user50787: I'd like to know please whether an Arduino can accept an HDMI signal from a satellite receiver, let it flow without any modification to the stream, and output it to TV?

user4143: No.
HDMI uses multiple serial data streams at gigabit rates. No Arduino is ever going to do that sort of thing.  If you want something programmable to do that kind of thing you need an FPGA.

50787: <p>I'd like to know please whether an Arduino can accept an HDMI signal from a satellite receiver, let it flow without any modification to the stream, and output it to TV?</p>
 4143: <p>No.</p>

<p>HDMI uses multiple serial data streams at gigabit rates. No Arduino is ever going to do that sort of thing.  If you want something programmable to do that kind of thing you need an FPGA.</p>
