The Adelaide Festival's former artistic director David Sefton is leading the charge to have the city's ailing arts venues keep up with those interstate.

Adelaide Film Festival is set to be one of the only events of its kind in 2020, ready to defy the effects of the COVID-19 pandemic to welcome crowds back to cinemas despite the global crisis.

Theatre shows will get a major boost with the release of thousands of extra tickets as Adelaide Festival Centre venues return to 100 per cent audience capacity this week.