• Journal of Korea Society of Industrial Information Systems
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• v.12 no.1
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• pp.54-60
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• 2007

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality multimedia content to the mobile environment. The system adopts the MPEG-4 standard for the main video, audio and other media format. For providing interactive contents, it also adopts the MPEG-4 scene description that refers to the spatio-temporal specifications and behaviors of individual objects. With more interactive contents, the scene description also needs higher bitrate. However, the bandwidth for allocating meta data, such as scene description is restrictive in the mobile environment. On one hand, the DMB terminal renders each media stream according to the scene description. Thus the binary format for scene(BIFS) stream corresponding to the scene description should be decoded and parsed in advance when presenting media data. With this reasoning, the transmission delay of the BIFS stream would cause the delay in transmitting whole audio-visual scene presentations, although the audio or video streams are encoded in very low bitrate. This paper presents the effective optimization technique in adapting the BIFS stream into the expected bitrate without any waste in bandwidth and avoiding transmission delays inthe initial scene description for interactive DMB content.

• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.363-378
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• 2006

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the mobile environment. The system adopts MPEG-4 standard for the main video, audio and other media format. It also adopts the MPEG-4 scene description for interactive multimedia contents. The animated and interactive contents can be actualized by BIFS(Binary Format for Scene), the binary format for scene description that refers to the spatio-temporal specifications and behaviors of the individual objects. As more interactive contents are, the scene description is also needed more high bitrate. However, the bandwidth for allocating meta data such as scene description is restrictive in mobile environment. On one hand, the DMB terminal starts demultiplexing content and decodes individual media by its own decoder. After decoding each media, rendering module presents each media stream according to the scene description. Thus the BIFS stream corresponding to the scene description should be decoded and parsed in advance of presenting media data. With these reason, the transmission delay of BIFS stream causes the delay of whole audio-visual scene presentation although the audio or video streams are encoded in very low bitrate. This paper presents the effective optimization technique for adapting BIFS stream into expected MPEG-2 TS bitrate without any bandwidth waste and avoiding the transmission delay of the initial scene description for interactive DMB contents.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.556-558
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• 2005

이동멀티미디어 방송 서비스의 국내 표준인 디지털 멀티미디어 방송(DMB) 시스템에서 대화형 컨텐츠는 MPEG-4 씬 디스크립션 정보에 의해서 이루어진다. 따라서 사용자 상호작용이 풍부한 컨텐츠일수록 씬 디스크립션이 전송되기 위해서 요구되는 비트레이트도 높아진다. 그러나 이동 단말에 고품질의 멀티미디어 데이터를 전송하는 지상파 DMB 환경에서는 씬 디스크립션과 같은 부가 데이터의 전송율을 매우 제한적이다. 그러므로 오디오나 비디오 데이터뿐만 아니라 씬 디스크립션 정보도 저대역폭 및 이동 단말을 대상으로 유효한 품질을 보장할 수 있는 형태로 인코딩되어야 한다. 본 논문에서는 컨텐츠를 전송하기 전에 인코딩된 MPEG-4 씬 디스크립션 정보를 파악하여 전송시점에 예상되는 비트율에 최적화되도록 재구성함으로써 씬 디스크립션 정보의 전송지연 및 손실을 최소화하는 방안의 연구 내용물 제안하고 실험결과를 소개한다.