Blur video track in Video Editor?

Question

How do I blur a video track in video editor? I want to animate a video track from sharp to blurred.

I already solved the problem in an inelegant way (by blurring the source video track in VirtualDub and then crossfading it with the sharp video track), but it would be nice to know how I can do it in Blender for future reference.

Answer 1

In 2.72, a Gaussian Blur effect was added to the VSE.

Simply keyframe the size to start at zero and increase to the amount you want.

Answer 2

You can use a Glow strip to get an acceptable blur. You can even animate the blur by key framing it.

1. Add a glow strip to the strip you want to blur.

2. Use the following settings for the glow strip. The key is enable 'Only Boost' in order to make sure the glow effect isn't added on top of the original image to make it extra bright.

Answer 3

Upgrade to 2.77, since there has been implemented a massive performance boost to the Gaussian Blur Effect Strip thanks to the Caminandes: Llamigos Project:

Speedup Gaussian Blur effect (8cde671)

(Image by Pablo Vazquez)

There's a more in-depth demonstration in Thomas Becks Developer sneak peek #26 - Video Sequence Editor (Blender 2.77) at 0:33.

Answer 4

The normal Gaussian Blur is extremally slow in Blender. Consider using the Fast Gaussian Blur instead.

There's no direct way of using the effects strip of this effect, but there's a workaround.

Generally, Blender's Video Sequence Editor is an awesome tool; however, it lacks some functionality like some effects the Compositor has.

For example, as mentioned above, there is no Fast Gaussian Blur which is a lot faster than the normal Gaussian Blur with a minor margin of error (see this page for a comparison; it's not exactly the Blender's implementation, but it's pretty close). Furthermore, as far as my preferences go, I actually prefer the look of the Fast Gaussian to the normal Gaussian Blur.

In order to get the Compositor functionality for the VSE strips, you can use an add-on called Edit Strip With Compositor.

Note: There's another add-on mentioned in this thread called VSE to Compositor, but it doesn't work for Blender 2.76b.

So, let's get to it.

First, install the add-on. If you don't know how to do this, see this post.

After installing and enabling it, you can start using the compositing functionality for the VSE. Here's a demo of it; however, he uses the other add-on mentioned above in the note, but they're not that different.

To apply the effects from the Compositor to the VSE strip, you need to follow these steps:

1. Select a video strip first (yes, unfortunately, you cannot apply the effects to the effects strips itself, but you can apply other effects on top of it).
2. Press N on your keyboard to open the Properties panel.
3. Scroll down in the Properties panel until you see the Edit strip with Compositor section.
4. Click the Set master scene button.
5. Check the Show options checkbox.
6. In the Compositing, choose the Compositing option from the drop-down list.
7. In the Editing Screen, choose the Video Editing option.
8. Optionally, you can enable the Add Viewer option.
9. Click the Create Comp from strip button on top of the section.
10. Click the Edit Composition button.
11. Now, this should look familiar. It should get you to the Blender's Compositor. Let's add the Blur effect. Open the Add menu by pressing Shift+A and select Filter → Blur from there.
12. Drag the Blur node over the connection path and once it becomes white, make a single click.
13. From the drop-down menu, select Fast Gaussian instead of Gaussian and choose your X and Y values for the blur size.

It should look something like this (except for the Backdrop which I have disabled):

14. Switch back to the Video Editor layout and voilà! You can notice that the blur effect is much more responsive now.
15. In order to animate the effects, you need to switch back to the Compositor and utilize the keyframing from there.

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