H.264 轉碼?視頻檢測?CS/BS 景區監控與導游多網融合系統

        作品以中山陵為應用背景，構建了 H.264 轉碼平臺+BS/CS混合模式+ WiFi/WiMAX 無線網絡的監控與導游系統，實現了智能移動視頻監控（事件檢測、報警發布）、移動導游（移動視頻、互動地圖界面）、高清播放等功能。 系統以H.264 轉碼平臺統一視頻格式，兼容異構圖像，降低約4 倍碼率， 無需更換攝像機等前端設備，獲得了可觀經濟效益。 

        針對無線IP 網絡帶寬受限、易受干擾，采取了圖像細節/運動的內容檢測， 自H.264 的NAL 層動態調整視頻幀率或分辨率，這一穿層視頻QoS 控制。 針對景區監控特點，綜合采用自適應背景消除與三幀差相結合的混合算 法、改進模板匹配等算法，在監控中心對“逆行”及“越界”等視頻事件進行 檢測分析預警，提高了監控效率。

        為適于地理視頻環境的導游和監控，構建BS/CS 混合網絡架構。利用客戶 端手持PDA 上SVG 地圖瀏覽器和ViewBox 視窗播放器，實現移動導游和媒體 播放，分別發揮BS 的易操作及跨平臺性、CS 的響應實時的各自優點。

        針對視頻事件檢測、H.264 實時轉碼、高清視頻再現等復雜運算，充分利 用 Intel 雙核嵌入之星開發平臺，及 IPP、MMX、Pthread 等手段進行優化，獲 作品 得了成倍性能提升。 這在高清數字電視，高速公路聯網智能監控，城市社區服務，水文檢測、 簡介電子政務等領域也有廣泛應用。
 
This work is designed for the application of Sun Yat-sen Mausoleum, a wireless video surveillance and tour guiding system is built which is based on the H.264 transcoding platform, BS/CS hybrid mode and WiFi/WiMAX networks. This system integrates intelligent mobile video surveillance (real-time monitoring, incident detection, alerting), mobile tour guide (VoD, interactive map over PDA) and HD video playback. 

Heterogeneous videos are transcoded to H.264 video stream by the system as a result that the original equipment could be saved and the efficiency of the channel can be much higher.
Due to the quality of susceptible wireless communication and the limited bandwidth , this system can timely focus on image contents of fast-moving or detail requirements while adaptively modifying the frame rate and resampling in the H.264 NAL layer to offer a better video QoS control. This system uses a combination of adaptive background subtraction and three- frame differencing algorithm, and an improved template match algorithm in the detection of retrograde and cross-border processing to increase the efficiency and accuracy of video monitoring. The BS/CS network structure is used to suit for different conditions of guiding and monitoring. The clients get multimedia and guidance services through SVG map and Viewbox explore which are supported by their handed PDA. This mode of service not only obtains the easy operation advantages of BS but also the real-time advantages of CS. With the optimizing of Multi-threading, IPP, MMX, on “Embedded Star”, the system could deal with many functions such as real-time video surveillance, real-time H.264 transcoding, HD video playback etc. with high efficiency. The system could also be used in the domains as follows: HDTV, expressway Network Monitoring, city community services, hydrometeorology surveillance E - government and so on.
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