When exporting a video using Quality Based VBR. You see something to the side called “CRF=INSERTNUMBERHERE”. Their arnt 100 CRF value’s and only go from 0 to 51. So what about every % value that is inbetween a CRF value change? Is their something in the background that very slightly changes that the middle percentage value’s change or is it all based on the CRF number that is presented? And if so. does that mean that the percentage value’s that dont change the base CRF value of the percentage do nothing?
The percentage is generic by design. Some encoders use CRF, some use qscale, some use QP, etc. The percentage is applied to the range of values that are legal for a given encoder. You mentioned 0 to 51. So 0% quality would be 51 and 100% quality would be 0, with all other values interpolated in between. It is possible that multiple percentage values will translate to the same CRF/qscale/QP value. This is fine. The CRF/qscale/QP value is what actually gets handed off to the encoder.