It seems that Taglib-sharp does not support files over 4GB. I want to edit things like title, descriptions, artwork, etc for large HD movie files. I have found a few comments in the code that seem to imply 64bit files are not supported. Anyone know if this is ever going to be supported? I'm also open to other suggestions in terms of alternative libraries.
Okay so here is the problem. What happens in that by default 64bit MPEG4 have their moov box placed after the mdat box. In taglib-sharp only the first 32 bytes of the file are read which is enough if the moov box comes first. To fix this you can use mp4box.exe to switch positions of the box or you can tick the "optimize for web" box in handbrake which will place the moov box first.