Jiarun Song

Xidian University · School of Telecommunications Engineering

Chroma from luma (CfL) in AOMedia Video 1 (AV1) utilizes the correlation between color components to derive the predicted chroma from the reconstructed luma. The mean of the predicted chroma, i.e., dc, is set to the chroma average of the neighboring regions. Since the neighboring regions have limited reference samples, the distribution of the codin...

Cloud virtual reality (Cloud VR) services usually introduce high latency in rendering and streaming, resulting in a mismatch between the visual and vestibular systems, causing user sickness and dizziness during the service. To solve this problem, asynchronous rendering technology is usually used to provide smooth viewing. The asynchronous solution,...

Parametric models of video quality are designed for service and network planning as well as video quality monitoring. They are widely applied in a broad range of applications especially when video streams are encrypted or even unavailable at all. Designing metrics in these models remains challenge due to limited available information. In this paper...

Viewport-adaptive streaming is now a widely embraced solution for transmission of 360-degree video, where users' perceptual quality after their head movement suffers from the temporary exposure of a low-quality area, as well as the related delay in quality refinement. In this paper, subjective experiments were conducted to investigate the human's p...

With the development of multimedia technologies and virtual reality display devices, omnidirectional videos have gained popularity nowadays. To reduce the bandwidth requirement for omnidirectional video transmission, tile-based viewport adaptive streaming methods have been proposed in the literatures. Challenges related to decoding the tiles simult...

With the development of immersive media technologies, omnidirectional video service has been popularized at an accelerated speed due to the sense of presence it offered. Accurately measuring user’s subjective sense of presence on virtual reality (VR) devices is urgently required by video service providers and VR device manufacturers to further impr...

Initial perceived quality (IPQ) reflects users’ perception when waiting videos to play, which directly determines user’s willingness to go on watching videos. However, IPQ has never been carefully analyzed and evaluated. In this paper, two types of subjective test methods were elaborately designed, where the IPQ scores were obtained. The accuracy o...

Recent years have witnessed the rapid development of mobile video services. The diversity of mobile devices and video services can result in a difference in a user's perceptual video quality, which presents a significant challenge for video quality evaluation. An objective assessment model is proposed that considers both video and screen characteri...

The popularity of HTTP-based video streaming services has been increasing in recent years. The quality of HTTP-based video streaming services is measured by the user's quality of experience (QoE). Perceptual quality (PQ), a strong indicator of the QoE, has been widely studied in the literature. Specifically, previous studies primarily focused on mo...

Parametric planning models are designed for estimating the video quality, which can be applied to effective plan, implementation, and management of network video applications and communication networks. However, different from the bitstream-based evaluation models, the planning models are not allowed to exploit the video streams, with only limited...

The diverse display screen imposes significant challenges for assessing the perceptual media quality across different mobile devices. In this paper, the perceived image quality on different mobile phones is investigated. Firstly, subjective experiments for image quality evaluation are implemented on 9 popular mobile phones and a broadcast-quality m...

Quality of experience (QoE) has significant influence on whether or not a user will choose a service or product in the competitive era. For multimedia services, there are various factors in a communication ecosystem working together on users, which stimulate their different senses inducing multidimensional perceptions of the services, and inevitabl...

Packet loss will make severe errors due to the corruption of related video data. For most video streams, because the predictive coding structures are employed, the transmission errors in one frame will not only cause decoding failure of itself at the receiver side, but also propagate to its subsequent frames along the motion prediction path, which...

In this paper a packet-layer model for video quality assessment is proposed to monitor the service quality of networked H.264/AVC video streaming in real-time. Using the information extracted from packet header, the frame type is first predicted, based on which the structure of the group of picture (GOP) is estimated since quality degradation cause...

Various factor in the communication ecosystem are acting together on the final experience of the users who use the related video services. In this paper, the joint effect in both the technology and the human domain is considered and incorporated to evaluate the users' quality of experience (QoE) with respect to the IPTV service. Here the parameters...

To realize real-time and non-intrusive quality monitoring for networked video, a content-adaptive packet-layer model for quality assessment is proposed. Consider-ing the fact that the coding distortion of a video is dependent not only on the bit-rate but also on the motion characteristic of the video content, temporal complexity is evaluated and in...

Packet-layer models are designed to use only the information provided by packet headers for real-time and non-intrusive quality monitoring of networked video services. This paper proposes a content-adaptive packet-layer (CAPL) model for networked video quality assessment. Considering the fact that the quality degradation of a networked video signif...

To realize real-time and non-intrusive quality monitoring for networked video, a content-adaptive packet-layer model for quality assessment is proposed. Considering the fact that the coding distortion of a video is dependent not only on the bit-rate but also on the motion characteristic of the video content, temporal complexity is evaluated and inc...