傳送於差異服務網路之H.264視訊重要性分類機制研究摘要近年來,隨著寬頻網路時代的到來,在網路上傳送多媒體服務已相當的普及,但多媒體視訊資料經過壓縮編碼之後,會產生不同重要性之視訊封包,若一視同仁的傳輸於網路上而遇到網路壅塞時,將使得視訊品質遭受到嚴重的影響。 模擬結果顯示,相對於傳統以畫面位置為基礎的分類機制,在相同的網路環境下,本論文提出的機制能改善接收的視訊品質達0.7dB。 |
Robust Significance Classification Mechanism for H.264 Video over Differential Service NetworkAbstractIn recent years, the delivery of video streaming services in Internet is popular and full of potential. However, an equal error protection scheme to all video packets in Internet will significantly degrade the video quality since the encoded and packetizated video packets have different significances. Therefore, this thesis proposes a Significance Classification mechanism (SC-TS) to classify the video packet importance from Temporal and Spatial domain simultaneously. SC-TS not only determines packet significance from the frame order in time domain but also utilizes error tracking concept to differentiate significances of video packets in the same frame. Moreover, for satisfying various video sequences with different coding properties, this thesis adds a learning algorithm of error propagation property to SC-TS, which is named Adaptive SC-TS (ASC-TS) in this thesis. While utilizing ASC-TS, the required error propagation ratio of next GOP is learned from the error propagation results of current GOP. Simulation results reveal that the proposed ASC-TS mechanism can effectively improve the received picture quality up to 0.7dB under the same network environment, compared with the traditional classification mechanism that determines the packet signification from temporal domain only. |