Sending 4K HDR content over Cat cabling.
TPC stands for Tipping Point Compression. It’s a new technology for sending 4K HDR content over Cat cabling and is a feature of some of HDANYWHERE’s latest MHUB and XTND products.
Why is TPC needed?
A growing number of HDMI input source devices (such as SkyQ and AppleTV) are now capable of outputting Ultra HD (4K) content with higher frame refresh rates for smoother motion and deeper, richer colour ranges, that push transmission data over MHUB/XTND’s HDBaseT link’s 9G video bandwidth ceiling, up to potentially 18G.
Good to know! Most content does not hit the 18G level.
HDBaseT data-rate ceiling = 10.2Gbit/s (9GB video)
UHD Blu-ray, broadcast and OTT
Most Blu-ray content is OK
The vast majority of UHD Blu-ray content will pass through an MHUB without any compression. UHD Blu-ray content generally plays at 24/30 frames per second (fps) with 4:2:0 & 4:2:2 10-bit HDR 10, HLG and Dolby Vision support. Requiring a max of 9GB.
Watch out for 10-bit HDR & HFR
Only a handful 4K Blu-ray titles have content of 24/30 fps 4:4:4 with 10-bit HDR 10, HLG = 11.14Gbps, so TPC becomes active to compress the content to below 9GB. Moreover, high frame rate (HFR) 60fps content is even rarer on 4K Blu-ray.
Arbitrary menus push the limits
4K 24/30 4:4:4 12-bit Dolby Vision = 13.37Gbps is not supported. However, no content is known. HFR devices – global 4K set-top-boxes (such as SkyQ) are forcing 50 or 60fps with 10-bit. Other devices such as AppleTV and Kaleidescape as a minimum use 60fps on their guide/menu screens for a fluid navigation experience.
An example…
For example, SkyQ silver box uses 50fps 4:2:0 and has an option for 10-bit, pushing the data-rate to 11.14Gbps, so TPC becomes active to apply compression reducing the content data-rate to below 9GB again. AppleTV’s optimal settings is to have the home navigation screen running at 50fps, 4:2:2 with 10-bit HDR (17.82 Gbps). Again, this is when TPC applies compression to achieve transmission over Cat cable.
So, what are the trade-offs?
Side-by-side viewing comparison tests of TPC vs original content, overwhelmingly concluded in results imperceivable to the human eye.
TPC does not change video resolution, frame rate and colour depth, only colour gamut (total range of colour). TPC keeps all Luminance data (Y) and only loses Chroma data ©, which the human eye has significantly less sensitivity.
HFR 50/60fps Dolby Vision or HDR10+ is not supported, and currently, there is no content.
Avoid compression
If you are worried about compression and would like to avoid it, use only the HDMI I/O ports only on any MHUB. TPC is a technology only applicable to HDMI-to-Cat transmission, it can be totally avoided when using the HDMI-to-HDMI I/O.