[MEncoder-users] x264 lossless, or is it?

[n0dalus]

On 12/6/05, Aleksandar Uzelac <uzi at galeb.etf.bg.ac.yu> wrote:
>
> i'm using several png files to create avi, and i want resulting avi to be pixel-exact (lossless, or is lossless something else?).
>
> here is command line (qp_constant=0 is lossless):
>
> mencoder "mf://*.png" -v -mf fps=0.25:type=png \
> -ovc x264 -ofps 25.000 -oac lavc \
> -lavcopts acodec=mp3:abitrate=192 \
> -x264encopts qp_constant=0 -o result.avi
>
> input and output png file example can be found here:
>
> http://galeb.etf.bg.ac.yu/~uzi/slike/input.png
> http://galeb.etf.bg.ac.yu/~uzi/slike/output.png
>
> output is taken from resulting avi file with "-vo png:z=9" option.
> this is not lossless, as you can see in output.png, compared to input.png file.
>
> or is it?
>
> cheers,
> aleksandar

I don't know if it changes anything, but -vo png:z=9 is highly
compressed. You should be using png:z=0.