無線網路之SVC串流擷取最佳化

Optimized Extraction for SVC Streaming in Wireless Networks

李佳穎(Jia-Ying Lee)

指導教授 ： 李昌明

國立中正大學/工學院/通訊工程學系/碩士(2012年)

摘要

現今隨著視訊科技不斷進步，有效利用於網路傳輸多媒體視訊串流的議題受到高度的注目。在網路傳輸中因存在通道的干擾和終端設備能力不同，造成封包的遺失和品質需求不同，在有限的網路資源下達到最有佳的傳輸效率，包含補償遺失的封包資料和有效提高影像品質，為視訊串流一個重要的課題。為了達到使用者的在多媒體的品質需求，可利用可調式視訊編碼選擇最佳的傳輸品質，因不同的階層有不同的重要性，所以必須選擇適當的階層作傳輸，並依據通道狀況針對不同階層的視訊串流加入適當的保護，以提升服務的品質。
本論文中針對可調式視訊編碼的品質可調性和時間可調性做評估，依據不同階層遺失狀況，統計階層間相關性，搭配傳輸層所得到的通道遺失率，模擬多媒體傳輸品質最佳化結果。可提供適當的保護碼碼率對不同階層做保護和封裝設計，得到整體群播品質最佳的結果。最後，實驗數據顯示Optimal Extraction依照位元傳輸率 (Bit-rate) 挑選傳輸階層和QL (Quality-Layer-based Extraction) 相比，在Soccer中有1.52 dB的品質提升，考慮有封包遺失狀況發生，非對等錯誤保護在不同封包遺失率下的PSNR平均差比對等錯誤保護在City影像提升0.564dB。

關鍵字

可調式視訊編碼

並列摘要

Recently, the developments of video streaming technology are interesting, especially in the network transmission. With channel noise and various requirements from the user, the issues of packet loss and different quality of broadcasting service are still open. The efficient technique to realize the video streaming must consider the recovery of lost data and scalability to satisfy the various demands.
In order to meet the requirement of error correction and scalability, Scalable Video Coding and Unequal Error Protection are considered in this thesis. To analyze the layer priority of quality scalability and temporal scalability, the statistics of the loss in different Network Abstraction Level Unit are calculated in the transport layer. Therefore the optimization of the best video broadcasting quality can be achieved in the wireless network. Both of the channel coding rate and the number of scalability layer would be decided by the proposed scheme. Finally, the experimental results show the proposed Optimal Extraction scheme with coding rate selection has improved the average transmission quality about 1.52 dB than QL (Quality-Layer-based Extraction). Considering the packet loss condition with the proposed Optimal Extraction scheme, unequal error protection has PSNR gain about 0.564 dB, compared with the equal error protection.

並列關鍵字

Scalable Video Coding

參考文獻

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