The CSA has authorized TDF to operate a third pilot channel to broadcast Ultra High Definition (UHD) experiments in Île-de-France, Nantes and Toulouse. Channel 83 joins channels 81 and 82, already in service since 2014, broadcast respectively on DTT frequency channels 26, 35 or 29.
This new project confirms that the move to UHD is now well underway industrially. This evolution is a central element of the DTT modernization announced by the CSA and supported by TDF, between now and the Paris 2024 Olympic Games.
On the road to Ultra High Definition
For the past five years, TDF has been conducting tests at its Eiffel Tower facilities. DTT channels 81, 82 and now 83 are pilot channels broadcast in UHD quality. In May 2018, this experimental mode was extended to the Île-de-France region, as well as to Nantes and Toulouse. Several "multi-city" experiments have been carried out on DTT for viewers equipped with UHD and DVB-T2/HEVC TV sets. In partnership with audiovisual manufacturers, TV channels and other partners such as the French Tennis Federation, TDF is broadcasting signals incorporating the latest enhancement technologies - including WCG (Wide Color Gamut for color palette), HDR (High Dynamic Range for contrast) and soon HFR (High Frame Rate for motion reproduction).
At the same time, viewers are progressively renewing their sets. In its consultation, the CSA noted that the migration to UHD is now well underway on an industrial level. In 2017, 31% of TV set sales in France were UHD models. The TV set installed base, which underwent significant renewal between 2011 and 2016 following the switchover from analog to DTT and then to HD, has now entered a new phase of renewal.
A new experience for viewers
Broadcasting images in UHD format, also known as 4K, offers viewers a new experience and unprecedented immersion: four times more definition than current high-definition television, color and luminance fidelity, and twice as many frames per second.
As part of UHD broadcasting trials, TDF partner ATEME is managing improved digital image compression. The compression gains achieved thanks to improvements in the implementation of the HEVC standard have made it possible to envisage the launch of a third UHD channel (reduction of the bitrate required for the UHD multiplex from 40 Mbits/s to 33 Mbits/s, and variable bitrate encoding of channels).
Les images UHD de ces expérimentations, filmées en SDR (Standard dynamique Range), ont été fournies par The Explorer, l’INA et St Thomas Production. Un travail de conversion et d’optimisation de ces images au format HDR10, a été réalisé en amont grâce à la technologie développée par l’Institut de Recherche Technologique B<>COM, démontrant ainsi la maturité de ce nouveau format.