id3_get_genre_id() returns the id for a genre. If the
specified genre is not available in the genre list, id3_get_genre_id()
will return FALSE
In an ID3 tag, the genre is stored using a integer ranging from 0 to 147.
<?php
$id = id3_get_genre_id("Alternative");
echo $id;
?>
This will output:
20
See also id3_get_genre_list() and id3_get_genre_name().