This article is an overview of how to use Blender's powerful Video Sequence Editor (VSE).
The Video Sequence Editor (VSE) in Blender is unique among 3-D modeling and animation programs. Currently, no other 3-D animation program allows 3-D content to be created and edited within the same application. With the VSE you can easily edit video, import image sequences to create animatics (timed storyboard sequences), or slideshows, and create special effects. The VSE makes Blender a one-stop powerhouse for creating 2-D and 3-D video, all within the same program.
Now let's take a closer look at Blender's VSE.
01) Start Blender and choose the "04-Sequence" layout from the menu near the top of the screen.
02) There are 5 window panes in the "Sequence" layout, but you will usually only need to work with the timeline panel, which has "0 2 4 6" printed vertically on the left side of the panel, and "0 0.1 1.0 1.1 2.0 ..." near the bottom of the panel. The Video Sequence Editor layout panel is similar to most video editing programs where multiple tracks of video can be arranged spatially on the Y-axis, and time extends from left to right on the X-axis.
The image above shows the VSE window with three video tracks. The playhead is represented by the green line on the left side of the window.
By default there is nothing to edit, so you will need to load in a video clip, or an image sequence. The "Add" menu is used to add video assets to the VSE panel. Let's assume you have a directory full of images that you will use as the basis for a video.
03) After you click the "Add" button you will see a file selector window for choosing a path to video or image files. The double-ended triangle button on the left of the window (shown below) is useful for viewing directories you recently went to from Blender. Don't forget to check what file paths appear in this menu, as it can be a huge time-saver. If it doesn't have any useful paths in it now it will after you use it, so remember that it's there.
04) Blender projects are rarely comprised of just a single file, especially where video is concerned, so plan ahead and make a unique directory for each project you work on. It's much easier to keep it all straight if you have a centralized place for the files you use for each project.
When you open an image sequence directory you will likely have dozens, or even thousands of files. To import all of the image files in a particular directory to the VSE, hit the "A" key, then click the "Select Images" button.
The image above shows an image directory with no images selected.
05) After hitting the "A" key you will see all of the images in the folder selected (highlighted in blue), above. The "A" key is a toggle for "all or nothing", so another tap of the "A" key will deselect all of the files in the listing.
To select or deselect images from the file list you may Right-Click a file name. This is handy if you want to exclude some files from the selection. Alternatively, you may Right-Mouse-Button drag around the names of any files you wish to include in the import.
06) When you have selected the files you want to import, click the "Select Images" button.
07) The image below shows a single video track in the timeline, and a preview of the current frame on the upper right.
08) Below is the menu that appear when you click the "Strip" button. You can see almost all of the key shortcuts you may need to know right here. You will find that it is worth memorizing some of these shortcuts because they are so much faster and more efficient than mousing about.
09) The video strip (track) in channel 1 below has been cut. First, the playhead (the green vertical line) was scrubbed (moved) to a desired place in time by dragging it, then the "K" key was hit where the cut was needed. Remember, "K" is for cut. All edits in the VSE are non-destructive, meaning that you are not actually cutting (alterning) the source file, you are merely changing references to points of time within the original file.
10) Here are some operations to try, to practice manipulating video tracks.
To move a video track to a different channel or position in time:
1. Right-Click a video track to select it.
2. Hit the G key to Grab (move) it. The track is now rubber-banded to the mouse pointer.
3. Move the track to a desired position, then Left-Click to place the track.
This selection process is used a lot in Blender: Right-Click to select an object; choose a command; Left-Click to apply the change.
To select more than one track:
1. Hold down the Shift key.
2. Right-Click one or more video tracks.
Note that when the Shift key is held down and you Right-Click a video track that is already selected, it will be deselected. The Shift key, in conjunction with a Right-Click is like a toggle, and is handy for quickly adding to or removing tracks from a selection.
To duplicate a track:
1. Right-Click a track.
2. Hit Shift + D.
3. Move the mouse to reposition the newly duplicated track.
To delete a track:
1. Right-Click a track.
2. Hit the Delete key, or the X key.
3. Hit Enter, or Left-Click the "Erase Selected" dialog.
To extend or shorten a track:
1. Right-Click a track on the far left or right side, on top of the left or right pointing triangles, so the corresponding triangle is highlighted in "white".
2. Hit the G (Grab) key, or the E (Extend) key.
3. Move the mouse to a new position in the timeline.
4. Left-Click to apply the change.
Note that when you shorten or extend a track you are not cutting the track, rather you are framing it in time to show more or less of the track's original duration. Extending a track past its normal duration causes the first or last frame of the video to show for a longer period, depending on whether the track is extended from the left (beginning), or right (end).
To select all or none of the video tracks:
Hit the A key.
To move the playhead in time:
Left-Click and drag the green vertical line within the timeline left or right.
Hit the Left or Right Arrow Keys to move the playhead backward or forward in time one frame at a time.
Note that hitting the Up or Down arrow keys moves the playhead forward or backeard 10 frames at a time.
To view the entire extent of a video, no matter how long or short it is, within the VSE window:
Hit the Home key.
Note that you can also quickly view any selected video track(s) within the entire extent of the VSE window by first Right-Clicking one or more video tracks, then hitting the . (period) key on the number pad.
11) Below is a VSE workspace layout with two video tracks. Track 0 is on the very bottom and is "special", so nothing can be placed in it (get used to that, it's a Blender thing). However, channels 1 and above are available. A color track below (gray) can be seen in channel 1, and an image track (purple) can seen in layer 2 above it.
Since the color track is spatially below the image track in channel 1, the image track will draw on top of it by default. This is true for all channels; higher numberd channels always dominate lower numbered channels, unless you add an effect, or tell Blender to draw the alpha layer of a particular video track through an effects channel. Below, are all of the standard effects available in Blender. Other effects are available through plugins, but most of the time the built-in effects take care of the job.
Most of the built-in video effects in Blender change the way pixels are displayed between video layers. The Multiply effect, for example, multiplies two colors for each overlapping pixel within the frame of two selected video tracks. Depending on the colors of the selected pixels, the effect may soften the hues of the colors within that frame, or eliminate them entirely if one of the selected videos is all or mostly black.
Each of the effects acts on the chosen video frames differently, but the easiest way to see how each effect works is by selecting a couple of video tracks and trying out the effect.
A very useful feature of the VSE is that it quickly lets you change an effect, or the source image(s) or video by hitting the C key. Select a video track, then hit the C key to see how it works. If you first select (Right-Click) a video track before hitting the C key you will have the option to change the source images or video. If you first select an effects track before hitting the C key you will be given a choice to change the effect.
12) You may add an effect to your project by clicking the Add button, shown below.
Alternatively, you may hit the Spacebar while the mouse pointer is within the main timeline workspace window of the VSE.
13) If you have an image that includes an alpha channel, you can use the alpha channel in conjunction with another track to key part of an image on top of another.
14) Insert a color generator track by clicking the "Add" button (refer to the image below).
15) Next we'll change the color generated by the track. With a color video track channel selected, click the "Scene" button (F10 is the shortcut for it), then the "Sequencer Buttons" button (it looks like a tiny cel of film), as shown below.
You can then click the colored rectangle in the "Effect" panel and choose the color you want the color generator to use. To select a color, move the pointer to the hue and saturation value you want, then hit the Enter key to choose it.
16) Below is an example of a gray background that is blended with a title. The title track includes an alpha channel, so by using an Alpha Over effect the text appears on top of the gray background. Of course the color generator track can be changed to any color you like, as shown in the steps above.
17) The image below shows the setup for a simple alpha effect. Note that the order of the video tracks is important if you want the effect to show up correctly. If the effect doesn't work:
1. Select the effects track.
2. Hit the C key.
3. Choose "Switch A <-> B", or "Switch B <-> A" to swap the layering order of the effect.
This is extremely useful, fast, and easy to do.
18) Here's what a title might look like alpha keyed on top of a black color generated track.
19) Below is the layout used to produce the above effect.
20) The image below shows how you can create a Fade-In visual effect. The Cross effect, combined with a black color generator image track (channel 1), and an image on channel 2 makes the image appear to fade-in over time.
The video sequence editor in Blender is amazingly versatile and useful for all kinds of production work. It is so fast, and so easy to set up that you may find yourself using it for particular projects, rather than higher-end dedicated video editors such as Adobe Premiere Pro and Apple's Final Cut Pro.
For more information about the VSE, refer to the official documentation on the Blender web site here: http://wiki.blender.org/index.php/Doc:Manual/Sequencer/Usage.