[MPlayer-users] -vo png question

[Chris Perry]

Hi there. I want to dump 8-bit RGB PNGs from mplayer using the -vo png  
option, however, it seems that mplayer changes the bit depth and even  
the number of channels based on what it observes in the source frames.  
For example, a pure black frame is encoded as 1 bit per pixel, 1  
channel instead of 8 bits, 3 channels. Grey images are 8 bits and  
single channel. Only color frames are encoded as 8-bit, 3-channel  
images.

Is there a way to disable this automatic behavior? Also, is there a  
way to have mplayer output compressed (but still lossless) PNGs?

Thanks,

- chris