Gaurav Pande

Gaurav Pande

Arithmetic Coding (AC) is widely used for the entropy coding of text and video data. It involves recursive partitioning of the range [0,1) in accordance with the relative probabilities of occurrence of the input symbols. A data (image or video) encryption scheme based on arithmetic coding called as Chaotic Arithmetic Coding (CAC) has been presented in previous works. In CAC, a large number of chaotic maps can be used to perform coding, each achieving Shannon optimal compression performance. The exact choice of map is governed by a key. CAC has the effect of scrambling the intervals without making any changes to the width of interval in which the codeword must lie, thereby allowing encryption without sacrificing any coding efficiency. In this paper, we use a redundancy in CAC procedure for secure multicast of videos where multiple users are distributed with different keys to decode same encrypted file. By encrypting once, we can generate multiple keys, either of which can be used to decrypt the encoded file. This is very suitable for video distribution over Internet where a single video can be distributed to multiple clients in a privacy preserving manner.

Gaurav Pande

With exponential increase in the volumes of video traffic in cellular net-works, there is an increasing need for optimizing the quality of video delivery. 4G networks (Long Term Evolution Advanced or LTE A) are being introduced in many countries worldwide, which allow a downlink speed of upto 1 Gbps and uplink of 100 Mbps over a single base station. In this paper, we characterize the performance of LTE A physical layer in terms of transmitted video quality when the channel condi-tions and LTE settings are varied. We test the performance achieved as the channel quality is changed and HARQ features are enabled in physical layer. Blocking and blurring metrics were used to model image quality.

Gaurav Pande

With exponential increase in the volumes of video traffic in cellular net-works, there is an increasing need for optimizing the quality of video delivery. 4G networks (Long Term Evolution Advanced or LTE A) are being introduced in many countries worldwide, which allow a downlink speed of upto 1 Gbps and uplink of 100 Mbps over a single base station. This makes a strong push towards video broadcasting over LTE networks, characterizing its performance and developing metrics which can be deployed to provide user feedback of video quality and feed-back them to network operators to fine tune the network. In this paper, we characterize the performance of video transmission over LTE A physical layer using popular video quality metrics such as SSIM, Blocking, Blurring, NIQE and BRISQUE. We conduct experiments to find a suitable no-reference metrics for mobile scenario and find that Blocking Metrics is most promising in case of channel or modulation variations but it does not perform well to quantize variations in compression ratios. The metrics BRISQUE is very efficient in quantizing this distortion and performs well in case of network variations also.