Yes, the script (from a translation by English actress, producer, director Eva Le Gallienne) is abridged from Ibsen, for television. No matter. This (and Ibsen's other plays) is incredibly difficult, demanding theatre - for performers and audiences. Every character's truth lies beneath the dialogue and action: the rich conflict and drama isn't on the surface.
It's easy for everybody to overplay or underplay Ibsen, and so wreck the carefully crafted builds and effects.
To study the differences in productions, compare this with the much later Diana Rigg production for television. In fact, there is no comparison.
Bergman wrings incredibly detailed and nuanced range from Hedda; always bordering on being "dangerous" without ever appearing "deranged." A consummate actress portraying a consummate, stifled, destructive actress.
Alternately steely cold, girlish, seductive, flirtatious, calculating, distraught, despondent, taunting, sorrowful, gleeful, provocative - sometimes within mere moments - Bergman's skills are a wonder to behold, even at the camera's close range.
So are those of Richardson, Redgrave, Howard and the rest.
Diana Rigg, no slouch as an actress, seems almost one-note when viewed against Bergman's triumph (though that may well be Rigg's director's fault).
Hedda is an easy character to make boring, nihilistic and ugly - which would repulse rather than spellbind an audience.
Bergman never lets go of her audience, or her colleagues; delivering Ibsen's particular, peculiar, tragic Hedda Gabler in all her ultimately monumental crumbling pathos and final loss of any shred of hope.
Magnificent!