Enable service quality middleware for MPEG Video Streams

Enable service quality middleware for MPEG Video Streams

(1) Introduction

Online Video Stream services have become very popular on the Internet in recent years. Video Streams are a type of concurrent processing. They send video images from the server to the client over the network and are played by the client video player.

The online video stream service system is an online, strict real-time multi-user system. It cannot be controlled in open networks (such as the Internet), and its performance is unstable and unpredictable. MPEG has gradually become the de facto standard for video encoding. One challenge for the MPEG Video Stream system is to provide the client with a high quality of service (QoS ). There are many software, such as Real Player, used for playing online video streams. Due to the characteristics of the open network, it is inefficient because it is almost impossible to improve the service quality of online video streams by adjusting network performance. People have made a lot of research on how to enhance the service quality of online video streams. These studies are divided into the following three types:

1. The new encoding algorithm and data structure are used to replace the existing video encoding data formats, making open networks more suitable for processing video images.

2. Use new protocols and new video image transmission mechanisms to replace existing popular protocols.

3. Prepare several video versions in advance. Each version has different resolutions or frame sizes, with different QoS levels. These versions can be played concurrently in different streams. Based on the network performance, the server selects the most suitable QoS stream for the client.

The main disadvantage of the first two methods is the need for a new video player or communication system. In fact, both methods are not feasible. The disadvantage of the last method is that it requires a lot of resources, including processors and bandwidth. Therefore, these methods are not popular.

We consider placing a middleware software system between the server and the client to provide value-added services to the C/S system. This is to enable the quality of service multimedia middleware. Most middleware designs and implements this method. They can observe the bandwidth QoS on the server side. However, the throughput between servers on the open network and each individual client is different. This method cannot provide a customizable QoS adjustment for each client. More importantly, these studies did not consider multiple encoding formats. Therefore, the QoS adjustment mode is not suitable for the features of the MPEG video encoding format.

To allow users to play videos with their favorite players, we solve this problem. That is, the use of "distributed enabling QoS middleware ". This middleware is located between the video server and the client video player. It consists of server ware and client ware. Since the throughput between the server and each individual client is different, the video QoS quality of each client is also different. In addition, when the network is blocked, some frames will drop. Dropped QoS can be mapped to skip MPEG frame modes. Therefore, the server does not need to transmit all MPEG frames to the client, but only some frames with the same QoS are transmitted to the client. This is the value-added service provided by distributed middleware.

QoS is a key success factor in the video stream system. There are two measurement factors: byte Transfer Rate and frame transfer rate.

MPEG consists of three different frames, which have different sizes and different video quality. This is a group frame scheme ).