Loading a non-mod 4 wide avi with avisource results in garbled output (checked with v2.60a5). See attachment.
Happens when opening as YV12:
I guess this has to do with that the fact AVIFile doesn't support non-mod4? Perhaps it's a good idea to throw an error that the user needs to open it as pixel_type="YUY2" (or any other non YV12/YV411 format).