HDMI – A common interface that rules home cinema
equipment for about 15 years now. While VGA with it’s
analogue signal was rather unreliable and DVI couldn’t
get past certain resolutions, HDMI made it’s way.

Together with DisplayPort, there are now two major interfaces to transmit video and audio. HDMI also is prepared to transfer Ethernet signals in order to allow basic networking (i.e. for display synchronizaton or the daisy-chained broadcast of video data between single screens.

DisplayPort however is limited to 4K with the actual 1.4 definition. Mostly used with computer displays, this might be sufficient but there are already 8K displays announced and even with 2 DP lines, there might be only a 30Hz refresh rate for 8K.

So either Displayport is upgrading the bandwidth with a new specification level or HDMI2.1 might be the solution…

Display resolutions supported

* = Uncompressed 8 bpc (24 bit/px) color depth with RGB or Y′C_BC_R 4:4:4 color format and CVT-R2 timing are used to calculate these data rates. Uncompressed data rate for RGB images in bits per second is calculated as bits per pixel × pixels per frame × frames per second. Pixels per frame includes blanking intervals as defined by CVT-R2.

** = Possible by using Y′C_BC_R with 4:2:2 or 4:2:0 subsampling (as lower bandwidth is required for compressed color channel depth)

*** = Possible by using Display Stream Compression (DSC)

**** = Uncompressed 8 bpc (24 bit/px) color depth and RGB or Y′C_BC_R 4:4:4 color format are assumed on this table except where noted.

***** = HDR10 requires 10 bpc (30 bit/px) color depth, which uses 25% more bandwidth than standard 8 bpc video. Uncompressed 10 bpc color depth and RGB or Y′C_BC_R 4:4:4 color format are assumed on this table except where noted.

Feature list of HDMI

DisplayPort Resolutions

* = Only a portion of DisplayPort’s bandwidth is used for carrying video data. DisplayPort uses 8b/10b encoding, which means that 80% of the bits transmitted across the link represent data, and the other 20% is used for encoding purposes. The maximum bandwidth of DisplayPort (10.8, 21.6, or 32.4 Gbit/s) therefore transports video data at a rate of 8.64, 17.28, or 25.92 Gbit/s.

** = Uncompressed 8 bpc (24 bit/px) color depth with RGB or YC_BC_R 4:4:4 color format and CVT-R2 timing are used to calculate these data rates. Uncompressed data rate for RGB images in bits per second is calculated as bits per pixel × pixels per frame × frames per second. Pixels per frame includes blanking intervals as defined by CVT-R2.

*** = Possible using YC_BC_R format with either 4:2:2 or 4:2:0 chroma subsampling as noted. 4:2:2 subsampling is only supported by DisplayPort 1.2 and above. 4:2:0 subsampling is only supported by DisplayPort 1.3 and above.

**** = Possible using Display Stream Compression (DSC), only supported by DisplayPort 1.4