As for installing ffmpeg, there is no install. What those guys told you, Michelle, is
like crushing a peanut with a sledgehammer.
First off, you get ffmpeg from
ffmpeg.org. Nowhere else.
Then, I say don't clutter up your boot partition with yet more things that don't really
belong there.
I have installed ffmpeg in M:\ffmpeg. There's nothing magic about my M drive. The point
is it isn't my boot partition, my C drive. I just unzipped the file I got from
ffmpeg.org into M:\ffmpeg. The unzip creates a subdirectory within M:\ffmpeg with a
weird & wild long name. Part of the name is the date of the build that was newest on the
day I went to
ffmpeg.org to get it. This is the end of the installation.
You should be using .bat files to execute ffmpeg. It has all these strange parameters
with weird spellings & special rules for their placement within the command. Don't try
to remember all that. And for the love of Pete, don't retype it every time. Use .bat
files.
Don't mess with your system SET PATH. There is a better way. It doesn't require
rebooting. In the M:\ffmpeg directory, I have a one-line .bat file that contains this
line:
SET ffmpeg=M:\ffmpeg\the long weird name I got from unzip\bin
Even if there's spaces in any of that, don't code any quotation marks. Just code it
exactly like that. I named this one-line script Setffmpeg.Bat. In every other script
in whatever directory on my system where I use ffmpeg or ffprobe or both, the first line
is this:
Call M:\ffmpeg\Setffmpeg
When I want to invoke ffmpeg, I execute this:
"%ffmpeg%\ffmpeg" whateverparms -i "whatever" moreparms "wherever"
Note the quotation marks. Always code quotation marks. Make it a habit. I think you
already do this, Michelle. That comment is for anybody else reading this.
Now suppose one day you want to get a new version of ffmpeg. No problem. Unzip the new
ffmpeg into M:\ffmpeg. Now M:\ffmpeg will contain 2 subdirectories with long weird
names.
Edit the one-line script M:\ffmpeg\Setffmpeg.Bat. Change the long weird directory name
to be the one from the new unzip. Save it. Presto. All your other scripts will
magically start using the new ffmpeg. No reboot required.
But there's a problem with the new ffmpeg? Go back into M:\ffmpeg\Setffmpeg.Bat & change
it back to the old long weird directory. Presto. All your other scripts will magically
revert to using the old ffmpeg. No reboot required.
But there are no problems with the new ffmpeg? Great. Delete the old subdirectory with
the long weird name. Now you'll have only 1 subdirectory with a long weird name in
M:\ffmpeg. No reboots required. No reboots, & no closing of any other applications.
It's so simple. It just requires a baby-level grasp of Windows concepts. I learned all
of these concepts within the first couple of months after I started to use Windows over
30 years ago. Aren't they teaching this stuff in schools any more? I didn't get it from
a course, either. It's in the Windows documentation. You can get it from Microsoft or
you can find untold piles of educational content about it around the web. This stuff
ain't rocket science. It's computer non-science. Computer science is more complicated
than this. This is just basic usage stuff.
I still hope you post more about what you did so we can debug it.