But there's a frequently recurring problem: what works for a few minutes or a half-hour doesn't necessarily work as a feature film: the characters usually don't have enough depth or breadth to warrant the expansion. The simple cat-versus-mouse formula of Tom and Jerry becomes tedious after a while.

Tom and Jerry made special appearances as animated characters in such MGM films as the 1945 Anchors Aweigh (Jerry dancing with Gene Kelly) and 1953 in Dangerous When Wet (the two of them swimming with Esther Williams).

Hanna-Barbera adapted two of its contemporaneous TV cartoons into movies in the 1960s. Hey There, It's Yogi Bear (1964) was the studio's first feature film, essentially an expansion of the basket-blagging-bruin's shorts, with songs and The Man Called Flintstone (1966) was made at the end of The Flintstones' TV run, with Fred Flintstone recruited as a secret agent (jumping on the bandwagon of the then-current TV and movie spymania - James Bond, The Man From UNCLE, Get Smart, et al). Again, there were songs.

Perhaps the filmmakers used the songs to differentiate the cinematic offerings from the TV ones, but the visuals often weren't much more spectacular than the cheap limited animation of the TV originals and the songs tended to be unmemorable and held up the action.

There were, of course, later film adaptations of both properties - the live-action/CGI Yogi with Dan Aykroyd providing the bear's voice was nothing special though the live-action/CGI The Flintstones, with John Goodman as Fred, has its fans. Scooby-Doo also found its way to the big screen in more recent years, proof that although Hanna-Barbera's low-budget, limited-animation TV output was often criticised, the characters still had a cultural presence.

Another 1960s TV producer, Jay Ward, relied on witty scripts to enhance the appeal of such characters as Rocket J. Squirrel and Bullwinkle Moose, George of the Jungle and Dudley Do-Right. Brendan Fraser starred in movies about George and Dudley and a CGI Rocky and Bullwinkle had stellar live-action villains in Robert De Niro, Jason Alexander and Rene Russo.

The film version of another 1960s cartoon, Underdog, had its superhero dog look realistic and nothing like his animated predecessor, which was more disconcerting than effective. A lesson might be not to stray too far from the original. Warner Bros made a few compilation movies stringing together classic cartoons with some wraparound animation: contrived but at least showcasing what people wanted.

Charles Schulz's long-running, hugely popular Peanuts comic strip, with its large cast and effective mix of the whimsical, intellectual and bittersweet, begat many animated TV specials from the 1960s on and perhaps inevitably, this led to movies. The first, A Boy Named Charlie Brown (1969) had songs by poet and songwriter Rod McKuen and was a hit; the second, Snoopy, Come Home! (1972) had songs by the Sherman brothers (Mary Poppins) and, for whatever reason, flopped, though two more (non-musical) films followed in 1977 and 1980. Schulz wrote the screenplays for all four movies. He died in 2000. A new film, The Peanuts Movie (2015) was made with CGI rather than the earlier films' hand-drawn animation.

We've had recent movies capitalising on current familiarity rather than nostalgia - the Simpsons, Beavis and Butthead and South Park, to name a few. These tend to seem like elongated TV episodes - many big-name guest stars have already "appeared" on the small screen, making such cameos less special, and the makers don't want to depart from the visual style of the TV originals too much.

The South Park movie included songs more successfully than most: its creators are aficionados of the musical (and co-wrote The Book of Mormon). Since they couldn't push the content envelope too much further than they had on TV, this worked out well.