I've got a project in which a user can upload audio and video files. When these files are uploaded, they are processed server-side using ffmpeg. However, I have noticed that multiple conversions will not run simultaneously. For example, if I upload a video, and then upload audio while video is processing, once the audio is uploaded it stops and waits for the video to finish processing before it will process the audio.
In another SO question, I noticed something called 'nohup'. I don't know what this is, but based on the posts it seems to me like it's something that allows the command to run without making the PHP script wait for it. This is not the result I would like. I need the current PHP script to wait for the process to finish. However I want to be able to trigger additional processes at the same time (not with the same running script, of course).