What H.265 is
H.265, also called HEVC, is the coding standard that followed H.264. It splits the picture into larger, more flexible blocks and sends only what changes between frames, so it needs less bitrate for the same clarity. An uncompressed 4K60 HDMI signal is far beyond what Wi-Fi can carry, so it has to be compressed before it goes on air.
How adaptive bitrate works
Channel quality changes with distance, obstructions and interference. The encoder adjusts its bitrate to match: more bitrate and detail when the signal is strong, less when it weakens, so the picture keeps moving. Compared with a fixed bitrate, the picture does not freeze or go black on a brief dip in signal.
Effect on picture and audio
Compression applies to the video; HDMI audio is handled separately, so multichannel LPCM and Dolby Digital or DTS bitstreams pass through without going through the video encoder. Text-heavy office screens, spreadsheets and surveillance views are the most sensitive to bitrate, so during selection send a real spreadsheet through a sample and look at it.
The ATE9430T and ATE9460 transmitters encode in H.265 with bitrate adapting to channel quality, up to 60 Mbps on ATE9460. The ATE9430R and ATE9461 receivers decode H.265 with low-latency decoding and frame sync. HDMI audio passes LPCM 2.0 / 5.1 / 7.1 and Dolby Digital and DTS bitstreams through.