• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.722-737
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• 2011

In this paper, we propose an estimation of network jitter that occurs when transmitting TCP packets containing MPEG-2 TS in progressive streaming service over wired or wireless Internet networks. Based on the estimated network jitter size, we can calculate required de-jitter buffering time to absorb the network jitter at the receiver side. For this purpose, by exploiting the PCR timestamp existing in the TS packet header, we create a new timestamp information that is marked in the optional field of TCP packet header to estimate the network jitter. By using the proposed de-jitter buffering scheme, it is possible to employ the conventional T-STD buffer model without any modification in the progressive streaming service over IP networks. The proposed method can be applicable to the recently developed international standard, MPEG DASH (dynamic adaptive streaming over HTTP) technology.

• ETRI Journal
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• v.36 no.2
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• pp.253-263
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• 2014

In the near future, traditional narrow and fixed viewpoint video services will be replaced by high-quality panorama video services. This paper proposes a visual-attention-aware progressive region of interest (RoI) trick mode streaming service (VA-PRTS) that prioritizes video data to transmit according to the visual attention and transmits prioritized video data progressively. VA-PRTS enables the receiver to speed up the time to display without degrading the perceptual quality. For the proposed VA-PRTS, this paper defines a cutoff visual attention metric algorithm to determine the quality of the encoded video slice based on the capability of visual attention and the progressive streaming method based on the priority of RoI video data. Compared to conventional methods, VA-PRTS increases the bitrate saving by over 57% and decreases the interactive delay by over 66%, while maintaining a level of perceptual video quality. The experiment results show that the proposed VA-PRTS improves the quality of the viewer experience for interactive panoramic video streaming services. The development results show that the VA-PRTS has highly practical real-field feasibility.

• Journal of Information Processing Systems
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• v.18 no.6
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• pp.729-740
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• 2022

Netflix, Amazon Prime, and YouTube are the most popular and fastest-growing streaming services globally. It is a matter of great interest for the streaming service providers to preview their service infrastructure and streaming strategy in order to provide new streaming services. Hence, the first part of the paper presents a detailed survey of the Content Distribution Network (CDN) and cloud infrastructure of these service providers. To understand the streaming strategy of these service providers, the second part of the paper deduces a common quality-of-service (QoS) model based on rebuffering time, bitrate, progressive download ratio, and standard deviation of the On-Off cycle. This model is then used to analyze and compare the streaming behaviors of these services. This study concluded that the streaming behaviors of all these services are similar as they all use Dynamic Adaptive Streaming over HTTP (DASH) on top of TCP. However, the amount of data that they download in the buffering state and steady-state vary, resulting in different progressive download ratios, rebuffering levels, and bitrates. The characteristics of their On-Off cycle are also different resulting in different QoS. Hence a thorough adaptive bit rate (ABR) analysis is presented in this paper. The streaming behaviors of these services are tested on different access network bandwidths, ranging from 75 kbps to 30 Mbps. The survey results indicate that Netflix QoS and streaming behavior are significantly consistent followed by Amazon Prime and YouTube. Our approach can be used to compare and contrast the streaming services' strategies and finetune their ABR and flow control mechanisms.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.2
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• pp.206-210
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• 2008

The most noticeable aspect of progressive streaming is the media playback during its download through TCP to avoid a lengthy wait for a content to finish downloading. By employing TCP, it is usually possible to detect lost packets by using the checksum and sequence numbering functions of TCP Thereafter, we can recover the lost packets by the retransmission function of TCP. However, there must remain enough amount of media data in the recipient buffer in order to guarantee seamless media playback even during retransmission. In this paper, we propose an efficient algorithm for determining the initial buffering time before start of playback to guarantee seamless playback during retransmission considering the probability of client buffer under-flow. The effectiveness of the proposed algorithm will be proved through extensive simulation results.

• IE interfaces
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• v.16 no.spc
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• pp.87-92
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• 2003

Progressive mesh representation and generation have become one of the most important issues in network-based computer graphics. However, current researches are mostly focused on triangular mesh models. On the other hand, solid models are widely used in industry and are applied to advanced applications such as product design and virtual assembly. Moreover, as the demand to share and transmit these solid models over the network is emerging, the generation and the transmission of progressive solid models depending on specific engineering needs and purpose are essential. In this paper, we present a Cellular Topology-based approach to generating and transmitting progressive solid models from a feature-based solid model for internet-based design and collaboration. The proposed approach introduces a new scheme for storing and transmitting solid models over the network. The Cellular Topology (CT) approach makes it possible to effectively generate progressive solid models and to efficiently transmit the models over the network with compact model size.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06a
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• pp.135-136
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• 2007

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2179-2187
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• 2008

The P2P technology has been widely used to distribute files efficiently, and its use in streaming is rapidly increasing. P2P streaming has issues about startup-delay, scalability, and real-time playback, however, what affects these factors has not been researched sufficiently. This paper suggests a buffering model for progressive download within mesh-based P2P system, which corresponds to downloading and playing the content at the same time. It is used to analyze PDF(Playback Deadline First), Rarest algorithms which are block-selection strategies of P2P streaming and proposes a mixed selection of them. The mixed block selection strategy dynamically performs different strategies based on whether the blocks to be played are received or not. In consequence, it enhances the QoS of streaming in a single peer point of view, as well as improving block distributions in an overlay network.

• ETRI Journal
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• v.43 no.3
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• pp.447-458
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• 2021

The quality of experience (QoE) of video streaming is degraded by playback interruptions, which can be mitigated by the playout buffers of end users. To analyze the impact of playout buffer dynamics on the QoE of wireless adaptive hypertext transfer protocol (HTTP) progressive video, we model the playout buffer as a G/D/1 queue with an arbitrary packet arrival rate and deterministic service time. Because all video packets within a block must be available in the playout buffer before that block is decoded, playback interruption can occur even when the playout buffer is non-empty. We analyze the queue length evolution of the playout buffer using diffusion approximation. Closed-form expressions for user-perceived video quality are derived in terms of the buffering delay, playback duration, and interruption probability for an infinite buffer size, the packet loss probability and re-buffering probability for a finite buffer size. Simulation results verify our theoretical analysis and reveal that the impact of playout buffer dynamics on QoE is content dependent, which can contribute to the design of QoE-driven wireless adaptive HTTP progressive video management.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.12
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• pp.3960-3969
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• 1996

A fluid flow inside a circular cylinder subject to horizontal and circular oscillation is analyzed theoretically. Under the assumption of small-amplitude oscillation, the governing equations take linear forms. The velocity field is obtained in terms of the first kind of Bessel function of order 1. It was found that a particle describes an orbit close to a circle in the central region and an arc near the side wall. We also obtained the Stokes' drift velocity induced by the traveling wave along the circumferential direction. The Eulerian streaming velocities at the edge of the bottom and side boundary layers were also obtained. It was shown that the vertical component of the steady streaming velocity on the side wall is almost proportional to the amplitude of the free surface motion.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2005.11a
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• pp.159-162
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• 2005

본 논문에서는 기존의 비디오와 오디오 중심의 멀티미디어 스트리밍 방법과는 달리 정지 영상의 스케줄 정보도 고려하여 전체 스트리밍의 QoS (Quality of Service)를 높이는 스트리밍 방법을 제안한다. MP4 콘텐츠의 분량이 커지고 내용이 복잡해질수록 비디오와 오디오 이 외의 데이터들을 더 이상 무시할 수 없게 된다. MP4의 장면 구성 정보를 알면 임의의 시점에서 재생되는 화면과 소리를 알 수가 있고, 이 정보, 즉 스케줄 정보를, 고려하여 정지영상 객체를 전송한다면 보다 효율적인 스트리밍이 가능하다 또한, 비디오와 오디오에 스케일러블 부호화를 적용하면 QoS를 높일 수 있듯이, 정지영상의 경우 Progressive JPEG을 이용하면 스케일러블한 전송이 가능하다. 이에 제안된 스트리밍 서버에서는 정지 영상 스케줄 정보와 정지 영상 객체를 Progressive JPEG으로 변환하여 스트리밍 서비스를 제공하고 있다.