Application Software Design For Webcam Monitor System In Android Mobile Platform

Since the users have the strong demand use the mobile to be able to watch the real timemonitoring that is used to be on the Windows platform. In another hand, there is scarcely anyreal-time network monitor playing software with good performance on Android mobileplatform, as there is no proper file parser. So I decided to fill the blank.So far, the professional surveillance camera usually supports using MJPEG, MPEG-4orH.264standard to compress image data and send. MJPEG format data are based on HTTPprotocol for transmission. It used to transmit data by RTP protocol when the camera compressvideo data by MPEG-4standard or H.264standard. This paper designs an application whichcould play real-time video send by network camera. The application runs on the mobile phonewhich use Android Platform.This software uses JAVA code to implement the receiver of image data that cameratransmitted by following the HTTP protocol and unicast RTP protocol. The software usesHTTP protocol to get MJPEG flow data, and analysis the flow data in JAVA layer. Then, itsplits the flow data into lots of single JPEG image data, and decode the JPEG image data oneby one with Android own decoding library. Video codec of the use of surveillance camerasare relatively more widely used video standard. However, due to real-time video streamingdata to send by side to side, the length of the file cannot be calculated. It is different withvideo files which stored in the disk. So that the MPEG-4stream and H.264stream cannotplayback because file parser error.The interface that parser MPEG-4stream of data and call decoding library is coded by C.The TS stream parser of H.264which used for camera is coded by JAVA. And the softwareuse JAVA to split the mixing data into the audio data and the video data which parsed into NAL unit. Then decode the NAL unit data by JNI decoding libraries. Now most of the mobilephone can't directly display the real-time streaming video that the camera caught, because itwas no corresponding file parser.Playback monitoring image need to ensure the correctness of the image data, and ensurethe real-time in time. But the correctness of the image data and the real-time in time aremutual restraint. In this paper it would be use frame dropping manager to achieve it. As thenetwork transmission environment complex, it will lost packet. Packet loss will lead to imagedecode error. If found this issue, it needs to discarded the related data together. Plus, it need toensure that the delta-T between display image with cameras capture image not be too big. Soit has to discard some data when the software or hardware could not process it in time. In thispaper, it design three buffer in different threads to control it for avoid the decode error whichcaused by frame dropping. In addition, this software use Multi-Touch and gesture recognitionto implement the function of control network camera action by mobile phone. The differentmanufacturer designs the different API. It will cause the application's compatibility is poor,and cannot be a product. In this paper, define external standard configuration files to solvethis problem.