Sure it is possible. Here is something similar I did using VLC to play all files in a folder.
It is using Automator to create a Service which appears as an option when you right click a folder in Finder.
The shell script code, if you go this way, I'll leave up to you to work out...you already know the commands you need to run, should be easy to work it out.
Just a final note. Your three commands take time so it will be hard to know where things are at - except for CPU usage. One suggestion would be to look into using addon libraries that provide progress dialog boxes like ASObjC Runner.
Good luck.
PS: This may be helpful... https://stackoverflow.com/q/1857050/348694