Tuesday, October 05, 2004
Surround sound For HD(tm) Radio Demonstrated
| (credit: medianetwork weblog)
Telos/Omnia and Fraunhofer IIS will carry our the first public demonstration of their new surround system for HD Radio™ at the NAB Radio Show in San Diego on October 6-8. They say the system delivers impressive full surround audio without compromising the stereo signal in any way. HD Radio, the new digital radio broadcast standard for the USA, works in the traditional FM and AM channels to deliver high quality digital audio to listeners. About 100 radio stations are already on-air using HD Radio technology, with many more planning to begin HD Radio broadcasts. The key to the system is that all the pieces of audio that go to the surround channels are present in the two stereo channels. Additionally, there is an ancillary data channel used for transmitting spatial information. The surround decoder, if present in the receiver, uses this information to move the pieces of audio to their respective positions, recreating the original multi-channel sound. In the system presented, 80 kb/s are used for the stereo channels and 16 kb/s for the surround information. The system is based on work by Fraunhofer IIS and Agere Systems in the area of "binaural cue coding". Three essential factors are required for the perception of a spatial audio image: level difference, time difference and coherence between channels. These values are represented as a function of frequency and time with very compact coding and allow for a huge data saving compared to transmitting all audio channels individually. Harald Popp, head of the Fraunhofer IIS Multimedia Realtime Systems Department notes, "Having invented MP3 we see surround as the next major audio enhancement. The sound is exquisite in the lab and will be as striking on air." Telos CEO Steve Church comments, "Radio station owners paid for an old-fashioned FM stereo license, but with this technology they could have a state-of-the-art digital surround license for no additional cost." The surround technology can work with any core stereo codec. Fraunhofer IIS has already presented it as an enhancement to MP3 and MPEG-4 HE-AAC, and work is underway to marry it with other codecs. # posted by Andy @ 11:13 UTC |
Monday, October 04, 2004
New efforts to curb pirate radio in London
| ( credit: medianetwork weblog )
A number of boroughs in London have joined forces to try to close down pirate radio stations in the British capital which are linked to drug dealing. The councils say the illegal broadcasts are used to advertise secret raves where drugs are sold. They also claim that petty crime is being committed by persons needing money to advertise on the stations. Residents living in the tower blocks where the antennas are located are often terrorised, and council officials need police protection to carry out raids. Now, Tower Hamlets, Newham and Barking, Hackney and Dagenham say they will work together to prevent the pirates from escaping across borough boundaries and displacing the problem. The councils will use court injunctions and antisocial behaviour orders to ban the rogue broadcasters from the capital. In Hackney alone, almost 50 masts have been removed so far this year. These measures are in addition to the efforts of media regulator Ofcom, which carried out 589 operations against pirate radio stations in London last year, and is on course for an even higher total at the end of 2004. # posted by Andy @ 10:16 UTC postCount('109688573820299785'); Comment (0) |
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