A few months back, in 'Korchnoi = Don Quixote', I featured a clip titled 'An old segment on a younger Korchnoi', which appeared to be a segment of a longer documentary. The full film has recently surfaced on YouTube and is even better than the 'Younger Korchnoi' extract.
The Great Chess Movie (1/3) (30:46) 'A Canadian chess documentary featuring Bobby Fischer, Mikhail Tal, Anatoly Karpov, Viktor Korchnoi, Jan Timman, Vassily Smyslov, Lajos Portisch, Anthony Miles, and many other historical grandmasters.'
The most recent events discussed in the documentary were played in 1981. The credits start 40 seconds into the clip: 'Starring Karpov, Korchnoi, Fischer, ...; Direction: Gilles Carle, Camille Coudari; Production: Hélene Verrier'.