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Topic: Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA (Read 33697 times) previous topic - next topic
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Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

This is not just a foobar2k question - please don't move this thread to the fb2k forums.


tl/dr: Does anyone know of a standard or quasi-standard of how metadata can be mapped between various tagging schemes (Vorbis comments, ID3, UPnP/DLNA, etc)?



Having tried to figure out sensible filenames, I realised that I don't know what I'm doing with tags either. I rip to FLAC, and convert to mp3. Because I use the mp3s more, I usually find tag errors in the mp3s first, but flac2mp3 has the potential to makes it easier to keep both collections in-sync.

The problem is, I want to understand what's happening (and what "should" happen) to the tags on their way from FLAC (Flac tags = Vorbis comments), to mp3 (ID3v2.3 or ID3v2.4) to a UPnP/DLNA server.

Knowing that the tags have a good probability of working and making sense whatever mp3 player or DLNA renderer I might use in the future is important. I don't want to keep messing around with them. Hence my desire to understand how they work and map.


I've found some useful information on-line, but not the whole story:

mp3tag has a helpful list...
http://help.mp3tag.de/main_tags.html

fb2k has a list of displayed tag names vs id2v3+4 mp3 tags...
http://wiki.hydrogenaudio.org/index.php?ti...ID3_Tag_Mapping
...and a list of ways it now knowingly breaks the standard...
http://wiki.hydrogenaudio.org/index.php?ti...y_1.1.6_changes

The description of Vorbis comments starts here...
http://wiki.xiph.org/index.php/VorbisComment
...with the list here...
http://xiph.org/vorbis/doc/v-comment.html
...newer additions here...
http://wiki.xiph.org/Field_names
...and a useful guide here...
http://age.hobba.nl/audio/mirroredpages/ogg-tagging.html

I can't find an on-line list of how fb2k maps Vorbis Comments to ID3. Is there one?

In dBpoweramp, if I dive deeply into the menus, there are options for changing how tags are mapped and named on screen. I can't find an on-line list that states what the defaults are.

Asset UPnP, Serviio, and some other DLNA/UPnP servers have options to try to make things work properly with various clients. My stuff tends to be thrown at Twonky and I had no idea what it was doing but found this on line...
http://www.twonkyforum.com/mediawiki/index...Twonky_Database

I've heard of (but not tried) MinimServer which tries to make the tags needed for classical music work properly.

The intricacies of making various things work is played out in full on the Linn forums, though thankfully they share some of the things they have created.


That's all I can find. Anyone have any other useful links?


Is there a "standard", or does everyone just try to figure it out for themselves?

It would also be nice to find documentation of the compatibility and quirks. e.g. for multiple values, do you add multiple tags or one tag with a specific delimiter etc. and e.g. what works on various players.

If anyone spots any flying pigs, feel free to mention that as well  .

Cheers,
David.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #1
I've found a similar thread on the mp3tag forums...
http://forums.mp3tag.de/index.php?showtopic=15983

It mentions an issue I hadn't noticed: ALBUMARTIST vs ALBUM ARTIST. I don't think worth worrying about with current fb2k versions though...
http://www.hydrogenaudio.org/forums/index....showtopic=92294
http://www.hydrogenaudio.org/forums/index....howtopic=100012

It also mentions an issue I had noticed...
DISCTOTAL or TOTALDISCS
TRACKTOTAL or TOTALTRACKS
vs track/totaltracks
...which isn't always cleanly mapped.


One thing that confused me at first is that most programs use some mapping from tag names to what they display on screen, and try to help you, but when you're trying to figure out exactly what tags are written this help isn't helpful!

Cheers,
David.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #2
Quote
but when you're trying to figure out exactly what tags are written this help isn't helpful!


yup, you can't tell with foobar at all. mp3tag is good for showing flac/vorbis comments in the extended tags dialog. if you really want to see what frames are written to an mp3 then the only useful thing i've found is axone.jar but it's cumbersome to use as it can only open one file at a time.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #3
Thanks marc2003 - I hadn't found that.

Googling for axone.jar also found this old thread...
http://www.hydrogenaudio.org/forums/index....showtopic=87844

which mentions Kid3...
http://sourceforge.net/projects/kid3/?source=dlp
...it doesn't give you the raw tags, but does show you the names of the TXXX fields. Unless I'm missing something, axone.js only shows you the values which is rather unfortunate! You can read them in Hexeditor.jar alongside but it's not ideal.

Cheers,
David.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #4
Quote
Unless I'm missing something, axone.js only shows you the values which is rather unfortunate!


just highlight each frame on the left to get the full name and value.






Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #5
That's great, thank you. Thank you for taking the time to post a screen shot or I might not have realise what you meant! Shame it's not in the core File>Tree view all in one place, but it's easier to flick through the individual TXXX frames than launch another program.

Cheers,
David.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #6
You might want to take a peek at http://www.mp3tag.de/

Not sure if that is exactly what you'll need.
But as far as tagging goes I've been using it for years.
And it does allow to list/edit non standard tags.
I've got it customized to also show replaygain tags in it's main listview for example.
It is also regularly updated so it's not collecting dust either.


One major issue tough is that it is custom tags/comments you are messing with.
Unless it's written down in some official documentation by the folks behind the audio/container format or tagging standard then it's anybody's guess whats out there and what matches with which.
iTunes for example has a lot of it's own iTunes specific tags again.

The HA Wiki would probably be a great place to map out what matches what across formats and tags.

Most of the "common practice" tags are the same across formats and players and tag software, but a lot of variants and outliers still exist. A Wiki might help developers come together on some of those.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #7
Did you totally miss the bits in the OP where he specifically said he has already incorporated MP3tag and our Knowledgebase into his research but wants more information?

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #8
*doh* I did see a mention of
Quote
mp3tag has a helpful list...
http://help.mp3tag.de/main_tags.html

But did not connect that as to him actually using mp3tag.
I was posting in relation to axone.jar and tag readers/editors so I probably got some blinders on focusing only on that part of the discussion.

And you mention the HA knowledgebase, I see no mention of any pages in the wiki which crossreferences meta tags, now if I missed that then my bad again.
But lest ignore my little blooper there and get back to the subject at hand.

My suggestion was to make such a page and pool our efforts and kill two birds with one stone sort of speaking.
The draft could be done on a Wiki talk page and then moved to the actual page when done for example.

And to make sure to get fully back on track with the OP...
I assume that there does exist some standards in some whitepapers, but these are probably stuck as pay only (MPEG, MP4 whitepapers?) then there is the BWF stuff. And RF64.
Microsoft "might" have some stuff on msdn.microsoft.com "somewhere", I'm sure someone here has access to those whitepapers and can help out?

Also, focusing on just FLAC/Vorbis and mp3 is too narrow. With tags being copied to and from, a tag from say mp4, or some obscure SID chipmusic format may find it's way to other formats at some point.
So a community classification project may actually provide results much faster. Just my two cents.


Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #9
Yes, I'm using mp3tag - though I wish I'd started using it years ago.

I agree that a good place for this information would be the HA wiki. Then of course other people can add information for other formats.

The information itself isn't so clear cut though. In practice, some tagging standards (especially with mp3) have to be abused just to make the files work with a wide variety of players. So, for example, we all know what an artist is, and what a composer is - but when tagging classical music it's de rigueur to put the composer in the artist field, and store the artist somewhere else...
http://wiki.slimdevices.com/index.php/Begi...de_To_Classical
(I know that's a squeezebox specific page, but pretty much anywhere classical tagging is discussed this suggestion comes up, even if not everyone uses it).

When people don't even agree on what the tags mean, it's hard to be definitive about a mapping between them. Lots of software tries though, so unless everyone does it completely differently, it must be possible to document the lose consensus that's out there. I think that's about as good as it gets when it comes to tagging!

btw, the official metadata dictionaries that I know of aren't behind a paywall...
http://tech.ebu.ch/lang/en/MetadataEbuCore
http://www.movielabs.com/md/md/
http://www.smpte-ra.org/mdd/index.html
...but apart from being less relevant or irrelevant to tagging CD rips, even they have poor or incomplete mappings.

It may be worth mentioning...
http://www.rovicorp.com/products/discovery...ta.htm#packages
http://prod-doc.rovicorp.com/mashery/index...APIs/Rovi-Music
...because they have had to think a lot of issues through, and this data is routinely mapped to tags by rippers. I'm not sure that's the most relevant link though.

Cheers,
David.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #10
I was/am hacking something together on the HA wiki, but look what I found...

http://wiki.musicbrainz.org/MusicBrainz_Picard/Tags/Mapping

...that's a pretty good answer!


It has some holes, but it's better than anything else I've found.

Cheers,
David.


Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #11
Here is my attempt. It is not finished yet! I intend to cull the items which don't map, but I'm leaving them ALL there for now to see if there's a soft mapping (TXXX or IPLS/TIPL) which works. I intend to organise it better too. Other formats can be added fairly easily from the URLs at the bottom of the table, but later. Anyway...

http://wiki.hydrogenaudio.org/index.php?title=Tag_Mapping


Here are some problems...

1. When inventing new frames for ID3v2, some sources just invent a new frame (especially a new ID3v2.3 frame with the same name as a real ID3v2.4 frame - but sometimes an entirely new T frame), some sources invent a new frame with an X at the start, and many use TXXX:framename (which is the correct method according to ID3.org). Any thoughts on these three approaches? Anyone seen yet another approach?

2. With Vorbis Comments, Who/what is using TOTALDISCS in preference to DISCTOTAL? ditto TOTALTRACKS vs TRACKTOTAL? If it's lots of things, then ideally you need to read+write both versions for compatibility, but the xiph.org docs only mention DISCTOTAL and TRACKTOTAL.

3. Given the now common mapping of TPE2 to Album Artist, is there a field left for Orchestra/Band? Given that TPE1 is mapped to Artist, it also loses its original meaning of "soloist". I guess soloists can now be listed first in one of the performer/musician/IPLS/TIPL fields, leaving TPE1 free for Orchestra? I only ask because I'm wondering how many IPLS/TIPL/TMCL vs Vorbis Comments mappings to figure out.


It gets worse if you assume that, when tagging classical music, some people will abuse Artist=composer - but that's for another day (and thread!).

Cheers,
David.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #12
Here is my attempt. It is not finished yet! I intend to cull the items which don't map, but I'm leaving them ALL there for now to see if there's a soft mapping (TXXX or IPLS/TIPL) which works. I intend to organise it better too. Other formats can be added fairly easily from the URLs at the bottom of the table, but later. Anyway...

http://wiki.hydrogenaudio.org/index.php?title=Tag_Mapping


OFFS! That's what I get for not being vigilant at checking the forums constantly.

*cough* http://wiki.hydrogenaudio.org/index.php?ti...Metatag_Mapping

This too is a rough draft. (I had it on my wiki userpage while working on it).
I was planning to work further on it but now that yours is up too.

This info need to be merged obviously.

Too many cooks in the kitchen I guess.


Quote
1. When inventing new frames for ID3v2, some sources just invent a new frame (especially a new ID3v2.3 frame with the same name as a real ID3v2.4 frame - but sometimes an entirely new T frame), some sources invent a new frame with an X at the start, and many use TXXX:framename (which is the correct method according to ID3.org). Any thoughts on these three approaches? Anyone seen yet another approach?

Seeing all the ID3v2 tags almost felt like my eyes was about to bleed (almost as nasty as the MP4/iTunes ones).
TXXX is defined as being user defined, so anything goes I guess.
I feel like many of the ID3v2 things have a "designed by committee" feel to them, where somebody said they wanted this or that without actually explaining why, and then later it probably never got used anyway.

Quote
2. With Vorbis Comments, Who/what is using TOTALDISCS in preference to DISCTOTAL? ditto TOTALTRACKS vs TRACKTOTAL? If it's lots of things, then ideally you need to read+write both versions for compatibility, but the xiph.org docs only mention DISCTOTAL and TRACKTOTAL.


Actually if you right click a entry in Foobar2000, then choose properties you should get a Poroperties window with a Metadata tab. If you double click "Disc Number" for example you should get a new window that shows the actual Field name, and Field value as it is stored.
Foobar2000 seems to use DISCNUMBER and TOTALDISCS and TOTALTRACKS for Flac, this clashes with what it says on Xiph.org and in my tables you can see I've got both variants listed for now.

Quote
3. Given the now common mapping of TPE2 to Album Artist, is there a field left for Orchestra/Band? Given that TPE1 is mapped to Artist, it also loses its original meaning of "soloist". I guess soloists can now be listed first in one of the performer/musician/IPLS/TIPL fields, leaving TPE1 free for Orchestra? I only ask because I'm wondering how many IPLS/TIPL/TMCL vs Vorbis Comments mappings to figure out.

ID3v2.x does allow multiple tags of the same kind so having more than one TPE2 is actually OK. I think MP4 (more correctly iTunes) is the only one that does not allow that?
VorbisComments standard encourages multiples of a field, it certainly makes searching/matching easier as you can get a hit on each member, having  them all separated by , or / in a singe field is not that search friendly and causes issues when sorting.


I think some kind of statistics gathering is needed.
I.e. Populate all fields in all the most popular software (players/taggers/editors/transcoders/media servers), and do so for all formats they support, then extract that info and see what they are actually stored as.
But it needs to be directed somehow, we already got two wiki pages now because of the lack thereof.


I like the way that the HTML5 working group (WHATWG) are doing things. They are basically adapting HTML5 constantly to reflect the common practice, and this means that only a few developers here or there need to adapt to the majority instead.
Maybe a similar approach could be done with the Tag Mapping/Metatag Mapping page.
But WHATWG has one awesome guy that act as the director to help filter the whole thing and thus avoids making the whole thing messy by having too many cooks.

I'd like to point out 2bdecided as a good candidate to oversee this project, you certainly frequent HA a lot

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #13
Seeing all the ID3v2 tags almost felt like my eyes was about to bleed (almost as nasty as the MP4/iTunes ones).
TXXX is defined as being user defined, so anything goes I guess.
I feel like many of the ID3v2 things have a "designed by committee" feel to them, where somebody said they wanted this or that without actually explaining why, and then later it probably never got used anyway.

I get the same impression from ID3v2.4's text tags, which have four different possible text encodings - three of which are just Unicode variants.

The format is littered with flags that nobody sets and tags that nobody uses that make it more cumbersome without really adding anything.  Yet despite having three different (and incompatible) ID3v2 versions, there's hardly any difference in capability between them which makes me wonder what the point is.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #14
Well, we're either great minds or fools because that's certainly thinking alike!

I nominate you - yours is much prettier. However, I'm still going to try to complete the data in mine from the sources I have. As you say, some kind of further analysis of what's out there is also needed.

I think some of the devil is in the detail. I intend to add explicit information about some of the non-obvious mappings, to make it more like a proper explicit standard. I see you have added notes along these lines.

I wasn't sure whether my numbered footnotes (listing the source of some information) would make it to the final cut. It's useful to track this stuff I think.

Like you, I categorised the tags, but using colours (green for easiest to map) and sections (to make finding + merging them easier). Your way makes sense too, though I think beyond a third level it'll get quite arbitrary. Amazing how persistently useful ID3v1.1 is.

Finally, I think ID3v2.3 tags made some sense when the standard was written, but they never made provision for a machine algorithm to know the different meanings, or defined a simple way to use a subset when you didn't care that much. If a tag can be one of three things (look at each of the artist fields), and another format has different fields for each of those three things (e.g. TEXT vs Lyricist and Author), then an automatic universal mapping is impossible. If normal lazy use reduces three separate tag values inconsistently into a single tag (TIT1, 2 and 3 just end up in TIT2 as the title), you're in trouble. Once certain software/hardware (most software/hardware) ignores key things (how many players sort by composer?), you're kind of doomed. That said, it's not quite as bad as I feared.

Impressive stuff though Rescator. I didn't even think of Matroska. I did think of Dublin Core/UPnP/DLNA, but haven't gone there yet. I have trawled all the links I provided earlier in the thread yet, just the ones listed below my table. I think I'll keep the references to where the non-obvious information came from until everything is finished.

It crops up in several places second-hand, but is there a first-hand source for the various Apple extensions to ID3v2.x? Or did people only figure it out from looking at mp3 files from iTunes?

Cheers,
David.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #15
Foobar2000 seems to use DISCNUMBER and TOTALDISCS and TOTALTRACKS for Flac, this clashes with what it says on Xiph.org and in my tables you can see I've got both variants listed for now.


this is incorrect. you cannot rely on what you see in the foobar properties dialog for what is actually inside the file. this does not show the internal name used. mp3tag will show you via the extended tags dialog or you can use the metaflac command line tool. currently there is no way to tell from within foobar itself. it still reads from both and what it writes is determined under file>preferences>advanced>tagging>vorbis & flac>metadata writing mode.



i actually took this next screenshot some time ago to show the difference between the 2 modes. i created 2 copies of the same track and tagged each one in foobar, switching modes for each one. the foobar properties dialog is not showing the difference but metaflac is....

https://dl.dropboxusercontent.com/u/2280132...ch/metaflac.jpg


Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #16
Foobar2000 seems to use DISCNUMBER and TOTALDISCS and TOTALTRACKS for Flac, this clashes with what it says on Xiph.org and in my tables you can see I've got both variants listed for now.


this is incorrect. you cannot rely on what you see in the foobar properties dialog for what is actually inside the file. this does not show the internal name used. mp3tag will show you via the extended tags dialog

Darnit! Thanks Marc.

Well, we're either great minds or fools because that's certainly thinking alike!

I nominate you - yours is much prettier.

We're both fools probably.
And I actually like the look of yours. Maybe a hybrid of sorts would be better. I know next to nothing about Wiki markup. So having some Wiki guru to help out on this would be nice.

Quote
However, I'm still going to try to complete the data in mine from the sources I have. As you say, some kind of further analysis of what's out there is also needed.

I think I'll hold off on mine until you have completed yours. I'm pondering just redoing it all locally in a database and then just export/prep it in some way that allows to copy'n'paste it into the wiki in one go.
Moving stuff around in the wiki itself is a pain. Small edits here and there is not an issue, but it was never designed for this stuff/type of editing.

Quote
I think some of the devil is in the detail. I intend to add explicit information about some of the non-obvious mappings, to make it more like a proper explicit standard. I see you have added notes along these lines.
I wasn't sure whether my numbered footnotes (listing the source of some information) would make it to the final cut. It's useful to track this stuff I think.

Yeah! You should probably steal the way I did the footnotes, they are autonumbering, autoordering, self referencing and linking within the page in both directions and a multiple can point to the fame footnote. As far as I can see this is the most powerfull/flexible way to do footnotes on the Wiki (though I'm sure a Wikiguru will laugh and point out something better though).

Quote
Amazing how persistently useful ID3v1.1 is.

Heh! Well the tags from it formed the base for all others I suspect. But damn the limited lengths and lack of extensibility is depressing. I stopped using it myself when I noticed text was cut off sometimes. Oops!

Quote
If a tag can be one of three things (look at each of the artist fields), and another format has different fields for each of those three things (e.g. TEXT vs Lyricist and Author), then an automatic universal mapping is impossible. If normal lazy use reduces three separate tag values inconsistently into a single tag (TIT1, 2 and 3 just end up in TIT2 as the title), you're in trouble.

Yeah! I felt my brain trying to escape through my ear at one point when looking at the multiple artist tags.

It's just as messy with others though like. Subtitle, Remixed By, Mixed By, Version. All these overlap or intersect in some way. VorbisComments treat Version as a Subtitle synonym. Matroska ... well, I think they got a little too eager and got all except Version in their standard.

Quote
Impressive stuff though Rescator. I didn't even think of Matroska. I did think of Dublin Core/UPnP/DLNA, but haven't gone there yet. I have trawled all the links I provided earlier in the thread yet, just the ones listed below my table. I think I'll keep the references to where the non-obvious information came from until everything is finished.

Might be one or two links at the bottom om my wiki that you haven't seen yet too.
Matroska is just the tip of the iceberg I'm sure. There is also BWF (used in WAV (RIFF)/RF64/Wave64, and maybe CAF as well).

Quote
did people only figure it out from looking at mp3 files from iTunes?

Looks like a lot of reverse engineering to me.


Quote
I nominate you

I'm probably not the best person for that, I'm awesome at telling people what to do, but just as easily to piss them off in the process (some might call that perfect delegation but...)...and besides you carry a little more weight around here, hence more respect, you did do an alright job with ReplayGain after all

But I tell you what. I'm happy to help out (obviously) and so are you (obviously).
So I guess that makes you and me the first fools in the Metatag Working Group, aka the Meta What Group now?

It would be nice to have some more peeps on this (especially some Wiki wiz).
With a handful of folks we could delegate some research tasks and editing tasks among us.
The discussion page on the wiki article page could be used to coordinate edits. while this thread could be used to help coordinate the research and delegation. (or would a new thread be more appropriate?)
I also like this open forum way of doing it as it allows others to poke us (like Marc did) and say "Hey your doing it wrong!"

Ideally the end result of all this will be a unifying standard or guideline that developers (and others, maybe even standard/format designers) can just pop by look at the Wiki article and save themselves, the end users and a while bunch of developers a lot of time and headaches. Or at the very least be able to use it to avoid some of the pitfalls of the existing ones.

And since it's a wiki, supplemental pages could be made to detail particular fields and maybe act as a guide for designing machine parsing of the most used fields at least.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #17
It's the first time I've typed a HA wiki page too - thanks for the hint about references - that's the way to do it!

I've found a couple of other comparison/mapping pages...
http://www.matroska.org/technical/specs/ta...mparetable.html
http://age.hobba.nl/audio/tag_frame_reference.html

Worrying, because we're heading into "the great thing about standards is that there are so many of them!" territory just for the mapping "standard"! At least they mostly agree.

I think the way TPE2 is universally stolen for album artist, leaving nowhere ideal for the band/orchestra of a classical work, is probably the biggest problem.

When I've got through all the existing sources and it's looking a bit neater, I would love it if the authors of the popular software packages could chip-in themselves.

I won't have internet access for ten days, but it doesn't mean I've given up.

Cheers,
David.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #18
I've found a couple of other comparison/mapping pages...
http://www.matroska.org/technical/specs/ta...mparetable.html
http://age.hobba.nl/audio/tag_frame_reference.html

Worrying, because we're heading into "the great thing about standards is that there are so many of them!" territory just for the mapping "standard"! At least they mostly agree.

Woa! That Matroska comparison there; wish I'd known about that sooner. You are a better Googler than me Sir.

Quote
I think the way TPE2 is universally stolen for album artist, leaving nowhere ideal for the band/orchestra of a classical work, is probably the biggest problem.

When I've got through all the existing sources and it's looking a bit neater, I would love it if the authors of the popular software packages could chip-in themselves.

I won't have internet access for ten days, but it doesn't mean I've given up.

*nod*
I'll use yours as the basis and then merge/blend mine in. I will probably keep the Primary separate like on mine, but instead of Secondary/Tertiary etc, I'll group the rest per their purpose instead. And then start adding all the other standards out there.

Going the common practice/current practice route (even if it's wrong at times) is smartest at first. Once that is done, folks can start to bump heads on whether old fields should change their meaning or new ones should be added etc.

Considering how quiet others are I'm guessing they are thinking "there's no way I'm touching THAT mess"

I mentioned I'd do a sort of database thing later locally here to help manage all these formats/tags, and the fact that you use the notes/refs I suggested is even more practical as they can actually stay/ride along in the database, the notes are semi-portable in a way.
Which is a good thing, some of those links you've found just revealed that I didn't shoot big enough for my own tables.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #19
OK, well I might get chance to add+fix some bits tomorrow, then it's yours for ten days.

Cheers,
David.

 

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #20
I think the way TPE2 is universally stolen for album artist, leaving nowhere ideal for the band/orchestra of a classical work, is probably the biggest problem.

When I've got through all the existing sources and it's looking a bit neater, I would love it if the authors of the popular software packages could chip-in themselves.


are these 2 points related or am i reading too much into it? i think it's probably a bit too late to be proposing changes.

the big behemoths like windows media player and itunes aren't ever going to change and i think other software is more or less forced to use what they do for maximum compatibility. take foobar for example. that wrote album artist and rating to TXXX for years. it also wrote id3v2.4 with no consideration for compatibility with other software at all. but now it uses defaults of TPE2, POPM and id3v2.3 and you can only assume the driving force behind all this change was for compatibility with WMP and windows explorer.

Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #21
I think the way TPE2 is universally stolen for album artist, leaving nowhere ideal for the band/orchestra of a classical work, is probably the biggest problem.

When I've got through all the existing sources and it's looking a bit neater, I would love it if the authors of the popular software packages could chip-in themselves.


are these 2 points related
No.

I meant it would be helpful to understand what some products do by hearing directly from their authors. I'm not expecting Microsoft or Apple to drop by or change anything.


I raised the first point because it would be interesting to hear good ideas for coping with it that allow sensible mapping. In an ideal world, sensible mapping that works whether someone has abused the artist fields for composer, or not. Might be impossible.

Cheers,
David.


Metadata/tag mapping between FLAC, mp3, and UPnP/DLNA

Reply #23
There are two things that I think would make it much better, but I don't know how to do either on a wiki.

Firstly, it would be helpful to be able to show/hide each column, letting people focus only on the format(s) they arer interested in, and reducing the table to less than one screen width if needed.

Secondly, I think a good way of highlighting the "main" tags would be to be able to optionally hide all the others, rather than separate them out permanently. When looking at the full list, it has less context (and obvious holes) when the main ones are separate. There seem to be three categories - main, others, and unmapped. It would be helpful to be able to toggle all three, with unmapped hidden by default.

I haven't finished the UPnP entries, or started some of the others. It's still here...
http://wiki.hydrogenaudio.org/index.php?title=Tag_Mapping
...but if you merge things, I think it needs a new search-friendly title like "Tag and Metadata mapping for audio files" with a list of the formats covered near the top.

That's me done for now. I'll point some folks at this thread to see what they think. Have fun.

Cheers,
David.