[MPlayer-users] how to get .png from YUV stream

[vitko]

I'm dealing with some very noisy videos and to guess good denoise or blur 
parameters I'm playing with "-frames 1 -vo png" to collect some frame samples to 
compare them visually.

I grabbed some RealVideo stream to play with it here for debugging purposes, but 
following command

    mplayer stork.stream -vf denoise3d=8:6:6  -vo png -frames 1

fails with

    ...
    VIDEO:  [RV30]  384x288  24bpp  30.000 fps    0.0 kbps ( 0.0 kbyte/s)
    ...
    VDec: vo config request - 384 x 288 (preferred csp: Planar I420)
    ...
    The selected video_out device is incompatible with this codec.

    FATAL: Could not initialize video filters (-vf) or video output (-vo).

I guess my RealVideo is YUV, whereas PNG needs RGB. If this is correct, is there 
any way to convert YUV to RGB before writing .png file? I've googled and 
searched mplayer man page for some time, found nothing (or maybe I'm just too 
dumb today :-)

POST SCRIPTUM: NO, I'm not really going to denoise 384x288 video, I just used it 
to feed my script quick and dirty. But maybe my DV is also YUV, so I'm trying to 
learn a bit.

Vit