There are some professionally filmed bits available - Now I'm Here, Bohemian Rhapsody and We Will Rock You (Freddie throwing bananas).
Video - downloads
an updated version of what Chinwonder2 did a while ago: linkmega.nz: link
Bits and pieces
The famous footage of Freddie Mercury on Superman with bananas comes from this concert.
Freddie Mercury (lead vocals, piano, tambourine),
Brian May (electric guitar, backing vocals, acoustic guitar),
Roger Taylor (drums, lead vocals, backing vocals, timpani, tambourine),
John Deacon (bass guitar)