[MPlayer-users] Comparison of different software scaler types

[Matthias Wieser]

Am Donnerstag, 16. Oktober 2003 13:31 schrieb Michael Niedermayer:

> On Wednesday 15 October 2003 12:05, Matthias Wieser wrote:
>
> > I have made a gimp file with both versions of the png files, where
> > you can toggle the display of the mplayer image to show the
> > differences. -> http://home.knuut.de/MWieser_/linear.xcf.tar.gz
> > (600kb)
>
> please tell us exactly what filters u used and which resolutions, and
> mplayer/mencoder commandlines used would be helpfull too
>
> [...]

The mplayer image is just the png-version of the image from http://
home.knuut.de/MWieser_/sws2/
(http://home.knuut.de/MWieser_/sws2/raw_detailliert_9_1.jpg)

The gimp image is the result of downscaling (and upscaling with nearest 
neighbour) the png-version of the "original" image from http://
home.knuut.de/MWieser_/sws2/
(http://home.knuut.de/MWieser_/sws2/orig.jpg)

The commandline used for the mplayer image can be found at the bottom of 
http://home.knuut.de/MWieser_/sws2/index.html:
--------------------
mplayer /big/Medien/Video/videotest/raw_detailliert.avi -ss 00:00:07 -vf \
crop=680:528:20:22,scale=340:264 -sws 1 -frames 2 -vo png -z 8
-------------------

After that I used 

-------------------
convert -scale 680x528 00000002.png 00000002_.png
------------------

to produce the mplayer png (and convert -quality 88 ergebnis/$unterverz/
$filename.png ergebnis/$unterverz/$filename.jpg to produce the jpegs)

The video raw_detailliert.avi was created with

-----------
mencoder tv:// -tv 
driver=v4l2:width=720:height=576:alsa:brightness=5:contrast=0:
\saturation=20:volume=40 \
-ovc copy \
-oac mp3lame -lameopts cbr:br=128 \
-o Video-`date +%d.%m.-%H%MUhr`.avi -endpos 00:00:10
-----------

Maybe worth a note: I used gimp 1.3.19 and gimp's bilinear downscale 
filter looks nearly the same to gimp's bicubic downscale filter. Even at 
upscale the difference is very small.

Regards,
   Matthias