Design And Implemention Of A Supermarket Advertising Video System Based-On Wi-Fi

Providing a guidance service in a supermarket can greatly help consumers quickly find what they want,so supermarket managers hope to find a cheap and automatic shopping guidance service solution.Based on this background,this thesis designs and implements a supermarket advertising video system with H.264 as the video coding standard and Wi-Fi as the wireless transmission method.The system includes an advertisement server and a terminal device.The software on the advertisement server compresses the advertisement videos using the H.264 video coding standard,and encapsulates it according to the RTP/RTCP transmission protocol,and then transmits it through Wi-Fi to the terminal device arranged in the supermarket.After receiving the advertisement videos stream,the terminal device decapsulates the data packets and decodes the H.264 video and playbacks it in real time.At the same time,the terminal device also collects the environment pictures in supermarket through the camera,and detects the faces in pictures,and counts the number of customers.The thesis designs and implements the software on the advertisement server includes H.264 video coding module and RTP encapsulation/transmission module,and improves the searching templates of motion estimation algorithm in inter-frame prediction in H.264 video coding.The H.264 video encoding module can compress the advertisement video with the H.264 encoding library.The RTP encapsulation/transmission module can encapsulate the stream into some RTP data packets according to the RTP protocol,and send the RTP data packets according to the RTCP protocol.The thesis designs the hardware of the terminal device based on a processing chip RK3288,and implements its components such as Wi-Fi module,Ethernet module,audio module,MIPI screen module,camera module,DC/DC module and storage module.The thesis designs the embedded software of the terminal device based on embedded Linux,builds the embedded Linux4.4 platform,and implements the RTP receiving/decapsulating module,H.264 decoding/playbacking module and environment video information collection module.The RTP receiving/decapsulating module can receive the RTP data packets from the advertisement server according to the RTP/RTCP protocol,and splices these packets to H.264 stream files.The H.264 decoding/playbacking module can decodes these stream files with the FFmpeg library,and playback them with the SDL library.The collection module can detect the faces in the pictures collected by camera with the V4L2 and OpenCV library,and count the number of customers in the market.The test of the supermarket advertising video system shows that the improvement of the searching templates of motion estimation algorithm in inter-frame prediction in H.264 video coding can reduce the run-time of coding while the original video quality is basically maintained.And the operation of system also shows that the system can work well.