[x264-devel] PSNR Calculation

[A. Mullius]

Oh, that's not good for my issue. I encode a video at different bitrates(100
kbit - 10Mbit) and resolution(320p to 1080p). Therefore I use the psnr as
metric to decide at which bitrate i go up to the next higher resolution. How
do you decide when it is better to use a higher resolution or a lower one at
a given bitrate?

Thx!


On Thu, Aug 11, 2011 at 4:46 PM, James Darnley <james.darnley at gmail.com>wrote:

> On 11/08/2011, A. Mullius <mullius87 at gmail.com> wrote:
> > Hi,
> >
> > how does the PSNR calculation of x264 work when i use e.g. --video-filter
> > resize:width=320,height=240 to encode a 1920x1080 video to 320x240? Does
> it
> > scale the encoded frame up to 1920x1080 or does it scale the original
> frame
> > down to 320x240 for the PSNR calculation? And which interpolation filter
> is
> > used for the rescaling in the PSNR calculation?
>
> The encoder gets the a frame at 320x240 and it uses this to calculate
> the psnr.  It never knows about 1920x1080.  The filter uses swscale to
> scale the image and uses a bicubic scaler by default.
> _______________________________________________
> x264-devel mailing list
> x264-devel at videolan.org
> http://mailman.videolan.org/listinfo/x264-devel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.videolan.org/pipermail/x264-devel/attachments/20110812/564698be/attachment.html>