Yu Songyu

Implementation of MPEG-2 transport stream remultiplexer for DTV broadcasting

This paper presents the design and implementation of an MPEG-2 transport stream (TS) remultiplexer, which is one of the most important pieces of equipment in a digital television broadcasting system. To achieve high performance as well as save hardware resources, the architecture of CAM+RAM is proposed to substitute simple RAM where a PID information table is generated. Compared to other methods, the two-step PCR correction approach can simplify the system significantly. Three data insertion modes are discussed in this paper. Among of them, the host-downloading architecture supports the system to work in a standalone mode when the contents of data are repeated with a fixed time interval or change not very fast.

Implementation of a new MPEG-2 transport stream processor for digital television broadcasting

We introduce a real-time, dual independent output MPEG-2 transport stream (TS) processor designed specific for the China HDTV testing zones. The processor is a single piece of equipment, of which the core functions are realized in FPGA and DSP. Key technologies include a program clock reference (PCR) correction and a packets controller, which are important for TS processing, are described in detail. An improved PCR correction scheme developed by the authors is also proposed.

Conservative staircase data broadcasting protocol for video on demand

Using multiple channels to broadcast a popular video is common in near video on demand (NVOD) systems. There are various protocols that adopt this method. Among those protocols, the harmonic protocol and its derivative protocols have the best performance in reducing the viewers waiting time under a given bandwidth. The staircase protocol is reported to have the lowest buffer requirement and disk I/O requirement to client end. However, two defects in staircase protocol that may cause video discontinuity at the client site are ignored. In this paper, we talked about these two defects and explained how they cause video discontinuity at the client site. Then, we presented the conservative staircase protocol. As its name implies, this protocol adopts a conservative bandwidth assignment to ensure the continuity of the video received. At last, we compared the performance of this protocol with that of the staircase protocol. The results showed that our protocol has a similar performance compared with the staircase protocol but with more practicability.

Using object multiplex technique in data broadcast on digital CATV channel

Data broadcast is a new kind of value-add service of DTV broadcasting and some data broadcast protocols have already been established. However, these protocols only describe the method for locating files in data streams, and a method for distribution of a large collection of files in one or more data streams is not provided. Research on this problem mainly focuses on how to decrease the wait time and some methods of allocating files on multiple streams based on access probability are proposed, but how to assign the file with a reasonable bandwidth is ignored. In this paper, we introduced an object multiplex algorithm to optimize the allocation of objects on a DTV channel. This method assigns different bandwidth statistically to a different object according to its size and access probability. In this method, both download time and wait time are considered. It adopts a modified virtual clock (VC) scheduling algorithm to multiplex files accurately and smoothly.Data broadcast is a new kind of value-add service of DTV broadcasting and some data broadcast protocols have already been established. However, these protocols only describe the method for locating files in data streams, method on how to distribute large collection of files in one or more data streams is not provided. Research on this problem mainly focus on how to decrease the wait time and some methods of allocating files on multiple streams based on access probability are proposed, but how to assign the file with a reasonable bandwidth is ignored. In this paper, we introduced an object multiplex algorithm to optimize the allocation of objects on DTV channel. This method assigns different bandwidth statistically to different object according to its size and access probability. In this method, both download time and wait time are considered. It adopts a modified Virtual Clock (VC) scheduling algorithm to multiplex files accurately and smoothly.

Real-time duplex digital video surveillance system and its implementation with FPGA

Real-time digital video surveillance systems are used in many fields, such as banks, buildings and supermarkets. The core part of system is a video multiplexer. In this paper, a novel hardware design of real-time duplex digital sixteen-picture processor is implemented with only one FPGA chip. Functions of the real-time digital video multiplexer include picture dividing/joining, video motion detection and video playback. Imaging quality and functions of the processor are much better than the traditional analog ones in practice.

Implementation of MPEG-2 transport stream remultiplexer with CPLD

Design of transport stream (TS) remultiplexer with CPLD is described in this paper. PID mapping and PCR correction are two important functions of TS remultiplexer. For saving resource, simple RAM architecture is substituted by the combination of content-addressable-memory (CAM) and RAM, when forming a high-speed PID information table. An uncomplex algorithm of PCR correction is given in this paper. Experiment result show that the jitter can be reduced to less than 74 ns.

A new subspace algorithm of blind channel estimation for OFDM systems

This paper proposes a statistical subspace algorithm for blind channel estimation in OFDM systems. The algorithm is based on a new input/output relationship which is obtained by a matrix transform on the transmission equation of the OFDM systems. The proposed algorithm is computationally simpler, and extends some results of the existing subspace algorithm. The simulation results are also presented.This paper proposes a statistical subspace algorithm for blind channel estimation in OFDM systems. The algorithm is based on a new input/output relationship which is obtained by a matrix transform on the transmission equation of the OFDM systems. The proposed algorithm is computationally simpler, and extends some results of the existing subspace algorithm. The simulation results are also presented.

An error robust macro-block mode decision for H.26L stream

With the rapid development of the Internet, more and more attention is focused on IP video streaming. We introduce an RD optimal macro-block mode decision scheme for the new H.26L video stream. Based on the statistical error propagation model of the Internet and the unequal NAL packet of H.26L, our new scheme can be more error robust than those currently adopted in the H.26L test mode.

Joint bit-rate allocation strategy for parallel HDTV video encoder

This paper presents a joint bit allocation strategy for parallel HDTV video encoders. The basic idea is to partition a HDTV picture into six smaller sub-pictures, then compress each sub-picture using a cheap MPEG-2 MP@ML encoder. Without coordination among sub-encoders, these encoded sub-pictures may have unequal picture qualities. To maintain a uniform quality HDTV picture, the HDTV video encoder uses the joint bit allocation strategy based on the following two issues: (1) scene change detection and (2) picture complexity.

A high speed transmission/reception circuit for HDTV encoder based on parallel FIFO structure

A data transmission/reception circuit based on parallel FIFO storage structure is introduced. It is used as a video data testing source for an HDTV encoder or used for encoded data test and analysis. It is designed for being inserted in a PCs AT bus. Under the control of a PC, it can transmit or receive data at very high speed. Its function, structure, characteristics and limits are explained, especially some design methods and design thoughts for increasing speed and storage scale as well as decreasing cost. The test results are also given.