Le primidi 21 brumaire, an CCXXV, Fred M. Sloniker a écrit : > I'm given to understand that, under the hood, two-pass and CRF are the same > thing, just that two-pass calculates the necessary CRF to get the desired > filesize. Is this correct?
I do not think it works exactly that way. For starters, it depends on the encoder: CRF are features of x264 and x265, they may not work exactly the same way. But the rule of thumb is: two-pass tries to average the quality at a given bitrate to have it as constant as possible, while CRF does constant quality right from the start. > And if so, is it possible to see what CRF was > selected in the two-pass encoding? I do not know how. > I'm experimenting with encoding two > versions of a video, one at a higher resolution than the other, and I'm > curious if I could encode the high-res one with two-pass, then somehow > encode the low-res one with the same CRF. Do not do that, it makes no sense. For starters, CRF is a local quality measurement. Using the same CRF with a lower resolution will result in lower overall quality. The scale of CRF - subjective quality is different for all resolution. Use the settings that make sense for your needs. What are the constraints that govern your choice of quality level? Regards, -- Nicolas George
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