Kai-Chao Yang

Error resilience supporting bi-directional frame recovery for video streaming

In this paper, we propose a novel coding dependency among video frames which supports efficient error resilience without adding any redundancy. Our approach is based upon reorganizing the regular GOP structure. The proposed scheme can effectively recover a lost frame and prevent the error propagation phenomenon. For a single frame loss, we guarantee that both of its next and previous frames still can be successfully decoded, thus we have sufficient temporal and spatial information to reconstruct the damaged frame. Our new coding structure even can recover successive lost frames. The experimental results showed that the video quality has a graceful degradation when the loss rate increases rapidly. Comparing with the conventional GOP, PSNR values can improve from 0.5 dB to 3 dB.

Design of frame dependency for VCR streaming videos

The structure of Group of pictures (GOP) is favorable for GOP-based random-access operations, while inside the GOP, the sequential coding dependency between frames is unfavorable for frame-based random-access or fast-scan operations. In a video streaming system, when some VCR operations such as fast-scan operations are performed, they may cause serious server load or network load due to the speed-up of transmitting frames. In this paper, we formulated the fast-scan and random-access operations of VCR functionality, and proposed a novel frame dependency to eliminate extra server load and minimize requirements of the network bandwidth when performing fast-scan and random-access operations. With the proposed structure, the server does not have to speed up the transmission rate of frames to fulfill the requested playback rate. The number of frames to be transmitted is also significantly reduced, and thus the network load can be decreased.

Application-oriented teaching of embedded systems

Education of embedded systems is essential for Computer Science and Electrical Engineering students. However, traditional courses of embedded systems in the university cannot satisfy all industrial requirements anymore due to the extreme wide applicable area of embedded systems nowadays. In this article, we propose a series of short courses for learning embedded systems. Three hardware platforms focusing on different applicable areas are applied in the courses, such that the course content can cover most popular applicable areas of embedded systems. The student feedback shows they learned much practical knowledge from the courses, and the courses also helped them to learn embedded software design for different applications.

Error resilient GOP structures on video streaming

In this paper, we describe novel coding dependencies among video frames supporting efficient error resilience in a video streaming system. Our approach is based upon reorganizing the regular linear GOP encoding structure to prevent the error propagation phenomenon and recover lost frames by interpolation. For errors taking place in a single frame, we guarantee that errors will not propagate to the neighboring frames. Therefore, both the past and future temporal information can be used to reconstruct the damaged frame. Furthermore, the proposed coding structures can also recover successive lost frames. In low power and low bandwidth circumstances such as some mobile devices, the proposed structures can also dynamically adjust the video quality level to adapt to a fluctuant network environment.

Restructuring GOP algorithm to reduce video server load on VCR functionality

We address serious video server load resulting from the VCR functionality, and the restructuring algorithm of frame dependencies is presented to reduce the server load and minimize the requirements of the network bandwidth. The requested frames are transmitted and decoded without sending any redundant data. Thus, even for the VCR operations with high speed factors, the server still sends data at normal transmission rate. The video server cost can significantly reduce as well

Universal Learning System for Embedded System Education and Promotion

In this article, the idea of the universal learning system for embedded systems is presented. The proposed system provides a complete learning environment consisting of the information collection center, preference estimation system, Q&A center, forum, and virtual classroom. The skeleton of the proposed system is a preference estimation system, which helps users know the relationship between different hardware kits and suggests suitable hardware kits to users to learn embedded systems. Then, the proposed system provides the virtual classroom and Q&A service for users to start their classes. Besides, users can share design samples and experience, and join discussions through the forum of the proposed system. For demonstration, three embedded hardware platforms are introduced and applied by the proposed learning system. The results show that most students feel the proposed learning system can effectively help with their embedded software design.

High-performance low-complexity bit-plane coding scheme for MPEG-4 FGS

MPEG-4 FGS (Fine Granularity Scalability) has received tremendous attentions because it has ability to adapt to the network bandwidth variation. In this paper, we present a novel and effective bit-plane coding technique to further improve the coding efficiency of MPEG-4 FGS. The proposed approach reveals three superiorities to the MPEG-4 FGS based bit-plane variable-length coding (VLC): (1) better video quality in about 1.2 dB in terms of average PSNR, (2) less memory requirement, and (3) lower implementation complexity and power dissipation. Thus, it is well suitable for efficient hardware or software implementations.

Support fast scan operations with video streaming technology

In this article, we present a novel approach to support fast scan operations for video streaming applications. Our approach is based upon reshaping the ordinary linear encoded GOP (group of pictures) structure into a hierarchically encoded binary tree, along with a proximity-based approximation scheme. Our scheme can support forward and backward fast playback operations at any speed-up factor with few bandwidth requirements even for the normal speed playback.