TWO FILMS by Robert Bresson, one of France's most rigorous and brilliant filmmakers, will be shown free Saturday at 1:30 at the National Gallery of Art's East Building auditorium. The films span a 45-year career: Les Dames du Bois de Boulogne (1945) was Bresson's second major film (cowritten by Jean Cocteau) and L'Argent was made in 1983. New York University cinema studies professor Annette Michelson will introduce them. The program, with intermission, should last about 3 1/2 hours. 737-4215.

The Sixth Annual Asian American Film Festival also begins Saturday, at the Biograph Theater at 12:30. Sponsored by the Asian American Arts & Media, the two-day affair will feature a premiere of local filmmaker Lori Tsang's 'Chinaman's' Choice and a reprise of Wayne Wang's 1981 comedy cult hit Chan Is Missing. The festival continues at 3 with shorts -- Ruby Yang's White Passage, Arthur Dong's Sewing Woman (nominated for Best Short Documentary in the 1983 Oscars), Henry Chow's Liru and Ismail Merchant's The Courtesans of Bombay. Sunday at 12:30, filmmaker Arnie Wong will introduce his animation shorts, Internal Transfer and Karma II, which will be followed by nine other shorts. At 3, producer Noel Izon will introduce George Ow Jr.'s Dollar a Day, 10 Cents a Dance, about early Filipino immigrants in the United States; as well as Briccio Santos' Damortisa, a feature about occultism. Admission is $4.50 per program ($3.50 for students and senior citizens) or $10 for the whole festival. 265-1883 or 265-5651.

The Hirshhorn Museum begins its fall series of free films this week. Friday at 8 (in the museum auditorium), it's Antonio Gaudi, a documentary on the Barcelona architect, by Hiroshi Teshigahara. Next Thursday and Friday, also at 8, Brigitte Berman's Academy Award-winning portrait, Artie Shaw: Time Is All You've Got will be screened. Coming up will be Raoul Walsh's Sadie Thompson (October 22) and Peter Greenaway's cinematic conundrum A Zed and Two Noughts (November 19). There is also a children's film series, Saturdays at 11, starting October 3 with A Boy Named Charlie Brown. 357-2700.

At the American Film Institute, the ongoing Yugoslavian festival will show Variola Vera (Friday, 6:30); Christophoros (Sunday, 6); The Melody Haunts My Reverie (Tuesday, 6.30); Dreaming of a Rose (Thursday, 8:45); and Heat and Dust by Ismail Merchant and James Ivory (Saturday, 3). Nonmember admission is $4.50 . . . At American University's Wechsler Theater (Mary Graydon Center), Buster Keaton's The General (Monday, 8:10; Thursday, 6:40) and Our Hospitality (Thursday, 5:30). Free . . . Public Production Group starts its new series of video workshops Saturday, including basic and advanced video editing. Call 347-7788 . . .