Year 52 - Issue 3 - December 2003
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Year 52 - Issue 3 - December 2003
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Cover |  |
Contents |  |
G.F. Barbieri Editorial |
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V. Mignone, A. Morello The DVB-S2 second-generation system for satellite broadcasting and Unicast Ten years ago the world-famous DVB-S system was defined and it is now operating all over the world. In 2003 the DVB Project has developed DVB-S2, the second-generation specification for satellite broadcasting. It benefits from more recent developments in channel coding (LDPC codes) combined with a variety of modulation formats (QPSK, 16APSK and 32APSK). When used for interactive point-to-point applications like IP based service navigation, it may implement Adaptive Coding & Modulation (ACM), thus allowing the transmission parameters to be optimised for each individual user, dependant on path conditions. Backwards compatible modes are available, allowing existing DVB-S services and STB’s to continue working during any transitional period |
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A. Falletto DVB-T and Access Services for disabled people The DVB Standard allows the distribution of programmes characterized by a greater audio and video quality and by increased capabilities to implement services to facilitate the access by disabled people. Three different categories of Access Services can be singled out: subtitles, audio description and sign language. In the digital platform, due to the on-board computational power, the decoders offer richer and more versatile applications. Subtitles can use enhanced graphics, icons and pictures. Audio descriptions can exploit the multichannel audio. In the case of sign language, there are studies to define downloadable applications where an avatar (virtual actor) reproduces the translator movements; this service can be enabled or disabled by the user, while this is impossible in the analogue version. |
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At the EBU Village | ||||||
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The Village of Ads | ||||||
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Metadata and Modelling A constant appointment is present, about the problems in defining and using metadata in environments of production and distribution of audiovisual contents and about the models in such environments.
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