[MEncoder-users] crf, qp, pass params (was - how do u set H264 video ID?)

[Andrew Berg]

 On 6/28/2010 10:59 PM, Goga777 wrote:
> - qp is really meant to be used if you know what you do, if you need
> to us lossless mode, or if you really want to _force_ low quants.
qp is used almost exclusively for testing nowadays. The only practical
use it has for real encodes is lossless (qp=0). If you want to use low
quantitizers, you have to set qpmin (it defaults to 10 and will not go
below that unless set otherwise, even if you use a qp lower than 10)
> Each now pass somewhat
> improves quality over the previous one.
I haven't found any evidence that supports the idea that 2-pass is
better quality than CRF as far as x264 is concerned (there are some
filters and other things that benefit from multipass, but not x264
itself), and I'm pretty sure each pass only improves accuracy (closeness
to the intended average bitrate). If anyone has any evidence, I'll
change my mind, but I've only heard people /say/ 2-pass is better and
not provide anything to back it up.