What exactly is Quality of Experience (QoE), why does it matter, how can it be measured and how can it be achieved? These questions and other key topics concerning the logistics of online content delivery were at the forefront of discussions at the BroadThinking 2018 seminar in Geneva. BroadThinking is the EBU's annual event dedicated to broadband media delivery, covering both front and backend aspects.
For keynote speaker Jan Devos, VRT's enterprise architect for online video and audio, QoE is a critical element of serving the audience. "The more content people consume online", he said, "the more they expect a higher standard. The quality of the stream is really important and the first step in that direction is measuring QoE."
VRT, through its participation in the EBU Flow pilot, is exploring a multi-CDN approach to content delivery as one means of improving QoE, measuring factors such as network availability, throughput and buffering in the player. For Maarten Tielemans of THEOplayer, however, this is only one part of the story: "We should not only focus on these technical things and try to improve them, because they alone will not make a good QoE.” In his presentation Tielemans emphasized the importance of context in which the user consumes the content and the design of the frontend, along with the technical aspects of the system.
A need for consistent Metrics
When it comes to measuring QoE, it was clear that metrics is an area that needs to be addressed urgently. It is currently almost impossible to reliably compare the results produced by different providers. Akamai's Will Law outlined the challenges involved in defining an agreed set of metrics, a task that the Consumer Technology Association has taken on. "There are two main problems: inconsistent events and properties available in the players, and inconsistent calculation and definition of the metrics provided in the players. We want to standardize the minimum necessary set of player metrics to allow comparison between providers."
Codecs was another hot topic at BroadThinking 2018. Delegates were eager to hear the results of early assessments of the new AV1 codec, a collaboration between the EBU and University RheinMain. Hans Hoffmann said the EBU would continue to follow the progress with AV1. "If the royalty-free promises are true then it is an interesting candidate, particularly in software-to-software domains", he said. The news came through on Day 2 of BroadThinking that the Alliance for Open Media had issued the first formal release of the codec, which suggests that interest will intensify over the weeks and months ahead.
A third headline theme at BroadThinking was the role of CMAF – the Common Media Application Format – which is emerging as a welcome solution to the problem of multiple competing distribution codecs. As Qualcomm's Thomas Stockhammer put it, "with respect to convergence around DASH and HLS, there seems to be a way forward working with two manifest formats but with a single segment format, CMAF." In Germany, the IRT is hopeful that CMAF can play a big role, particularly with the growing footprint of HbbTV 1.5 (or higher) televisions with MPEG-DASH support.
Smart speakers and media consumption
The commercial success of smart speakers put the devices on the agenda at BroadThinking as well. Conference attendees discussed opportunities for online content delivery through voice activated interfaces, ways for audiences to interact with this content and, again, the challenges regarding the Quality of Experience. Patchy support for smaller languages and regional dialects emerged as one of the biggest hurdles to overcome in this regard. Several EBU Member organizations, including the BBC, are currently experimenting with voice activated devices and investigating their potential.
EBU Members and conference participants can access videos and PDFs from BroadThinking 2018 here.