【摘要】 为了提高MPEG-4FGS码流在可变比特率信道上的传输效率,该文根据用户需求和信道特性,对该信道上的FGS码率分配问题进行了分析和建模,将其描述为一个多码率限制条件下的优化问题。分析了FGS码流率失真函数的特性,设计了一种迭代等D优化算法。理论分析证实该算法可得到码率分配问题的最优解;实验结果表明该算法能获得比已有算法更好的视频传输质量和效果,并能满足实时性的需求。该码率分配的问题描述和解决算法能够达到FGS码流在可变比特率信道上高效传输的目的。更多还原

【Abstract】 The transmissionefficiency of MPEG-4 fine-granular scalability (FGS) bit-streams over variable bit rate (VBR) channels was analyzed using a rate allocation model. The problem was analyzed as an optimization problem with multiple constraints including the user requirements and the channel characteristics. An iterative equi-distortion optimization algorithm was developed to solve the problem with consideration of the rate-distortion (R-D) characteristics of FGS video bit-streams. Theory analysis demonstrates that the solution is the optimal solution of the rate allocation problem. Simulation resultsshow that the method has better performance than other methods and can work in real-time.更多还原