As per docs, the default behavior for show and share is to assign a
thumbnail based on the length of the video:
Check out:
http://www.cisco.com/en/US/docs/video/digital_media_systems/5_x/5_3/showandshare/user/guide/edit-delete.html#wp1079137
TABLE: Please match the # for each section:
If your video is ...
1. less than 3 seconds long
2. Between 3 and 8 seconds long
3. 8 seconds or longer
It uses this frame for the thumbnail...
1. 0 seconds
2. 4 seconds
3. 8 seconds
If you have a video that is longer than 8 seconds, but the title shot only lasts for 5 seconds, the automatically generated thumbnail may not contain your video title. Or, if you recorded a message, the system may have captured an unflattering facial expression for the thumbnail. Use this procedure to correct the situation.
http://www.cisco.com/en/US/docs/video/digital_media_systems/5_x/5_3/showandshare/user/guide/edit-delete.html#wp1079137
The procedure to modify the thumbnail is listed in the link above. You
need to go to your uploaded videos and click "Edit Video" then follow
the instructions above to move the slider where you want the thumbnail
to be.
Please keep in mind that video editing is only possible for some video
formats:
Table 6-1 Video Format Editing Support
http://www.cisco.com/en/US/docs/video/digital_media_systems/5_x/5_3/showandshare/user/guide/edit-delete.html#wp1080725
I hope this helps!
Cheers!
T.
