Video Editor and Compositor playing along

Something I don’t quite understand about Blender’s integrative design, is where does it store all the information from it’s different subprograms?

I have a video editor and I have a compositor. I’m normally used to having both in one program, and if I bring in video it doesn’t show up in the compositor.

Where are these stored? How do I specify what I want to render - the animation, the compositor or the video editor?


I am on my phone, so please forgive me if I answer a little wrong due to being unable to verify on Blender (let me know if you get Blender to compile on Android, k?)

The first thing to clear up is that the compositor works on single frames at a time, only. If you want to do basic Compositor-like stuff, you’ll have to use the layers and strips in the VSE.

Second, there is a checkbox in the Render tab, under post-processing, that has checkboxes to enable the Sequencer. If it is checked, AND the VSE has data in its timeline, then it is run instead of a Render when you [Ctrl+F12]. It will fall back to full animation render if either of those conditions are false.

So, this allows a good way to run things: 1) Render out to .png’s, 2) Add them as a strip in the VSE, 3) Set your output type to a video encoding. Now you can get a very quick video output by [Ctrl+F12], or you can in-check “Sequencer” and see your output back to .png and redo your full render with [Ctrl+F12].

One more thing: the VSE strips are only references to the images. If they change on disk (such as by getting deleted when /tmp is cleared on reboot, or if you render from another .blend), then there go your renders. This is why one of the first things I do when setting up an animation .blend is reset the output dir to something like //render .

Does this clear most of it up for you?


Yeah, how these things connect behind the scenes can be confusing. Personally I prefer to create a new Scene in my Sequence editor, to have completely separate render settings. I’m still a bit afraid of mixing multiple Scenes within a .blend in general, but this usage Just Works.

Another confusing thing in the beginning is rendering with file output nodes in the compositor. The nodes save files when doing individual f12-renders, but the “settings” render doesn’t. And the “settings” render is determined by the “composite” node.

The compositor can use movie clips or video. Select image input node then load a movie. It will change to suit. You could make a node comp scene and load its output in another scenes vse as a strip. You do have to set node frame values.

3point this has been debated a lot in the past. I remember most discussions concluding that while it might work in principle it might not actually work in practice.
Have you actually ever managed to put this into practice to do any real work with it?
Last time I tried it was so painfully slow that it wasn’t worth it. I’m wondering if things are any different now.

Just did it and works well, if you can copy frame Start end settings(see new addon) and if we could then proxy render for playback and if we get back Scene lock. All would be fine. Very close

Interesting. A couple questions for you guys:

The “input” options of the compositor node do not allow a parameter of the VSE output, and concurrently I don’t see the an option for the “add” option in VSE of the compositor ouput .

And what is this new node?

Movie clip is from tracking tool and the only way to access comp nodes in vse is from rendered sequence or by setting up another scene. You would then add that as a scene strip.

Well, in that case I can’t wait to try it out. But what’s the new copy frame start/end settings addon? Must be missing something

From what I understand, you are discussing something I am interested in in Blender, I would like to find a solution for adding color-grading (more advanced than just Color Balance in the VSE) with Movie Clips/Image Sequences as input AND having a more or less realtime playback.
I am a beginner Blender user and I tried to understand what you were suggesting by googling and wiki’ing with irregular success.
What do you mean by a “scene lock” ?
I created a scene with only Compositing ticked in the Proprieties>Render tab, added Image node, loaded .MOV file, Source: Image Sequence, added Composite Node, connected both.
Created another scence, only Sequencer selected in the Render tab, created Scene strip pointing to first scene. I don’t see the Composite Node output but the default 3d scene with the cube instead.
Same thing the other way round : VSE scene render layer as input in a second Node comp scene.
Did I miss something ?

Is it possible to automate the render of frames in the Compositor with Python scripting ?
In the VSE options, the Prefetch value is very useful. Maybe with some Python magic it could be possible to implement something of this kind in the Node system, e.g render 48 frames ahead and before. Kind of like After Effects’ RAM Preview.
About proxies, as I understand it, it should be lower resolution proxies only, and not add compression ! It would defeat the whole point of color grading…

Anyway I think this would be about tweaking and smart hacks, as explained, the node comp is not made for playing back.

OK, got it to work, thanks.

  1. Set up two (or more) scenes. Name them as to know which scenes are which. I’ll refer to them as “A” and “B”. Choose “A” as the root scene.

  2. Go to the compositor in scene “B”, choose movie clip as the node and hook it up to the composite node, with any other nodes in between. When you choose the sequence, only specify the first file of the sequence.

  3. Go to the VSE in scene “A”, the root scene, and choose “insert scene” as one of the strips. You’ll see an option to select the camera - select the default in scene “B”. That’s it!

Whatever, no worries, and no, I haven’t. I see that there are still bugs, but it seems like a good script - has it been finished?

Its pretty good but you will have to ask the dev about what is missing. Try it out and give some feedaback at the thread :wink:

Just tried the multi strip composite in r44154 and got this error.

Turns out that any strips you want to round trip to the compositor with this script need to have their names shortened. Just go to the strip properties and rename the strip. Also keep the name “scene” in the master scene name.