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?