USB Type-C Connector Will Now Support HDMI 1.4b Signaling

HDMI, LLC used IFA to announce new support functionality for the USB 3.1 Type C connector. When placed in Alt mode, supporting chip sets can now use HDMI1.4b signaling over the connector.

USB is probably the most ubiquitous wired connector worldwide and the addition of the new Type-C version to the USB 3.1 specification is opening it up to incredible new capabilities. The general features of the USB Type-C connector includes:

  • Up to 100W charging
  • Over 10Gbps data rates
  • Reversible connector
  • Multiple video modes
  • Flexible Vendor Defined Messages (VDMs) for authentication and security

With 24 contact points and 10 configurable conductors, it can deliver 4K 60 fps video. This allows your mobile device or external hard disc drive to deliver content to your 4K TV or monitor.

The most interesting aspect of USB 3.1 is the Alt mode. Here, the 10 conductors can be used in novel or standard ways. For example, standardized signaling protocols like MHL 3.0, ThunderBolt 3.0, DisplayPort 1.3/1.4, and now HDMI 1.4b can all be implemented using this connector, or something proprietary. These modes need to use Power Delivery communication, which is the protocol which also manages how power is applied (direction, voltage and current).

The standard also supports compression of the video (DSC). DSC is a visually lossless standard that is approved for up to 3:1 compression ratios. This can be used to lower the data rate for 4K video, thereby saving power and extending battery life on the mobile device. DSC allows 4K30 4:2:0 at 1.5 Gbps; 4K30 4:4:4 at 3 Gbps and 4K60 4:4:4 at 6 Gbps.

USB 3.1 Type-C connectors are starting to now show up on mobile devices and TVs. The Vidity hard disk drive platform for providing Blu-ray quality UHD content uses this interface probably using DisplayPort 1.4 signaling, which can support HDR10.

HDMI 1.4a and 1.4b were developed in 2010 and 2011 mainly to support 3D formats. It uses 10.2 Gbps signaling and can support 4K playback at 24,25 and 30 fps in 4:4:4 8-bit or 4:2:2 12-bit formats. That means it is OK for the first phase of UHD content, but obviously not the newer 50/60 fps content and content with HDR and WCG.

While it will not therefore support HDR10 playback, it actually can support Dolby Vision playback. HDMI 1.4a/1.4b and 2.0 can support Dolby Vision dynamic metadata via a proprietary signaling scheme which is due to be a standardized implementation shortly. – CC