Black thumbnails for video

[merfimcfarland]

These items all have a black square as the thumbnail due to the first seconds of the video being black. If this kind of aesthetic matters, these should be fixed:

• https://keep.lib.asu.edu/items/127383
• https://keep.lib.asu.edu/items/127382
• https://keep.lib.asu.edu/items/127469
• https://keep.lib.asu.edu/items/127504
• https://keep.lib.asu.edu/items/127505
• https://keep.lib.asu.edu/items/127283
• https://keep.lib.asu.edu/items/127529
• https://keep.lib.asu.edu/items/127530
• https://keep.lib.asu.edu/items/127581
• https://keep.lib.asu.edu/items/127022/members

[seth-shaw-asu]

Ideally, we would be able to find thumbnail settings for the videos that would avoid the black first frame-based thumbnail, but that will require some additional investigation.