[mad-dev] Re: mad-dev Digest, Vol 18, Issue 3

[Sayak]

Hi Khalid,

If I have understood your problem correctly, you want to extract ID3 tag and 
if possible Lyrics Tag in MP3 file. For version2(v2), it is stored after the 
encoded data, to extract it, you have to go at the end of the file. I have 
done this in my own way. What I did was like this,

1. fseek(pFile, filesize - 10000, SEEK_SET);

This 10000 number was arbitrary. To accomodate Lyrics space. But if it is 
only ID3 tag present in the file, you can reduce this number to a mere 100.

2. fread(pBuffer, 1, 1000, pFile);//Lyrics Tag is also present
Otherwise go 10 byte at a time.
ststr(pBuffer,"ID3"). If strstr does not work in your compile(possible), go 
by the stupid process of matching byte by byte.

When you found the ID3 tag, extract the information as per the specification 
of ID3 tag.

You have to do this even before start decoding MP3 file.

In case of encoding write the information, write the information after 
encoding is done.
<ID3>
<FILE>
<Artist>




</Artist>
</FILE>
</ID3>



In Case of version 1(v1) however ID3 tag is at the beginning of the file. 
Then you dont have to go at the end of the file.

Kind Regards,

Sayak



----- Original Message ----- 
From: <mad-dev-request at lists.mars.org>
To: <mad-dev at lists.mars.org>
Sent: Wednesday, January 17, 2007 1:30 AM
Subject: mad-dev Digest, Vol 18, Issue 3


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> Today's Topics:
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>   1. MP3 tag (Khalid Aallouche)
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> ----------------------------------------------------------------------
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> Message: 1
> Date: Tue, 16 Jan 2007 07:41:19 +0200
> From: Khalid Aallouche <khalid.aallouche at tut.fi>
> Subject: [mad-dev] MP3 tag
> To: mad-dev at lists.mars.org
> Message-ID: <20070116074119.76hpnvh4pw0cck4o at webmail.tut.fi>
> Content-Type: text/plain; charset=ISO-8859-15; DelSp="Yes";
> format="flowed"
>
> Hi all,
>
> I send you that email because I want to extract the Genre (rock,
> salsa...) from the MP3
> file. I have studied libid3tag source code and I don't know how to
> perform that. I will
> be very grateful if someone can help me.
>
> In a second step, I want to write tags in an MP3 file (tagg v2).If
> someone can tell if
> it's possible to do that with libid3tag.
>
> Thank you for your comprehension
> b.r,
> Khalid
>
>
>
> End of mad-dev Digest, Vol 18, Issue 3
> **************************************
>
>