defined APE tag keys/frames

[Prodoc]

Hi,

Please forgive me for my ignorance, I might be completely off here, but since Frank Klemm seemed to be the only one hosting some complete information about APE tags I hope you don't mind me contacting you guy's for some questions about the tags [1].

I send this e-mail to Frank directly as well but I did not get a reply and after I send the e-mail, the website was taken down for some reason. If you know a mirror of the mentioned page, please let me know.

To clear things up a bit first: where did the APE tag system originated from? I'm a bit confused and not a 100% sure because the name would imply that it originated from the Monkey's Audio format, though that site doesn't realy contain any info about it.

I'm currently working on a tag frame reference of the different tag sets (ID3, APE, Vorbis, Matroska, etc.) and because of that I've got several questions about the defined APE tag keys [2].

I'm having trouble creating an accurate mapping of the following tags because the exact definition isn't exactly clear to me.

- FILE
Does the location of the file need to be stored in the tags of the
same file? What exact type of location are we talking about since it
has to be a URL?
- CATALOG
Just any kind of catalog id/number of any kind/type of catalog?
Wouldn't the type of catalog (e.g. by which company or website
(imdb.com or something)) need to be known?
- MEDIA
I don't get this one, what is it that you want to have stored in this
tag? Is it like the WWWAUDIOSOURCE (WOAS) frame in ID3 [3]? WOAS is
used to point to the official webpage for the source of the audio
file; e.g. if the audio is "extracted" from a movie. This doesn't
explain the Source Media Number/Total Media Number and Source Time
though.
- INDEX
Indexes for quick access? Quick access of what? Can this key be
compared to the MPEGLOOKUP (MLLT) frame in ID3 [4]? This one is used
for a MPEG location lookup table to increase performance and accuracy
of jumps within an audio file. Or am I completely off here? :-)
- RELATED
Location to what kind of related info?
- ABSTRACT
Abstract as in a description of the content? If so, why does it need
to be a link?

Thank you in advance for your time and help.

Cheers,

Age Bosma


[1] http://www.personal.uni-jena.de/~pfk/mpp/s...sv8/apekey.html
[2] http://hobba.hobba.nl/audio/tag_frame_reference.html
[3] http://www.unixgods.org/~tilo/ID3/docs/id3...rames.html#WOAS
[4] http://www.unixgods.org/~tilo/ID3/docs/id3...rames.html#MLLT

[Ganymed]

To clear things up a bit first: where did the APE tag system originated from? I'm a bit confused and not a 100% sure because the name would imply that it originated from the Monkey's Audio format, though that site doesn't realy contain any info about it.

AFAIK, the APEv1 tag was introduced by Matt from Monkey's Audio and extended to APEv2 by Frank Klemm.

I only have the description from Frank Klemm's list, so I'm only guessing:

- FILE
Does the location of the file need to be stored in the tags of the
same file? What exact type of location are we talking about since it
has to be a URL?

I've never seen any file with this tag field. File paths in APEv2 are expressed as URIs like

file:/directory/file
file:./relativedirectory/filename
file:./filename

- CATALOG
Just any kind of catalog id/number of any kind/type of catalog?
Wouldn't the type of catalog (e.g. by which company or website
(imdb.com or something)) need to be known?

This is the EAN/UPC or the labels catalog number for this media.

- MEDIA
I don't get this one, what is it that you want to have stored in this
tag? Is it like the WWWAUDIOSOURCE (WOAS) frame in ID3 [3]? WOAS is
used to point to the official webpage for the source of the audio
file; e.g. if the audio is "extracted" from a movie. This doesn't
explain the Source Media Number/Total Media Number and Source Time
though.

I think Klemm means the media type here, e.g. "CD", "DCD". Source media number would always be 1 - except for double CDs or CD sets. Don't know what Source Time is good for.

- INDEX
Indexes for quick access? Quick access of what? Can this key be
compared to the MPEGLOOKUP (MLLT) frame in ID3 [4]? This one is used
for a MPEG location lookup table to increase performance and accuracy
of jumps within an audio file. Or am I completely off here? :-)

Sorry, I don't know

- RELATED
Location to what kind of related info?

Anything related - link to AMG review, artist page on Amazon.

- ABSTRACT
Abstract as in a description of the content? If so, why does it need
to be a link?

Since Klemm was restricting the recommended maximum size of an APEv2 tag to 1KB between 8KB, I think he wanted to use external information on this large fields.

Btw: You can find the APEv2 page from Frank Klemm still in Google's chache.

Best regards,
~ Florian

[Prodoc]

Thank you for your reply.

I've never seen any file with this tag field. File paths in APEv2 are expressed as URIs like

I found it a bit strange that the location had to be stored in the file itself. Would there be any reason to do so?

This is the EAN/UPC or the labels catalog number for this media.

Specifically the labels catalog number you think?

I think Klemm means the media type here, e.g. "CD", "DCD". Source media number would always be 1 - except for double CDs or CD sets. Don't know what Source Time is good for.

Sound reasonable, stupid of me that I didn't think of this option.

Btw: You can find the APEv2 page from Frank Klemm still in Google's chache.

Aye, I thought about this as well and made a mirror of the page just in case. Since Musepack.net is now one of the kind of official Musepack sites, shouldn't this info be hosted on this site?

[Shy]

Specifically the labels catalog number you think?

Exactly.

Frank Klemm's site is still online as always, the difference is that unfortunately you must click the "I'm not a citizen of the European Union" link in order to view it. This is a sort of a protest by him about the recent batch of highly restrictive digital media laws and software patents being embraced by the EU.
We do plan to add more technical info to Musepack.net in the future.

Edit: Due to the expiration of the university hosted account, we offer a mirror.

[Mr_Rabid_Teddybear]

rjamorim has also made it available at the Hydrogen Audio Wiki now...

thanks for the links mr. rabid