Congested Male Guinea Pig making crackling sound

Sounds like the beginning of a possible URI. Unfortunately many (maybe most) pet store guinea pigs come with illnesses and/or parasites. I'd take him to a good exotic vet tomorrow. Guinea pigs go downhill very quickly when they are ill, and it's much better to treat a URI in the early stages. This is particularly true for young pigs, because they can't take the antibiotic that's most effective against URIs as it stunts their growth pretty badly.

If that's your cage in the picture, it's not large enough for one pig, much less two. Males need a LOT of room to be able to live together peaceably. Click on the Main tab at the top of this page for recommended cage sizes.

The other thing to do is to make sure both pigs are males. Pet stores are also notorious for missexing pigs. You can check against the pictures at www.cavyspirit.com/sexing.htm, or just turn them both over and compare the pertinent parts.

I don't see a cage or another pig in the video.

He does sound like he's sick, though. I'd get him to the vet asap. He probably needs antibiotics.

Once he's recovered I'd adopt him a companion. Don't buy--check for rescues and shelters near you.