Some new kids on the block in home-entertainment continue to grow rapidly. Sales of Blu-Ray HD more than doubled in the first quarter, while digital downloads were up 19 percent, according to a report from the Digital Entertainment Group. Both formats are still a small piece of the overall pie—DVD sales were $2.9 billion in the quarter versus $230 million for Blu-Ray and $487 million for digital downloads. But Blu-Ray’s sales were up 400 percent last year, for a total of $750 million, and companies like Netflix (NSDQ: NFLX) and Blockbuster (NYSE: BBI) continue to make inroads against traditional DVD sales with digital delivery of home movies.

DVD sales dropped 14 percent for the quarter. Both Time Warner (NYSE: TWX) and Viacom (NYSE: VIA), which report earnings this week, own studios (Warner Brothers and Paramount) that make a large portion of their revenue from DVD sales.