Transitions are brutal

Hi,

I have a amd64 tripple core 3.1 ghz system with 4 GB of ram running Gentoo Linux, 64bit-compiled. I am running kdenlive-0.8, recently updated from 0.7.8 to see if it helped resolve this problem, which it didn't. My graphics chip is a radeon hd4250, if that matters.

The problem is, that when I apply even the most trivial transition, the playback speed in kdenlive gets extremely jerky (choppy, staccato, whatever), making it extremely difficult to edit anything. For example, in the current movie I'm editing, I wanted to have a couple different versions of the same clip, one at full size, and the other zoomed in on different faces. If I use the pan and zoom effect, however, the clip becomes so slow and jerky, that it is impossible to do any editing. I'm not panning here, and I'm not compositing, just simply zooming in 300%. That doesn't seem like it should be terribly mathematically challenging for the cpu. Other effects are really choppy and slow too, compositing and fading, for example.

I look at the cpu, and I see that it isn't pushed as hard as it could be. It jumps anywhere from 30% to 95% on one core, but it is not pinned at 100% or anything like it. The other two cores don't seem to be doing much at all. The memory isn't maxed-out either.

I'm wondering if there is some setting, or compile time option of some component I'm missing here that is making this so difficult. I have tried messing with all the settings on the "Settings:Configure Kdenlive" drop-down menu, but nothing seems to help. I have enabled frame-dropping on the playback as well, but it either doesn't help, or isn't enough. My computer is not a wimp... I'm sure that there must be something I can do.

Can someone please give me a hand?

Thank you!

this very much depends on the video you are using. I have a Core i7 3GHz with 6GB of RAM, but if I throw 1080i MTS footage in Kdenlive, it dies completely.

If you are editing HD footage, I suggest this might be your problem. Have you come across proxy clips? When starting a new project, you can enable proxy clips in the project setup, then, when you add videos over the size specified, they are automatically rendered to low res "proxies", that are then used when editing.

When it comes to render, the original clips are used.

If you have a multi core CPU, there is an experimental option to run kdenlive of multi cores in the preferences also

Wow... that is really cool. I wondered what the heck that meant, and I must have completely blown by the muti-processor part. Maybe I'll give that a shot too.

And yes, I was shooting video at 1920x1088 at 23.97 fps. That is video taken from an Canon EOS 7D. I'm pretty new to this, so I'm not sure what to expect. I did some minor editing many years ago, but the resolution was nothing like it is now, so I have to get my bearings.

If you know of any good literature that would help me with using KDEnlive, I would really appreciate it. I am a bit of a noob when it comes to codecs and whatnot.

Thanks for your help.

G

Same, I have always edited stuff from DV tapes (ages ago), so was also initially stuck with editing HD footage. Proxies is incredible though and makes it so easy to edit and render, I use them for all my projects.

The user manual is all being put together here: http://userbase.kde.org/Kdenlive

So that might be worth a look, I haven't read through much stuff there, but it is a new place that people are collaborating to get the manual created.

Good luck anyway, post back if you have any more questions!