When I try and speed up or slow down a clip of a AVCHD file I get a plain grey screen for the whole duration. Damn frustrating considering I'm editing some sports footage. Does anyone know how to rectify this?

Always running into problems with Kdenlive

Hi,

If you had looked down the Topic list, you would see that just two down there is a discussion on the Speed effect. Quite frankly, I think that at this moment in time, it's just broken.

Personally I never use it, I always use "slowmoVideo" for speedup or slowdown.

i too have issues with the motion efffect (slow down or speed up) when I try to apply it to .ts clips captured with my Haugpauge HD-PVR (within xubuntu) capturing my xbox 360 at 720p@59.97 BUT the speed effect works fine on .mov files captured with my iphone 5s.

is slowmoVideo a linux app available to ubuntu users? I am running xubuntu 12.04.3.

Yes, slowmo is also available as a deb package. It's a great tool, albeit I used it only once so far, I highly recommend it. It did a fine job on my under water 1080p 25fps footage to the extent possible.

I had this same problem with AVCHD clips. I worked around it by transcoding the AVCHD to a different format (e.g. mp4) and then apply the speed affect.
You can expect a loss of quality and larger file size because of the transcoding.
Note: I also had problems with mismatched frame rate and the speed affect, I had to make sure the project frame rate matched the clip frame rate, otherwise kdenlive would just crash when trying to preview the affect.