Create encryption for Y3000 Hidden Camera

I am interesting in finding someone who can write software or firmware to modify standard Y3000 secret cameras such as the ones below. The idea is that as the footage is taken it is encrypted on the SD immediately after filming is stopped. The footage can then only be decrypted when the file is accessed, using a password. The encryption must be as strong as AES256 or equivalent. You can use any programming language which will work.

http://www.amazon.co.uk/Y3000-720P-Camcorder-Camera-Black/dp/B00843I3NQ

To show that you have read this advert, please place the words "Camera Encryption" in the title. We do NOT have a copy of the firmware for this device so you must be able to obtain one or explain to us how to obtain it.