A media analyst has come out with a report that delivers bad news for many media companies — although it should come as good news to Disney and Cinemark.

Deadline.com reports that Nomura Securities’ Michael Nathanson fired a “warning shot” this morning “as he lowered his Q2 earnings-per-share estimates for Viacom, News Corp., Time Warner and Scripps Networks — but raised for Disney and Cinemark. (He left CBS, Discovery and Regal unchanged.)”

The generally sour tone of Nathanson’s analysis is expected to come as a disappointment to investors after what has been an upbeat first six months of 2012. “For example, Scripps shares were up nearly 30%, followed by Disney (+28%), Discovery (+26%), News Corp. (+23%) and CBS (+19%),” the story reports.

The upticks, the report notes, were mainly due to market optimism rather than improved earnings.

“Perceptions could change later this month when companies begin to file their Q2 numbers.” the story reports. “With television’s scatter ad market weakening, ‘We expect national broadcast and cable network advertising to decelerate’ from 6.5% year-over-year growth in Q1 to just 2.2% in Q2, [Nathanson] says.”

The bottom line, according to the report: “Nathanson reduced his Q2 earnings per share forecast for Scripps by 13% to 87 cents, with Time Warner -5% to 57 cents, News Corp. -3% to 31 cents, and Viacom -2% to $1. He raised Disney 3% to 93 cents and Cinemark 8% to 37 cents.”