HDMI 1.4 spec cable capable of doing 10.2 Gbit/s (even the cheap ones need to achieve this throughput to be 1.4 spec) 1080p (8-bit per channel) raw decompressed video frame frame uses 1.24 Gbps of the cables bandwidth. 4k (12-bit per channel) raw decompressed frame uses 3.82 Gbps If you buy any modern HDMI cable it has more than enough bandwidth to account for any error correction required due to any signal loss happening on the HDMI cable even when transferring raw uncompressed video data. Now I'm not sure if the HDMI protocol compresses any of the data for transfer. But even if you factored that the blu-ray player would decompress it's frames and send them raw over HDMI you would need a pretty bad cable before you see image quality issues. Edit: from HDMI.org "One of the advantages of HDMI over other connection technologies is its enormous carrying capacity, which makes compression unnecessary." So it looks like HDMI does indeed transfer raw uncompressed video data.