The following media formats can be uploaded to your embed signage account:
Images (.jpg, .png, .gif, .svg)
Video (.mp4, mpeg, .avi, .mov, .wmv, .webm, .flv)
Audio (.mp3, .wav, .oga)
Other (.html, .swf, .otf, .ttf)
Recommended File Sizes
A list of file size recommendations can be found here.