Video watermarking plays a key role in copyright protection domain of today's world. In the following paper, a blind watermarking algorithm is being proposed in which the watermark information is being embedded by little alteration of some of the value of DCT coefficients of luminance part of video during encoding it in MPEG-2 style. It is obvious that for any type of watermarking the three parameters, robustness, perceptibility and payload capacity must be simulated in order to provide better results . But unfortunately there is always a trade off among all these three parameters. But the proposed algorithm focused on one more issue, 'elapsed time', a serious concern in video watermarking. The special care must be taken that how much time the system takes to embed the watermark. The algorithm is being tested also against several intentional and unintentional attacks to judge the robustness of this scheme. To maintain the perceptibility issue the value of threshold is manage in such a way that the quality of video must not being compromised during the embedding process. Therefore, the superiority of this algorithm is that our approach has covered three characteristics and evaluated better results as compared to the existing techniques proposed by other researchers.