Segmentation mode

In earlier versions of ELAN on-the-fly segmentation was offered in a separate window in which segments could only be created on one tier at a time. This functionality has now been moved to the Segmentation mode in the main window. The layout of the window looks much like that of the Annotation mode but the segmentation mode is designed for rapid creation of segmentations only: it does not provide the means to enter text into annotations. Annotations are not created based on a time selection (like in Annotation mode) but are created by marking begin and/or end time of segments by pressing the Enter key. This can be done both when the media player is playing and when the media player is paused.

There are two main elements specific to the segmentation window, a configuration panel in the tab pane and the timeline based segmentation area. The on the fly segmentation can be performed on root tiers (i.e. tiers with a tier type with stereotype "None") and on depending tiers of type "Included In". Only tiers of these types can be displayed in the segmentation area. There is only one tier editable at a time and it is displayed at the top, just beneath the timeline, decorated quite distinctly from the other tiers. The Up and Down Arrow keys can be used to navigate through the list of tiers and quickly change the tier that is editable. The editable tier remains in the list, with a red marker indicating its position. This makes it easy to see which tier is the previous (up) or next (down). The media player doesn't have to be paused for changing the editable tier.

In general the segmentation process consists of the following steps:

  1. Select the candidate tiers for segmentation via the right-mouse context menu in the tier name area.
  2. Configure the behavior of the keystroke in the Segmentation panel.
  3. Use the media controls to play the media file or use the keyboard shortcuts (see Playing a document & making selections).
  4. Do either of following:
    1. Press ENTER to start/end an annotation unit, while the movie or sound file is playing
    2. If the tier type of the selected tier has a controlled vocabulary and the entries of this CV have shortcut keys, press the shortcut key of the desired CV entry instead of ENTER to start/end an annotation unit. See also The creation of a CV.
  5. Annotations are created immediately and every new annotation is a separate item in the undo/redo list (in contrast to the old segmentation implementation).

Figure 3.17. Segmentation mode

Segmentation mode


Configuring the behavior of the segmentation keystroke

The following options are available for the segmentation keystroke (Enter):

  • two keystrokes per annotation; the first keystroke marks the begin, the second the end of the annotation
  • one keystroke per annotation; the end time of one annotation is the begin time of the next. This creates a chain of adjacent annotations
  • one keystroke per annotation, each annotation has a user definable, fixed duration. The keystroke marks either the begin or the end of the annotation

An additional option, the delayed mode, allows for compensating for the time lag between the observation of an event and pressing the key. The value (in milliseconds) is subtracted from the time value of the keystroke.

Editing annotations

The alignment of annotations on the editable tier can be modified by dragging with the mouse. When the mouse hovers over an annotation it is highlighted in green. Depending on the position of the mouse either the whole annotation can be dragged, the left boundary or the right boundary can be modified. When the mouse is over an annotation, pressing the Backspace key or the Delete key deletes that annotation.

Clicking on the annotation that is highlighted, or altering the boundaries, not only activates the annotation, but also creates a selection, painted in blue. This way you can play the selection quickly (see Playing a selection) and correct the annotation unit if needed. You can also create a selection yourself by clicking and dragging the mouse. See How to make a selection) for more information on creating selections.

Figure 3.18. The mouse over an annotation

The mouse over an annotation


The right mouse button context menu contains items for zooming, for changing the font size and for deleting the annotation at the position of the mouse click. Zooming can also be done with the zoom slider in the lower right corner of the segmentation view.

Figure 3.19. The context menu

The context menu


Merging annotations and splitting annotations

To merge two annotations, make a right click on the annotation and from the menu that pop-up select either Merge with annotation before or Merge with next annotation . Use can also use shortcut keys CTRL+A to merge with next annotation and CTRL+B to merge with annotation before. For detailed explanation on merging see Merging annotations.

To split an annotation, make a right click on the annotation at the point where the annotation is to be split into and select Split Annotation from the menu that pops up. For more information see Split Annotations.

Step-and-Repeat playback mode

In addition to the standard play/pause buttons and the play selection button, there is a button for starting and stopping playback in step-and-repeat mode. In this mode the player starts at the current position, plays a segment of n milliseconds m times and then moves the cursor t milliseconds forward. Then the next iteration starts. This mode has to be stopped explicitly, it is not stopped by e.g. clicking in the viewer.

Figure 3.20. Step and Repeat configuration

Step and Repeat configuration


A configure button next to the step-and-repeat button shows a little settings panel in which the user can set the duration of the interval, the number of times it should be played, the pause between successive runs and the step size (number of milliseconds) for moving the interval forward.

This playback mode is new and still experimental.

Keyboard shortcuts

The following keyboard shortcuts are available in this mode:

  • ENTER marks the begin and/or end of an annotation. The annotation is created on the active, editable tier.
  • UP select the tier that is above the current tier in the list of tiers
  • DOWN select the tier that is below the current tier in the list of tiers
  • DELETE deletes the annotation under the mouse pointer (highlighted in green)
  • BACKSPACE deletes the annotation under the mouse pointer (highlighted in green)
  • CTRL+SPACE start/stop the step-and-repeat playback mode