Hi all,

I do hope someone can help me with this because I'm at my wit's end (not a very long wit admittedly :-)

I was working on a project earlier in the year, then, in mid March, had to drop it temporarily due to other work priorities.

Now, I'm coming back to it, there's clearly something wrong with the rendering.

The embedded video shows, first, a 30 sec sample of the original rendering from March 2011, then the same sample rendered today.

As can be seen from the second sample, there is distortion that looks like an interlacing problem on the wipes. More importantly, at 44.280 sec, 50.160 sec and 56.040 sec, a few frames from the second clip appear before the wipe starts.

A few things that may help someone to figure this out:

1) These artefacts only occur in rendering. During playback the monitor shows no sign of them.

2) I checked and the few vagrant frames before the wipes are definitely not a case of the transitions being slightly out of alignment with the start of the clips - that was my first thought.

3) To make doubly sure that I hadn't changed anything, I opened a backup file from March and rendered the first 30 seconds of it, without changing any settings. The second sample is a result of that.

4) Although the layering looks very complicated, it isn't on the master file. I had previously rendered the complex layering as hufyuv clips. The master file simply wipes between each hufyuv clip.

5) These rendering were made with xvid, but I tried a few others (mpeg4, hufyuv, ffv1 etc.) all with the same artefacts resulting.

6) Some time between March and now, I updated my system to OpenSuse 11.4 with KDE 4.6.

7) My current kdenlive is 0.8-1.5. I'm not sure what I was using in March, but it was probably the latest available for OpenSuse at the time.

8) According to MediaInfo, the original sample was created by Lavf52.102.0; today's sample by Lavf53.4.0

I hope someone can shed some light on this. I would really like to get back into this project, but I'm reluctant to pursue it if the rendering problem cannot be solved.

Thanks in advance for any suggestions offered.