After two days of confronting the joys and terrors of television's future, movie producers, lawyers, advertisers, economists and TV salesmen could only agree today on one thing--Americans should not be made into outlaws for using videotape recorders.

Motion Picture Association of America President Jack Valenti told a congressional hearing here Monday that the 3.5 million recorders now in use are "to the American film industry what the Boston Strangler was to women." Consumer advocate Carol Tucker Foreman likened Valenti to "the troll under the bridge" for insisting that recorder makers--and thus recorder buyers--pay a royalty to the movie studios.

But all agreed that Congress should move quickly to free consumers from the threat of civil penalties for recording movies and other programs on television, a danger raised by an Oct. 9 U.S. Circuit Court of Appeals ruling that such home recording violates federal copyright law.

The effect of the court's ruling has been delayed while the case is appealed to the U.S. Supreme Court. Several bills have been introduced in Congress repulsing the court's attack on home recording, but videotape manufacturers and movie makers are expected to continue battling over whether a special royalty fee should be charged for the sale of recorders and blank recording tapes.

Valenti told the House Judiciary Committee's subcommittee on courts, civil liberties and the administration of justice that without the royalties, the film industry would suffer great financial loss from the cheap taping of movies and other programs. He said the audio recording industry, whose complaints the committee will hear Wednesday, is losing $2 billion a year because of home taping.

Valenti warned that moviemakers may have no choice but to keep their best films off of free television and show them only to Americans affluent enough to buy first-run movie tickets, pay cable TV fees or buy prerecorded cassettes and cassette players. In his statement, Valenti said, "Lower-income Americans will continue to depend on free television which . . . soon will become a wasteland filled with game shows and other inexpensive programing." Actor and producer Clint Eastwood told the subcommittee headed by Rep. Robert Kastenmeier (D-Wis.) that most producers depended on television and cable sales to break even or make a profit, and free video recording would cut into that business.

Industry experts have speculated that royalties levied on manufacturers might average $50 per recorder (now priced at $500 to $1,000) and $1 per blank tape (now about $12 to $15 each). Manufacturers and moviemakers dispute how much of this extra cost would be passed on to consumers.

The royalty bill introduced to the House and Senate would also probably bring an increase in the rental fee for prerecorded movies, now as little as $2.50 a night, by forbidding such rentals without the studio's permission.

Testifying today, former Federal Communications Commission chairman Charles D. Ferris said moviemakers were attempting to get an extra windfall when there was no evidence that home video recording was cutting into their business. He said when a television watcher records a program he would otherwise miss, that increases the size of the television audience and eventually increases fees paid by advertisers to the networks and by the networks to the movie producers.

Along with electronics industry spokesman Jack Wayman and economist Nina Cornell, Ferris presented surveys indicating videotape recorder owners use their machines more for recording programs they would otherwise miss than for building up a library of films to trade with friends and save on theater tickets and cable fees. Valenti yesterday presented survey data indicating the opposite.