A Design of Adaptive Rate MPEG-4 Player

• Main Authors: Lee Yunhsuan, 李韻玄
• Other Authors: 蔡國煇
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/82152157746235317036

碩士 === 國立海洋大學 === 資訊科學學系 === 90 === With the evolutions of multimedia technology and the release of image compression standards (MPEG-1/2/4), high—quality multi-media products are widespread gradually. People are getting used to the applications of digital multi-media. But the most common way is to save the data in the media and to play it on the computer or player later. On the era of Internet, another more attractive solution is the streaming server. Instead of downloading the whole content, users watch the content during the downloading, which not only saves the time and space, but also provides the capabilities for the interactive playing. The quality of streaming multi-media depends on the quality of networks and also the client’s decoding power. In our research, we assume that the Internet already provides sufficient quality for the streaming, and the client uses its CPU to perform the decoding, which is a common situation in the lower-end embedded system. Our experiment shows that if the client cannot provide enough CPU resource to decode all the picture frames it received, some frames are dropped and others might get blurred due to the reference relationship between frames. A monitor mechanism was proposed to actively notify the server so that the server can dynamically adjust the frame rate up and down. On the other hand, users can decide the playing quality themselves, which bypassed the automatic adjustment.