1. Am I doing it right? I ve seen a php extension call php_ffmpeg. Not sure if I can use it to achieve my goal instead.
2. If I proceed to do those things above, Will there be a problem if I try to call those 3 commands at the same time? Will they even be executed? It takes a while for me to convert a small video by using the command prompt.
Obviously, you need to set the variables for the original file name ($uploadFilename) and the name of your newly created output file ($finout). But that works for me. And depending on how you installed ffmpeg, you may find that you need to reinstall it. There are a variety of addons/extra codecs. For myself, I found the basic ffmpeg install would have issues with webm. I needed to install it with additional codecs activated.