12MP JPEG Support

[Luxonis-Brandon]

Start with the why:

The current implementation of the video/image encoder on DepthAI is set to a max of 8MP such that both video encoding and still encoding can co-exist. This is because the video encoder can handle a maximum resolution of 8MP when running at 30FPS, and the same encoder is used for both. So if the resolution is set to 12MP, video encoding is not possible.

It can however handle still JPEG encoding at full 12MP, but when set to this mode, video cannot be encoded.

It is possible to pull the full 12MP raw frame off of DepthAI (using the color stream) while the h.265 8MP/30FPS is running, but this is costly in terms of bandwidth.

And in some cases it may be desirable to pull 12MP JPEG stills off.

Move to the how:

Implement a mutual-exclusive 12MP JPEG output mode which would then prevent 8MP (4K; 2160p) video encoding.

Move to the what:

Support 12MP still output.