no_file.mp4')
  File "<stdin>", line 1, in <module>
  File "/home/usr/audiofile/audiofile/core/info.py", line 213, in has_video
    video_format = run(cmd)
  File "/home/usr/audiofile/audiofile/core/utils.py", line 86, in run
    out = subprocess.check_output(shell_command, stderr=subprocess.STDOUT)
  File "/usr/lib/python3.8/subprocess.py", line 415, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
  File "/usr/lib/python3.8/subprocess.py", line 516, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['mediainfo', '--Inform=Video;%Format%', 'no_file.mp4']' returned non-zero exit status 1.

I am also not getting the binary_missing_error, but also "mediainfo cannot be found. Please make sure it is installed" is a little bit none saying to me.

Do you think it makes sense to include an os.path.isfile(file) at the beginning?

[hagenw]

Thanks for testing this out.
I figured out, that we also have a mismatch between the reported error and the documented error for other functions as well and I created #154.

For audiofile.has_video(), I decided to stay with the current approach for wav, mp3, ogg, flac files, as the functions should be as fast as possible and checking if a file exists takes time. I updated the docstring accordingly:

and added a test for it.

Now we get:

>>> audiofile.has_video('no_file.wav')
False
>>> audiofile.has_video('no_file.mp4')
...
RuntimeError: 'no_file.mp4' does not exist.

Regarding your other comment. When mediainfo is missing I get a meaningful error message:

$ sudo mv /usr/bin/mediainfo /usr/bin/mediainfo.bak
$ touch empty.mp4
$ python -c "import audiofile; audiofile.has_video('empty.mp4')"
...
FileNotFoundError: mediainfo cannot be found.
Please make sure it is installed.
For further instructions visit: https://audeering.github.io/audiofile/installation.html

[schruefer]

Thanks for the updates!

Regarding your other comment. When mediainfo is missing I get a meaningful error message:

Yes, this is fine. I meant, that it is no meaningful error message if the file is missing.

Look, good to me.