Parsing id3 data from local audio file in Firefox

I am developing Firefox addon

with SDK

, which lists the audio files on your computer with require("sdk/io/file").list()

.
I am creating an array of file paths using the method above and passing that array to the contentScript

attached to Panel

.
Then it Panel

iterates over the array and displays all the files it finds.

Now I am trying to use JavaScript-ID3-Reader , so I can read ID3

data from each file and display that data next to each file.
I am trying this (read local files) from within contentScript

eg.

var f = new File([""], "file:///home/user/audio.mp3");
ID3.loadTags("audio.mp3", function () {
        var tags = ID3.getAllTags("audio.mp3");
        console.log(tags.comment + " - " + tags.track + ", " + tags.lyrics);
}, {
        dataReader: FileAPIReader(f)
}); 

      

        
        
        
      

    

But I get the output ..

undefined - undefined, undefined

      

        
        
        
      

    

/home/user/audio.mp3

contains the following data ID3

found from http://web.ist.utl.pt/antonio.afonso/www.aadsm.net/libraries/id3/ .

Artist
    A Perfect Circle
Title
    Annihilation
Album
    eMOTIVe
Year
    2004
Comment
Genre
    Pop/Rock
Track
    1/12
Lyrics

      

        
        
        
      

    

Here is another test I tried ...

function getID3 (file) {
        var url = file.name;
        console.log(url); // console.log: addon: /home/user/audio.mp3
        ID3.loadTags(url, function () {
                var tags = ID3.getAllTags(url);
                console.log(tags); // console.log: addon: {}
                console.log(tags.artist); // console.log: addon: null
        }, {
                dataReader: new FileAPIReader(file)
        });
}

var f = new File([""], "file:///home/rob/audio.mp3", {type : "audio/mpeg"});
getID3(f);

      

        
        
        
      

    

Does anyone know what could be wrong with this? /home/user/audio.mp3

exists on the filesystem.