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Digital TV is rolling on with full force recently. Within its capability of transmitting data along with the audiovisual contents, TV program providers can serve their viewers interactively, by offering the customized applications, which run at their viewers' set-top boxes. However, the traditional remote controller, with limited signal transmission distance and designed functionality, restricts the usage scope of applications on DTV within a specific space. In order to defeat this limitation, we devise a novel solution which allows mobile appliances in an IP network, e.g., mobile phones and laptops, to control set-top boxes. Through our special designed system collaborating with a media center responsible for complex multimedia tasks, (such as transcoding and broadcasting digital content), viewers can remotely command their own set-top boxes to record the DTV programs and to watch pre-recorded ones, respectively, by using numerous mobile appliances with the ability to access an IP network. Finally, the experiments proved that our implemented system is very efficient and effectively to control set-top boxes to execute multiple commands in the heterogenous environment combining the DTV network with the IP network

This paper provides a data placement method based on rate staggering to store scalable video data in a disk-array-based video server. Scalable video means a video which is coded in such a way that subsets of the full video bit stream can be decoded to create low quality/resolution videos. Supporting layered multiple resolutions from a video server is very desirable in many applications. Note that in a disk array the video data corresponding to different rates of the same video clip are not required to reside in the same disk. In view of this, we propose and explore in this paper the approach of rate staggering, i.e., staggering video data in the disk array based on data rates, it is shown that the advantages of the proposed rate staggering method include: (1) minimizing the intermediate buffer space required by the server, (2) achieving better load balancing due to finer scheduling granularity, and (3) alleviating the disk bandwidth fragmentation. These advantages enable a video server using the rate staggering method to provide feasible solutions to some video stream requests which cannot be met otherwise. The system throughput can thus be increased. We also conduct several simulations for various applications. These experimental results show that the rate staggering method can significantly improve the performance of a VOD system.

Multimedia streams impose tight temporal constraints since different kinds of continuous multimedia streams have to be played synchronously. We devise in this paper a adaptive transmission scheme to ensure the error-resilient and synchronous playback of audio and video streams based on the real-time transport protocol. Realization of our adaptive transmission control is composed of a series of operations in three stages, namely, (1) dynamic reordering mechanism, (2) error-resilient mechanism, and (3) adaptive synchronization mechanism. In this paper, an empirical study is conducted to provide insight into our adaptive transmission scheme. As validated by our performance study, the adaptive transmission mechanism is able to strike a good balance of both stable playback and the end-to-end delay reduction. Furthermore, we analyze the jitter resistance, the end-to-end delay, and video quality in order to enhance the applicability of this scheme to more applications that require the transmission of multimedia data.