Can we upload different video thumbnails instead of using the auto-generate ones?

Due to the auto-publishing and multi-platform distribution service of Lightcast, we auto-generate a gallery of thumbnails with an intelligent algorithm (detecting graphics, logos and movements), from which you are able to choose. In order to make your upload available for publishing instantly upon successful transcoding, the system auto-selects one of the thumbnails. You can always change the auto-generated thumbnails on the "video edit" page. Go to "Video Archive" and click on the video you would like to change the thumbnail for and switch to "Images". 

In regards to uploading still images and have them resized and displayed as thumbnails and/or still image on the players: You can upload your own image (video thumbnail) on the "Images" tab as .jpg or .png player background image. This will replace the auto-generated thumbnails.