The original issue is that the `timeout` in `subprocess.run()` does not work properly, so I try to use `subprocess.Popen()` instead. There are two references I found, [1] is the implementation of `subprocess.run()` and [2] is the example for `Popen.communicate()`. Surprisingly, [2] works for me, and seems the `with` statement is the cause of the issue.

I created a snippet [3] to reproduce the bug, note that `ffmpeg` is needed to run the script. Ideally, all the time should be less than 0.1 or just a little bit greater than 0.1, but when using the `with` statement, the result would be much larger than that.

[1] https://github.com/python/cpython/blob/0f9c9d53283420a570850aa92869d032b40d4fba/Lib/subprocess.py#L489
[2] https://docs.python.org/3/library/subprocess.html#subprocess.Popen.communicate
[3] https://gist.github.com/huxuan/d58a5899be9b42e0936c71dd7884442a

Seems it is a false negative report. Close it temporarily.