Is there a way to warp the time in the sequence editor. So basicly a clip will play at normal speed, and then play faster, slower, or even backwards based on the ipo curve? Or will I have to build a plug-in for it?
tbc++
1-I tried to do it. and could not acheive to controle speed.
2-I don’t think a plugin will let you do soo, as it work on a per-frame basis.
3-The only time control you can get in blender is on internal animation.
4-This belong to the blender general Q&A. bah anyway.
This is what i’m aware of. but maybe someone else will know a super trick to do so?
tbc++:
these kinds of questions belongs to “Blender General” which means it is related how Blender work and its features.
so therefore I moved it for you…but please next time, try to post correct 
There are several ways to do what you want but I think that the best method would be to use the time ipo when you render your animation
from the docs:
http://www.blender.org/modules/documentation/htmlI/x6288.html
old but good thread:
https://blenderartists.org/forum/viewtopic.php?t=4375&highlight=repeating+animation
if you try to just slow down an existing animation clip it will just become jerky like when you put a vcr on slowmo…
I think that there is a sequence plugin already that reverses an animation btw - never used it though so not sure how well it works
There is a plugin called Twixtor, but not free at all.It uses a smart interpolating way.
it’s better to do that in post-prod because blender render time in less.
@meltdown: twixter and the Blender-Sequenzer are 2 different Ballgames
just check this out:
http://www.revisionfx.com/rstwixtorprice.html
if you slow down an animation in blender with the time ipo, beware (if the ipo goes down, the anim plays backwards), I found it better to render in single.tga frames and then virtualdub the video. this will prevent the above mentioned slow-mo effect. actually I find it allways better to get a smooth and crisp looking video
I followed the link:
http://www.blender.org/modules/documentation/htmlI/x6288.html
and got the world/mist page
what we’r looking for is this: time-ipo
http://www.blender.org/modules/documentation/htmlI/x6653.html
If you “slow down the video,” in the sequence editor, it doesn’t take long for the animation-effect to fall apart. You need to affect the object’s motion during the animation step. The animation process will generate motion-blur and use oversampling (OSA), both of which are crucial in achieving a realistic, pleasing effect.
The “Time” IPO is used to control speed.
Complex video-filters for achieving the illusion of fast- or slow-motion do exist, but they are compromises; things you use when dealing with “live video” when you have no choice.
oops! thanks for pointing that out birras, I have absolutley no idea how that happened - I could have sworn that I was looking AT the page when I copied the url to my clipboard… oh well, I will try to be more careful next time. tbc++ mentioned that he even wanted to reverse the animation so I thought that the time ipo would be best . I don’t think that playing with the time ipo should effect the osa at all though and motion blur may be tricky depending on the effect he wants- I mean if it is slow-mo does he even want motion blur? Personally I would render a clip at normal speed, adjust the time ipo, render a slow-mo clip, reverse clip, etc. and then just tie them together with the seq editor - that way you can make any adjustments to each clip ( for motion blur for instance) to get the effect that you want. This also gives you the chance to choose the transition between each clip. Anyway, check out the right link this time (http://www.blender.org/modules/documentation/htmlI/x6653.html) and I hope it helps