A U.S. Department of Justice spokeswoman would not comment Friday on reports that the agency is investigating patent management firm MPEG LA for allegedly trying to suppress an open-source video compression format supported by Google.The Wall Street Journal said Thursday that the DOJ has launched an antitrust investigation of MPEG LA over a long-standing dispute with Google and its rival VP8 video codec. MPEG LA officials have claimed that the VP8 video codec uses patents managed the company. MPEG LA, which manages patents related to the high-definition video encoding standard H.264, announced in February it was looking for patents "essential" to the VP8 video codec. MPEG LA members include Apple and Microsoft.Google acquired VP8 as part of its purchase of On2 Technology in 2009. Google then released VP8 as an open-source standard last May.Early this year, Google announced it was dropping support for H.264 in its Chrome Browser.Representatives of Google and MPEG 4 weren't immediately available for comment.Grant Gross covers technology and telecom policy in the U.S. government for The IDG News Service. Follow Grant on Twitter at GrantGross. Grant's e-mail address is email@example.com.