Why is it that when I encode a mov using the new CBR setting in ffmpeg, that the output file size is smaller than when using the VBR setting (standard SVCD setting)? My understanding of CBR is that it is a constant bit rate of 2500bps and VBR is variable bit rate up to the max limit of 2500bps. Only from the vbr version being larger in size it appears that the encoding rate must go over the 2500bps. Does anyone know why this is?