id3lib - how to use??

[kroka]

Hello,

I am a commercial developer using runrev/livecode for a while now. In my latest project, an mp3 database for handling and sorting large amounts of mp3's for a radio station, the customer asked me to read and write the ID3 tags of the mp3's.

I found the id3lib for runrev by Mark Smith which seems to do everything I need, so I don't need to reinvent the wheel. Last updated 2007, but still available on RevOnline.

Only problem: the link to the website where some documentation and examples are promised, is dead. So is the whole domain. There is no help or doc included in the package.

Does anybody know about this plugin - and does anybody still have some example or docs about it? It's not really self-explanatory. I have been trying around for a while.

Any help is really appreciated!

Thanks

kroka

[Klaus]

Hi kroka,

alles fit in Bärlin?

OK, although I did not work witht ehis lib yet, I found it on my harddisk and even a read me file!
I attached it here and I hope it will get you started.


Best

Klaus

Edit: The extension txt is not allowed.

Hmmm, OK, copy/paste here:
######################################
id3lib v1.0.0
May 2007

id3lib is a library for Revolution that allows the reading of all versions of ID3 tags. It can also write the tags, but only in the v2.3 format, so effectively converting any edited tags to v2.3, whatever version they have been before editing. This was a decision based on the fact that it will be a great deal of work to support writing all tag formats, (though I plan to do it), and the fact that v2.3 seems to be the most widely used version. v2.4, being more recent, might seem like the one to support first, but egregious abuse of, and non-compliance with the 2.4 spec by both Apple (in iTunes) and Microsoft (in everything) have made it's wide adoption unlikely. (Not that they haven't done 2.3 fairly wrong, but not as badly).

id3lib will also read iTunes (.m4a and .m4p) tags, but cannot write them.

At the moment, this document only describes a subset of what is in id3lib, but I've decided to release it now in order to see how it fairs in use, and because what I suspect is quite a lot of what people might use it for is ready to go.

Full support for embedded pictures is quite close, (and if you dig around in the script, you may be able to figure out how to get them out of the tag - no writing as yet).
I'm also fairly close to getting comment frames working properly.
---------------
To start, make sure that you have id3lib open.
To read the tag from a file, get the full path to the file, and pass it to the id3_setFile command, so:

id3_setFile someFile

id3lib now reads the file, and if it the file is not one that can have an id3 tag, it puts an error message into the result.
Now, you can access the various parts of the id3 tag (frames, in the jargon). id3lib provides simple functions for getting the most commonly used frames:

Title, Artist, Album, Year, Track Number, Disc Number, Genre, and others.

The functions are
id3_getTitle()
id3_getArtist()
id3_getAlbum()
id3_getTrackNumber()
id3_getDiscNumber()
id3_getGenre()
id3_getComposer()
id3_getLyricist()

So:
put id3_getTitle() into tTitle.

id3lib also provides the function id3_getTextFrame(), which you can use to get some of the other, less widely used frames. You have to pass the correct ID fro the frame you want as a parameter, so

put id3_getTextFrame("TENC") into tEncodedBy

Obviously, you will need to know the various IDs used in the spec, so you can see a list of them here.
The full spec can be got from http://www.id3.org/d3v2.3.0

The id3v2.3 spec allows the choice of unicode or plain text in many of the text frames, but not in all. Among the frames in which unicode is not allowed are : TrackNumber(TRCK), DiscNumber(TPOS), Year(TYER) and Genre(TCON).

The values returned from these text frames can be plain text, or unicode (UTF-16). If you need to know which was returned, you can call id3_LastFrameWasUnicode(), if it returns true then the last returned value was unicode, plain text if false.
--------------
Writing tags.

Having read a tag, you can edit the tag using the commands:

id3_setTitle
id3_setArtist
id3_setAlbum
id3_setTrackNumber
id3_setDiscNumber
id3_setGenre
id3_setComposer
id3_setLyricist

each command takes an appropriate string as a paramater, and optionally a boolean value to indicate the use of unicode. So:

id3_setTitle someTitle
id3_setTitle fld "title"
id3_setTitle the unicodeText of fld "title",true

It isn't necessary to include "false" when using plain text, but you can if you want. However, if you pass unicode, but don't include "true", the unicode string will get messed up.
Again, for text frames not included in the above list, you can set them using id3_setTextFrame, with the same rules governing unicode.
Finally, when you've finished editing the tag, you write it out to the file using id3_updateFile.
See the script of this stack for a working example of the various handlers.
------------
Genres

I've included a function id3_getGenreList() which return a list of the genres originally supported in v1 of the id3 spec. (See the script of btn "Genre:" in the demo stack).
These genres are supposed to be stored as numbers (id3lib does the necessary lookups for this), but the spec allows for 'refinements' which can be textual. So it seems to me that you can set any old string you like as a genre, and in practice this seems to be what most implementations do.
------------
Mark Smith
May 2007

[kroka]

Hi Klaus,

ja, alles fit hier im schönen Berlin.

Wow - that was fast. And it's exactly what I needed!

Thank you very much. I'm grateful!

Kroka

[matthiasr]

Hi Kroka,

it seems there is a newer version (from 2008) here at Mark´s On-Rev site

http://marksmith.on-rev.com/revstuff/files/

Unfortunately Mark Smith died in November 2009.

Regards,

Matthias

[marksmithhfx]

Hi Kroka,

Unfortunately Mark Smith died in November 2009.

Matthias

I am very sorry to hear that... it looks like he was doing some very impressive work.

From another, unrelated, Mark Smith

-- MS