Creative teams hand over a frame that was built to be seen whole. A player that slices it to fill a slot is not optimizing. It is changing the ad the advertiser bought.
What gets lost in the crop
The logo, the price, the end card and the disclosure are usually at the edges. Those are the parts a center-crop removes first. The impression still counts. The message does not.
Fit the slot without cutting the work
Use a player and a set of sizes that can letterbox, scale or swap to a supplied alternate. If a size does not exist, ask for it. Do not invent it with a crop.
