After years of riotous concertizing, The Who announced last year that their 1982 North American tour would be their last together. This is the videotaped version of the group's final concert, at Toronto's Maple Leaf Gardens. (HBO is presenting the concert as part of a four-day musical festival, July 1-4.) Like the Rolling Stones, the four members of The Who are rockers approaching middle age. Mick Jagger seems eternally energetic, but the fierce onstage force of The Who seems diminished on this tape. There is none of the trade-marked guitar-smashing by Peter Townshend at the end of the show. Townshend, Roger Daltrey, John Entwistle and Kenney Jones give strong renderings of their classics, from Pinball Wizard and Baba O'Riley to My Generation and Won't Get Fooled Again. But the bad-boy danger is missing. The stage is overlit for TV, and visual effects such as slow-motion and freeze-frame shots interfere with the concert's immediacy. Still, this program is a rare and entertaining look at a group that has stood the test of almost two decades.