Quote:
Originally Posted by Chengbin
Suppose I encode a video using CRF x, and it output a video that is 800MB, now I use 2 pass, and specify the size to 800, which way of encoding would provide higher quality?
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As far as I know if you create two files of the same size, one with CRF (1-Pass) and one with 2-Pass, then the difference in quality between these two files will be very small. Most likely you wouldn't be able to notice it. The difference is: With 2-Pass you know the final size in advanced, with CRF you don't. But in 2-Pass mode you need to decide for a target average bitrate, which isn't easy, as different sources require different bitrates to look good! In CRF mode you can simply specify a level of quality (very roughly) and the decoder decides the required bitrate for you.
In short: If you are targeting for a certain level quality and you don't care about filesize, then find the highest possible CRF value that still satisfies your eyes and use that CRF value for all your encodes. And if you are targeting for best possible quality for a restricted filesize (e.g. 700 MB for a CD-R or 4,7 GB for a DVD+R) then use 2-Pass mode.