[Ohrrpgce] SVN: teeemcee/10047 read_mp3_metadata() using libmad, to read duration/channels/sample/bitra

[subversion at HamsterRepublic.com]

teeemcee
2018-02-20 06:21:50 -0800 (Tue, 20 Feb 2018)
522
read_mp3_metadata() using libmad, to read duration/channels/sample/bitrate/type of an MP3 file

However, does not read ID3 tags. libmad doesn't do that, although the libmad
authors also wrote libid3tag to handle that.
(I added some code recently to read ID3 data by running madplay; I don't make
use of that here yet.)

This metadata is currently only displayed in old games which contain MP3 music
or sfx.
Also, requires libmad to be linked (see next commit)

Added read_file() and formation_duration() utility functinons
---
U   wip/audioedit.bas
U   wip/audiofile.bas
U   wip/audiofile.bi
A   wip/lib/mad.bi
U   wip/util.bas
U   wip/util.bi