The Buffer panel displays the results of the analysis (for AVC and HEVC video formats only). For unsupported video formats, nothing is displayed in this panel. The buffer parameters are based on the SEI values. If SEI is not available, the parameters are reconstructed using the stream level\tier. If HRD parameters for an AVC file are absent, the graph will not be constructed.
From what data is the graph plotted in the panel buffer? Which formats are supported?