Does there exist a digital wireless broadcast protocol?
Your requirements are quite demanding. Nordic do some 2.4GHz radios that might cope, or you could pair up a couple of them to get dual channel operation.

If you need more range the ISM bands (433, 868, 915MHz) are a good bet, but data rates are nowhere near what you want. 500kbps maximum. Again, you could have four radios on different channels perhaps.

The reason you have having trouble finding anything is that a radio capable of what you want is going to be quite a complex device, most likely with some kind of ARM processor and DSP attached. It will need to do error recovery, and even then will be expected to tolerate a certain number of bit errors per second which can be masked in video.

It would help to know more about your application.