Michal Ries

Video Quality Estimation for Mobile H.264/AVC Video Streaming

The scope of this paper is the estimation of subjective video quality for low-resolution video sequences as they are typical for mobile video streaming. Although the video quality experienced by users depends on spatial (edges, colors, ...) and more considerably on temporal (movement speed, direction, ...) features of the video sequence, most of the well-known methods are based on spatial features. This paper presents a new reference-free approach for quality estimation based on motion characteristics. The character of motion is determined by the amount and direction of the motion between two scene changes. In this paper, two methods are presented. The first method, presents the design of a quality metric based on content adaptive parameters, allowing for content dependent video quality estimation. The second method estimates video quality in two steps. Firstly, the content classification with character sensitive parameters is carried out. Finally, based on the content class, frame rate and bitrate, the video quality is estimated. The performance of the proposed methods is evaluated and compared to the ANSI T1.801.03 metric. The results show that the motion-based approach provides powerful means of estimating the video quality experienced by users for low resolution video streaming services.

Content Based Video Quality Estimation for H.264/AVC Video Streaming

The scope of this work is the estimation of video quality for low resolution video sequences typical in (mobile) video streaming applications. Since the video quality experienced by users depends considerably on the spatial (edges, colors, ...) and temporal (movement speed, direction, ...) features of the video sequence, this paper presents a two-step approach to quality estimation. Firstly, shots between two scene changes are analyzed and their content class is found. Secondly, based on the content class, frame rate and bitrate, an estimation of quality is carried out. In this paper, the design of the content classifier as well as an appropriate choice of the content classes and their characteristics is discussed. Moreover, the design of quality metric is presented, based on the mean opinion score obtained by a survey. The performance of the proposed method is evaluated and compared to several common methods. The results show that the proposed approach provides powerful means of estimating the video quality experienced by users for low resolution video streaming services.

Motion Based Reference-Free Quality Estimation for H.264/AVC Video Streaming

The scope of this paper is the estimation of subjective video quality for low resolution video sequences as they are typical for mobile video streaming. Although the video quality experienced by users depends on spatial (edges, colors, ...) and more considerably on temporal (movement speed, direction, ...) features of the video sequence, most of the proposed methods are based on spatial features. This paper presents a new reference free approach for quality estimation based on motion character. The character of motion is determined by the amount and direction of the motion between two scene changes. In this paper, the design of a universal reference-free video quality metric is presented. The design of the quality metric is based on content adaptive parameters, allowing for content dependent video quality estimation. The performance of the proposed universal metric was evaluated with various video content types and compressions settings. The results show that the proposed approach provides powerful means of estimating the video quality experienced by users for low resolution video streaming services

Empirical study of subjective quality for Massive Multiplayer Games

Online gaming is a member of the real time interactive multimedia services. This service suffers from all impairments on the networking layer that increase the latency, respectively the responsiveness. The quality of service (QoS) of online gaming is becoming an important issue due to a massive increase of online games (Half-life, War-craft) with a significant player community. The purpose of this project is to investigate the impact of network impairments (delay, jitter) on the perceived QoS. We hereby focus on massively multiplayer online games (MMOG), due to their amount of active users and their popularity. The initial step is to develop a test setup for subjective quality evaluation for MMOG games. The final outcome of this paper is to propose a QoS metric for online gaming.

Audiovisual quality estimation for mobile streaming services

3G mobile terminals supporting audio and video streaming services became reality although the perceptual quality for such low bit rates is limited. To select optimal codec parameters for audio and video, it is important to consider corresponding quality requirements based on human perception. The intention of this paper is to estimate perceptual audiovisual quality for low bit rate videos. We performed subjective perceptual experiments for audio, video and audiovisual quality for music and speech video contents. These experiments were carried out for different audio and video codecs supported by todays mobile terminals. Furthermore, we study the simultaneous influence of music and speech quality on subjective perceptual video quality and mutually compensation effect that occurs in this context. Finally, we propose audiovisual metric for an automated quality estimation.

Audiovisual quality estimation for mobile video services

Provisioning of mobile video services is rather challenging since in mobile environments, bandwidth and processing resources are limited. Audiovisual content is present in most multimedia services, however, the user expectation of perceived audiovisual quality differs for speech and non-speech contents. The majority of recently proposed metrics for audiovisual quality estimation assumes only one continuous medium, either audio or video. In order to accurately predict the audiovisual quality of a multi-media system it is necessary to apply a metric that takes simultaneously into account audio as well as video quality. When assessing a multi-modal system, one cannot model it only as a simple combination of mono-modal models, because the pure combination of audio and video models does not give a robust perceived-quality performance metric. We show the importance taking into account the cross-modal interaction between audio and video modes also code mutual compensation effect. In this contribution we report on measuring the cross-modal interaction and propose a content adaptive audiovisual metric for video sequences that distinguishes between speech and non-speech audio. Furthermore, the proposed method allows for a reference-free audiovisual quality estimation, which reduces computational complexity and extends applicability.

Universal smart energy communication platform

Online data collection is crucial for increasing efficiency of energy consumption and reducing environmental impacts. Moreover, utility market liberalization and parallel EC requirements on smart measurement brought new challenges for utility and telecommunication providers. More Advanced Metering Infrastructure (AMI) networks have been proposed with not clear widely accepted solution. Our study investigates feasibility of cost efficient measurement architecture based on already deployed network and home access technologies. Developed system running on the smart home gateway acts as a multi purpose enabler providing a real time smart meter data collection and visualization, but can be used for any home automation services as well.

On the Willingness to Pay in Relation to Delivered Quality of Mobile Video Streaming

Provisioning of mobile video streaming became reality. The next evolution step in mobile video streaming is to allocate resources optimally from both the service provider and the user perspective. Therefore, it is important to determine the relation between the willingness to pay (WTP) and the delivered quality of mobile video streaming. In order to determine this relation we performed tests on subjective quality and WTP with the most frequent content types, codecs and their settings. A further analysis shows clearly a mutual dependence between subjective video quality and WTP.

QoE evaluation of high-definition IPTV services

Quality of Experience (QoE) in the context of high definition IPTV represents a purely subjective measure from the users perspective of the overall value of the service provided. QoE cannot be taken simply as objective quality parameter of the service, but must also take into consideration every factor that contributes to overall user service perception. This paper introduces typical challenges and approaches for QoE testing of HD IPTV services. We provide an overview of influence factors, with a special focus on content types and characteristics, and we provide decision criteria for selecting subjective testing methods for IPTV research studies. We furthermore highlight related key results and learnings from the ongoing European research project OptiBand.

IP home gateway as universal multi-purpose enabler for smart home services

There are many candidates for a communication infrastructure between the smart home gateway and service providers, distribution centers or end-users accessing smart home applications remotely. Optimally the access technology should be already deployed in order to minimize initial investments and in parallel must provide sufficient reliability and security even for critical applications. Therefore, we focused at already deployed platforms which have a strong potential to become the key communication technologies for smart home domain. Furthermore, we investigated the applicability of residential gateway access technology for emerging home automation services. Finally, we developed and demonstrate a middleware solution enabling the “state of technology” IP-based home gateway to serve as a universal multi-purpose enabler for connected home automation systems like alarm systems, smart metering and grid, photo-voltaic energy production systems, etc.ZusammenfassungEs gibt eine Reihe von Möglichkeiten, eine Kommunikationsinfrastruktur zwischen einem Smart Home Gateway, Dienstleistungsanbietern und Verteilnetzbetreibern einzurichten, die gleichzeitig auch den Endbenutzern den Fernzugriff auf Smart Home-Anwendungen erlaubt. Die bevorzugte Zugangstechnologie sollte jedoch idealerweise schon weit verbreitet und verfügbar sein, um Anfangsinvestitionen zu minimieren, und muss parallel dazu auch noch für kritischen Anwendungen ausreichende Zuverlässigkeit und Sicherheit aufweisen. Daher wurde in diesem Beitrag ausschließlich auf bereits in Betrieb befindliche Plattformen mit hohem Potenzial als Schlüsseltechnologien für Smart Home-Kommunikation fokussiert. Darüber hinaus galt es, die technologische Eignung des so genannten „Residential Internet Gateway“ für neue Home Automation-Dienstleistungen zu untersuchen. Letztendlich kann anhand einer konkret entwickelten Middleware-Lösung aufgezeigt werden, dass handelsübliche IP-basierte Internet-Home-Router durchaus nutzbringend als universelle Mehrzweck-Gateways für die Vernetzung und Steuerung von Hausautomationssystemen wie Alarmanlagen, Smart Metering, Smart Grid-Boxen und Photovoltaikanlagen eingesetzt werden können.