First time post, (relatively) long-time Kdenlive user. Thanks to all the developers who make it available!
I am currently working with a Kodak Playsport portable HD camera, which is capable of 60fps at 720p. I took some 60fps footage with the intent to slow it down during editing, but Kdenlive currently re-samples all clips to the project's designated frame rate (I want my finished product to be 29.97, so that's what everything gets re-sampled to). I found that you can "force" whatever frame rate you want if you right-click the clip and select Clip Properties, so I set it to the clip's native frame rate (59.94) to see what would happen. Not what I expected; the clip still played at 29.97, but it was playing slower now. I assume that "forcing" the frame rate meant it was now using all frames in the file, but still at the same speed of 29.97 frames per second, thus the video would play at half-speed. Perfect!
I had a little bit of trouble getting the clip I wanted in the clip monitor (if I clicked ahead in the progress bar, it would simply start the clip over from the beginning), but I finally got it in the project timeline and it looked fine. Then I tried to render it. What I got was the intended effect (60fps at half-speed), but it was the beginning of the clip, not the section I had selected in the monitor.
I'd like to file a bug report, but I'm not sure where it belongs. Is this a Kdenlive issue or an MLT issue? Any help would be appreciated, thanks!