"Swann in Love" is a quietly brilliant film. For this we can thank the directing of Volker Schlo ndorff, the writing of Peter Brook, the inspired acting of Jeremy Irons -- and Ornella Muti in the role of her life. And, oh yes, Marcel Proust.

First, to clear the air about Proust, from whose 3,000-page "Remembrance of Things Past" the Swann episode is a mere 200-page snippet: The book, among the finest novels ever written, is happily and utterly immune to translation into film or any other medium, as Proust himself surely would have agreed. So let's leave the old boy in his cork-lined bedroom. We are talking about a movie, not an illustrated book.

The story is simple: Swann, a Parisian dandy, is overwhelmed with jealous love for the courtesan Odette, and we follow him in his anguished pursuit of her around the fringes of 1885 Paris society for 24 hours, torturing himself and her with his suspicions, spying on her, sending his friend the ineffable Baron de Charlus to quiz her, hobnobbing with her parvenu friends, being humiliated -- even though all along he understands perfectly well that the woman "wasn't even my type!"

In a remarkable bit of film conjuring that elegantly depicts the nature of his madness, Swann rushes about Odette's house at 2 in the morning wildly searching for a rival lover. Suddenly we see a man in evening dress bolt through the lobby and out the door. An instant later we realize it is not an interloper. It is Swann himself . . .

Schlo ndorff has brought 19th-century haut Paris to life with his lingering shots of hothouse flowers, gleaming silver, beautifully polished furniture glinting in candlelight, his brocades and whispering silks, his cluttered rooms lit only by softly crackling fires in ornate fireplaces, his carriage clocks that chime politely one after the other as background to some muted conversation.

It is a stifled world, close, as unhealthy as Swann's passion, a world of murmurs and servants, of clothes that must be taken off and put on endlessly, layers and layers of them, a world in which a lonely man tells his troubles to his coachman, who cannot reply, a night world of yellow streetlights reflected in rain puddles on the cobbles. You can smell the air in these scenes, and inhale with relief the freshness of the wet street after idling for hours in the overstuffed chambers of the rich.

Jeremy Irons fits so neatly into the character of Swann that you can imagine him smelling those perfumed drawing rooms, too. His sad eyes and somewhat passive face, almost too sensitive for his own good, invite us into his haunted mind, there to speculate, as Proust did, on what he can be thinking. Irons also gets Swann's sense of humor just right, in those occasional flashes of merciless clarity when he sees his ridiculous self exposed in full flight.

Alain Delon comes close with his Baron de Charlus but misses the brittleness and waspish intelligence of that fantastic painted creature, who has been described too thoroughly to be grafted onto a famous movie actor's familiar face. Marie-Christine Barrault is hysterical as the upstart vulgarian Mme. Verdurin, Fanny Ardant makes a dashing if slightly too red-blooded Duchesse de Guermantes, and many minor characters seem specially constructed for their roles. Roland de Chaudenay's Forcheville, in particular, is a masterpiece: Goofy, chinless and fatally dapper in his scarlet hunting jacket, he reveals himself instantly to the world as the jumped-up clerk he is.

But the real heroine of "Swann in Love" is Ornella Muti, who has never before been called upon to do much but display her sumptuous beauty.

It is Muti who holds the picture together. It is her sexual force, her sweet, sensual honesty -- for the morality of the senses has its own commandments -- that energizes this entire dim world of insipid Victorians. Proust didn't seem to like the character of Odette much, but Muti rescues her and turns her into the very focal point of the picture.

She is not at all the sort of person one usually thinks of for Odette de Cre'cy. Irons has said he always imagined a slim Parisian with a cold, chic quality, yet here is Muti, lush as August in a city of eternal January, laughing at Swann's somewhat mean-spirited attempt to control her, own her, pin her into his butterfly display case, and in effect dismissing the entire aristocratic society that will not receive her into its drawing rooms.

Her first appearance (not counting the preview of her breasts in one of Swann's musings) is curious because it is so quiet. We have been led to expect a grand entrance, but she turns up in a scene like an incidental character, just as she entered Swann's life.

At the end, magnified and triumphant as some great musical theme, she fills the screen, and it is her figure, striding off into the distance to freeze in a faded snapshot, that closes the film.

(Proust's hair would have stood on end. But then, it isn't his picture.)

Film must always be simpler than prose, if only because there isn't time to get across the myriad impressions of any given moment in actual life, while a writer can at least try. Schlo ndorff's solution to Proust's magnificent complexities is to reduce them to a simplicity that has little to do with the original but makes sense on its own terms.

At times the dialogue seems too busy with exposition as it fills in various details from the book, and certain events destined to be examined and reexamined in future chapters, to be studied from a dozen different angles, are presented here with the literalness of a photograph, bald of any context. Yet they are given a new significance in the screenplay. And they work.

For example, at one drawing room concert Swann suddenly stops, listens intently to the music, seems to be profoundly moved. Proustians know he is hearing the "little phrase" in the music of Vinteuil (read Debussy, Franck, Saint-Sae ns), a brief passage from which the author took off on an acute discussion of how music moves us, and exactly why it moved Swann. The film doesn't attempt to explain what is going on.

But wait. Be patient. (You knew this movie was going to be slow.) A few minutes later we hear the same music when Odette appears, and we understand that Swann associates her with it.

More than once the director thus appropriates Proust's images for his own quite different use. He also adopts the author's rigorous clarity of expression, editing so cleanly that he can move back and forth in time without ever losing us.

He may, however, have tried to bite off too much in the epilogue, which seems to be hoping to encapsulate or at least suggest all the rest of Proust's long story. Probably it was necessary to show what became of Swann and Odette, but the sudden rush of information, coming after this leisurely examination of a single evening, is rather indigestible.

"Swann in Love" is not exciting. It is a film to sink into, perhaps to learn from, as it quietly explores the labyrinth of the human heart. If you have never read a word of Proust, see it in all confidence. It stands by itself -- all you have to do is pay attention. If you know Proust and love him, see it twice: the first time to reassure yourself that it can never be filmed, the second time to savor a deliciously good movie.