BEIJING — The secret's out about next week's Beijing Olympics opening ceremony. Be ready for a dramatic countdown, giant whales, an illuminated globe and performers flying through the air like Peter Pan.

A South Korean television crew filmed a rehearsal of the show earlier this week at the massive Bird's Nest national stadium, leaking the first video from a show so closely guarded that practice sessions have been protected by three rings of checkpoints. Cast and crew were required to sign confidentiality agreements.

A Beijing Olympics official said today the report by South Korean broadcaster SBS, which was then circulated online, was "disappointing." Sun Weide, spokesman for Beijing's Olympic organizing committee, would not say whether SBS would be punished, only that officials were "checking into the situation."

"But the fragments cannot demonstrate the full picture of the spectacular opening ceremony," Sun said in a statement.

There were no huge surprises from the footage shot in the darkened stadium, though it gave a glimpse of the lavishness of the 3 1/2-hour opening ceremony next Friday with an expected cast of 10,000.

China's most famous film director, Zhang Yimou ("Raise the Red Lantern," "House of Flying Daggers"), spent the last three years designing the spectacle, trying to boil 5,000 years of Chinese history into a 50-minute show.

Undulating white columns apparently simulated a waterfall, and giant blue whales were projected onto the strips of roof bordering the opening of the top of the stadium. The video showed a giant blue-and-green illuminated globe on the floor of the stadium at one point.

The rehearsal included contemporary dancers dressed in black and others twirling ribbons, dozens of drummers, martial arts experts, and several colorfully dressed performers suspended by wires and floating above the audience.

One segment featured a half-dozen actors on a raised platform surrounded by hundreds of other performers, while cymbals clanged noisily in the tradition of Beijing opera.

The most impressive part of the show was a countdown accompanied by drums, the SBS report said. Footage showed rows of hundreds of people, flashing cards to form the number two, then one, while chanting lustily in Chinese. Strobe lights flashed.

An SBS crew filmed the rehearsal without having to sneak in, a network official said. SBS, one of South Korea's major TV networks, shares Olympic broadcasting rights in Korea with two other networks.

"Nobody stopped us when we entered the main stadium on Monday. Chinese officials let us in after we showed our ID cards and we shot the rehearsal," the official from SBS told The Associated Press from Beijing by telephone. He asked not to be identified as he was not authorized to speak to media.

SBS spokesman Park Jae-man said it was regrettable if Beijing Olympics organizers felt offended by the broadcast.

"The purpose of the broadcast was aimed at heightening enthusiasm toward the Beijing Olympics by showing South Korean viewers the magnificence of the opening ceremony, there was no other intention," Park said, adding that his company didn't secretly tape it.

Unconfirmed media reports have said that anyone who violates the opening ceremony confidentiality agreement was subject to jail time. However, Zhang laughed off questions about such a punishment during a news conference earlier this year, saying "Who is going to deliver such a judgment?"

The video of the rehearsal was circulating on Chinese message boards up until this morning, but no working versions could easily be found in China by early afternoon.

A few details about the ceremony had been trickling out since rehearsals began at the Bird's Nest earlier this month.

Organizers have not been able to hide the enormous bursts of fireworks exploding around the stadium at night. The show will include dozens of smiley face bursts and is expected to feature fireworks in the shape of a yellow dragon with red peony flowers in the background.

The main artistic director of the fireworks show has said fireworks will be launched from more than 1,800 sites around the city, including major urban areas from Tiananmen Square to the Bird's Nest stadium.

Like many aspects of the Beijing Games, the opening ceremony has become a political issue. Steven Spielberg sparked controversy in February when he withdrew as an artistic adviser to protest what he saw as China's refusal to do more to help end the humanitarian crisis in Sudan's Darfur region.

While President Bush has said he would attend the opening ceremony, German Chancellor Angela Merkel and Canadian Prime Minister Stephen Harper have said they plan to stay away. French President Nicolas Sarkozy is scheduled to attend, after first threatening to skip it.

One part of the opening ceremony still remains top secret. It is not known how the Olympic cauldron will be lit, and who will be the final torchbearer.

Chinese media reports have speculated that the cauldron will be lit by a fire-breathing dragon or phoenix.