hey dude, welcome. P&O Aust is great, really relaxed. You'll be in polo and shorts literally most the time, and white shoes (can be anything - converse are popular, but any canvas shoe or sandshoes if you're into comfy - you'll need to wear socks if you're filming on the islands - sand gets everywhere). Formal night is the blacks (once a week). Not sure about bringing your own shorts, it's a specific khaki colour with embroidered logo. If you're working outdoors or deck parties you'll get outdoor gear.
Um as far as personal stuff goes, everyone chills out in t-shirts/singlets and boardies/jeans with thongs (flip flops), or hoodies/jumpers if cold. That goes for crew areas and pretty much everywhere the ship visits too. Take swimmers & flipflops, one nice outfit for fancy outings. If you're a girl (can't tell, sorry) anything goes, wear what you want. If you're on NZ cruises you need something warm for under your shirt if you get cold easy, the island cruises are cold the first two nights then hot. The coastals can be pretty hot too but only til May.
I'm not a videographer so can't help there sorry.
Dunno which ship you're on but have a great contract, might see you around.