Bug 364888

My wife has the habit of taking long clips, and she's a bit shaky on holding the camera. I usually cut the pieces of the clips that I can use, and add them to the project, then run the vid.stabilize over them, add the .mlt to the project, and finally am able to get a stabilized clip on the timeline. This is a lot of steps, and a lot of extra files added to the project.

It would be great if we could have vid.stabilize implemented as a filter, avoiding the creation of many smaller clips and .mlt files. 

The way I envisage this to work, is that when the effect "vid.stab" is applied to a clip on the timeline, you get the same functions in filter effects as you do on the popup menu if you stabilize a clip with clip jobs today. 
Once the focus is gone from the effect, or when an accept button is pressed, then the melt can render the .mlt file for the frame range in question, and throw it in the cache, pretty much like a proxy. Since proxies are not supported on .mlt files anyways this would make sense. A nice gui effect for the rendering process on the timeline would be awesome, but is not a requirement.
If the frame range changes, or the sliders are moved, the .mlt has to be re-rendered, but this does not have to be a blocking operation for work to continue and can happen in the background. 

If this is a workable solution, then it can also be applied to other filters that may require a two pass system. I'm thinking of ffmpegs' deshake filter here, but there may be other examples. 

Reproducible: Always