19-06-2012, 04:05 PM
Optimal Description Bandwidth Assignment for Multiple-Description-Coded Video
Optimal Description Bandwidth Assignment.pptx (Size: 1.71 MB / Downloads: 35)
Large-Scale Multimedia Streaming
The server has a video to be streamed to a large group of users
It may use multiple unicasts, IP multicast, peer-to-peer overlay multicast
Need to effectively satisfy user bandwidth heterogeneity
Mobile streaming: 100 Kb/s
Internet streaming: 500 Kb/s
MPEG video: 1 Mb/s
HDTV: 10 Mb/s or more
2 orders of magnitude difference!
MDC: Strength and Issues
Strength:
Provides more choices of streaming rate to match user receiving bandwidths.
Descriptions are independent. More robust to network dynamic.
Issues:
Optimal description bandwidth assignment
Coding efficiency Optimal description #.
Research Setting
Consider a video stream to be accessed by a large pool of users with heterogeneous bandwidths.
Users employ a “greedy” approach to maximize their video quality.
Each user joins the descriptions so that the total bandwidth best matches the receiving bandwidth without overflowing
The server encodes the video into multiple descriptions and advertise them to the users.
It has a good picture on the user bandwidth profile it is serving.
Contribution Highlight
Problem formulation and complexity analysis
Optimization problem with coding efficiency consideration
NP-hard proof
Exact solution and threshold value
Polynomial time algorithm to match all the receiving bandwidths, when description # is no less than threshold.
An efficient heuristic: SAMBA
Virtually matches the optimum
Optimal choice for description #.
Related Work
MDC was first proposed to enhance performance of telephone system, in Bell’s Lab.
A comprehensive survey of MDC can be found in [1].
Much of previous work on MDC only focus on the error resilient techniques [2][3].
To the best of our knowledge, [4] and [5] have addressed the description bandwidth assignment in MDC.
Our work advances in
General formulation with coding efficiency consideration
Exact solution and threshold value
Study of optimal description number