This started happening probably about two months ago on my fully updated 930 as well. Speaker phone not working, video recording not working, regardless of portrait or landscape mode. I found the only video that does record sound is when I plug in my Apple earbuds - it uses that microphone, because when testing it with headphones that don't have a microphone it again doesn't work with a lot of noise, the sound coming through very slightly, only barely able to be heard when putting my ear right up against the mic.
I also just used the Windows recovery tool to format and restore my phone. This at least seems to have fixed the delayed screen rotation issues that also plagues these cursed phones.
Lumia help on Twitter was also not very helpful, only offering the most rudimentary suggestions to fix the problem.
On top of this, my phone has no warranty.
This is my first Windows phone, having moved from iPhone, and I have to say, I love the phone but its so darn buggy and more importantly, the support is next to non-existent. Hopefully Microsoft's new approach to the Lumia range, with fewer phones, will bring more focused support.