Being handed a box of home movies taken by a late, great, largely forgotten rock star with authorization to turn them into a documentary is many a filmmaker’s dream.

Such was the opportunity granted Danny Clinch, Taryn Gould, and Colleen Hennessy when Lisa Sinha, partner of Blind Melon lead singer Shannon Hoon, gave them over 250 hours of footage and 200 hours of audio recordings taken by him from 1990 until his untimely death in 1995.

All I Can Say, the brilliant, distilled version of that treasure trove, allows Hoon to tell his story in atypical cinematic fashion, laced with his witty humor, candid reflections, and creative talent — and a devastating ticking clock.

Up front about Hoon’s demise at age 28 by accidental drug overdose, the directorial team shows the last footage he ever shot — mere hours before he was found unresponsive on the band’s tour bus in New Orleans — within the film’s opening minutes.

This decision turns All I Can Say into a race against time as viewers see how much Hoon and his bandmates can accomplish during that span, and are afforded the fascinating prospect of looking for warning signs that may have eluded the frontman and those around him.

Most rock docs would settle for footage of remorseless young musicians making asses of themselves on tour, prompting viewers to wag fingers at stereotypical problematic behavior, but Hoon eschews such clips and instead presciently calls out and criticizes his own poor choices. Frequently unfiltered about his emotional and psychological issues, Hoon is also refreshingly honest about his struggles with sobriety and various deep-seated fears.

Insightful as these confessionary moments are, All I Can Say is far from one giant therapy session. Hoon’s camera passionately chronicles Blind Melon’s ascent — due in large part to smash hit “No Rain,” whose opening lyrics give the film its title — while demo recordings, musings on the transcendent nature of Neil Young on stage, and Hoon’s handling of Rolling Stone’s desire to put him on its cover present a complex artist and a loving human.

Live performance clips lensed by Sinha, official footage of Blind Melon’s memorable Woodstock ’94 set, and various non-musical historical moments nicely round out the visuals, and interviews with journalists provide welcome specifics on the band’s rise. The audio recordings also allow Hoon to make astute observations on the tenuous nature of fame, which take on tense new meaning after the death of Kurt Cobain makes a deep impression on his similarly tender soul.

Near the end of All I Can Say, Hoon reveals that he got a camera because registering everything in the moment had become impossible and he wanted to eventually look back on what he and Blind Melon experienced. Though he tragically never got that chance, the filmmakers have provided that opportunity for the masses — and their exceptional work should at last put Hoon in the same breath as other ’90s rock greats, especially the ones who left this planet far too early.

Grade: A-minus. Not rated, but with adult content, language, and graphic nudity. Available to rent starting June 26 via Grail Moviehouse

(Photo: Oscilloscope Laboratories)