I have a series of ISO files that contain films. I found some subtitles for those films in SRT format and would like to add the subtitles to the films. The problem is that there is one SRT file for each film but the ISO files contain two or three films each. I have no idea how to add multiple SRT files to an ISO and have each SRT file synchronize with a specific film on the ISO. As far as that goes, I have never added subtitles to an ISO that contains only a single movie either but, from the Googling I've done, it sounds easier. But I haven't found any discussions yet of how to add multiple SRT files to an ISO that contains multiple films. Can anyone tell me how to do it? Unfortunately, I have to stick to free tools so that may make it harder to do the task I want to do. I am willing to convert the ISO to other formats if necessary. For instance, if you tell me how to convert the films in the ISO to AVI, then I can do the rest myself with DVDFlick, which I've used several times. But if there is a simple way to do the task without having to convert the ISO first, that may be even better.