The great public demand for a five-hour video biography of Gen. Douglas MacArthur has been answered at last! Imagine the dinner-party plans that this one will cancel! "American Caesar" begins its long march to the sea Sunday night at 7 on Channel 5. The concluding two hours air Monday at 8.

Already the subject of a passable Hollywood movie biography, as well as the William Manchester book from which the documentary was adapted, "Caesar" bounces between contrasting views of this illustrious and irascible military figure -- he is damned, then praised, then damned with faint praise -- with documentary techniques that are strictly standard. It's an anti-innovative approach, devised by executive producer Michael Maclear perhaps to be straightforward, but in truth pretty dull.

The least inspired gimmick is having director John Huston recite the words of MacArthur. He often does this on camera, staring into the audience's face. To be charitable, he's not much to look at. In the classic TV documentary series "The Valiant Years," Richard Burton spoke the words of Churchill but as accompaniment to newsreel footage. He was never seen. Perhaps the producers of "Caesar" came up short on the historical footage, and so they give us more of John Huston than even Mrs. Huston would care to see.

Those who can't get enough of generic World War II boom-boom shots or who like to pig out on the politicking of the past may nevertheless find themselves embroiled again in MacArthur's wars with Washington. Though a national hero of epic proportions, MacArthur saw his political dreams burst at the 1952 Republican convention when he was eclipsed by the infinitely more personable Eisenhower and when, great orator though he was, he gave what narrator John Colicos calls "the worst speech of his career -- banal, wretchedly delivered."

And so he . . . just . . . fades . . . away, called "the greatest general this country has produced" by one of the interviewed experts and "the greatest actor of all time" by another.

"American Caesar" is distributed by Turner Broadcast Services, part of Ted Turner's broadcasting empire. Though billed as an "action biography," whatever that is, it might be seen as an example of the kind of innocuous news documentary Turner would initiate were he by some foul stroke of national bad luck actually to take over CBS, as he (and so many others!) keeps threatening to do. Good heavens, just think, there are ways in which television could actually get much, much worse.