dropped frames

[WarpEnterprises]

It was sometimes written how dropped frames are handled by AviSynth.

1) Is there a nice way to let AviSource tell the frame status (dropped, keyframe, normal) other than using this:


(source.cpp)
...
pbiSrc->biSizeImage = bytes_read;

char b[80];
sprintf(b, "AVISource-Frametype %6.d%s%s\n", n, dropped_frame ? " D" : " ", !pvideo->IsKeyFrame(n) ? " " : " K");
OutputDebugString(b);

return !ex ? ICDecompress(hic, flags, pbiSrc, srcbuffer, &biDst, buf)
...


It may be useful to create Trim() - scripts to delete or replace those D-frames.

2) Is there a way to let AviSynth CREATE a dropped frame? I can't find the code where the frame properties (or index?) is made...