I do this kind of work for a living and and there are ways to convert this kind of file, unfortunately they are not cheap. Two programs I use are "Cleaner" and "Permier Pro". Cleaner is a program that will convert many file types and Premier pro is a video editing system. Both these programs cost in the range £300 to £600 each. There may be someone out there that knows of a program available for free download. You will have to decide how serious you are about doing this kind of work and If it is something you will be doing a lot of.