With the proliferation of camera equipped cell phones and the deployment of the higher data rate 2.5G and 3G infra structure systems, providing consumers with video-equipped cellular communication infrastructure is highly desirable, and can drive the development of a large number of valuable applications. However, for an uplink wireless channel, both the bandwidth and battery energy in a mobile phone are limited for video communications. In this paper, we pursue an energy efficient video communication solution through joint video summarization and transmission adaptation over a slow fading wireless channel. Coding and modulation schemes and packet transmission strategy are optimized and adapted to the unique packet arrival and delay characteristics of the video summaries. In additional to the optimal solution, we also propose a heuristic solution that is greedy but has close to optimal performance. Operational energy efficiency-summary distortion performance is characterized under an optimal summarization setting. Simulation results show the advantage of the proposed scheme with respect to energy efficiency and video transmission quality.
The goal of video summarization is to select key frames from a video sequence in order to generate an optimal summary that can accommodate constraints on viewing time, storage, or bandwidth. While video summary generation without transmission considerations has been studied extensively, the problem of rate-distortion
optimized summary generation and transmission in a packet-lossy network has gained little attention. We consider the transmission of summarized video over a packet-lossy network such as the Internet. We depart from traditional rate control methods by not sacrificing the image quality of each transmitted frame but instead focusing on the frames that can be dropped without seriously affecting the quality of the video sequence. We take into account the packet loss probability, and use the end-to-end distortion to optimize the video quality given constraints on the temporal rate of the summary. Different network scenarios such as when a feedback channel is not available, and when a feedback channel is available with the possibility of retransmission, are considered. In each case, we assume a strict end-to-end delay constraint such that the summarized video can be viewed in real-time. We show simulation results for each case, and also discuss the case when the feedback delay may not
With the deployment of 2.5G/3G cellular network infrastructure and large number of camera equipped cell phones, the demand for video enabled applications are high. However, for an uplink wireless channel, both the bandwidth and battery energy capability are limited in a mobile phone for the video communication. These technical problems need to be effectively addressed before the practical and affordable video applications can be made available to consumers. In this paper we investigate the energy efficient video communication solution through joint video summarization and transmission adaptation over a slow fading channel. Coding and modulation schemes, as well as packet transmission strategy are optimized and adapted to the unique packet arrival and delay characteristics of the video summaries. Operational energy efficiency -- summary distortion performance is characterized under an optimal summarization setting.