You can not apply mosaic to a video.
If there is something you want to hide in the video, we suggest you the following:
- If the video part is irrelevant to the content you want to convey, cut it out and use only the necessary part
- If content can be conveyed by image files, extract images from the video and then apply mosaic to them
- Add mosaic to a video using other editing software before uploading it to Teachme Biz