網路與多媒體科技的快速發展促使多媒體通訊的應用與服務範疇相對擴張。多樣化的多媒體服務日亦普及。在異質的無線網路環境下之多樣化的應用服務將使視訊傳輸因為使用者需求的不同，面臨比以往更大的挑戰。在頻寬變動的考量下，視訊資料需提供更多的位元率彈性提供適當的服務。而對於不同的應用層面，視訊的編碼與格式轉換亦是不可忽視的議題。而在網路端的技術可提高視訊傳輸在網路狀況不佳之下的接收品質。當同時考量網路與視訊位元率之狀況時，適當的調適性傳送機制，期可在所傳送的視訊資料與傳輸條件之間做最佳的資源分配，達成高品質的視訊傳輸。因此，現階段將不同應用服務的多媒體與網路技術加以整合，有相當程度的必要性。本整合型計畫中之各子計畫即是以多媒體視訊在異質無線網路環境中傳輸為考量，提出針對各種可能遭遇問題之解決方案。本計畫包含五個子計畫，本計畫總體目標為以三年的執行期限，在異質無線網路的環境下 ，設計即時、高品質、符合應用層面之視訊傳輸技術。本計畫內容將針對具變動性的網路環境發展出視訊轉換編碼之技術，可調式音視訊編碼系統，多視角視訊編碼系統，並在網路端對行動網路換手，跨層網路控制與QoS (Quality of Service)等議題提出整合之研究方案，最後將各子計畫技術結合，同時考慮編碼端與網路端資源，提出跨階層之傳輸最佳化設計。期能在現今多媒體通訊的應用上，提供幾近完善且多樣化之服務品質。 ; With the prosperous development of advanced digital signal processing techniques, telecommunications, and Internet deployment, the applications of multimedia communication are drastically broadened. The video transmission under the heterogeneous wireless environment has encountered severe challenges due to the various requirements. The transmitted video stream is supposed to provide bit-rate flexibility to meet the variation of channel bandwidths. In additional, video code conversion and multiple view angle coding are necessary for different applications. Moreover, it is expected that the delivery scheme is intelligent to adjust the transmission parameters adaptively to optimize the resource allocation based on the network conditions. Consequently, the integration of multimedia signal processing and network multicasting techniques is considerably important. This is a team project that includes 5 projects to develop a complete video delivery system with multiple functions including multicast handover and QoS, video transcoding, multi-view video coding, scalable video/audio coding, and cross-layer rate adaptation and optimization. It is expected to have two major outcomes when the project is completed. One is to propose and develop algorithms for enhancing coding efficiency and network utilization based on the heterogeneous network environment. The other is to integrate these techniques developed by each project and to provide high quality services for multimedia applications. ; 研究期間 9808 ~ 9907
