Hi all,

Have been rendering fine with Kdenlive for a while. Came to do a small project yesterday and found it was taking ages to render. Estimated time stays on about 1 minute 48 seconds, left it for about 30 mins before cancelling and it was on about 4%. The project is about 1 min 20 long, outputting to MPEG4 as I always do.

What I found with this project is that only 1 CPU (Core i7) is being used at 100%, normally all CPUs are being used at around 60-70%. The 100% usage of 1 core moves between all 8 of them, which is bizarre. It stays on each one for around a minute, then the 100% starts on another.

If anyone can help with this I would appreciate it, will log this as a bug if it isn't just something I have done wrong

Have checked the CPU count is set to 8 BTW

I am running Ubuntu x64 10.10 with packages built by sunab as of today, 23/04/11

Cheers

OK, just a few more tests. Also seems to happen with proxy clip creation, have also tried rendering with proxies on and off, all works out the same.

Will try a full removal and re-install of kdenlive and see what happens

Screenshot attached of CPU activity, you can see where the activity swaps between cores

Just done a full reinstall, but the same thing is happening. Logged a bug report here http://www.kdenlive.org/mantis/view.php?id=2101

UPDATE

OK, I think there are 2 issues here. I started deleting bits out of the project and found 1 clip that when I removed it, the project started rendering fine, faster than not at all anyway. So looks like I have a bad bit of video, which I need to clean up, not sure how?! Any ideas on that would be great, might just re render it with WinFF

The single CPU issue remains though, I am positive this didn't use to work like this, maybe someone can confirm either way?!

MPEG-4 encodes very fast - not really much need to use multiple encoding threads there, maybe just 2. The encoding is being held back by the decode and processing, which is running on a single core by default. v0.8 with Mlt 0.7.0+ includes parallel processing, which can help a little, but it is not a silver bullet [1] (e.g. decoding of a file via ffmpeg can not be accessed by multiple mlt threads). You can try increasing processing threads in Settings > Environment, but I do not recommend more than 4.

[1] http://www.linux-mag.com/id/8515/

Thanks very much for the info. I will give the parallel processing a go on my next project.

I found in the end that I had a dodgey clip, either that or Kdenlive didn't like rendering MTS sped up to 3200%. I had to re-render all of my MTS clips to MPEG4 and then re-add them to the timeline for this to work, otherwise I got black clips in the rendered file, maybe a bug?

Cheers