Hello, my language is bad, but I have a question.
I have got camera JVC Everio create files *.mod (mpeg video: 720x576, 9200kbs, upper field first, audio: 4800kHz, DolbyDigital 356 kbs). I use Ulead Video Studio and when I activate option Don't conwert mpeg files, program create file mpg very fast, render only transition, title etc. In Kdenlive files are rendering from begin to end and quality file is a little bad. How sort of parameters I must set?
Thank you for good program for linux, its very intuicive and usefull. Good work.

Kdenlive 0.7.3 is deprecated. Please upgrade to Kdenlive 0.7.4 which relies on mlt 0.2.4 and provides much better exports, with adequate bitrates. Could you upload some footage and register your camcorder in our database, please?

What you are asking for is an option to "pass through" the parts that are not affected by effects, but that is not available in Kdenlive. Others have requested, and it may come, but likely not any time soon.