I have truncated a video clip to a small section. If I adjust the section to 2300% speed (or smaller), it does start from the right point in time (according to my cut). If I adjust it to 2400% (or larger) the section clip suddenly shows a completely different part of the original video clip. Reproducible: Always Version 15.04.0-0ubuntu1~ubuntu15.04~ppa2 from kubuntu-backports
Do you still have this problem? I just encountered the same problem. Applications 15.08.
I can confirm the issue that the speed effect causes the clip to be clipped (in my case only on the right side) when using high values: https://www.youtube.com/watch?v=bZUAowpFyTI I can reproduce this by following your steps but increasing the values a little: https://youtu.be/rY4odVLQTHk There are small inconsistencies when using 2300%/2400% but at 3000% the area of the clip definitely gets screwed up in my case. I used https://archive.org/download/StockVideoGameVideo/TriggerRallyGeneralPurposeVideo.mp4 (MPEG4 download at https://archive.org/details/StockVideoGameVideo ) for testing.
Same over here.
Cannot reproduce with recent Kdenlive 16.04.2/beta 16.07.90, MLT 6.2.0+ and the new timewarp-based speed effect. This seems to be fixed.