Potsdam, Germany (December 16, 2005)–Each year, the great and the good of European television, radio and internet production gather to celebrate quality programming and production in a week of festival and competition known as Prix Europa. For an event held to celebrate innovation and quality, it was fitting that the inaugural concert at this year’s festival was broadcast in 5.1 surround sound using the WorldNet Oslo multichannel audio codec from APT.
Mahala Rai Banda, a Romanian group from the Gypsy ghettos around Bucharest, opened the festival on October 15, and the concert was broadcast live by Radiomultikulti and on EBU satellite. A Roma band was selected to mark the first year of the Decade of Roma Inclusion, an initiative aimed at ending discrimination against Europe’s largest minority. “It’s all the more exciting that this concert will not only open this year’s edition of Prix Europa, but will also mark the opening of the Radio Day of European Cultures, during which many broadcasters across Europe will again devote their radio programs to European cultures,” said festival manager, Susanne Hoffmann.
Traditionally, the Prix Europa has always been held in Berlin’s Broadcast Centre, the home of RBB (Radio Berlin-Brandenburg) which is entrusted with the recording and transmission of this event by the European Broadcasting Union (EBU). In a break from tradition, the 2005 event was moved to the historic Auditorium Maximum in the grounds of the University of Potsdam, but RBB retained control of the broadcast.
The Prix Europa event has previously been the focal point for several multichannel audio experiments, but this year a concerted effort was made to seek out a neat, effective and reliable solution to transmit the surround sound mix from the Auditorium Maximum to the RBB Broadcast Centre and onwards to Westdeutscher Rundfunk (WDR) in Cologne for satellite distribution. While the stereo transmission was carried out using standard ISDN codecs, the solution chosen for the 5.1 content was the WorldNet Oslo from APT. This multichannel audio codec enabled the surround sound mix to be transmitted on a single 2MB E1 link with phase correlation between all six channels.
Using a single E1 line was not only a tidy and cost-effective solution but also provided ample capacity, easily accommodating the highest-quality transmission mode. To fulfill the quality requirements of the master file format, RBB used the enhanced apt -X coding algorithm sending 22 kHz audio at 24-bit resolution depth. Even at this level of operation, only 1.728 kBit/s of the 1.920 kBit/s E1 link was utilized. The low delay, which is key feature of the enhanced apt-X algorithm, also meant that RBB were able to provide a seamless real-time transmission.
The enhanced apt-X stream was received in Cologne and decoded by the second WorldNet Oslo unit. From there, the decoded signal was routed to various in house destinations within WDR using AES/EBU and finally converted to the Dolby AC-3 format for distribution on Germany’s ARD Satellite. The broadcast could then be received by all owners of a set-top box with in-built Dolby 5.1 decoder while the 5.1 signal was simultaneously looped back to the venue for monitoring by the sound engineers in the OB van.