Prior to last week’s Academy Awards, the majority of Americans had never even heard of the movie “Once,” John Carney’s Irish musical that was shot for less than $150,000 and snatched up quickly at the 2007 Sundance Film Festival for an underwhelming price tag of $1 million.

But as musician-actors Glen Hansard and Markéta Irglová took to the Oscar stage last week, first to perform their nominated duet “Falling Slowly” and later to accept the award for Best Original Song, “Once” broke its way into the mainstream. “This is such a big deal, not only for us, but for all other independent musicians and artists that spend most of their time struggling,” Ms. Irglová said upon being introduced a second time by the host, Jon Stewart, after her earlier acceptance speech had been cut short. “The fact that we’re standing here tonight, it’s just to prove, no matter how far out your dreams are, it’s possible.” Possible, yes. But given current trends in the movie industry, where indie titles are finding it increasingly difficult to gain traction with mainstream audiences, the Oscar triumph of “Once” was improbable at best.

For years now, the cinematic disparity between a city like New York or Los Angeles and the remainder of the country has been obvious. Films (such as “Once”) regularly open on the coasts and never make their way inland. But what was illustrated so clearly by “Once” during its headline-inspiring six-month run in New York theaters last year — slowly attracting bigger crowds through word of mouth as its box-office haul swelled northward from $1 million to $10 million — was the uphill challenge now facing smaller titles, even in America’s largest cities.

Not too long ago, the ascent of a small gem like “Once” wasn’t such an exceptional case. In most major markets, independent films were given the needed screens and time to gain momentum by way of critical raves and word of mouth. But talk to any number of movie industry insiders — those affiliated with both distributors and theaters — and they will tell you that such success stories are becoming ever more unlikely.

“The window is definitely shrinking,” the vice president and general manager of New York’s IFC Center, John Vanco, said. “Art house films that, in the past, would play for 40 or 50 or 70 weeks, [such as] ‘La Cage Aux Folles’ and ‘El Topo,’ are, if not a thing of the past, then at least an exceedingly rare phenomenon these days. The theatrical engagement is, by necessity, more of a pit stop for most films now on their way to ancillaries than it was back when theatrical was primary and unchallenged by so many other movie-viewing options.”

Today, Mr. Vanco said, films are zipping through New York screens at faster and faster speeds. In part, the congestion is due to a growing mountain of titles — many shot digitally with shorter production schedules — all vying for big-screen debuts.

But just as problematic are the ever-changing qualification rules employed the Academy of Motion Picture Arts and Sciences. This year, for example, documentary films must screen theatrically a particular number of times in both New York City and Los Angeles by the end of July, meaning that dozens of projects are already fighting it out to secure slots at venues that are already booked through the summer. Meanwhile, most small-scale films just want a screen, any screen, on which to play.

Mr. Vanco and others also point to an intensifying battle for coverage in the city’s press outlets. Just as so many publications are cutting back on space for film criticism, an increasing glut of short-lived art-house titles can often lead to shorter reviews — or no reviews at all.

Even casual moviegoers in the city are starting to notice the shrinking half-lives. “Last fall, I was out of town when ‘Rocket Science’ opened up in town, but I heard good things about it and planned on seeing it when I got back from vacation,” Brooklyn resident John Farrell said while waiting in line at the Angelika Film Center Friday night. “But when I got back two weeks later, it was already gone. It’s like you have to catch it opening weekend or you don’t even have a chance.” It’s enough to make one wonder how many other gems such as “Once” are getting plucked from theaters before they have time to blossom.

Some observers say the problem stems from theaters becoming saturated by movies, often low-budget documentaries, that have no business showing in a theater environment. “Quite simply, there are way too many documentaries being released in theaters for anybody’s good,” said Mark Urman, the head of theatrical at THINKFilm, noting that a considerable number of New York screens on a weekly basis are being occupied by nonfiction films. “The vast majority [of these films] don’t warrant it, and what’s happening is that documentaries that would be much better served by a premiere on cable are flooding and clogging the theaters and guaranteeing that those who deserve the space are getting crowded out. It results in every title getting mediocre business.”

Mr. Urman’s frustration, though, is tempered with a sense of confidence that we are already witnessing the opening, turbulent chapter of a major “market correction.” That is, many distributors and filmmakers are beginning to realize that there is more money to be made — and attention to be found — in pursuing alternative avenues of distribution.

He pointed to this year’s Sundance Film Festival, with its limited number of distribution deals, as a direct reaction to the disastrous acquisitions that came out of the festival in January 2007. Throughout last year, Sundance’s most prominent titles suffered cruel fates in a crowded marketplace. “Grace Is Gone” was purchased for $4 million and went on to earn just $37,000 in America. The documentary “My Kid Could Paint That,” bought for $1 million, brought in $230,000 domestically. “All you have to do is look at the numbers,” Mr. Urman said. “There weren’t that many deals coming out of Sundance this year. Things have definitely slowed down, and the watershed moment will occur when more of these filmmakers realize that there is still a huge appetite for these films — and even more journalistic possibilities in terms of getting coverage — by considering new avenues of consumption. You started to see it this year out in Park City, where one of the best docs went at a very high price, but to a broadcaster, not a theatrical distributor. The more this happens, the more the tide will start to turn.”

ssnyder@nysun.com