There might potentially be some system in which MATLAB could keep up with that, such as with a high performance graphic card and a gigE camera, but most systems would not be capable of it.
4k resolution is about 8.3 megapixel. Multiply by 3 color components of 8 bits and multiply by 30 fps, and the overall data transfer requirements are just under 6 gigabits per second, without taking into account overheads.
6 gigabits per second requires one of:
- USB 3.2 generation 2 (10 gigabits per second)
- 10 gigabit Ethernet
- Thunderbolt 1 configured creatively, in theory, but Thunderbolt 2 or later in practice (dual bidirectional lanes each 20 gigabits)
USB3.0 is not able to keep up.
That is just the hardware issues. Issues about generating ffast enough interrupts and turning it around and out to the render thread.
I would not say that it is outside of the capacity of all current systems, but not common.