The same guide says:
Aliases are limited in power; the replacement only happens in the first word. To have more flexibility, use a function. Aliases are only useful as simple textual shortcuts.
...
Functions in Bash are somewhat like aliases, but more powerful. Unlike aliases, they can be used in scripts. A function contains shell commands, and acts very much like a small script; they can even take arguments and create local variables.
The bot is slightly more unfriendly in recommending against aliases in favor of functions.
So i tend to agree with pendrachken:
pendrachken wrote:You should be able to.
This is why I recommended a script though, it's easier to do what you want and have comments interspersed throughout to remind you of what tit is doing. That can you can just plop the script into the $PATH on any machine with BASH and ffmpeg and use it without having to either replace the stock .bashrc or cut / paste lines into the stock one to get the functionality back.