Chu-Chuan Lee
National Central University
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Publication
Featured researches published by Chu-Chuan Lee.
international conference on communications | 2009
Chu-Chuan Lee; Ya-Ju Yu; Pao-Chi Chang
The video streaming applications are full of potentials in the IP dual stack network that supports IPv4 and IPv6 protocols simultaneously. However, the significances of video packets belonged to various video sequences are different. An equal error protection to all video packets in the IP network will degrade the video quality significantly. This paper proposes an Adaptive Significance Determination Mechanism in Temporal and Spatial domains (ASDM-TS) for H.264 videos over IP dual stack network with DiffServ model. ASDM-TS determines the video packet significance simultaneously in temporal and spatial domains. From the temporal domain, ASDM-TS evaluates the packet significance based on the estimated error propagation if a packet is lost. From the spatial domain, ASDM-TS computes the packet significance based on the content complexity belonging to a packet. Moreover, ASDM-TS is adaptive to various video sequences with a self-learning method. Compared with traditional schemes, simulation results show that the proposed scheme significantly improves the accuracy of signification determination up to 15% and effectively improves the received video quality up to 0.7dB in PSNR.
pacific-rim symposium on image and video technology | 2006
Chu-Chuan Lee; Pao-Chi Chang; Shih-Jung Chuang
Video packets have different significances due to the video coding property. When delivering video data without priority strategy over the Internet, it will seriously degrade the received picture quality. This paper proposes an Unequal Priority Arrangement (UPA) mechanism for video transmission on differentiated service networks. UPA determines the priority of a video packet according to the evaluation from both temporal and spatial domains simultane-ously. From the temporal domain, UPA evaluates the packet significance based on the temporal position of the packet and the induced error propagation if the packet is lost. From the spatial domain, UPA evaluates the packet importance based on its content, where the ratio of intra-refreshed MBs is used. Moreover, according to the video complexity, UPA can flexibly adjust the weight based on the evaluation results from temporal and spatial domains. Simulation results show that delivering video data with UPA on differentiated service network outperforms traditional temporal-based and spatial-based priority strategies up to 1.8 dB and 1 dB, respectively.
international conference on multimedia and expo | 2004
Chu-Chuan Lee; Pao-Chi Chang
Due to the burstiness property of compressed videos, an effective video traffic description scheme is important for efficient network bandwidth management. This paper proposes an elastically deterministic video traffic regulating mechanism (ED-VTR) that models and regulates the video traffic based on constraints of available decoder buffer space. In contrast to traditional methods, ED-VTR generates a transmission schedule that contains a series of monotonically decreasing bandwidth requests. Simulation results show that, using lower initial bandwidth and smaller decoder buffer requirement, ED-VTR can effectively reduce the complexity of bandwidth management and still hold the advantages of traditional traffic smoothing and deterministic traffic modeling methods.
international conference on conceptual structures | 2002
Chu-Chuan Lee; Chin-Wei Lin; Pao-Chi Chang
We propose an improved video traffic modeling scheme, delay-tolerant multi-leaky-bucket (DTMLB), for video streaming applications over the Internet. Based on the original multi-leaky-bucket modeling method (MLB), DTMLB parameterizes the actual traffic cumulative function instead of the empirical envelope function used by MLB. Moreover, DTMLB incorporates different delay tolerance characteristics among I-frames, P-frames, and B-frames of video to improve the overall bandwidth utilization. Simulation results show that DTMLB provides higher modeling accuracy and higher bandwidth utilization than the MLB and the peak rate modeling methods do. Furthermore, in our simulations, DTMLB generates the least burst traffic into the subsequent nodes of networks among all three methods tested.
pacific rim conference on multimedia | 2008
Ya-Ju Yu; Chu-Chuan Lee; Pao-Chi Chang
This paper proposes a Flexible Significance Classification (FSC) mechanism for video data over managed IP networks. FSC determines the video packet significance in both temporal and spatial domains. In the temporal domain, FSC evaluates the packet significance based on the estimated error propagation provided a packet is lost. In the spatial domain, FSC computes the packet significance based on the content complexity in a packet. Compared with traditional significance classification scheme, simulation results show that the proposed mechanism can significantly improve the accuracy of signification determination by up to 13% and effectively improve the received video quality by up to 0.54dB in PSNR.
Journal of The Chinese Institute of Engineers | 2006
Chu-Chuan Lee; Pao-Chi Chang
Abstract A deterministic service model assisted by a sufficiently large playback buffer space can provide bounded delay guarantees for video packets and simplify network resource management. However, many popular mobile terminals do not have sufficient memory capacity for deterministic video services since the embedded memory is limited and needs to be shared by numerous software programs and masses of personal data. This paper improves the traditional deterministic modeling approach for delivering pre‐stored videos to mobile clients with QoS guarantees. The limitation of playback buffer space, the network delay jitter, the processing load of resource management, and the QoS guarantee are considered in the proposed mechanism. Some traffic smoothing operations are integrated into the proposed mechanism for reducing the playback buffer demand and data rate variation. This paper further proposes a smart video frame skip algorithm, originating at the sender for preventing possible overflow problems due to insufficient playback buffer space. The algorithm can determine the most suitable temporal range for skipping frames and prevent arbitrary discarding from inappropriate video frames such as I‐frames on the client side. Simulation results reveal that the proposed mechanism can effectively remedy situations of insufficient playback buffer space while still maintaining the advantages of deterministic services.
IEICE Transactions on Communications | 2005
Chu-Chuan Lee; Pao-Chi Chang
Regarding IP-based video applications over wireless networks, the multi-layer header overhead may significantly affect the estimation of target video encoding bit rate and the effective throughput of wireless network. Based on the existing header structure of video packets, this study intends to deal with the header overhead problem from the end-to-end viewpoint. This paper first proposes a simple yet robust closed-form that can determine accurately and timely the optimal video payload length at the video sender based on the current wireless channel condition. The contribution can effectively improve the WLAN throughput and enhance the error resilience effect of scalable video data simultaneously. This study further explores the impact of multi-layer header overhead to the video coding work and proposes a Dynamic Header Overhead Accommodation (DHOA) scheme, which is executed in the video compression layer, to adjust dynamically the available video encoding bits for accommodating the header overhead in advance. The contributions of this paper are robust for various IP implementations such as IPSec (IP Security) over different 802.11 standards. Analytical and simulation results verify the accuracy and effectiveness of the proposed dosed-form and header accommodation method. Using DHOA, the bandwidth mismatch between the actual bandwidth demand of packetized video data and the available network bandwidth is no more than 1.1% regardless of the packet sizes used in this paper.
symposium on applications and the internet | 2004
Chu-Chuan Lee; Shao-Wei Chen; Pao-Chi Chang
To cope with vastly increased unique IP addresses demand, an IPv6 specification with enhanced QoS capabilities was standardized by IETF. However, an effective interface for the priority mapping between the video application and RTP protocol is still required for the QoS provision of IPv6 networks. In addition, involving IPv6 based wireless networks, how to decide a suitable video payload length is still a trade-off problem. Therefore, this paper first proposes a payload priority field into the video packet header of application layer for providing sufficient priority information to the lower OSI layers. Moreover, this work develops an adaptive packetization mechanism integrated with scalable video coding for providing unequal error protection to the layered video data. Furthermore, a simplified IPv6 multimedia platform that comprises of a video streaming server, video clients, and an AAA server is implemented. Through simulations with different video sources, the proposed mechanism shows great efficiency and strength.
Journal of High Speed Networks | 2006
Chu-Chuan Lee; Pao-Chi Chang
Archive | 2005
Chia-Hu Chang; Chu-Chuan Lee; Pao-Chi Chang