1. A method for implementation of a hypothetical reference decoder (HRD) for scalable video coding (SVC), comprising: determining values of variables included in a bit stream indicating a dependency layer, temporal layer, and quality layer of a scalable layer i, i being an integer; and determining HRD parameters corresponding to said scalable layer i, the determined HRD parameters including at least one bit rate parameter, wherein the bit rate parameter is determined based on bits for the scalable layer i and its dependent layers, wherein the determined HRD parameters further include initial coded picture buffer (CPB) removal delay, initial coded picture buffer removal delay offset, CPB removal delay, and decoded picture buffer (DPB) output delay, wherein the determining HRD parameters comprises: determining the CPB removal delay and the DPB output delay by using explicitly signaled parameters from a picture timing SEI message in the bit stream for each temporal layer, wherein the picture timing SEI message also indicates the number of temporal layers in the bit stream, and determining the CPB removal delay and the DPB output delay to be the same for scalable layers corresponding to different spatial layers or quality layers at each temporal layer.