I have a DVD that my client wants re-edited. They need the re-edited footage in as high a quality as possible so please, what's the best technique to convert the Video TS file (losing little or none of the quality), to a file FCP can handle?
For the very best quality export your video to a stand alone quicktime file with the 8 bit uncompressed codec. DVDs are 8 bit Ycbcr and using the 8 bit codec ensures that there is no color or re-compression issues.
MPEGStreamclip isn't a terrible application, but I've seen a lot of posts of people reporting problems with it. MPEGStreamclip fails to properly read the DVDs aspect ratio on some DVD and other people have reported frame drops and field order reversal issues. I would recommend the application that I wrote called DVDxDV over MPEGStreamclip. Try them both and decide for yourself.
Brad Wright is software engineer, so it may be difficult to understand what he is saying. He is always happy to explain his greater detail.