How can I connect clips from the timeline in the video editor to the compositor to add some nodes-color correction, rgb curves etc., to every single clip, or to all of them at once?
If you are already working on the video editor and just want to do color correction, then you can do it with an Adjustment Layer:
- Press Shift + A and add Effect Strip > Adjustment Layer.
- Press N to bring the Properties panel, scroll to down to the Modifiers and from the Add Strip Modifier drop down menu, you can select whatever you want this strip to do: color balance, curves, etc.
It will affect the strips below, meaning it can affect several strips (several footage clips) at the same time.
You probably want to have same effects in VSE as in a compositor. You can do it through scene strips. Go to the compositor add new scene, check 'use nodes' option and connect to 'compositor' output node, then go to your VSE and add scene strip. Now you can switch back and forth between two editors and use them as you like (the only thing is that it really slow process)
More Detailed Explanation:
every time you create a new scene you create new composite (I think 'after effects' and every other compositing software has this concept),
in your composite you have your images videos etc. you change colors apply effects and so on,
when your composite is ready you go to VSE add scene (composite), you have composited, and do your video editing.
you can import multiple scenes and every scene can have multiple images and videos, if you've worked with software like Photoshop or GIMP you are probably know how layers work, so in Blender's Compositor you can have same effect by using 'Mix' node, it sort of stacks your images, videos and 3D onto another and by choosing right blend mode you can achieve desirable effects,
you have to keep in mind though that blender uses top-to-bottom stacking order instead of bottom-to-top like Photoshop, GIMP etc. Also keep in mind to activate Compositor in 'Post Processing' panel. Oh and if you have in your VSE viewer 'Open GL Preview' enabled it will render only your 3D even though you composited it.
Advice you will hear quite often is to render each composite as image sequence first and add them in vse instead of using scene strips, performance wise it would result in a huge gain.
You also can watch this video: http://www.blendernation.com/2013/06/14/tip-caching-node-compositing-using-vse/ it sums up the whole process.
You must remember that the VSE strips are unique to the VSE. You can load movie clips elsewhere (tracker, compositor) but they do not correspond with the VSE directly. The only way to import media from elsewhere in Blender (IIRC) to the VSE is via Scene strips or Masks. A VSE Movie clip strip is only a local, unique instance of another datablock elsewhere in Blender.
The VSE only uses local instances of external media.
The actual current solution is to define other scenes as wrappers for external media. That is a scene would be named for the camera clip or shot that it holds. This scene would have a Compositor set for grading the shot and its corresponding audio strip on its own VSE timeline.
In your master edit scene, you add the camera native strip and this Composited/color grade scene strip and Meta strip them together (making sure to sync both to start at their first frame). You would then cut with the metastrip (using a proxy of the footage if required) and at picture lock, switch to the graded scene strip.
This workaround(?) fails to provide correspondence between the edit and the source footage however, so multiple grades from alternate sections of the same source media could be an issue. This depends on length of source of course, as single short shots probably don't change much. While long screen captures or wild recordings can last hours (changing all the time).
And you must remember that this solution is useful for single shot effects, like Color Grade, Chromakeying, Masking, Blur effects and image alterations. But it won't reflect any VSE mixing effects, like dissolves or alpha overs between shots.
If you have clips in the Sequence editor and Sequencer is enabled, they will be used to render. In Render settings > Post Processing:
They will be effected by the composite nodes if Compositing and Composite nodes are enabled.
You can add clips into the compositor with the movie clip node (Add node > Input > Movie Clip)
From the wiki:
In addition to modelling and animation, Blender has a fully functional Video Sequence Editor as well as an advanced node-based editor that also manipulates a video stream. Compositing Nodes operate equally well on images or video streams, and can apply detailed image manipulation on the stream.