|
|image = Transmission in the Brazilian standardization structure.jpg |image_size = |alt = |caption = SBTVD Standards Structure |first_published = |version = 0.0 |version_date = November 11, 2007 }} The audio and video compression aspects of the Brazilian Digital Terrestrial Television Standards are described in the three documents published by ABNT, the Brazilian Association of Technical Standards (''Associação Brasileira de Normas Técnicas''), the〔ABNT, the Brazilian Association of Technical Standards (''Associação Brasileira de Normas Técnicas'')〕 ABNT NBR 15602-1:2007 - Digital terrestrial television - Video coding, audio coding and multiplexing - Part 1: Video coding; ABNT NBR 15602-2:2007 - Digital terrestrial television - Video coding, audio coding and multiplexing - Part 2: Audio coding; and ABNT NBR 15602-3:2007 - Digital terrestrial television - Video coding, audio coding and multiplexing - Part 3: Multiplexing signals. The standard was written by telecommunications and television experts from many countries with their works coordinated by the SBTVD Forum and cover in detail all the aspects of video and audio coding that applies to SBTVD. The complete document can be found and downloaded freely in English, Spanish and Portuguese at ABNT's website. ==Introduction== Audio and video coding changes are some of the additional technological updates added to the standard. The adoption of Recommendation ITU-T H.264 (MPEG-4 AVC, Advanced Video Coding) as the compression tool allowed for a great leap in quality in all applications: from high definition to low resolution videos. The High Profile is the video compression profile adopted for SDTV and HDTV signals, while the Baseline Profile is used for 1-Seg content. Differently from the Japanese system, the coding level specified for the Brazilian system allows the deliver of low resolution video content of up to 30 frame/s for portable receivers. Audio coding has also seen improvements in the Brazilian specifications. The choice for the MPEG-4 AAC standard combines greater performance and flexibility with low signaling overhead. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「ABNT NBR 15602」の詳細全文を読む スポンサード リンク
|