M4A genre parsing in TagLib 1.6

[patrick machielse]

Hi,

I'm using TagLib 1.6 to parse tags in aac/m4a files. The metadata for  
these has been edited with iTunes (9.x) (this will be the most likely  
scenario for this type of files, I suppose).

I have noticed that the String returned for genre() is consistently  
different (wrong) for _some_ genres. For example:

iTunes 'Alternative' => TagLib reads 'Ska'
iTunes 'Ska' => TagLib reads 'Death Metal'

However, on genres such as 'Alternative & Punk' and 'Classical' iTunes  
and TagLib are in complete agreement...

Is this a known issue (not pointing a finger to either iTunes or  
TagLib)? Is there a build option to default to iTunes genres, or is  
there some other solution?

Thanks,
patrick
--
Patrick Machielse
Hieper Software

http://www.hieper.nl
info@...

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On Thu, Oct 29, 2009 at 4:11 PM, patrick machielse <patrick@...> wrote:

> Hi,
>
> I'm using TagLib 1.6 to parse tags in aac/m4a files. The metadata for
> these has been edited with iTunes (9.x) (this will be the most likely
> scenario for this type of files, I suppose).
>
> I have noticed that the String returned for genre() is consistently
> different (wrong) for _some_ genres. For example:
>
> iTunes 'Alternative' => TagLib reads 'Ska'
> iTunes 'Ska' => TagLib reads 'Death Metal'
>
> However, on genres such as 'Alternative & Punk' and 'Classical' iTunes
> and TagLib are in complete agreement...
>
> Is this a known issue (not pointing a finger to either iTunes or
> TagLib)? Is there a build option to default to iTunes genres, or is
> there some other solution?

No, it isn't a known issue. There are two ways to store genre in MP4
files, as text or as ID3v1 genre number. The textual ones are read
correctly, the problem is with the numeric ones. ID3v1 indexes them
from 0, MP4 apparently from 1. The code currently assumes they are
indexed from 0 and incorrectly looks them in the the ID3v1 genre
table.

--
Lukas Lalinsky
lalinsky@...
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[patrick machielse]

Op 29 okt 2009, om 16:38 heeft Lukáš Lalinský het volgende geschreven:

> On Thu, Oct 29, 2009 at 4:11 PM, patrick machielse  
> <patrick@...> wrote:
>
>> I have noticed that the String returned for genre() is consistently
>> different (wrong) for _some_ genres. For example:
>>
>> iTunes 'Alternative' => TagLib reads 'Ska'
>> iTunes 'Ska' => TagLib reads 'Death Metal'
>>
>> However, on genres such as 'Alternative & Punk' and 'Classical'  
>> iTunes
>> and TagLib are in complete agreement...
>
> No, it isn't a known issue. There are two ways to store genre in MP4
> files, as text or as ID3v1 genre number. The textual ones are read
> correctly, the problem is with the numeric ones. ID3v1 indexes them
> from 0, MP4 apparently from 1. The code currently assumes they are
> indexed from 0 and incorrectly looks them in the the ID3v1 genre
> table.

Thanks for this information.

What is the current status of m4a support beyond the abstract Tag  
interface -- if any?. I have been looking at Items returned by  
MP4::Tag::itemListMap(), and I found useful nuggets of information  
like 'cpil' and 'tmpo', but for my application I really need access to  
the album art atom 'covr'. So far it seems TagLib cannot find that  
atom, and it seems that MP4::Item has no support for binary data --  
which figures.

Should I file bug reports / feature requests for these issues?

Thanks,
patrick
--
Patrick Machielse
Hieper Software

http://www.hieper.nl
info@...

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On Thu, Oct 29, 2009 at 6:13 PM, patrick machielse <patrick@...> wrote:
> What is the current status of m4a support beyond the abstract Tag
> interface -- if any?. I have been looking at Items returned by
> MP4::Tag::itemListMap(), and I found useful nuggets of information
> like 'cpil' and 'tmpo', but for my application I really need access to
> the album art atom 'covr'. So far it seems TagLib cannot find that
> atom, and it seems that MP4::Item has no support for binary data --
> which figures.
>
> Should I file bug reports / feature requests for these issues?

No need to, this is already fixed in SVN. I was planning to do a new
release last weekend and the one before, I'm not going to make more
false promises. :) But it will be released soon. Although, if you
could check out the code from SVN and let me know if it works well for
you before the release, it would be great.

--
Lukas Lalinsky
lalinsky@...
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