All DVD player have content protection against pirating. The only thing that can decode the signal is a viewing device (your TV). Which means you cannot decode the video even if you split it off. When you plug your DVD player into a TV, the DVD player negotiates over the I2C bus to see if it can accept the video.
If your video source is an HDMI camera, content is obviously not protected. The I2C negotiation still takes place and you can use the pixel bus from a standard off-the-shelf HDMI receiver and store it in a frame buffer. The ARM processor can then access (arbitrate) for the same memory. By allocating a circular buffer to video storage, the ARM could read a frame of video just after it was written into memory. If the processor can keep up with video rate, then all you need are two frames of storage and ping-pong between read/write.
High Definition Content Protection (HDCP) is the secret weapon which prevents you from coping the content.
