Hello,

I've just started using Kdenlive. I have 2 source clips, each 480p24 H264. I'll call them Clip A and Clip B. Here's what I have in my timeline.

Part of Clip A - Part of Clip B - Different Part of Clip A.

What happens when I render this section is that the last frame from the first Clip A ends up being rendered in front of the different clip A at the end, even though there's an unrelated clip between them. I've checked to be sure it isn't sloppy editing on my part by changing the last clip section in the timeline, and the effect remains. Does anyone know why this is happening, and what, if anything, I can do about it?

If you trim the beginning of 'Different Part of Clip A' by a couple of frames does the problem go away?
What is your version?

I was using the latest version as of the op. Trimming the clips doesn't fix the problem, it just changes which frame gets transposed. I'm thinking the cause is related to pulling the 1st clip from memory and then not properly seeking for the first frame. When I get home tonight, I'll try the latest version to see if it works any better.

Edit:

I've uploaded a sample video of the problem to youtube here: http://www.youtube.com/watch?v=VKe2gQmzaB8

At about the 38 second mark, the video transitions from the widescreen clip to the 4:3 clip, and the last frame from the previous 4:3 clip is rendered in front of the second clip. This frame is not supposed to be there, so moving the cut points doesn't change or fix the problem. I just upgraded to 0.8.0 release, and this problem still exists.

No one else is having this problem? Nobody has any idea where this artifact could be coming from? The sources are DVD's that I ripped personally, and converted (using handbrake) to h264. Mediainfo is attached for one of the sources. Is this a format that MLT/Kdenlive doesn't like very much? Would putting it in a different container possibly help?

Another update: I just attempted the same sort of clip arrangement in the bundled kdenlive virtualbox image (running kdenlive 0.7.4) and it does NOT exhibit the same behavior. So either this problem was introduced in a later version of kdenlive or MLT, or I have something in my Ubuntu virtualbox configured wrong. It may be possible that my saved project is actually messed up as well. I'll make adjustments to my virtualbox environment to see if that changes anything. I'll also try to recreate the issue from scratch from within my normal working environment.

EDIT: Ok, I've tried everything I can think of to fix this. I've updated my VBox settings to match that of the downloadable package (except for debian. I have Ubuntu). I"ve installed missing codecs. I've uninstalled and reinstalled kdenlive. I've recreated the project from scratch. I still have the same issue as in the first post. I can't be the only one who has this problem. Only thing I haven't done is transcode the clips (because transcoding the full movie would result in a huge file. I swear this issue must have something to do with the way kdenlive seeks to a part of a video when switching clips. Perhaps it isn't properly dumping the memory from the last time it used that source clip

Edit Again: I think I found a work around. If I put the offending clip on a separate video track, the problem does not happen.

Edit the 3rd: Spoke too soon. As soon as the project material goes back up to the original video track, the offending frame pops up there instead. See http://www.youtube.com/watch?v=WJhSulbicfE

FIXED.

Per this thread http://www.kdenlive.org/forum/x264-video-streams-mkv-containers-do-not-playback-correctly-within-clip-monitors-mlt-05x

Setting MLT_NO_VDPAU=1 seems to have fixed this issue.

VDPAU is disabled by default since version 0.7.0 of MLT due to strange issues like this and instability with parallell processing. I do not know if distribution packages are enabling it.