One other thing.
An MTS stream is a funny thing. It's an MPEG-2 Transport stream and is far from being ideal to use in DVD because it is already heavily compressed. Edit this & recompress to a secondary MPEG-2 file & the quality will inevitably degrade. If your footage is intended for DVD and not BD-ROM, then shoot instead in SD.
What frame rate are you shooting in? Also, what is your target resolution/TV STandard?
I ask as you may well be better off shooting in 24p SD instead of something that is called "HD" but in reality is nothing of the sort.