VirtualDub cannot properly load H.264 Lossless video from AVI or Avisynth

[Jedi787Plus]

System: Windows Vista 64-bit Service Pack 2
Software: VirtualDub 1.8.8 AMD64, ffdshow tryouts revision 3028 (64-bit, the version bundled with K-Lite Codec Pack x64), Avisynth 2.5 64-bit (the one last built by squid_80 from Doom9)

Whenever I open an AVI file that contains H.264-lossless video (encoded with x264 using "Single pass - lossless" option) directly with VirtualDub AMD64, I only get a solid black screen. If, instead of directly opening the AVI, I write an Avisynth script using AVISource() and open the AVS with VirtualDub AMD64, I get a solid green screen. If I manually specify the colorspace (RGB24 or YV12) either thru VirtualDub's Video\Color Depth menu or via the AVS, I get either solid black (RGB24) or solid green (YV12). However, when I open the same AVI or AVS with 32-bit VirtualDub, the video loads properly.

If, instead I use DirectShowSource() on my AVS and add Veedub64.exe to ffdshow's allowed application list, then VirtualDub AMD64 crashes when trying to open the AVS. However, the AVI itself plays properly on 64-bit Windows Media Player, given 64-bit ffdshow is installed.

What is wrong with what? VirtualDub AMD64? 64-bit ffdshow? 64-bit Avisynth? Or something else on Windows Vista 64-bit?

[Jedi787Plus]

Well, I think I solved myself the problem. I just spotted a new version of VirtualDub AMD64 (1.9.6) AND a new revision of 64-bit ffdshow (3096). I can now directly open the lossless-H.264 AVI with VDub or open it via Avisynth 64-bit using AVISource() (DirectShowSource() will still crash VDub, however).