blu ray authoring problems

hi everyone

i have hd video files on my hardrive in various formats such as .mp4, .mkv, .ts,

now my goal is to make a blu ray disc to watch on my player, everytime i attempt to do this in all types of different programs such as nero and powerlink it always takes hours re-encoding the files but i do not understand why as all the files i have use the codecs : avc/h264 or mpeg-4 and 2. why does it do this as they are already hd compatable files.

are there any programs that allow me to do this without reencode as sometimes the quality loss is horrible.

thanks