Would hugely appreciate some guidance on how to do this. E.g. I have two mpegs at 832x604 10fps which I simply want to join together. No editing/effects/transitions, just a join. I have tried creating custom profiles matching the source resolution and custom rendering templates of various formats with various options, and nothing gives me a decent output video. The closest I can get is a wobbly looking video which looks like the really old-fashioned interlaced TVs look like. Most of the time I end up with a 0 byte file, or a 4k file with no video channel (according to mplayer).
Without this I am afraid kdenlive is useless to me, and I will have to reluctantly leave its community :-( Thanks for any help you can offer.