The EBU was showing various demonstrations and we looked at the BBC/NHK hybrid log demo, which the EBU is positive about, and also at a demonstration of high frame rates – material shot at 50Hz and 100Hz. The EBU is looking at different shutter angles and also the impact on viewers and is working with the 4Ever project. The group pointed out that, although 4Ever had said at the IHS event last week in IFA, that the viewer impact of 100Hz was smallish if you compared 100Hz native content with 50Hz material interpolated by the panel using MEMC, it was fairer if you compare 50Hz interpolated with 100Hz interpolated. In this case on a scale of 100, viewers see around 15 points of difference (compared to 10 for UltraHD resolution and 20 for HDR).
The EBU was also showing the NHK/BBC hybrid log gamma proposal for HDR standardisation with HDR content being shown directly displayed at the same time on an SDR display, without any support for the standard, as well as an HDR monitor, where, of course, it looked better. The point was to show that the same stream can be sent to existing devices without a problem. The EBU is very concerned about systems that need dual layers – it simply doesn’t believe these are feasible in live broadcast productions so it also thinks that dual stream systems will not be standardised for broadcast.
Now, some of the systems, such as Dolby Vision, also have single stream versions that include the metadata in a single broadcast stream. However, the EBU told us that it was getting no answers to the question of what happens if the metadata doesn’t arrive or is broken. For that reason, it likes the NHK/BBC proposal. It’s understood that the system only works well up to a lower peak brightness than Dolby Vision (it seems OK in tests at up to around 2,000 cd/m²), but there is a feeling that mass market sets may never get up to the high brightness of up to 10,000 cd/m² that Dolby and others talk about. (4Ever said at IFA that it had found discomfort at more than 1,500 cd/m² of brightness)
The organisation is also working on production and usability guidelines for HDR for its members (public service broadcasters in Europe), such as the levels of brightness and contrast. It plans more user research to further understand this.
