World's first Ultra High Definition broadcast in DVB-T2 with content in HDR, WCG and AC-4

On the occasion of the 4K Summit in Seville, RTVE, in collaboration with Cellnex Telecom, Hispasat, Dolby and Sapec, will carry out this pioneering experience as well as the first simultaneous global UHD broadcast in DVB-T2, DVB-S2 and HbbTV.

On the occasion of the celebration of the contest 4K Summit On November 5 and 6 in Seville, RTVE, in collaboration with Cellnex Telecom, Hispasat, Dolby and Sapec, will present two world novelties that show the advances not only in the differentiating characteristics that Ultra High Definition (UHD) offers compared to High Definition, but also in its dissemination through the different platforms used by citizens.

The RTVE Chair at the ETSIT of Telecommunications at the Polytechnic University of Madrid has been in charge of coordinating the different actions carried out to materialize this collaboration.

Coinciding with the 4K Summit in Seville, the world's first Ultra High Definition broadcast will take place in DVB-T2 with content in HDR, WCG and AC-4

Cellnex Telecom has launched a 500 W transmitter, providing coverage to the city of Seville from the Valencina emission center. The DVB-T2 modulation used allows transmission of up to 34 Mbps, a bit rate sufficient to broadcast the world's first UHD broadcasts with High Dynamic Range (HDR), Wider Color Gamut (WCG) and Dolby AC-4. These broadcasts can be received in Seville during the 4K Summit on UHF channel 36.

Dolby Vision is a new imaging technology that offers an enhanced visual experience, increasing brightness, contrast and color gamut by combining HDR and WCG. Although most content is captured and rendered using technology that reproduces the colors and brightness of the real world, much of that richness is lost when it reaches the audience. This is because current colorimetry standards are based on the technological limitations of existing televisions, which drastically reduces color gamut, brightness and contrast. Dolby Vision allows the use of the full range of colors, reflections, brightness and contrast, faithfully reproducing them on televisions that incorporate this technology.

The encoding used is HEVC, over which a metadata channel is sent with the additional information for HDR. This allows devices that do not support HDR to play content in Standard Dynamic Range (SDR).

On the other hand, Dolby AC-4 is a new audio format in the Dolby Audio family, which responds to current and future needs for next-generation audio and video services, including broadcasting and streaming distribution over the Internet. Key elements of Dolby AC-4 have been standardized at the European Telecommunications Standards Institute (ETSI) as TS 103 190, adopted by DVB as TS 101 154 and are ready for incorporation into next-generation audiovisual services.

This demonstrates the common will to work to achieve an adequate standardized UHD service (that is, a complete DVB UHD-1 Phase 2), in accordance with what has been agreed by the EBU and DVB.

UHD in DVB-T2, DVB-S2 and HbbTV

Although UHD demonstrations had already been carried out in DVB-T2 and DVB-S2 previously, with RTVE content encoded in HEVC by Sapec and distributed by Cellnex Telecom and Hispasat, the event in Seville will be the first time that they are presented simultaneously together with an RTVE HbbTV (hybrid television) service that also offers content in UHD.

For this last service, a set of videos with a resolution of 3840 x 2160 encoded in HEVC have been used, both in 25p and 50p, with MP4 encapsulation, using different qualities with constant binary regimes (10, 15, 20 and 25 Mbps) and progressive download.

In this way, the door is opened to the introduction of UHD in the “Red Button” of RTVE and the coexistence between broadcast and broadband environments is shown in the foreseeable future.