In most cultural arenas, August is a slow month, a prelude to the big events lining up to welcome the winter solstice. Not so with DVDs, which enjoyed a remarkable month, climaxing with this week’s releases. Almost inevitably, these include restorations and improved editions of films you may already own. In some cases, however, the refurbishing is so impressive you simply have to bite the bullet.

In 2001, Image released an apparently definitive 219-minute edition of Fritz Lang’s 1922 spectacle, “Dr. Mabuse the Gambler.” Now Kino comes along with a version 50 minutes longer (a few minutes might have been wisely shaved with better timed intertitles).The result is an even more dazzling whirlwind of action and deception, with elaborated plot points and even-handed tempo. In addition to being more complete, the new version is sharper-looking and boasts a superior, expertly synchronized musical score by Aljoscha Zimmerman.

If you are not already addicted to Lang’s adventures in serial paranoia (addiction is probably required when contemplating a four-and-a-half-hour silent movie), Mabuse — the ultimate nihilistic anarchist — quickly works his malign magic.The character was a pulp response to the Joseph Conrad of “Under Western Eyes”; in Lang’s hands, he is, as Siegfried Kracauer put it, the transitional monster between Caligari and Hitler, but a lot more fun than either of them. This film has the momentum of a train. You need a break to catch your breath.

Kino has also released Joe May’s “Asphalt” (1929), an absorbing, late-silent urban melodrama. Involving a tender-hearted cop and an ambivalently good-hearted femme fatale (memorably played by Betty Amann), “Asphalt” ingeniously combines footage of Berlin with fastidiously designed interiors, and hums with steady tension despite the anticipated denouement.

Last fall, Criterion released a magnificent restoration of “Wages of Fear,” one of the greatest adventure films of the 1950s. Yesterday it released an equally enthralling upgrade of its rival: Akira Kurosawa’s 1954 epic, “Seven Samurai.” The 207-minute film is spread out over two discs, along with galleries, trailers, and a Toho-TV documentary; a third disc includes a new documentary on the film’s origins and a two-hour 1993 conversation with the director. Putting the extras aside, the old Criterion version is perfectly acceptable, but this one is far better: The grays we have become accustomed to are replaced by vivid blacks and whites, which underscore Kurosawa’s Olympian style, forged with a telephoto lens and daringly rhythmic edits.

Criterion is also putting back into print Jacques Tati’s 1967 comic masterwork and devastating financial folly, “Play Time,” in a two-disc edition, with a clean print that remains shorn of the nearly 30 minutes that were cut (and apparently lost) after its debut. Tati, who satirized the soullessness of modern life by building a soulless city, demands an appetite for whimsy and a willingness to patiently explore long distance framing, in which activity occurs in the foreground, background, on the edges, or everywhere at once. Paradoxically, the movie, conceived for a large screen, plays well on a laptop, where the eye can quickly peruse the mise-en-scéne. Still, only repeated visits can take it all in.

For a harsher satirical edge and unembarrassed belly laughs, Criterion offers Pietro Germi’s “Seduced and Abandoned” (1964), his worthy follow-up to “Divorce Italian Style,” released on DVD last year. Both films take on Sicily’s outlandish patriarchal customs, venturing into comic situations and complications with seeming abandon that, on reflection, betray a mathematic precision.

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Three comic kings who don’t require subtitles are also refurbished, rereleased, or newly collected. The big news regarding Image’s 90th Anniversary Edition of “The Chaplin Mutual Comedies” is that new footage has been found and interpolated. Most notable is “One A.M.,” one of Chaplin’s greatest solo flights — not as the tramp, but as an inebriated aristocrat who spends nearly half the running time trying to climb a staircase, after which he is obliged to wrestle a Murphy bed. The 12 two-reelers made in 1916–17 represented a dramatic maturity in Chaplin’s work, leading to the feature-film breakthroughs; they are presented on two discs, while a third is given to a sentimental documentary (oddly augmented with a defensive essay by its director) and a film portrait of Chaplin’s comic nemesis, the beetlebrowed Eric Campbell.

HBO has finally reissued “Richard Pryor Live in Concert,” in a bare bones DVD that captures him at his peak in 1979. Pryor mimics whites and blacks, dogs and flies, his heart and penis, and plays the audience like a fiddle. This is not one of those cautiously edited comedy performances with convenient cutaways to laughing people. Pryor stalks the stage, propelling himself while latecomers find their seats, and as he begins to pick up speed, the audience rarely interrupts him with laughter because it is caught in a sustained roar. This is a genuine movie, thanks to director Jeff Margolis, who knew the material well enough to know how best to cut from one camera to another.

In April, Fox released “The Mel Brooks Collection,” an irresistible compendium of seven films he directed, including “Blazing Saddles” (on loan from Warner), and his production of “To Be or Not To Be,” directed by Alan Johnson and co-starring the glorious Anne Bancroft. As of this week, however, you can buy singly his surprisingly affecting adaptation of Ilf and Petrov’s novel “The Twelve Chairs”(1970), his silent yet mordant send-up of Hollywood, “Silent Movie” (1976), and his Hitchcockian semi-musical, “High Anxiety” (1977), which, like most of Mr. Brooks’s best work, punctured the thin-skinned.

Gregory Hines wears a toga in Mr. Brooks’s “History of the World, Part 1,” but he’s more at home in tap shoes in two dance films released by Columbia — Taylor Hackford’s “White Nights” (1985) and Nick Castle’s “Tap.” Neither is a great film, but they are better as DVDs, which allow you to fast-forward to the many good parts. Mr. Hackford’s film is a souvenir from the evil days of the Soviet Union, burdened with a plot contrived enough to make Helen Mirren look embarrassed at having to recite her expository dialogue. Ah, but then there are the opening eight minutes, which include a Mikhail Baryshnikov number ending with his suicide by hanging, Hines’s vodka-induced autobiography in dance, and their long-delayed and entirely satisfying pas de deux — reasonable tradeoffs for cold war platitudes.

For dance lovers, “Tap” (1989) is a must-have disc, as much for the extras, which include interviews with veteran dancers, as the film. Sammy Davis Jr., in his last movie, turned in his best film work since “Porgy and Bess.” The oldtimers’ tap dancing “challenge,” despite too many reaction-shot cutaways, is one of the most savory face-offs on film. Savion Glover, still in his teens, radiates charm and smarts, marking his promise with one number. Still, it’s Hines’s film, and he carries it on his pugnaciously sloping shoulders and in his cynical lidded eyes. His dancing expands on the attitude and elegance of John Bubbles while charging into a new realm — percussive, assertive, and uncompromising, not least in his nostalgic regard for a fading tradition.

Finally, New Yorker Video has brought out Henning Carlson’s flawless “Hunger” (1966), one of the few great films based on a great novel. Working with cinematographer Henning Kristiansen, Carlson achieves near three-dimensionality by shooting Per Oscarsson (in an indispensable performance) in his inky black suit and hat against a flat gray background. When Oscarsson shifts to the background, the coat turns gray. Stranded in Kristiania, in 1890, Knut Hamsun’s vagabond writer reels from starvation, yet spurns several offers of money, refusing to eat until he can buy food with earnings from his work. Instead, he tastes sawdust, paper, and bones. Carlson’s film, as fresh as when it opened in New York 40 years ago, deftly captures Hamsun’s first-person desperation and humor. Not the least timeless aspect of this film is Krzysztof Komeda’s John Lewis-influenced musical score. It’s all of a piece.

Mr. Giddins’s latest book, “Natural Selection: Gary Giddins on Comedy, Film, Music, and Books,” is available from Oxford University Press.