Screen Record And Playback System Based On H.264/AVC

With the rapid development of computer multimedia technology in recent years, it hasbeen accustomed to using the rich multimedia technology to transmit information, it isricher and more intuitive with the use of dynamic video than static pictures or text. Screenrecord and playback system can record the computer screen changes, generation video andplayback, it can be used to create software tutorials or teaching video, desktop operationmonitoring, production of courseware video, Remote Desktop, etc. Screen recordingprocess periodic screenshots and video encode, the process is relatively time-consuming,and occupy high CPU resource. Use larger screenshots interval can reduce the CPUutilization, but can’t record every screen changes, it is difficult to remain low CPUutilization and record every visible screen changes in screen recording. Taking intoaccount encode efficiency, video quality and bit rate, screen recording should choose anappropriate video coder.This paper designed and implemented a screen recording and playback system(SRPS), includes screen recording, video codec, video playback. Propose a new screencapture method, it can reduce and union a lot of redundant screenshots, and reduce CPUutilization under Windows platform. H.264is a high-performance video codec, it cangenerate high-quality, low bit rate video, provide error detection, low bandwidth, verysuitable for transmission in the network. And compared to MPEG-4, H.263, H.264generated lower, higher quality and smoother, smaller video. This paper designed andimplemented screen record and playback functions using the H.264codec in SRPS system,SRPS also supports MPEG-4, MS Video1, RM, XVID and other codec. This paper studythe relationship between video quality and quantization factor in H.264encoder, provide areference for user to balance video bit rate and quality.System performance tests show that the new screen capture method has low CPUutilization; And small quantitative factors make video more clear and more large,moderate quantitative factors values can balance video quality and size.