To find the dimensions of an uploaded video, go to the Video panel on the Review screen in DPG.
Native Video - Adding a custom thumbnail
Overview
You can add a custom thumbnail to your video file by attaching an image to it in the DPG Admin. Most people choose to use a still from their video, but you can use any image that you like.
Prepare your thumbnail
The thumbnail should be the same dimensions as the video.
Add thumbnail to video file
Upload the video file using the Uploader. On the review screen, open the Replace panel. Select the image file you want to use as the thumbnail and click the Replace button.
The custom thumbnail will now display in the DPG Admin.
It will also appear on any websites where the video features.