Library "libraw:20"
After this little change your example works as expected.But - and it seems there is always a 'but' - when I try to get a thumbnail from my DNG's it generates a zero byte jpg. At first I thought it is a timing problem and put a
Wait
after the line intReply = libraw_dcraw_thumb_writer(pPoint, strThumbNail)
It still generates an empty jpg file.I have been thinking about it and came to the conclusion that my DNG's don't have any embedded jpg as I am shooting raw only. libraw tries to extract the jpg and exiftool generates thumbnail out of the DNG I guess.
Nevertheless, it was a good exercise for me to get into the world of external libraries.