OK, in this case, adding extra filter would be too much work. I thought, that you maybe changed the playback routine itself.
This is a fragment from a script that I had to change:
pushib 12 ;distance top
pushib 15 ;distance left
pushiw 0x95 ;FLAGS
pushib 25 ;distance bottom
pushib 16 ;distance right
pushiw 256 ;number of colours
callkb PlayVMD().config
FLAGS contains one of the following values:
0x20 = small movie
0x21 = doubled movie
0x24 = small interlaced movie
0x25 = big interlaced movie
...which is ORed with other values such as brightness boosting strength.
I find the constant change from normal non-interlaced mode to movie interlaced scenes somewhat distracting.
That's another reason that brought me to create this patch.
The problem isn't that the movies are compressed in 256 colours, but rather that the display engine renders the graphics in 256 colours.
I have tried forcing the engine to display movies in TrueColour, but without success. As for the blurring filter, I'll make a mind note as for a possible future project.