What tags do AMG, GD3, MusicBrainz and FreedB support?

[d2b]

...and how are they mapped when using CD Ripper to rip a CD to different file formats or the Converter to transcode to a different format? Is there a comprehensive table that shows what tags these on-line databases support and how the various formats ingest or ignore them?

In our case, we are ripping CDs for our radio station library using the FLAC encoder. We add the information in the standard fields listed (Artist, Album Artist, Genre and so on) as well as in a few custom fields that we've added, such as UPC and Label. It's not clear if any (or which) of the on-line databases retain or ingest these tags when we submit the the metadata before ripping. It's also not clear what happens to this information when transcoding from one file format to a different one.

Furthermore, I've seen CDs that have had a few tags returned from one or more of the databases with non-standard Vorbis Comments such as STYLE=xxxx. Where did that usage originate? Is there a 'common usage' standard that we should know about for extending the range of Vorbis Comments. (Note that we are doing just that for our own needs, but perhaps re-inventing the wheel, or worse yet, spinning ours.)

I know that dBpoweramp (by default) maps some common field names to their Vorbis comment equivalents, such as Comment --> Description, but when trying to sort out the bigger picture, it would seem reasonable that somewhere there must be a master table that shows the equivalent metadata field names and values, how they relate to one another depending on file format, and which of those are actually ingested and used by the various on-line database sites.

We tag our FLAC files as best we can according to the Vorbis Comment standards, such as they are, but we have a need to add additional VCs, such as ALBUMARTIST, UPC, COPYRIGHT and so on. It would be good to know if this information is going to be retained, lost or ignored when transcoding to another file format or when submitting to on-line databases.

Can you shed a lot of light on this subject, or point us to the resource(s) that can illuminate this topic?

Thanks in advance...

"d2b"

[Spoon]

AFAIK there is no comprehensive table.

Style would have come from AMG. Any tag which is not Artist, Title, Album (ie the simple ones) are not defined in vorbis comments, so there is nothing wrong with writing a style tag. If you never need style you can direct CD ripper not to write it.

[d2b]

Is it not possible to learn what tags are supported by AMG or GD3, and in what form they are ingested?

Is it not possible to learn how dbpoweramp MC handles vorbis comments (standard or home-made custom VCs such as UPC) when transcoding to another file format such as MP3?

Examples: Is ALBUMARTIST mapped to BAND when transcoding from FLAC to MP3? What happens when I submit metadata to AMG for a CD that is going to get a UPC vorbis comment when I rip it...does AMG ingest the UPC value?

[Spoon]

>Is it not possible to learn what tags are supported by AMG or GD3, and in what form they are ingested?

Put a popular disc in the drive and manually retrieve from a single provider, you will see all the tags supplied by that provider.

Albumartist is mapped to band when using mp3, that is because band is the standard for albumartist in mp3.

You would have to ask AMG what they do with submissions.