Implement correct Vorbis Comment standard for FLAC tags with multiple values

[kkhan 16]

I have noticed a problem with multiple tags for FLAC files; the correct Vorbis Comment standard does not seem to work with MB3.  As an example for the album Peter White Christmas three separate Album Artist tags should be recognised (separated by nulls) as follows:

 

Album Artist=Peter White

Album Artist=Mindi Abair

Album Artist=Rick Braun

 

Instead MB3 only recognises the last value (Rick Braun) ignoring the first two.

 

However, the ID3V2 standard of recognising the following as a mulivalue tag for both MP3 and FLACs does work.

 

Album Artist=Peter White/Mindi Abair/Rick Braun

 

This is incorrect as most tagging and playback software (other than MB3) assumes the Vorbis Comment standard. This poses several practical problems:

1. As far as I am aware, most tagging software transparently implement the ID3V2 standard for MP3s and the Vorbis Comment standard for FLACs. Thus for FLACs tagged with either MP3Tag, MediaMonkey4 and Foobar; MB3 simply did not recognise muliple value tags. It did, of course, for MP3s.
2. It is, of course, possible to force an ID3V2 type muliple value tag in a FLAC but then the tagging workflow becomes an exception.  Also the sorting functionality in the tagging software becomes inconsistent with what MB3 sees.
3. Other software which does implement the Vorbis Comment standard could become crippled.  For example, I also run Asset uPNP server to stream music to my hifi system; it currently correctly interprets all standard multivalue tags whether MP3 or FLAC.  If I were to force multivalue tags in FLACs to conform to ID3V2 standards; Asset uPNP would stop recognising multivalue tags for FLACs.  In tests all it sees is a single value "Peter White/Mindi Abair/Rick Braun".

This is a fairly severe problem for a very large collection such as mine.  At the moment I am simply accepting that for FLACs (the majority of my collection), contributing artists will not be fully indexed by MB3,  The consequence of this is that I predominantly use Asset uPNP to listen to music rather than MB3 which is a shame as MB3 is a feast for the eyes (as well as the ears).

 

[Luke 37008]

can you google and download ffprobe, follow this:

 

https://gist.github.com/nrk/2286511

 

and post the output? thanks.

[kkhan 16]

Here is the output.  I notice that ffprobe has only picked up the last of the Album Artists (Rick Braun ignoring ALBUM ARTIST=Peter White and ALBUM ARTIST=Mindi Abair).  Have checked with a hex editor that the other two tags are there.

 

{
    "format": {
        "filename": "test.flac",
        "nb_streams": 2,
        "nb_programs": 0,
        "format_name": "flac",
        "format_long_name": "raw FLAC",
        "duration": "306.933333",
        "size": "30262708",
        "bit_rate": "788776",
        "probe_score": 50,
        "tags": {
            "TITLE": "River",
            "ARTIST": "Rick Braun",
            "ALBUM": "Peter White Christmas",
            "GENRE": "Jazz - Smooth",
            "COMMENT": "CDDA Verified\r\nPeter White is an extraordinary and fluent acoustic guitarist whose skills are world-renown. Mindi Abair is a double-edged talent from her fluid saxophone to emotive vocals. Rick Braun is a masterful trumpet/flugelhorn player whose warm tones transform the simplest melody into a work of art. They have separately sold literally millions of records and anticipate the acceptance to this special performance of Christmas chestnuts.",
            "ORGANIZATION": "ARTizen Records",
            "ENCODER": "reference libFLAC 1.1.2 20050205",
            "ENSEMBLE": "Peter White",
            "track": "06",
            "DATE": "2007",
            "ALBUM ARTIST": "Peter White",
            "album_artist": "Peter White"
        }
    }
}