An easy way to play a video from its CID hash is to put the hash in https://ipfs.video/ and click Use IPFS Gateway to play it directly on that page, or click Open at ipfs.io to view the video in a new tab.

IPFS gateway URLs are in the form https://ipfs.io/ipfs/<CID> and can be used to view the file in a standard web browser. The ipfs.io URL can be created by appending the CID hash to https://ipfs.io/ipfs/