I've been playing around with libid3tag 0.15.1b for a couple days now, and I'm at a loss when it comes to manipulating multiple tags in the same file.
When reading a file with only one tag (either V1 or V2), reading/parsing the frames and fields works more or less as I'd expect given the API functions in id3tag.h.
Where I run into trouble is when I read an MP3 file with both V1 and V2 tags. The first thing I do after opening the file is call id3_file_tag() to get a pointer to a tag. What I find confusing is that even though the tag's ID3_TAG_OPTION_ID3V1 option is set, walking the field list only gives me the frames from the V2 tag:
for(i=0;i<tag->nframes;i++) { frame=tag->frames[i]; /* etc. */ }
Poking around a bit in file.c it appears the id3_file structure maintains references to all of the individual tags in the file, but looking through the API functions available in id3tag.h, I don't see how to access any tag other than the primary (via the id3_file_tag() function).
So my question is, how do I access the fields of a V1 tag when a file has both V1 and V2 tags? Are the V1 fields stored in the primary tag structure along with the V2 fields? If so, why can't I access them when I walk the list of the other (V2) frames? If they're stored in a tag structure other than the primary, how do I access it?
Thanks,
- Cedric