626 research outputs found

    Video streaming

    Get PDF
    B

    Packet loss visibility across SD, HD, 3D, and UHD video streams

    Get PDF
    The trend towards video streaming with increased spatial resolutions and dimensions, SD, HD, 3D, and 4kUHD, even for portable devices has important implications for displayed video quality. There is an interplay between packetization, packet loss visibility, choice of codec, and viewing conditions, which implies that prior studies at lower resolutions may not be as relevant. This paper presents two sets of experiments, the one at a Variable BitRate (VBR) and the other at a Constant BitRate (CBR), which highlight different aspects of the interpretation. The latter experiments also compare and contrast encoding with either an H.264 or an High Efficiency Video Coding (HEVC) codec, with all results recorded as objective Mean Opinion Score (MOS). The video quality assessments will be of interest to those considering: the bitrates and expected quality in error-prone environments; or, in fact, whether to use a reliable transport protocol to prevent all errors, at a cost in jitter and latency, rather than tolerate low levels of packet errors

    Reduced reference image and video quality assessments: review of methods

    Get PDF
    With the growing demand for image and video-based applications, the requirements of consistent quality assessment metrics of image and video have increased. Different approaches have been proposed in the literature to estimate the perceptual quality of images and videos. These approaches can be divided into three main categories; full reference (FR), reduced reference (RR) and no-reference (NR). In RR methods, instead of providing the original image or video as a reference, we need to provide certain features (i.e., texture, edges, etc.) of the original image or video for quality assessment. During the last decade, RR-based quality assessment has been a popular research area for a variety of applications such as social media, online games, and video streaming. In this paper, we present review and classification of the latest research work on RR-based image and video quality assessment. We have also summarized different databases used in the field of 2D and 3D image and video quality assessment. This paper would be helpful for specialists and researchers to stay well-informed about recent progress of RR-based image and video quality assessment. The review and classification presented in this paper will also be useful to gain understanding of multimedia quality assessment and state-of-the-art approaches used for the analysis. In addition, it will help the reader select appropriate quality assessment methods and parameters for their respective applications

    Reducing the complexity of a multiview H.264/AVC and HEVC hybrid architecture

    Get PDF
    With the advent of 3D displays, an efficient encoder is required to compress the video information needed by them. Moreover, for gradual market acceptance of this new technology, it is advisable to offer backward compatibility with existing devices. Thus, a multiview H.264/Advance Video Coding (AVC) and High Efficiency Video Coding (HEVC) hybrid architecture was proposed in the standardization process of HEVC. However, it requires long encoding times due to the use of HEVC. With the aim of tackling this problem, this paper presents an algorithm that reduces the complexity of this hybrid architecture by reducing the encoding complexity of the HEVC views. By using Na < ve-Bayes classifiers, the proposed technique exploits the information gathered in the encoding of the H.264/AVC view to make decisions on the splitting of coding units in HEVC side views. Given the novelty of the proposal, the only similar work found in the literature is an unoptimized version of the algorithm presented here. Experimental results show that the proposed algorithm can achieve a good tradeoff between coding efficiency and complexity

    Hybrid video quality prediction: reviewing video quality measurement for widening application scope

    Get PDF
    A tremendous number of objective video quality measurement algorithms have been developed during the last two decades. Most of them either measure a very limited aspect of the perceived video quality or they measure broad ranges of quality with limited prediction accuracy. This paper lists several perceptual artifacts that may be computationally measured in an isolated algorithm and some of the modeling approaches that have been proposed to predict the resulting quality from those algorithms. These algorithms usually have a very limited application scope but have been verified carefully. The paper continues with a review of some standardized and well-known video quality measurement algorithms that are meant for a wide range of applications, thus have a larger scope. Their individual artifacts prediction accuracy is usually lower but some of them were validated to perform sufficiently well for standardization. Several difficulties and shortcomings in developing a general purpose model with high prediction performance are identified such as a common objective quality scale or the behavior of individual indicators when confronted with stimuli that are out of their prediction scope. The paper concludes with a systematic framework approach to tackle the development of a hybrid video quality measurement in a joint research collaboration.Polish National Centre for Research and Development (NCRD) SP/I/1/77065/10, Swedish Governmental Agency for Innovation Systems (Vinnova

    Measuring quality of video of internet protocol television (IPTV)

    Get PDF
    141 p.La motivación para el desarrollo de esta tesis es la necesidad que existe de monitorizar la calidad de experiencia del vídeo que se proporciona en una red IPTV (Internet Protocol Television). Esta necesidad surge del deseo de los operadores de telecomunicaciones de proporcionar un servicio más satisfactorio a sus clientes y alcanzar mayor penetración en el mercado. Los servicios sólo pueden tener éxito si la calidad de experiencia se garantiza. Las redes IPTV (Television sobre IP) son por naturaleza susceptibles a pérdidas de paquetes de datos que afectan a la calidad del vídeo que recibe el usuario. Entre los factores que contribuyen a la existencia de pérdida de paquetes de datos se encuentran la congestión de red, una planificación de red inadecuada o el fallo de algún equipamiento de la red. La calidad de experiencia de un vídeo se ve afectada por una serie de factores como por ejemplo la resolución, la ausencia de errores en las imágenes, la calidad de la televisión, las expectativas previas del usuario y muchos otros factores que se estudian en esta tesis

    Measuring quality of video of internet protocol television (IPTV)

    Get PDF
    141 p.La motivación para el desarrollo de esta tesis es la necesidad que existe de monitorizar la calidad de experiencia del vídeo que se proporciona en una red IPTV (Internet Protocol Television). Esta necesidad surge del deseo de los operadores de telecomunicaciones de proporcionar un servicio más satisfactorio a sus clientes y alcanzar mayor penetración en el mercado. Los servicios sólo pueden tener éxito si la calidad de experiencia se garantiza. Las redes IPTV (Television sobre IP) son por naturaleza susceptibles a pérdidas de paquetes de datos que afectan a la calidad del vídeo que recibe el usuario. Entre los factores que contribuyen a la existencia de pérdida de paquetes de datos se encuentran la congestión de red, una planificación de red inadecuada o el fallo de algún equipamiento de la red. La calidad de experiencia de un vídeo se ve afectada por una serie de factores como por ejemplo la resolución, la ausencia de errores en las imágenes, la calidad de la televisión, las expectativas previas del usuario y muchos otros factores que se estudian en esta tesis
    • …
    corecore