[pinterf]

Originally Posted by TheFluff

Continuing the discussion from here, let's talk about those nasty memory offsets again.


In Avs+ all these size_t's are (32-bit signed) int instead. In Avisynth it doesn't really matter in practice because a frame is always allocated as one big chunk of memory, and nobody really has any use for more than 2^31 bytes of vfb. If you ever wanted to stop doing this though and use one individual pointer per plane like VS does, this won't fly because you can't reliably stuff a 64-bit pointer in a 32-bit integer, and it's generally bad coding practice to not use size_t (or ptrdiff_t) for these things.

Way back in the day ultim claimed that he didn't want to follow IanB's lead and switch to size_t because it'd break a number of completely irrelevant plugins (that would have been trivial to recompile). I didn't realize it at the time, but I'm pretty sure that in practice, he was wrong even on the technical aspect. If you look at these functions above, the only one that conceivably might end up getting called by plugins in reality is VideoFrame::GetOffset(), and I'm 99% sure that its return value just gets passed in a register and zero-extended, so as long as you keep passing the same old less-than-2^31 offsets, everything will keep working just fine (but most plugins just use GetRead/WritePtr). New VideoFrames and VFB's are only constructed by env->NewVideoFrame, so changing the signature of the VideoFrame constructor shouldn't be an issue.

Thanks, then it's worth a try.