Tao Fang

GOP-based channel rate allocation using genetic algorithm for scalable video streaming over error-prone networks

In this paper, we address the problem of unequal error protection (UEP) for scalable video transmission over wireless packet-erasure channel. Unequal amounts of protection are allocated to the different frames (I- or P-frame) of a group-of-pictures (GOP), and in each frame, unequal amounts of protection are allocated to the progressive bit-stream of scalable video to provide a graceful degradation of video quality as packet loss rate varies. We use a genetic algorithm (GA) to quickly get the allocation pattern, which is hard to get with other conventional methods, like hill-climbing method. Theoretical analysis and experimental results both demonstrate the advantage of the proposed algorithm.

A novel unequal error protection approach for error resilient video transmission

We address the problem of unequal error protection (UEP) for MPEG-2/H.263 video over a wireless packet-erasure channel. Unequal amounts of protection are allocated to the different frames of a group-of-pictures (GOP) to provide a graceful degradation of video quality as packet loss rate varies. We use a genetic algorithm (GA) to get the allocation pattern quickly. Theoretical analysis and experimental results both demonstrate the advantages of the proposed algorithm.

Two-Dimensional Channel Coding Scheme for MCTF-Based Scalable Video Coding

The motion-compensated temporal filtering (MCTF)-based scalable video coding (SVC) provides a full scalability including spatial, temporal and signal-to-noise ratio (SNR) scalability with fine granularity, each of which may result in different visual effect. This paper addresses a novel approach of two-dimensional unequal error protection (2D UEP) for the scalable video with a combined temporal and quality (SNR) scalability over packet-erasure channel. The bit-stream is divided into scalable subbitstreams based on the structure of MCTF. Each subbitstream is further divided into several quality layers. Unequal quantities of bits are allocated to protect different layers to obtain acceptable quality video with smooth degradation under different transmission error conditions. Experimental results are presented to show the advantage of the proposed 2D UEP scheme over the traditional one-dimensional unequal error protection (1D UEP) scheme. Comparing the proposed method with the 1D UEP scheme on SNR layers, our method gives up to 0.81-dB improvement for some video sequences

An error-resilient GOP structure for robust video transmission

Recent advances in technology have resulted in a significant growth in wireless communications and widespread access to information via the Internet, which have resulted in a strong demand for reliable transmission of video data. The challenge of robust video transmission is to protect the compressed data against hostile channel conditions while bringing little impact on bandwidth efficiency. In motion-compensated video-coding schemes, such as MPEG-1 or MPEG-2, an I frame normally is followed by several P frames and possibly B frames in a group-of-pictures (GOP). In error-prone environments, error happening in the previous frames in a GOP may propagate to all the following frames until the next I frame, which is the beginning of the next GOP. In this paper, we propose a novel GOP structure for robust transmission of MPEG video bitstream. By selecting the optimal position of the I frame in a GOP, robustness can be achieved without reducing any coding efficiency. Another advantage of the proposed GOP structure is also analyzed: compared with the conventional GOP structure, it provides reverse-play operation for MPEG video streaming with much less requirement on the network bandwidth. Experimental results demonstrate both the robustness of the proposed GOP structure and the efficient reverse-play functionality it leads to.

Two-dimensional channel rate allocation for SVC over error-prone channel

The motion compensated temporal filtering (MCTF) based scalable video coding (SVC) provides a full scalability including spatial, temporal and signal-to-noise ratio (SNR) scalability with fine granularity, each of which may result in different visual effect. This paper addresses a novel approach of two-dimensional unequal error protection (2D UEP) for the scalable video with a combined temporal and quality (SNR) scalability over packet-erasure channel. The bit-stream is divided into scalable sub-bit-streams based on the structure of MCTF. Each sub-bit-stream is further divided into several quality layers. Unequal quantities of bits are allocated to protect different layers to obtain acceptable quality video with smooth degradation under different transmission error conditions. Experimental results are presented to show the advantage of the proposed 2D UEP scheme over the traditional one-dimensional unequal error protection (1D UEP) scheme

A novel interleaving algorithm for robust video transmission

In this paper, we propose a novel interleaving scheme for robust transmission of video sequences. By optimally grouping macroblocks (MB) into slices, robustness can be achieved with negligible reduction in coding efficiency. We group MB into slices considering the maximal minimal distance of these MB. Since every lost MB has as many as possible spatial neighbors that belong to other correctly received slices, an error-concealment mechanism has a lot of information it can employ for efficient concealment. Experimental results demonstrate the robustness of the proposed scheme.

Efficient content-based resynchronization approach for wireless video

Recent advances in technology have caused a significant growth in wireless communications, which have resulted in a strong demand for reliable transmission of video data. The challenge of robust video transmission is to protect the compressed data against hostile channel conditions while bringing little impact on bandwidth efficiency. In this paper, using results from a simplified macroblock-based segmentation algorithm, we propose a framework called content-based resynchronization for the effective positioning of resynchronization markers such that the image quality of foreground can be improved at the expense of sacrificing unimportant background. We do this because, in applications such as video telephony and video conferencing, foreground is typically the most important image region for viewers. Experimental results demonstrate that this scheme significantly improve the perceptual quality of video sequences for robust video transmission.

Robust group-of-picture architecture for video transmission over error-prone channels

In motion-compensated video-coding schemes, such as MPEG, an I frame is normally followed by several P frames and possibly B frames in a group-of-picture (GOP). In error-prone environments, errors happening in the previous frames in a GOP may propagate to all the following frames until the next I frame, which is the beginning of the next GOP. In this paper, we propose a novel GOP structure for robust transmission of MPEG video bitstream. By selecting the optimal position of the I frame in a GOP, robustness can be achieved without reducing any coding efficiency. Experimental results demonstrate the robustness of the proposed GOP structure.

A novel resynchronization marker positioning approach for robust video transmission

The challenge of robust video transmission is to protect the compressed data against hostile channel conditions while bringing little impact on bandwidth efficiency. Among the state-of-art error-resilient techniques, resynchronization has been proved to be a very effective tool. In this paper, using segmentation results, we propose a framework for the positioning of resynchronization markers such that the image quality of foreground can be improved at the expense of sacrificing the unimportant background. Experimental results demonstrate that this scheme significantly improves the subjective quality of video sequence for robust video transmission.

Content-based resynchronization for robust video transmission

Recent advances in technology have resulted in a significant growth in wireless communications, which have resulted in a strong demand for reliable transmission of video data. The challenge of robust video transmission is to protect the compressed data against hostile channel conditions while bringing little impact on bandwidth efficiency. Here, using macroblock (MB)-based segmentation results, we propose a framework for the positioning of resynchronization markers such that the image quality of foreground can be improved at the expense of sacrificing the unimportant background. Experimental results demonstrate that this scheme significantly improves the subjective quality of video sequence for robust video transmission.