speed effect works in preview, after render video freezes wherever speed effect was used.

I've been using kdenlive for a long time now, its always worked great for me, but this has got me stumped.

I run Linux mint version 14, kdenlive 0.9.2 is the version in the repo. I always had crashing issues with that version so I updated to the latest git version about a month ago. Worked great for months.

But all of the sudden the speed effect is acting up. I take my video, cut the pieces I want sped up, move those little clips into a separate video channel, apply speed to each of them, set the speed to 300% and everything looks great in the preview, but when I render the video at every point where there should be a sped up section there is a super slowmo clip of the beginning of the video. Like literally under 1fps.

I'm confused and frustrated.
I figure it has to be fairly simple, but I'm tired, confused and want this video edited and done already.

Hope someone has some ideas for me,


Boy, it sure could be, I don't get corruption of the frames, but i do get the repeating slow problem.

It literally plays the first 2 seconds of the video in superslowmo every time i use the speed effect.

I wonder what version hes running?

I've got:
kdenlive: 0.9.5+git20130205.f610a587-0ubuntu0~sunab~quantal1
melt: 0.8.8+git20130205.9fd121cd-0ubuntu0~sunab~quantal1
frei0r-plugins: 1.3.0+git20130119.c3fdd674-0ubuntu0~sunab~quantal1
ffmpeg: 6:0.8.5-0ubuntu0.12.10.1

has to be a bug, i know i've used the speed effect for fast and slow motion many times, but i can't recall if i updated anything that would have broken it.

I'll run through the update history on my machine quickly

Ok, I just rolled back to 0.9.4, downgraded libmlt, melt, frei0r plugins and everything i could find kdenlive depended on (no core os stuff though)

Doesn't seem to make change anything, messing with some other stuff now, hoping i can either make it work, or break it worse (i'd go eat some lunch if i broke it worse lol)


I do have the same issue: Speed effect simply slow down the frame to nearly not movement.
I am running Kdenlive 0.9.4 with linux Mint 13 Maya.

I confirm that I used the speed effect without problem in the past few months, but do not know either what update could have broken it.

Very frustrating.


Could this be this http://www.kdenlive.org/mantis/view.php?id=2963 defect which is resolved with changes in melt ?

I don't know for sure but it sounds pretty similar.

From the link provided, I don't understand the answer from ddennedy. Could you detail?

I tried this: http://forum.ubuntu-fr.org/viewtopic.php?pid=10973991#p10973991 (full reinstallation of Kdenlive, melt and mlt libraries

but without any success. The issue remains for me.

Right. Looks like you probably installed from sunabs kdenlive-release repository which will be version 0.9.4 of kdenlive and 0.8.8-0ubuntu0 of melt (https://launchpad.net/~sunab/+archive/kdenlive-release)

As described http://kdenlive.org/download-development

you might want to try sunabs bleeding edge version which may have the speed effect fixed.

sudo add-apt-repository ppa:sunab/kdenlive-svn && sudo apt-get update && sudo apt-get install kdenlive

Which is this https://launchpad.net/~sunab/+archive/kdenlive-svn

This will give you melt 0.8.8+git20130226.928ea3c5-0ubuntu0 kdenlive 0.9.5+git20130301.1392e602

Hi ttguy,

Unfortunately, no more luck with this.
I proceeded the same way: Via Synaptics, I uninstalled Kdenlive, melt and mlt librairies (+ I removed the kdenlive sources)
then reinstalled kdenlive following your instructions.

The issue remains.

However, I noticed that if my current version of Kdenlive is 0.9.5, my version of melt is 0.8.8+git20130220.f03d0f54-0ubuntu0~sunab~precise1 (as shown in synaptics)

I do not know what it means, but it's different that what you expected.

Maybe you should also explicity install the mlt from from the ppa:sunab/kdenlive-svn

Because it does not look like you have the very latest that sunab has to offer there.

Sorry for late reply.

I somehow discovered that my Nvidia graphic card was not properly recognized and somehow managed to crash the whole system.
Now I am back with a fresh install of Linux Mint 14. And my Nvidia graphic card is now properly handled thanks to the bumblebee project.
However, still no luck: The video freezes wherever speed effect is in use... :(

ttguy, I am afraid that I do not know how to proceed with the install of mlt from ppa:sunab/kdenlive-svn.
I confirm that this kdenlive-svn shows correctly in my list of "other software" in the list of sources for update. But then what? How can I retrieve the very latest version of mlt? thanks in advance.

In synaptic package manager you can sort packages by origin (using the left hand buttons). Select LP-PPA sunab/kdenlive-svn as the origin and then synaptic will show all the packages from sunabs PPA. The upgradable packages will have a exclamaition point icon. In my screen shot the kdenlive packages are upgradable.
Right click one of the mlt packages and mark for upgrade - the rest will also get marked then.
Click the apply button.

Even with the newest packages from kdenlive-svn installed, I still see problems with the speed effect. In my project I have a clip region to which I apply the speed effect of 600%.

1. mlt calculates a different new length compared to kdenlive. For instance, if I position the cursor at the beginning of the speed clip in the time line then it will play that region at increased speed but will be finished before the region ends. In consequence, the final game will get repeated as long until play reaches the clip region end as set in the time line.

2. In contrast, positioning the cursor at the beginning or somewhere in between and the moving the cursor frame by frame using the cursor keys results in the proper result, i.e. there are no repeated filler frames at the end.

3. When rendering this region I get a similar result as with 1., so that the speed-up clip is to short and thus gets padded using the final frame. But I also get a lot of corrupted frames near the end of the region.

4. The order of effects applied to a clip with a speed effect also seem to matter. For instance, when I first place effects for, say, color correction and only then the speed effect, then the color corrections won't be applied at all, only the speed effect. It seems that the speed effect needs to be the topmost one in the effects stack in order to avoid all kind of strange things happening.

Looks like another bug different from 2963 which is "Speed effect makes kdenlive crash". But Diveo - you are not seeing crashes. Someone should raise it in mantis

I will try to create some descriptive screen shots both from kdenlive as well as the rendered result and file a bug on this issue with the mantis bug tracking system. This is a longstanding and really annoying issue as it basically makes the speed effect useless in many situations.


On my instal the video does not freeze after speed effect but the audio of any footage following becomes choppy in the rendered version. So I have issues too.

kdenlive 0.9.5+git20130301.1392e602-0ubuntu0~sunab~precise1
frei0r 1.3.0+git20130119.c3fdd674-0ubuntu0~sunab~precise1
melt 0.8.8+git20130220.f03d0f54-0ubuntu0~sunab~precise1

Double Hmmm.

I just repeated my test I got the same result.

And then I noticed another build of kdnelive in sunabs ppa. Installed that.

And now my test works. Speed effect next to regular video. Renders good. Audio good. - One off test though.

My system is now

kdenlive 0.9.5+git20130306.4af66752-0ubuntu0~sunab~precise1
frei0r 1.3.0+git20130119.c3fdd674-0ubuntu0~sunab~precise1
melt 0.8.8+git20130220.f03d0f54-0ubuntu0~sunab~precise1

There could be a workaround for people with this issue - just render the speed bit of the video by itself as a lossless output and then import that rendered version. It would probably work.