Broadcast 3D Opportunities Expand With Relaxation of HDMI Specs
Opportunities for 3D broadcasting are seen likely to expand with an updated HDMI spec that adds broadcaster-friendly encoding formats while relaxing hardware requirements for legacy set-top boxes. First hints of the updated spec, HDMI Version 1.4a, came in a cryptic Christmas Eve e-mail from HDMI Licensing (CED Jan 4 p1).
The HDMI V1.4a update for broadcast 3D came as quickly as the licensor promised in pre-CES interviews. HDMI’s announcement Thursday reiterated its resolve to make “the 3D portion” of the V1.4a spec available publicly on its website to “companies and organizations that are not HDMI Adopters but require access to this portion of the specification,” as HDMI Licensing President Steve Venuti vowed before CES his organization would do. In most cases, access to detailed specs is limited to HDMI licensees, through a closed site. Some broadcasters, and the OEMs that make their set-top boxes, aren’t among the HDMI adopters.
The V1.4a spec gives bandwidth-limited broadcasters the means to send 3D content to existing receivers and set-tops. While the newly-devised packaged media platforms like Blu-ray and videogame consoles have few such limitations, terrestrial, cable and satellite distributors must live within the spectrum allotted to their current HD delivery systems. Those limitations preclude the full 1080p that Blu-ray 3D’s “frame-sequential” formatting can deliver to each eye. Yet, broadcasters can deliver credible 3D viewing at 1080i and 720p if they're given formatting dedicated to their allotted and fixed bandwidth, Venuti and others have said.
Those broadcast-friendly formats use so-called “top-and-bottom” and “side-by-side” compression. Both are allowed for use by broadcasters under HDMI’s V1.4a spec. Broadcasters can use one or the other or both as they wish, depending on the content. TV makers must make displays capable of rendering both. Source units, like cable or satellite set-tops, must support at least one of the formats. Which format a set-top supports would depend on what format or formats the broadcaster intends to transmit. Some might use both. According to what broadcasters have told HDMI, top-and-bottom is best for movies and TV shows, while side-by-side is preferable for live sports.
HDMI Adopters have 90 days from the publication of the V1.4a spec to build and sell compliant products, HDMI Licensing said. That also applies to MVPDs that want to use their legacy boxes to use the new HDMI signaling. From what we're told, the MVPDs can issue a firmware-upgrade for their boxes. That couldn’t be confirmed Friday.