Proxy Caching Mechanisms with Quality Adjustment for Video Streaming Services
Proxy Caching Mechanisms with Quality Adjustment for Video Streaming Services
复制标题
视频流服务的具有质量调整的代理缓存机制
DOI：
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发表时间：
2003
影响因子：
0.7
通讯作者：
H. Miyahara
中科院分区：
文献类型：
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作者：
Masahiro Sasabe;Y. Taniguchi;N. Wakamiya;M. Murata;H. Miyahara
WWW系统中广泛使用的代理机制通过“代理服务器”提供低延迟的数据传输。通过将代理机制应用到视频流系统中，我们期望在不增加系统负载的情况下，实现高质量、低延迟的视频分发。此外，如果用户请求由于可用带宽、终端系统性能和用户对感知视频质量的偏好方面的异质性而不同，则在代理中适当地适配缓存的视频数据的质量是有效的。在本文中，我们提出了代理缓存机制，以实现高质量和低延迟的视频流服务。在我们提出的系统中，视频流被划分为块，以有效地使用缓存缓冲区。代理高速缓存服务器被假定为能够通过视频过滤器来针对请求调整高速缓存或检索的视频块的质量。我们评估我们提出的机制所需的缓冲区大小，播放延迟和视频质量，通过模拟实验。此外，为了验证我们的机制的实用性，我们实现了我们提出的机制在一个真实的系统，并进行了实验。通过从多个性能方面的评估，表明我们提出的机制可以在异构环境中为用户提供低延迟和高质量的视频流服务.关键词：视频流服务、代理缓存、质量调整、MPEG-2
The proxy mechanism widely used in WWW systems offers low-delay data delivery bymeans of “proxy server”. By applying proxy mechanisms to video streaming system, we expect that high-quality and low-delay video distribution can be accomplished without introducing extra load on the system. In addition, it is effective to adapt the quality of cached video data appropriately in the proxy if user requests are diverse due to heterogeneity in terms of the available bandwidth, end-system performance, and user’s preferences on the perceived video quality. In this paper, we propose proxy caching mechanisms to accomplish high-quality and low-delay video streaming services. In our proposed system, a video stream is divided into blocks for efficient use of cache buffer. A proxy cache server is assumed to be able to adjust the quality of cached or retrieved video blocks to requests through video filters. We evaluate our proposed mechanisms in terms of the required buffer size, the play-out delay and the video quality through simulation experiments. Furthermore, to verify the practicality of our mechanisms, we implement our proposed mechanisms on a real system and conducted experiments. Through evaluations from several performance aspects, it is shown that our proposedmechanisms can provide users with a low-latency and high-quality video streaming service in a heterogeneous environment. key words: video streaming service, proxy caching, quality adjustment, MPEG-2