Fixed duration annotations varying in time

ELAN
1

Hi,

In segmentation mode, I’m using one annotation per keystroke fixed durations. My duration is 3850ms.

On the whole, this is working well. But when exporting my annotation statistics, there are a couple of issues. I’m not sure if these are problems because of my ELAN setup or due to a software glitch.

  1. ELAN is rounding up to 3.88sec - when I’ve set the specific time in ms I don’t understand why the segments are longer. It’s important for this segment to be as close to 3850ms as possible.

  2. Occasionally, there are segments that deviate from the 3.88secs pattern and show that the segment length was 3.92secs instead. You can see these highlighted in the image below. Is there a reason for this seemingly random deviation? Is there a way I can ensure consistency? I didn’t change the segment duration so not sure why this is occuring.

elan image
elan image1512×1125 292 KB

Any advice would be appreciated!

2

Hi,

Maybe these outcomes are the result of a preference setting labeled “Create annotations aligned with video frames”. This is in the preference pane Edit->Preferences->Edit Preferences->Editing. When this setting is enabled begin and end time of new annotations are rounded to video frame boundaries and, depending on the exact time position of the keystrokes, the resulting duration of annotations can vary (one frame off).
If this setting is indeed enabled, you could disable it and try again. (Or, alternatively, set a fixed duration that is a multiple of the frame duration, although it is then still possible that a few annotations are off by one frame.)

-Han

3

Hi Han,

Thanks for the quick response! So I had a look at my settings and I did indeed have that ticked!

This worked perfectly.

Thanks!