Moving Multimedia Simulations into the Cloud: a Cost-Effective Solution

Researchers often demand bursts of computing power to quickly obtain the results of certain simulation activities. Multimedia communication simulations usually belong to such category. They may require several days on a generic PC to test a comprehensive set of conditions depending on the complexity of the scenario. This paper proposes to use a cloud computing framework to accelerate these simulations and, consequently, research activities, while at the same time reducing the overall costs. A practical simulation example is shown, representative of a typical simulation of H.264/AVC video communications over a wireless channel. This work shows that, by means of a commercial cloud computing provider, the gains of the proposed technique compared to more traditional solutions using dedicated computers can be significant in terms of speed and cost reductio

Sensor-Based Real-Time Adaptation of 3D Video Encoding Quality for Remote Control Applications

The availability of stereoscopic mobile devices, such as mobile phones, on the consumer market allows to attempt the development of low-cost remote control systems that can provide a real-time 3D video feedback. In this work we show how implement such a communication system by considering the stringent latency constraints of the remote control scenario. To reduce the impact of this issue, we observe that part of the latency is due to the limited processing power of the mobile device that cannot sustain video transmission at high quality with low latency. Thus, we propose to dynamically change the latency-quality trade-off at the transmitter to optimize the quality of experience as perceived by the operator of the remote control system, by taking into account, in real-time, the dynamics of the control operations. In more details, low-cost accelerometer and gyroscopic sensors are employed to decide in real-time how much latency has to be privileged over quality and vice versa, by selectively reducing the quality of one of the views in favor of a reduced overall latency. Comparisons with a non-adaptive higher-quality but also higher-latency system show that the operators prefer the adaptive system despite the video quality is slightly reduced in dynamic control conditions

Foveated Video Streaming for Cloud Gaming

Good user experience with interactive cloud-based multimedia applications, such as cloud gaming and cloud-based VR, requires low end-to-end latency and large amounts of downstream network bandwidth at the same time. In this paper, we present a foveated video streaming system for cloud gaming. The system adapts video stream quality by adjusting the encoding parameters on the fly to match the player's gaze position. We conduct measurements with a prototype that we developed for a cloud gaming system in conjunction with eye tracker hardware. Evaluation results suggest that such foveated streaming can reduce bandwidth requirements by even more than 50% depending on parametrization of the foveated video coding and that it is feasible from the latency perspective.Comment: Submitted to: IEEE 19th International Workshop on Multimedia Signal Processin

A cost-effective cloud computing framework for accelerating multimedia communication simulations

Multimedia communication research and development often requires computationally intensive simulations in order to develop and investigate the performance of new optimization algorithms. Depending on the simulations, they may require even a few days to test an adequate set of conditions due to the complexity of the algorithms. The traditional approach to speed up this type of relatively small simulations, which require several develop-simulate-reconfigure cycles, is indeed to run them in parallel on a few computers and leaving them idle when developing the technique for the next simulation cycle. This work proposes a new cost-effective framework based on cloud computing for accelerating the development process, in which resources are obtained on demand and paid only for their actual usage. Issues are addressed both analytically and practically running actual test cases, i.e., simulations of video communications on a packet lossy network, using a commercial cloud computing service. A software framework has also been developed to simplify the management of the virtual machines in the cloud. Results show that it is economically convenient to use the considered cloud computing service, especially in terms of reduced development time and costs, with respect to a solution using dedicated computers, when the development time is longer than one hour. If more development time is needed between simulations, the economic advantage progressively reduces as the computational complexity of the simulation increases

Performance vs Quality of Experience in a remote control application based on real-time 3D video feedback

This paper presents a preliminary study that relates the ability in performing remote control tasks with 3D video feedback and the users' quality of experience (QoE) when users are asked to judge the video quality only. The QoE has been evaluated by means of traditional subjective quality experiments, while an objective performance indicator (alignment error) has been used in the remote control task. Results show that, unexpectedly, even a relatively poor subjective video quality still provides sufficient 3D perception to achieve satisfactory alignment performanc

Comparing temporal behavior of fast objective video quality measures on a large-scale database

In many application scenarios, video quality assessment is required to be fast and reasonably accurate. The characterisation of objective algorithms by subjective assessment is well established but limited due to the small number of test samples. Verification using large-scale objectively annotated databases provides a complementary solution. In this contribution, three simple but fast measures are compared regarding their agreement on a large-scale database. In contrast to subjective experiments, not only sequence-wise but also framewise agreement can be analyzed. Insight is gained into the behavior of the measures with respect to 5952 different coding configurations of High Efficiency Video Coding (HEVC). Consistency within a video sequence is analyzed as well as across video sequences. The results show that the occurrence of discrepancies depends mostly on the configured coding structure and the source content. The detailed observations stimulate questions on the combined usage of several video quality measures for encoder optimization

Smartphone-based 3D real-time vision system for teleoperation

We present a small form factor 3D vision system that can easily be mounted in any system for teleoperation and presents a low-latency suitable to perform interactive control. The proposed system is based on a commercial 3D smartphone that integrates a stereoscopic camera and a wireless connection. The smartphone has been customized to acquire and transmit stereoscopic video in real-time by means of a special purpose software that runs on the Android operating system. We believe that the choice of a compact solution based on an open source framework and commercial off-the-shelf hardware, will promote the widespread adoption of this architecture by interested developers in multiple scenario

Efficient Support for Video Communications in Wireless Home Networks

This paper investigates the performance of video communications over wireless networks employing the recently proposed Time-Division Unbalanced Carrier Sense Multiple access (TDuCSMA) coordination function. TDuCSMA is fully IEEE 802.11 standard compliant but offers novel bandwidth management capabilities. In this work the peculiar characteristics of TDuCSMA are configured and exploited to maximize the performance of video communications in a realistic home networking scenario. Simulation results show significant performance improvements with respect to legacy IEEE 802.11 network. The video quality gains are up to 13 dB PSNR with 500 ms playout buffer, while the average delay of the video packets is much lower, for the same amount of video traffic offered to the network. These results significantly contribute to enhance the quality of experience of the users of the video communicatio

Practical Distributed Video Coding in Packet Lossy Channels

Improving error resilience of video communications over packet lossy channels is an important and tough task. We present a framework to optimize the quality of video communications based on distributed video coding (DVC) in practical packet lossy network scenarios. The peculiar characteristics of DVC indeed require a number of adaptations to take full advantage of its intrinsic robustness when dealing with data losses of typical real packet networks. This work proposes a new packetization scheme, an investigation of the best error-correcting codes to use in a noisy environment, a practical rate-allocation mechanism, which minimizes decoder feedback, and an improved side-information generation and reconstruction function. Performance comparisons are presented with respect to a conventional packet video communication using H.264/advanced video coding (AVC). Although currently the H.264/AVC rate-distortion performance in case of no loss is better than state-of-the-art DVC schemes, under practical packet lossy conditions, the proposed techniques provide better performance with respect to an H.264/AVC-based system, especially at high packet loss rates. Thus the error resilience of the proposed DVC scheme is superior to the one provided by H.264/AVC, especially in the case of transmission over packet lossy networks

Content-Based Group-Of-Picture Size Control in Distributed Video Coding

Controlling the group of picture (GOP) size in distributed video coding (DVC) is a difficult but important task since it has a direct impact on the coding performance. This paper presents a framework to adaptively control the size of GOPs in a Wyner-Ziv encoder by means of encoder-side decisions based on support vector machines (SVM) that uses simple features extracted from the original video content. To train the SVM, firstly this work proposes how to compute the sequence of GOP sizes with the best rate-distortion performance given the set of GOP sizes that can be used during the encoding process. Then, an algorithm based on the previously trained SVMs is presented to control the actual GOP size each time a new decision can be taken at the encoder. Results show that the proposed algorithm can achieve a rate distortion performance close to the ideal one. Moreover, comparisons with a reference adaptive GOP size selection algorithm in the literature shows gains up to 2 dB PSNR in the best condition