I have an avi that has the 4CC code of div3 (according to G-Spot)

So, it uses the DivX MPEG-4 Low Motion codec, and G-Spot says I have this installed, with filename: DivXc32.dll

I want to process this with AviSynth. Apparently, DivXc32.dll only supports RGB output, but I'd like to try and avoid using ConvertToYUY2() in my AviSynth script.

I was thinking that if I changed the 4CC code, I could use a decompressor that *does* offer YUY2 output, and avoid a needless colorspace conversion. But I wonder when 4CC code changes are appropriate. Would it be okay to just change the 4CC code to DivX? I have the DivX Pro 5.02 codec installed. Can DivX Pro 5.02 decompress div3 content? Is there some guide/chart out there which gives a list of safe substitutions? Wouldn't I *always* want to use DivX Pro 5.02 to decode my avi's when possible? Should I just register the div3 4CC code to be mapped to DivX.dll? How would I do this, and is it a good idea, and what other 4CC code material can be decoded by DivX.dll?