I worked with some film makers who received some grant money to produce some historical documenteries. I was not involved in the grant - so I don't know what hoops they had to jump through.
They were able to purchase various video & audio equipment I believe one of the documentaries did show on PBS (I 'm certain they did show on some local cable channels). It turns out they were not that terribly creative (the filming and production had no real artistic vision) - but the soundtrack I prepared did win an award (no money, just a wall mounted plaque - which the film makers kept).
As others have indicated, to obtain a grant the work must have certain artistic, historic or social value (all rather subjective).
There are publications and web sites that identify government agencies that offer grants. There are also private grants available (watch PBS - the credits often identify corporate and private funding).