Design And Implementation Of Multi-task Interference-free Streaming Video Recording Software

With development of web technology and promotion of network bandwidth, YouTube, Netflix, Youku and other web video sites has appeared and rised. Web video application has become an important way for people getting information, even instead of television partly. But video websites would never store every video for too long time, or users hope to see a live match later while having a rest, that is why offline playback was on demand which is like a television videotape. A lot of users want to put streaming video into local storage, even into mobile device, for watching anywhere and anytime, whatever the network is connected or not.However, most websites providing online playback service has no download service, even prevent users downloading video files by complex technique; videos of a few websites was able to be downloaded but that does not always works. Considering the method itself of downloading video files is limited with different websites’ video delivering strategy, we need more widespread method to store online videos to local.In this paper, a kind of software for streaming media screencast was introduced, which is based on window screenshot and audio data intercept on Windows operating system. Using the software, the user could make screencast for streaming videos, while video and audio hiding completely into background and never disturbing user’s other jobs with computer. In addition, several screencast tasks could be running concurrently, which never affects each other. Users could conveniently fetch online video so long as she could play it.The program was developed on Delphi integrated development environment, that get each frame of video through Windows API of window screenshot. intercept bottom audio functions and gain audio data through API hook, and combine them into the whole video file. On multiprocessing architecture, multitask parallel was implemented. More than that, several methods to locate video area and judge video playback finished was designed to provide better user experience similar to downloading video file.