Abstract
MPEG-2是一個受廣泛應用的視訊編碼標準，諸如視訊會議、數位廣播、高 畫質數位電視等，因此它在數位通訊裡伴演著一個重要的角色。在衛星通 訊上，由於大氣的情況變化莫測，傳輸的MPEG-2碼串會由於天候的影響， 產生了隨機或是聚集的錯誤。而錯誤對MPEG-2碼串的傷害力很大。因此， 本篇論文提供一些方法去對抗錯誤的產生。我們藉由錯誤更正碼去組合一 個錯誤更正的控制系統，來抵抗錯誤的發生。如果錯誤率太高無法由保護 碼所解決，本篇論文提出隱蔽錯誤的方法補救錯誤所造成的視訊品質破壞 。結果顯示，藉由錯誤更正的控制系統與隱蔽錯誤的方法，在一般氣候的 錯誤率下皆能保護良好，對於錯誤所造成的視訊黑塊也能恢復到可接受的 品質。本篇論文除了對MPEG-2單層編碼作模擬實驗，亦對空間解析度延伸 編碼、信號雜訊比延伸編碼作探討。 MPEG-2 is an international video coding standard for broadapplications such as video conferencing, digital broadcasting,and HDTV. It plays an important role in digital communication.For satellite communication, due to varying atmosphericcondition and rain attenuation, random or bursty errors may occurin the MPEG-2 transport stream. However, the MPEG-2 bitstream isvery vulnerable to errors. Hence we propose some means to combaterrors. The FEC system is implemented to protect the bitstreamand error concealment techniques are used to compensate the lostregions of a picture due to the errors which can not be correctedby the FEC system. The error concealment schemes of two-layersystems such as spatial scalable systems and SNR scalable systems are proposed. It is shown that the error concealment schemes giveoverall visual quality acceptable even under severe transmissionerror environments.