In this paper we present a novel two stage algorithm for improving video coding efficiency. The proposed method combines video cut detection and adaptive GOP structure. At first, we have proposed a new technique of frames' comparison for the shot cut detection. The majority of existing methods compare pairs of successive frames. We compare actual frame with its motion estimated prediction. We also present adaptive threshold. The efficiency of novel technique for video cut detection was confirmed through experiment and compared to the commonly used ones in the terms of recall and precision. The next step is to situate I frames to the positions of detected cuts during the process of video encoding. Finally the proposed method is verified by simulations and the obtained results are compared with fixed GOP structures of sizes 4, 8, 12, 16, 32, 64, 128 and GOP structure with length of entire video. Proposed method achieved the gain in bit rate from 15,33% to 50,59%, while not degrading PSNR in comparison to simulated fixed GOP structures.

Abstract. In this paper we present the methods used for the analysis of video based on mutual information. We propose a novel method of abrupt cut detection and a novel objective method for measuring the quality of video. In the field of abrupt cut detection we improve the existing method based on mutual information. The novelty of our method is in combining the motion prediction and the mutual information. Our approach provides higher robustness to object and camera motion. According to the objective method for measuring the quality of video, it is based on calculation the mutual information between the frame from the original sequence and the corresponding frame from the test sequence. We compare results of the proposed method with commonly used objective methods for measuring the video quality. Results show that our method correlates with the standardized method and the distance metric, so it is possible to replace a more complex method with our simpler method.

Our paper deals with utilization of Quality of Service (QoS) mechanisms for backbone IP network capable of transport of voice, data and video services. The first part presents selected QoS mechanisms for multiservice IP networks. The next part discusses impact of selected QoS mechanisms on multimedia traffic through simulations. In the final part we have proposed combination of QoS methods for selected network configuration.

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