Almost unnoticed by the public, Janne Liljeblad has been putting some time into making a very interesting editing program for videos. With the Flowblade tool, amateurs can quickly bring a vacation video into form, while professionals can create broad effects and animation based on the available functions.

Despite its slim size, the program provides more useful tools than many of its competitors. With Flowblade, you can arrange the clips on multiple tracks, create effects flexibly over so-called keyframes, and process numerous video formats. Even with this multitude of features, Flowblade provides a clear and uncluttered interface that simplifies getting on board. Somewhat more complicated, however, is the current installation of the Python software (see the "Installation" box).

On the Surface

After startup, a large main window will appear (Figure 1). In the upper left corner are a few tabs that provide numerous effects for video completion. To the right is a black preview screen at startup. The bottom of the window has the timeline for assembling the finished video.

Figure 1: The main Flowblade window is well organized, but it requires a lot of screen real estate; making it smaller won't work.

Flowblade stores the current state of the work and its settings in a project file. To create an initial blank project, click File | New . Under Project Profile choose the video format. If you have a DV camera, choose DV/DVD PAL . If the camera records in AVCHD format, choosing HD is a good start, but your camera manual should tell you exactly which format to use.

To assemble videos from different sources, use the drop-down list to choose the format in which you want to assemble them eventually. Creation of a DVD would most likely use DV/DVD PAL . Here, Flowblade adjusts the preview pane to the selected format, but not much else happens.

The program creates a small preview icon for each uploaded video file. In the presettings, you determine which intermediary directory the clips should go into. Use Edit | Preferences to make the presettings. Click next to Thumbnail folder on Select folder and choose a suitable location on your hard drive. Flowblade doesn't identify the selected directory in the presettings, so you should keep track of it. Close the window by clicking OK .

Battling the Material

Next, load all the clips you want to assemble for your video project. Ensure that the Media tab is activated in the upper left, then click Add above the pane to the right and select one of the clips in question. The clip will appear in the list on the Media tab with the preview icon and its runtime in seconds (Figure 2).

Figure 2: The Media tab collects all the project video clips. The zingst5.avi clip is just 23 seconds long.

Gradually drag all the other videos over using Add . Depending on the video file, this step may require some patience. Flowblade likes to pause unresponsively from time to time especially with HD videos, but the wait is definitely worth it.

Once all the clips are loaded, you can drag them one at a time into the timeline at the bottom and organize them there. Often only a small part of each clip needs work; this is especially true for vacation videos where the camera is simply left to run. To crop a video in advance, double-click it on the Media tab to open it in the preview pane on the right.

Use the buttons under the preview pane to navigate to the new starting point for the clip. The double arrows advance the clip at a faster rate; the arrows with the vertical line move one frame at a time. Alternatively, you can drag the orange vertical line under the preview pane to the left or right. This "scrubbing" method is effective in navigating smoothly through the video.

HD videos can run pretty slowly through the preview pane under some circumstances – sometimes taking a few seconds per frame. A little patience (or a faster computer) is helpful here.

As soon as you find the new clip starting point, click the play button. Move to the end of the new clip and click the left square bracket. The brackets also appear as guides in the white bar below the preview pane (Figure 3).

Figure 3: Flowblade shows the clips demarcated by bracket symbols. The clip times appear just above the preview pane.

Flowblade now takes only the parts of the clips between the bracket symbols. To correct any mistakes, you can simply redo the bracket settings or remove the brackets by clicking the button with the two angular brackets.

Track Elements

Once the appropriate selections are set, you can click the button to the far right of the window just above the timeline. (The mouse-over identifies it as Append Monitor Clip Range .) The clip then shows up as a bar on the timeline. The timeline in turn has many tracks on which to arrange your clips. The tracks are consecutively numbered, with V tracks denoting complete videos and A tracks denoting audio material intended primarily for commentaries and background music. The preview track automatically goes to V1 (Figure 4).

Figure 4: Here the 00003.MTS video is positioned on the timeline. The vertical line corresponds to the frame in the preview pane. The left and right arrows in the upper right are undo and redo functions.

Each video clip appears on the timeline as a purple bar. The bar's length represents the clip's duration in the video, with the runtime showing at the top. Use the magnifying glass buttons above the timeline to enlarge or shrink the display, or use the mouse wheel instead.

Refresh the timeline through the buttons under the preview pane. Be sure that the Timeline button is active; with the Clip button active, you'll see only the selected videos in the Media pane. As soon as you refresh the clips, the vertical line in the timeline moves to the exact position of the preview frame. As in the orange bar of the preview pane, you can scrub through the entire video by dragging the vertical bar.

You can use the same method to add more clips to the timeline. Each clip goes to the end of track V1 by default. To change the order of the clips, simply drag a clip to another position in the track. A yellow arrow shows where the clip reattaches when you release your mouse button (Figure 5).

Figure 5: Flowblade adds clip zingst5.avi between 00003.MTS and 00004.MTS at the yellow arrow.

Unlike other video editing programs, Flowblade ensures that no gaps occur between clips on the timeline. To move a complete video into the timeline, simply drag and drop it from the Media pane. The yellow arrow indicates its position again. Be sure that the video lands in the V1 track – the other tracks play another role further on.

Cutting Board

A video clip in the timeline provides several opportunities to cut or shorten it. To cut a clip at a certain point, move the vertical line to the corresponding location and click the razor blade button, or you can press X.

To remove a clip from the timeline completely, click it and activate the button just to the left of the razor blade (Splice Out Clip ) or press the Delete key. All subsequent clips will automatically slide back to fill the gap.

To cut the beginning or end of a clip, Flowblade provides a special but not especially easy tool to use (Figure 6). To begin, move the vertical timeline marker on the clip you want to cut. To cut off the beginning, position the line near the beginning; to cut off the end, position the line as close as you can to the end of the clip. Then, click the third button from the left above the timeline, marked One Roll Trim when you roll over it. If you select the wrong clip, avoid using the Undo function; instead, click the second button from the left marked Insert Move .

Figure 6: Use a special tool to cut the beginning of a clip.

Once you've selected the correct clip, an icon of two opposing triangles appears in one corner of the clip. Click the icon and drag it to the desired spot after the beginning or before the ending. If that's not accurate enough, use the two sharp brackets under the preview pane. With the clip at the correct length, you can click the Insert Move button above the timeline.

Roll Trims

Flowblade even provides an interface for repositioning two clips. The length and position of the both clips are preserved in the timeline. This is known as a two roll trim. The effect is best observed in practice with the trim function. Do this by lining up three clips and cutting the middle of the middle clip in half on the vertical line with X.

Next, position the vertical line on or at least as near as possible to the interface and click the fourth button to the left above the timeline (Two Roll Trim ). Flowblade marks the two clips and adds the two triangles icons on each side of the interface. Now, drag the interface to the middle of the clip on the right. As soon as you release the mouse, the first clip lengthens and the second one gets shorter. The total duration has not changed.

Effects

To assign an effect to a single clip, select it with a right mouse click and look for a desired effect under Add Filter . For example, to convert a video to a black and white creation, choose Add Filter | Color  | Grayscale .

You can add many other effects, which Flowblade refers to as "filters." A clip under an effect is signified by a small icon in the upper right of its timeline bar. To set the filter properties, click the Filters tab next to Media (Figure 7).

Figure 7: The Grayscale and Cartoon filters apply to the 00003.MTS clip. To the right are the two settings for the Cartoon filter.

To ensure that you've applied the filters to the correct clip, double-click the clip in the timeline to view the applied filters in a list below. To the right of each filter name is an on/off icon with which you can deactivate or reactivate the filter.

Once you mark a filter in the list, the settings, if any, for it appear in a pane to the right. To remove a filter completely, select it and click Delete . The selection of filters depends on whether you've installed the "Frei0r" effect collection.

Blending

Blending between two clips in Flowblade is done via compositors and can be a bit awkward; however, the technique provides quite a bit of flexibility. With some practice, you can even create picture-in-picture effects.

To blend one clip effectively into another, both clips must be repositioned as shown in Figure 8, on two separate tracks. Where the tracks overlap is where the blending happens.

Figure 8: Although it looks like the Dissolve applies to the entire upper clip, after some fine tuning it limits itself to the overlapping parts of the clips only.

To move the second clip, simply drag and drop it to the track just above it. Unfortunately, in its keenness to allow no gaps, Flowblade positions the second clip at the leftmost position on the track. To prevent this, click the first button on the left (Overwrite Move ) above the timeline. In this mode, Flowblade now tolerates gaps, and you can easily slide the clip along the track as in Figure 8 in a slight offset to the track below it. If you play the arrangement in the preview pane, you'll see how the upper clip covers the lower one in the overlapping area.

The current Overwrite Move mode enables not only gaps but also lets you position clips exactly as you want on the timeline, without regard for any other clip.

If you insert the first few minutes of a family celebration on track V1 right on top of a beaming member of the family, then that family member is history. You should therefore always revert to the usual (Insert Move ) mode by clicking the second button from the left.

To complete the blending, you can right-click the clip in the upper track. From the menu, choose Add Compositor  | Dissolve to activate a compositor that makes the video transparent. Flowblade adds the transparent black Dissolve bar shown in Figure 8 to mark it.

The settings for the blending are on the Compositors tab, which should have opened automatically (Figure 9). Select the track you want to blend into as the Destination Track , which is V1 in this case. A destination track must be lower in number than the source track.

Figure 9: Settings for the compositor Dissolve allow for control of the blending effect.

Key Points

Next, you can move the vertical timeline to the place where you want the blending to occur – that is, at the end of the bottom clip. Note the grey bar that represents the timeline and the red line indicating the position of the timeline marker. Once you've found the proper location, drag the Opacity ) slider to 0 . Click the plus sign to activate the change, and that's it.

When you look at the video in the preview pane, the program should fade smoothly from one clip to the next. In Ubuntu 12.10, however, the application refused to apply the effect and it was missing in the final video. The reason could not be determined at press time.

Take another look at the compositor settings on the grey bar. You can see two diamond-shaped markers. Each of these so-called keyframes marks where the settings for the dissolve function change. You can jump from marker to marker via the two buttons to the right of the plus and minus buttons. The minus button serves to remove the keyframe just under the red line. Use the same method to apply other compositors. Create wipes by using Add Compositor | Region . The Wipe Type settings include a variety of effects.

A problem occurs when you move the upper clip on its track: The compositor doesn't move with it. To remedy this, right-click the compositor and choose Sync with Origin Clip . You can get rid of an unnecessary compositor with the Delete button.

To output the final video to a file, go to the Render tab and set the folder in which you want Flowblade to save the file and set the name. Unmark the check box next to Use Project Profile and select the resolution you want the completed video to have.

To create a DVD, choose DV/DVD PAL and an Encoding Format , which should be MPEG2/.mpg . Once you click Render , Flowblade creates the video. Depending on its length and your computer's processing power, this process can take up to a few hours.

Conclusion

Although Flowblade's cutting functions are easy to learn, applying effects requires a bit more practice and experimentation. In return, the software pays you back with the compositor and its complex collages.

If you want to delve deeper into the software, check out the wiki, which provides a comprehensive, albeit rather terse, set of instructions [2]. Additionally, Vimeo shows three video tutorials on how to create a simple project, make cuts, and make best use of the compositor. The links to the tutorials are on the project homepage.

Developer Janne Liljeblad plans to add more professional features in upcoming versions. Among these features are rotoscoping [3], a VU meter [4] for sound recordings, and the ability to save in the EDL exchange format.