[Resolved] MP3 tags

[DjDollarBill]

Ok, some may know I have been working on this FOREVER (it seems that way) I am trying to scan a directory for mp3 files and read the found tags.

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 
        FolderBrowserDialog1.ShowDialog()
        Dim srch As String = FolderBrowserDialog1.SelectedPath
        Dim str As New ArrayList
        getMP3Files(str, srch.ToString, "*.mp3")
        For Each s As String In str
        MessageBox.Show(s)
                End Sub
 
    Private Sub getMP3Files(ByRef str As ArrayList, ByVal startingDir As String, ByVal ext As String)
 
        str.AddRange(System.IO.Directory.GetFiles(startingDir, ext))
        Dim dirs As String() = System.IO.Directory.GetDirectories(startingDir)
        If Not dirs.Length = 0 Then
            For Each d As String In dirs
                getMP3Files(str, d, ext)
            Next
        End If
    End Sub

That gets my the files ok. And I have found this class to read the tags. But have not yet been able to get it right. Please, can someone help???

Imports System
Imports System.IO
Imports System.Text
 
Namespace Ambientware.multimedia
    Public Class ID3Util
        Private songTitle As String
        Private artist As String
        Private albumTitle As String
        Private year As String
        Private comment As String
        Private cdTrack As Integer
        Private genre As String
        Private mp3 As FileStream
        Private id3StartV1 As Long
        Private id3StartV2 As Long
        Private id3Version As Integer
        Private id3Tag(128) As Byte
        Private completeTag As String
 
 
        Sub New(ByVal mp3FilePath As String)
            mp3 = File.OpenRead(mp3FilePath)
            id3StartV1 = mp3.Length() - 128
            id3StartV2 = 0
            setVersion()
            populateFields()
            mp3.Close()
        End Sub
 
        'Retrieves the song title from the id3 tag
        'return A string representing the song title
        Public Function getSongTitle() As String
            Return songTitle
        End Function
 
        'Gets the name of the artist
        'return A string representing the artist name
        Public Function getArtist() As String
            Return (artist)
        End Function
 
 
        'Get the name of the album
        'return A string representing the name of the album the mp3 is from.
        Public Function getAlbumTitle() As String
            Return (albumTitle)
        End Function
 
 
        'Get the year the song was recorded.
        'return A string representing the year the song was recorded.
        Public Function getYear() As String
            Return (year)
        End Function
 
 
        'Get the comment, if any, from the id3 tag
        'return A string representing the comment portion of the id3 tag
        Public Function getComment() As String
            Return (comment)
        End Function
 
 
        'Get the track number from the cd
        'return The track number from the album.
        Public Function getCdTrack() As String
            If (cdTrack = -1) Then
                Return ("Unknown")
            Else
                Return (cdTrack.ToString())
            End If
        End Function
 
 
        'Get the genre of the song
        'return A string value representing the content genre, if available, of the mp3.
        Public Function getGenre() As String
            Return (genre)
        End Function
 
 
 
        Private Function populateFields()
            Dim genres As String() = {"Blues", "Classic Rock", "Country", "Dance", "Disco", "Funk", "Grunge", "Hip-Hop", "Jazz", "Metal", "New Age", "Oldies", "Other", "Pop", "R&B", "Rap", "Reggae", "Rock", "Techno", "Industrial", "Alternative", "Ska", "Death Metal", "Pranks", "Soundtrack", "Euro-Techno", "Ambient", "Trip-Hop", "Vocal", "Jazz+Funk", "Fusion", "Trance", "Classical", "Instrumental", "Acid", "House", "Game", "Sound Clip", "Gospel", "Noise", "AlternRock", "Bass", "Soul", "Punk", "Space", "Meditative", "Instrumental Pop", "Instrumental Rock", "Ethnic", "Gothic", "Darkwave", "Techno-Industrial", "Electronic", "Pop-Folk", "Eurodance", "Dream", "Southern Rock", "Comedy", "Cult", "Gangsta", "Top 40", "Christian Rap", "Pop/Funk", "Jungle", "Native American", "Cabaret", "New Wave", "Psychedelic", "Rave", "Showtunes", "Trailer", "Lo-Fi", "Tribal", "Acid Punk", "Acid Jazz", "Polka", "Retro", "Musical", "Rock & Roll", "Hard Rock", "Folk", "Folk-Rock", "National Folk", "Swing", "Fast Fusion", "Bebob", "Latin", "Revival", "Celtic", "Bluegrass", "Avantgarde", "Gothic Rock", "Progressive Rock", "Psychedelic Rock", "Symphonic Rock", "Slow Rock", "Big Band", "Chorus", "Easy Listening", "Acoustic", "Humour", "Speech", "Chanson", "Opera", "Chamber Music", "Sonata", "Symphony", "Booty Brass", "Primus", "Porn Groove", "Satire", "Slow Jam", "Club", "Tango", "Samba", "Folklore", "Ballad", "Power Ballad", "Rhytmic Soul", "Freestyle", "Duet", "Punk Rock", "Drum Solo", "Acapella", "Euro-House", "Dance Hall"}
 
            songTitle = byteArrayToString(id3Tag, 3, 30)
            If (Not verify(songTitle)) Then
                songTitle = "Unknown"
            End If
 
            artist = byteArrayToString(id3Tag, 33, 30)
            If (Not verify(artist)) Then
                artist = "Unknown"
            End If
 
            albumTitle = byteArrayToString(id3Tag, 63, 30)
            If (Not verify(albumTitle)) Then
                albumTitle = "Unknown"
            End If
 
            year = byteArrayToString(id3Tag, 93, 4)
            If (Not verify(year)) Then
                year = "Unknown"
            End If
 
            comment = byteArrayToString(id3Tag, 97, 30)
            If (Not verify(comment)) Then
                comment = "Unknown"
            End If
 
            cdTrack = id3Tag(126)
            If (cdTrack <= 0) Then
                cdTrack = -1
            End If
 
            If ((id3Tag(127) >= 0) And (id3Tag(127) <= 125)) Then
                genre = genres(id3Tag(127))
            Else
                genre = "Unknown"
            End If
 
            completeTag = "SongTitle: " + songTitle + "\nArtist: " + artist + "\nAlbumTitle: " + albumTitle + "\nYear: " + year + "\nComment: " + comment + "\nTrack# " + getCdTrack() + "\nGenre: " + genre
        End Function
 
 
        'working function to return the string from the varios byte arrays 
        'that make up the ID3 tags in the MP3 files
        Private Function byteArrayToString(ByVal arrByte() As Byte, ByVal intBeginPOS As Integer, ByVal intLength As Integer) As String
            Dim enc As New System.Text.ASCIIEncoding
 
            Return enc.GetString(arrByte, intBeginPOS, intLength)
        End Function
 
 
        Private Shared Function verify(ByVal field As String) As Boolean
            Dim validChars As String = "  abcdefghijklmnopqrstuvwxyz1234567890-!`~!@#$%&*()_=+[{}]|\\<>,./?  "
            Dim found As Boolean = True
            Dim i As Integer
 
            field = field.ToLower()
 
            For i = 0 To field.Length = 1
                If (validChars.IndexOf(field.Chars(i)) = -1) Then
                    If (field.IndexOf(i) <> 0) Then
                        found = False
                    End If
                End If
            Next
            Return found
        End Function
 
 
        'Determine which version of the ID3 tags we are dealing with
        Private Function setVersion()
            Dim type As String = ""
            Dim strTmp As String = ""
            Dim X As Integer
 
            mp3.Position = id3StartV1
            mp3.Read(id3Tag, 0, 128)
 
            strTmp = Me.byteArrayToString(id3Tag, 0, 3)
 
            If (strTmp.ToUpper.Equals("TAG")) Then 'Then we've got a version one
                id3Version = 1
            Else 'We've got version two
                mp3.Position = id3StartV2
                mp3.Read(id3Tag, 0, 128)
 
                strTmp = Me.byteArrayToString(id3Tag, 0, 3)
 
                If (strTmp.ToUpper.Equals("ID3")) Then
                    id3Version = 2
                Else
                    id3Version = -1
                End If
 
            End If
 
            If (id3Version = 1) Then
                mp3.Position = id3StartV1
                mp3.Read(id3Tag, 0, 128)
            Else
                mp3.Position = id3StartV2
                mp3.Read(id3Tag, 0, 128)
            End If
        End Function
 
 
        'Get the id3tag version.
        'return The id3 verison of the tag (1 or 2)
        Public Function getID3Version() As Integer
            Return (id3Version)
        End Function
 
 
        'Get the complete id3tag
        'return A string representing the complete id3 tag as a concantenation of all the values.
        Public Function getCompleteTag() As String
            If (id3Version = 1) Then
                Return (completeTag)
            Else
                Return ("Not a valid tag")
            End If
        End Function
 
    End Class
End Namespace

[jmcilhinney]

What is the issue so we know what we're looking for?

[DjDollarBill]

I am trying to use the class, but have yet been able to sort out what I need to do. I have tried passing the filepath as a string and as an array index with various errors (most have to do with invalid casts and null ref's) None of my breakpoints are being reached and most errors are in the assembly which is no help to me. It seems like I'm just missing something in the class use. I did go with your suggestion (playing with music files) but it was REAL slow and have since been trying all sorts of stuff.

[DjDollarBill]

Ok .. I got a few things sorted, but am still getting a null ref exception in this block. Does anyone see the prob?

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim mp3try As Ambientware.multimedia.ID3Util
 
        FolderBrowserDialog1.ShowDialog()
        Dim srch As String = FolderBrowserDialog1.SelectedPath
        Dim str As New ArrayList
 
 
        getMP3Files(str, srch.ToString, "*.mp3")
        For Each s As String In str
            'MessageBox.Show(s) testing that files are found
            Dim m As New DjMediaData
            m.Title = mp3try.getSongTitle()
 
 
        Next
 
    End Sub

[jmcilhinney]

Where do you assign to the mp3try variable to be able to use its getSongTitle method, or is that a Shared method? If it is Shared then you should strictly be using the class name to identify it as such. If it's not, then that's your problem.

[DjDollarBill]

problem solved at long last !