點對點螢幕分享服務隨著Apple AirPlay推出後，成為熱門的影音分享服務，為此，Wi-Fi Alliance
訂定了新的Miracast標準。另一新興之雲端互動式螢幕分享服務則是透過Internet將遠端伺服器執
行的螢幕畫面分享至使用者，讓使用者可透過互動介面操控遠端伺服器，雲端遊戲、雲端智慧家
庭、Remote Play、Thin Client及遠端桌面即是此服務之應用。螢幕分享服務由於其互動操作的應用
需求，因此如何整合螢幕畫面擷取、編碼、串流、解碼及播放等技術，達到極低延遲的串流服務
已成為此服務成功與否之關鍵技術，本文將針對串流抹除碼原理做詳細介紹，並提出一個可達到
極低延遲之動態串流抹除碼技術，所設計之技術可依照資料重要性及網路頻寬等變化來動態調整
傳輸資料之保護強度，使其可在網路狀況不佳時，提升保護強度，改善串流抹除碼的保護效能，
降低資料封包傳輸所造成延遲；而在網路狀況良好時，節省串流抹除碼所需傳輸之保護位元資料。

Screen sharing services have received extensive attention since Apple Inc. announced screen
mirroring functionality, called airplay, on their products, such as iPhone, iPad and iTV. To provide screen
sharing service on heterogeneous platforms and devices, Wi-Fi-Alliance also announced a peer-to-peer
wireless screencast standard based on Wi-Fi direct connections. Besides, there are also many envisioned
applications of screen sharing, such as cloud gamming, cloud play, remote play, thin-client, remote desktop
control and so on. The key of screen sharing applications is how to provide ultra -low latency interactive
streaming service by developing and integrating new ultra-low delay techniques, such as screen capture,
screen video encoding/decoding and streaming. This paper addresses the ultra-low latency transmission by
using a new channel code, called streaming erasure code, which can provide theoretical bound on maximum
transmission delay. In this paper, the theory of streaming erasure code and the relevant research works will
be introduced in detail. Then, this paper proposes a modified streaming erasure code to improve the generic
streaming code by taking the priority and importance of data segments and network dynamics into account.
The proposed technique can dynamically generate longer code to provide stronger protection for data packets
with higher importance or priority when the network conditions become worse. On the contrary, a shorter code
will be yielded for data packets with lower priority when the network conditions become better to reduce the
amount of delivered data bits.