VBR headers, and even ID3v2

In a March 2004 post on this list, this little snippet came up:

> On Mar 30, 2004, at 2:17 PM, Glenn Maynard wrote:
> >>* There's no support for reading Xing/LAME VBR header tags in libmad,
> *>>* but
> *>>* the code to do it can be found in madplay (see tag.c).
> *>*
> *>* Note that this code doesn't parse "Info" tags, which are just Xing
> *>* tags but are usually written for CBR files (probably to not confuse
> *>* players which assume existance a Xing tag means VBR).
> *
> Actually since version 0.15.1b, it does -- at your suggestion, in fact.
> It also reads any LAME tag following the Xing info, which contains
> Replay Gain information.
>
>
Now I have version 0.15.1b, but I don't know how to access this data -
specifically, the computed length of the file.

Also, I read somewhere that support for ID3v2 headers was being built into
MAD. Is there any truth in this, or should I be doing it on my own?