Please try this values first:
-ofps 20 -vf-add scale=320:240 -vf-add expand=320:240:-1:-1:1 -srate 44100 -ovc xvid -xvidencopts bitrate=350:max_bframes=0:quant_type=h263:me_quali ty=4 -oac lavc -lavcopts acodec=mp2:abitrate=128
How to build in the delay option:
-ofps 20 -delay -0.2 -vf-add scale=...
And how to build in the speed option:
-speed 0.96 -ofps 20 -vf-add scale=...
At least a little extract of www.mplayer.hu's documentation to expand:
expand=w : h : x : y : o : a : r
Expands (not scales) movie resolution to the given value and places the unscaled original at coordinates x, y. Can be used for placing subtitles/OSD in the resulting black bands.
<w>,<h>
Expanded width,height (default: original width,height). Negative values for w and h are treated as offsets to the original size.
EXAMPLE:
expand=0:−50:0:0
Adds a 50 pixel border to the bottom of the picture.
<x>,<y>
position of original image on the expanded image (default: center)
<o>
OSD/subtitle rendering
0: disable (default)
1: enable
<a>
Expands to fit an aspect instead of a resolution (default: 0).
EXAMPLE:
expand=800:::::4/3
Expands to 800x600, unless the source is higher resolution, in which case it expands to fill a 4/3 aspect.
<r>
Rounds up to make both width and height divisible by <r> (default: 1).