APETag parsing in MPEGfile.cpp

[harish jenny]

Thanks for the link and update!




________________________________
 From: Sander Jansen <s.jansen at gmail.com>
To: harish jenny <harishjennykn at yahoo.com>; taglib-devel at kde.org 
Sent: Thursday, 22 August 2013 8:06 PM
Subject: Re: APETag parsing in MPEGfile.cpp
 







On Thu, Aug 22, 2013 at 7:48 AM, harish jenny <harishjennykn at yahoo.com> wrote:

Hi,
>
>I have a file which has APEtag as well as Id3V1 tag.
>
>However , MPEG::File::findAPE() function is not able to detect APE footerLocation.
>
>When I add the code something like - 
>
>    seek(d->hasID3v1 ? -160 : -32, End);
>
>    long p = tell();
>
>    if(readBlock(8) == APE::Tag::fileIdentifier()) {
>      d->APEFooterLocation = p;
>      seek(d->APEFooterLocation);
>      APE::Footer footer(readBlock(APE::Footer::size()));
>      d->APELocation = d->APEFooterLocation - footer.completeTagSize()
>    + APE::Footer::size();
>     
 return;
>    }
>  ++  else
>  ++  {
>  ++      seek(!d->hasID3v1 ? -160 : -32, End);
>
>++       long p = tell();
>
>++        if(readBlock(8) == APE::Tag::fileIdentifier()) {
>++          d->APEFooterLocation = p;
>++          seek(d->APEFooterLocation);
>++          APE::Footer footer(readBlock(APE::Footer::size()));
>++          d->APELocation = d->APEFooterLocation - footer.completeTagSize()
>++        + APE::Footer::size();
>++          return;
>++        }
>++    }
>
>it is
 able to parse APEtag. 
>
>Does the standard say , if ID3V1 tag is present , then check for APETAGEX in -160 location from end ?
>


According to this:
http://wiki.hydrogenaudio.org/index.php?title=APEv2_specification


The id3v1 tag should come last. I don't think you'll find many players that can support a id3v1 tag not located at the end. 


Is it fine to parse again from -32 location since I was able to find proper metadata?
>

No, as a matter of fact, if you can read a id3v1 tag at -128 and read a apetag at -32, it means the file is most likely broken (ie. overlapping tags, id3v1 is truncated by the apetag).


Cheers,

Sander
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