I’ve been writing a series of articles comparing the two strongest non linear video editors on the Linux platform. Cinelerra is free and Open Source; MainActor is a commercial product. So far I’ve covered generalities, installation, and first impressions. Now I’m going to move into more useful territory: editing. Part 1 of this article will cover MainActor; part 2 will deal with Cinelerra. To start with, I set the bar pretty low; I will use two short MPG clips, and run them back to back with a fade transition in between. Here are some MPGs if you need some to play along with.

MainActor

Let’s start with MainActor. To load clips, right click in the browser window, and choose “Add Media clip(s)”.

The file browser allows you to preview clips with thumbnails, and generally works pretty well. Once added, clips can be organized into folders, renamed, joined, converted to MPG, and probed for scenes (how well all of this works is subject to a later article.)

Next step is to edit the clip. To do this, drag it from the browser to the media player. When the media player has focus, you can advance forward and back using the left and right arrow keys (pressing shift in combination will fast forward or rewind). Set your cut points using [ to punch in, and ] to punch out. The portion that will be used is marked in a brighter color the player’s timeline. (The green line marks the current frame.)

Now, to add the edited clip to your movie, you click-and-hold with the mouse cursor on the media player image, and drag to the timeline. Once you drop it, the video tracks will be rendered with thumbnail previews, and the audio track with a waveform.

While this is straightforward, there are some definite quirks, mostly associated with adding additional clips. There are three editing modes in the timeline, as indicated by these icons:

Left to right they are labeled “insert”, “overwrite”, “fill”. To illustrate their behaviour, watch what happens when I drop a second clip into the second video track, with some overlap.

Insert (default):

Overwrite:

Fill:

I think it is unfortunate that Insert is the default mode, as it is the least useful and the most error-prone. Fill is by far the safest mode to work in, as it won’t destroy the layout of anything you’ve previously put together on the timeline. I can see Overwrite being potentially useful, although personally I never use it.

Now to apply the transition. First, you need to choose the transition from the browser. (This is another poor UI decision on the design team’s part: the browser has tabs for both clips and effects. Since you are working primarily with clips and effects, it would be nice if these were in their own windows so that you didn’t constantly have to click back and forth between the views when browsing. Better still would be the ability to spawn as many browser windows as you liked.)

In thumbnail mode, the effects are presented as little animations which give a preview of what the effect does. This is helpful, as the names aren’t always fully evocative (try to define “Random Dissolve” vs “Chaotic Dissolve” without actually trying them out).

To apply a transition effect, you have two choices; in the timeline you can either a) have your clips back to back in the same video track, and drag and drop the transition to the join, or b) you can have them overlapping on seperate video tracks, and drag and drop the transition to the beginning of the second clip. The latter method is far more precise; in the former, MainActor will pop up a confusing dialog asking whether you wish to “trim widen clip” or “move second clip”, which basically means do you wish to let it adjust your punch out point from the first clip, or move the second clip forward so that it overlaps by the necessary amount.

Transition, same track:

Transition, seperate tracks:

By clicking on the time-bar at the top of the timeline window, you set the position of the “current frame”, which is synchronized between the timeline, the preview window (where a snapshot is shown) and the effects window. By pressing the left and right cursor keys in any of these windows, you can step forward and back, frame by frame, and thus fine tune your transitions.

If you want to deviate from the defaults of an effect or transition, double click it in the timeline window; that’ll open up controls in the effects window, which you can adjust either for the entire duration of the effect, or over time:

The adjustment graph represents the value of that particular parameter at that point in time in your movie, over the duration of the effect on the timeline. To change the value, drag the slider left or right (you may need to right click and “add key” first, if only one key is defined.) The graph is definitely a little quirky (perhaps even buggy), but you will soon learn how to manipulate it consistently.

Finally, all that remains is to export your movie. You may have noticed the yellow bar at the top of the timeline window; this is used to control the region that background rendering works on, if background rendering is enabled; the amount that has been rendered is indicated by the green bar above the yellow. (Background rendering does decrease overall performance, and I have seen it decrease stability in a previous version of MainActor, so you may decide to switch it off at some point.) Once you click the export icon (or ctrl E), the export dialog pops up, which allows you to choose the (output) format in quite some detail (you have a choice betwen DV AVI types 1 or 2, DV DIF, or MPG of various flavors; of course you can also choose output resolution, sampling rate, encoding, etc.) My 8 second clip, consisting of two source clips and one transition, took 17 seconds to render at DVD quality.

Stability, Overall Ease of Use

Simple editing in MainActor is not without its quirks, but it is quite workable. If you only ever are going to use one or two video tracks, you can easily get away with using the software with one monitor, although 19″ or higher would be preferable. I did manage to crash MainActor once while writing this article, and that was by dragging a clip to the timeline (this seems to be to do with the audio encoding rate of the clip; the files it has most trouble with are AVIs from my digital camera with 11Khz audio tracks.)

Onwards…

Next I’m going to write about the same exercise using Cinelerra. After we’re done with simple editing, I’ll move onto more complicated projects.

All In Series

1. MainActor vs Cinelerra -- Background
2. MainActor vs Cinelerra -- Installing
3. MainActor vs Cinelerra -- UI, First Impressions
4. MainActor vs Cinelerra -- Simple Editing, Part 1
5. MainActor vs Cinelerra -- Simple Editing, Part 2

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