10. Tips and Tricks

Making your own template

Making your own template is not too difficult. Two templates are provided already. You might want to read up on the XSLT specification, and you may want to peek into the generate.command script which is in the CCTunes package.

If you need any help, asking will never hurt. I don't always have time to answer everything, but you may be lucky. If you feel like giving back the template once it's finished that would be nice. If you want to link to me for giving inspirational credit, that would be nice too.

Combining templates

At the moment there are two templates. One for making a list-like html page, and one for making a "peephole" view of the library in one big html page. These two approaches can be combined by using the same destination folder for outputting.

Using ImageMagic or GraphicConverter

If you are dissatisfied with the quality of the small images in the peephole view, like I am, you can choose to use ImageMagick to convert the images from higher size to lower size.

You will need to install it using fink or compile it yourself, both should be easy and with a simple set of commands on the prompt you convert all images like this:

find outputdir -name *-high -type f -exec convert -resize 60x60 {} {}-low.png \;

If you have a utility like GraphicConverter, which came for free with my laptop, you can easily generate 60 by 60 thumbnails from the images by using the batch mode to set the Max Size.

Using perl to get the images out of the mp3 files

It used to be so that the images were extracted from the MP3 files using perl libraries and a little perl script. This is how it was done.

A link that got me on the way was on the ever interesting macosxhints website, http://www.macosxhints.com/article.php?story=20030429003250559, in which one of the comments describes almost perfectly what needs to be done. Almost, but for the fact on how to get to open a file based on the url. Of course, this is not hard to do, using some parsing, and I have my "Perl in a Nutshell" book on my desktop, but getting used to this perl thing I thought there must be a module already out there that does this for me. Now, that's the URI::URL module we've installed, and it was mentioned in the book.

There we have our perl script, which takes as argument a unix file path and a filename to write the png file to. If this script does not find the corresponding tag, it just creates a link to a nopic.png file instead of the destination file, so that we can put in a nice icon when the image is missing in the mp3.

#!/usr/bin/perl

no strict 'refs';
use Getopt::Long;
use IO::File;
use MP3::Info;
use URI::URL;

$url1 = new URI::URL shift;
$unixpath = $url1->unix_path();
$e = $ARGV[0];
if ( -e $e || -l $e ) {
    system("/bin/rm " . $e);
}
if (my $mp3tag_id3v2 = get_mp3tag($unixpath, 2, 1)) {
    my $tag = "PIC";
    my $result = $mp3tag_id3v2->{$tag};
    $result =~ s/^(.....).//;
    if (length($result) > 0)
    {
      open $f, "> $e";
      print $f $result;
    }
    else
    {
      system("/bin/ln -s ./nopic.png " . $e);
    }
}
else
{
   system("/bin/ln -s ./nopic.png " . $e);
}

To invoke this for the set of MP3's that the library existed of, a little hack was needed which added a little comment in the XML file so that when grepping for the getPicture command a bash script was generated that used the perl script to extract all the images.

I have understood that a Microsoft implementation of the XSLT parsing implements something like callbacks, in which you can call a script from within your XSL file. That's a good idea, nice, but since it isn't in the XSLT specification it is not very compatible to depend upon it. But if you do, you might want to check that out. The approach described did work too, however.