Had an AviSynth script which used to work OK on my old PC but not on my new one.
The first problem was that AviSynth’s AVISource command failed to find a codec for the DV (AVI) file I was trying to read. DirectShowSource worked OK but AVISource didn’t, implying that there was no VFW codec for DV functioning on the new PC. Indeed, the new machine had no DV Codec installed – because there isn’t one as default in XP. When I installed the MainConcept’s DV Codec then the problem went away.
Next issue was when I put the AviSynth scipt thru VFAPI, it produced an audio-only stream. Indeed in retrospect when I had dragged the file to VFAPI the video options had been greyed-out. Same script worked OK on the old PC. GSpot revealed that it worked on the old PC because that PC included an “RGB Color Space Convertor” DLL, namely LMVRGBxf.DLL. This turned out to be part of Nero, which was indeed installed on the old PC but not the new. Begs the question of whether such a file should ideally be on a PC and if so what are the choices? Regardless, taking note of the “colour space convertor” description, guessed (correctly) that all I had to do was alter the end of the AviSynth script to use ConvertToRGB24 instead of ConvertToRGB32.
With those two fixes, VFAPI processed both video and audio aspects of the DV file and consequently the resulting *_vfapi.avi file was now fully (video and audio) playable in both Media Player and Sony Vegas.