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[AndrewFG]

One of my users reports that when MC does a Play To a 3rd party renderer, it sends albumArtist = (Multiple Artists) in the metadata tags. I assume that this is something invented by MC and not something in the original track metadata tags. Is that correct? (I don't have the user's original track, so I cannot check it myself).

The following comments (except the footnote) only apply for the case that MC is the one supplying the tag (otherwise please ignore):

• If MC is generating this albumArtist = (Multiple Artists) tag, then it seems to me to be a highly spurious and useless piece of information, since MC also sends multiple artist = <name> tags, and presumably the renderer can count. So why do it??

• Personally I don't think that MC should be "inventing" tags like this. If the track has an albumArtist, then MC should send it; and if the track has multiple artists (and/or authors) then it should send them all. However if no such tag exists in the original track, then nothing should be sent.

Note: I think a similar argument applies to the creator tag; but admittedly in the case that a track has an albumArtist, multiple artists, and multiple author(=composer) tags, it is extremely hard to decide which of these shall be sent as the creator tag. (Feel free to discuss among yourselves...)

[csimon]

This may be something to do with the Album Artist (auto) tag.  If this is being used to populate the metadata then it is understandable that (Multiple Artists) gets sent. I don't know if there is any configuration where you can specify when to use Album Artist (auto) over the normal Album Artist tag?

[AndrewFG]

This may be something to do with the Album Artist (auto) tag.  If this is being used to populate the metadata then it is understandable that (Multiple Artists) gets sent.

Excuse my ignorance, but why is this understandable? I don't understand... :-(

[csimon]

Album Artist (auto) is a MC-invented tag whereby it genereates something in place of an empty Album Artist tag.  So if it's included in any views or configuration where it's sent to another device then its the user's fault that it's being used! As long as MC allows the user to choose between Album Artist and Album Artist (auto) though.  See http://wiki.jriver.com/index.php/Album_Artist_and_Album_Artist_%28Auto%29

But if MC is using this field in some areas in preference to the normal field and there is no way for the user to override it then, yes, the problem is with MC.

Album Artist (auto) is automatically populated with "(Multiple Artists)" if the album contains more than one artist, so that's why it's understandable that this string appears if the Auto field is being used over the proper one.

[csimon]

It strikes me too that multiple Artist tags is not the same thing as an album artist of "Multiple/Various Artists"...

A compilation album will obviously be by various artists, but one track might have artists of David Bowie and Queen.  threfore I think it's right and proper that MC might send, for that particular track:

Artist: David Bowie
Artist: Queen
Album Artist: Various Artists

[AndrewFG]

Album Artist (auto) is a MC-invented tag whereby it genereates something in place of an empty Album Artist tag.  So if it's included in any views or configuration where it's sent to another device then its the user's fault that it's being used! As long as MC allows the user to choose between Album Artist and Album Artist (auto) though.  See http://wiki.jriver.com/index.php/Album_Artist_and_Album_Artist_%28Auto%29

But what is the point of doing this? Why do I need to be told if a track has more than one artist, when I can see for myself the names of the artists on the screen?

Now to be more specific: We have a situation where MC does a Play To a renderer (in my case a Squeezeplayer by Whitebear); MC sends the (Multiple Artists) nonce to the renderer; the renderer has a back end connection to (say) Last.fm scrobbler and forwards the nonce to it; result is that the user's scrobbler statistics get filled up with the nonce -- not very useful I would say...

[csimon]

But what is the point of doing this? Why do I need to be told if a track has more than one artist, when I can see for myself the names of the artists on the screen?

Cause the track artist(s) can be different from the album artist(s).  The string "(Multiple Artists)" is an album-level tag, not a track-level one.  You can have single track artist but still have "(Multiple Artists)" as an Album Artist.

[csimon]

Now to be more specific: We have a situation where MC does a Play To a renderer (in my case a Squeezeplayer by Whitebear); MC sends the (Multiple Artists) nonce to the renderer; the renderer has a back end connection to (say) Last.fm scrobbler and forwards the nonce to it; result is that the user's scrobbler statistics get filled up with the nonce -- not very useful I would say...

I'm not familiar with scrobbling at all I'm afraid, but I guess it's some of play count facility?

In which case, why would Whitebear send the Album Artist?  Surely if you want to record the fact that you've listened to a track by one or more artists, it should send the track artists not the album artist.

[AndrewFG]

I'm not familiar with scrobbling at all I'm afraid, but I guess it's some of play count facility?

Correct.

In which case, why would Whitebear send the Album Artist?  Surely if you want to record the fact that you've listened to a track by one or more artists, it should send the track artists not the album artist.

Let me answer this with a question: "In which case, why would MC send (Multiple Artists) to Whitebear? Surely the internal workings of MC should not be exposed to other external devices which end up trying to double guess the internal automatic logic of the Control Point concerned?"

IMHO MC should only pass on the real tags from the orginal track, and should NOT pass on anything invented by itself for internal purposes...

[csimon]

Let me answer this with a question: "In which case, why would MC send (Multiple Artists) to Whitebear?p

Because the user has decided they would prefer to propogate the Album Artist (Auto) tag rather than the Album Artist tag.

IMHO MC should only pass on the real tags from the orginal track, and should NOT pass on anything invented by itself for internal purposes...

The Album Artist (Auto) tag is not for internal purposes, it's for assisting people with cataloguing/tagging/publishing their music collection if they haven't got round to populating the tags themselves.

In areas where I've come across the (Auto) tag, MC allows you to choose between Album Artist (Auto) and the normal Album Artist tag.  If, in a Play To scenario, MC isn't honouring the user's choice and is sending Album Artist (Auto) regardless of the user's choice then, yes, it's a fault of MC.  Or perhaps int he particular situation you are describing, MC doens't offer a choice and always sends the (Auto) tag, in which case yes, it's  fault again.  But to be honest, I've never seen the phrase (Multiple Artists) appearing as an album artist on any of my DLNA renderers or control points, as I've switched the (Auto) functionality off.  In my case, MC is not sending its own generated field.  That leads me to think there's something not right in your customer's configuration, but without seeing that then I can't say for certain.

[bob]

If specified by the filters, we return:

What we send...
if upnp:artist is requested
MC's artist where role = Performer (if artist is not empty)
and
MC's album artist(auto) artist role = AlbumArtist (if album artist auto is not empty)

if dc:creator is requested
MC's artist

if upnp:albumArtist is requested
MC's album artist(auto) albumArtist (if album artist auto is not empty)

So for the purposes of scrobbling which is track based you should use the artist role = performer or dc:creator, not the albumArtist.

[AndrewFG]

If specified by the filters, we return:
...

Hi bob,

I was referring to what you send to the player in the track metadata in SetAvTransportUri and/or SetNextAvTransportUri. In this case there is no filter whereby the renderer can select what it will receive. And in this case you are just sending albumArtist, artist@role=AlbumArtist and creator tags with the value (Multiple Atrists). And I don't think you ought to be doing that...

[bob]

Hi bob,

I was referring to what you send to the player in the track metadata in SetAvTransportUri and/or SetNextAvTransportUri. In this case there is no filter whereby the renderer can select what it will receive. And in this case you are just sending albumArtist, artist@role=AlbumArtist and creator tags with the value (Multiple Artists). And I don't think you ought to be doing that...

Is it sending Artist role=performer? It should if there is one for the track.

[AndrewFG]

Is it sending Artist role=performer? It should if there is one for the track.

Yes.

[bob]

So I'm thinking our logic makes sense (to us anyway  )
If you are scrobbling a track you should use the artist role=performer not album artist.
You can also edit the album artist field if you chose to say something like "foo and his bar mates"

Since one can have a list of artists in the artist field, perhaps we should present them differently. I'll need to check into how multiple artists are supposed to be presented in uPNP.

[kacper]

If specified by the filters, we return:

What we send...
if upnp:artist is requested
MC's artist where role = Performer (if artist is not empty)
and
MC's album artist(auto) artist role = AlbumArtist (if album artist auto is not empty)

if dc:creator is requested
MC's artist
hi. For people who speak English poorly is not known who to ask
if upnp:albumArtist is requested
MC's album artist(auto) albumArtist (if album artist auto is not empty)

So for the purposes of scrobbling which is track based you should use the artist role = performer or dc:creator, not the albumArtist.

[AndrewFG]

if upnp:albumArtist is requested

By the way, as far as I can tell, this "upnp:albumArtist" tag, is not in any of the UPnP, Dublin Core, or DLNA specifications. Please correct me if I am wrong. I have no idea where it came from, nor indeed why so many people seem to use it.  ?

[bob]

By the way, as far as I can tell, this "upnp:albumArtist" tag, is not in any of the UPnP, Dublin Core, or DLNA specifications. Please correct me if I am wrong. I have no idea where it came from, nor indeed why so many people seem to use it.  ?

Twonky or perhaps Asset?
Looks like they have both done it for a while.

[AndrewFG]

By the way, as far as I can tell, this "upnp:albumArtist" tag, is not in any of the UPnP, Dublin Core, or DLNA specifications. Please correct me if I am wrong. I have no idea where it came from, nor indeed why so many people seem to use it.  ?

Twonky or perhaps Asset?
Looks like they have both done it for a while.

Hmm. In my day job I work for a company who is a member of the UPnP forum, which gives me access to the UPnP Certification Test Tool. Two days ago they released a new version of this test tool, so I took the opportunity to test Whitebear on it. Whitebear scored an "orange/warning" due to the presence of "upnp:albumArtist" tags in its ContentDirectory DIDL; so I replaced them with artist@role=AlbumArtist entries instead.

I will be quite honest: Whitebear scored "red/failure" on quite a few points. These are fixed in the next upcoming release. But then I ran the tests on MC, and you scored "red/failure" on quite a lot more points than me. So I am in good company    ...