taglib/taglib — pull request #454 by TsudaKageyu (2014-10-20 12:28:28+00:00)
Title: Skip duplicate ID3v2 tags in MPEG files.

I created a new patch for #450 and got the output like this:
```
TagLib: ID3v2.4 no longer supports the frame type TDAT. It will be discarded from the tag.
TagLib: MPEG::File::firstFrameOffset() - Duplicate ID3v2 tag found.
-- TAG (basic) --
title - "No Ones Ugly After 2 AM"
artist - "Left Wing Fascists"
album - "All Fired Up"
year - "1991"
comment - ""
track - "7"
genre - "Punk"
-- TAG (properties) --
ACOUSTID_ID - "45be336e-51da-4fb8-9d5d-11c52d7d80a1"
ALBUM - "All Fired Up"
ALBUMARTIST - "Left Wing Fascists"
ALBUMARTISTSORT - "Left Wing Fascists"
ARTIST - "Left Wing Fascists"
ARTISTSORT - "Left Wing Fascists"
DATE - "1991-01-01"
DISCNUMBER - "1/1"
GENRE - "Punk"
LABEL - "Skyrat Music"
MEDIA - "Digital Media"
MUSICBRAINZ ALBUM RELEASE COUNTRY - "US"
MUSICBRAINZ ALBUM STATUS - "official"
MUSICBRAINZ ALBUM TYPE - "album"
MUSICBRAINZ_ALBUMARTISTID - "1fc55b7b-dec1-480f-8599-5c1ac8313c06"
MUSICBRAINZ_ALBUMID - "fa0c535c-8bfa-4795-a26d-99cb6c8497e7"
MUSICBRAINZ_ARTISTID - "1fc55b7b-dec1-480f-8599-5c1ac8313c06"
MUSICBRAINZ_RELEASEGROUPID - "1b4fb8df-a3ca-4d00-b22b-8a5a2282b150"
MUSICBRAINZ_TRACKID - "a00754f0-f4f4-4e7f-9cf7-72800fb9a474"
ORIGINALDATE - "1991"
SCRIPT - "Latn"
TITLE - "No Ones Ugly After 2 AM"
TRACKNUMBER - "7/11"
-- AUDIO --
bitrate - 128
sample rate - 44100
channels - 2
length - 2:13
```
However, as I mentioned in #450, I'm not sure it's worth to merge. I'd like to wait the discussion there.