得到MP3中隐藏的信息

王朝vb·作者佚名  2006-01-08
窄屏简体版  字體: |||超大  

得到MP3中隐藏的信息

为了保护音乐者的版权,在MP3文件中有一段特意存储版权说明的信息,众多的MP3播放器软件都提供了修改和读取MP3文件中隐藏信息的功能,那么这些信息到底存储在哪里呢?如何得到这些信息呢?本文将为大家提供得到MP3信息的模块。

首先,定义一个公共类型Mp3tag如下:

Public Type Mp3tag

Artist As String ’Artist 存储歌手信息

Album As String ’Album 存储唱片专辑信息

Title As String ’Title 存储标题信息

Year As String ’Year 存储年代信息

Comments As String ’Comments 存储备注信息

Genre As Integer ’Genre 存储音乐风格序列

End Type

然后,定义一个获取MP3信息的函数,它将返回这些信息,代码如下:

Public Function GetMp3Tag(FName As String) As Mp3tag

Dim Artist As String

Dim Album As String

Dim Title As String

Dim Year As String

Dim Comments As String

Dim Genre As Integer

If FName = "" Then Exit Function

If Dir(FName) = "" Then Exit Function

Dim FileNum As Integer

FileNum = FreeFile ’得到一个自由的文件号

Dim strInput As String

Open FName For Binary Access Read As FileNum ’以二进制形式打开文件

If LOF(FileNum) < 128 Then

Close FileNum

Exit Function

End If

Seek FileNum, LOF(FileNum) - 127 ’把文件指针移动到MP3信息处

strInput = Space(3)

Get FileNum, , strInput

If strInput <> "TAG" Then ’如果没有发现信息标识,就关闭文件

Close FileNum

GoTo Done:

End If

strInput = Space(30)

Get FileNum, , strInput

Title = Trim(strInput)

strInput = Space(30)

Get FileNum, , strInput

Artist = Trim(strInput)

strInput = Space(30)

Get FileNum, , strInput

Album = Trim(strInput)

strInput = Space(4)

Get FileNum, , strInput

Year = Trim(strInput)

strInput = Space(30)

Get FileNum, , strInput

Comments = Trim(strInput)

strInput = Space(1)

Get FileNum, , strInput

Genre = Asc(strInput)

Done:

GetMp3Tag.Title = Title

GetMp3Tag.Artist = Artist

GetMp3Tag.Album = Album

GetMp3Tag.Year = Year

GetMp3Tag.Year = Comments

If Genre < 0 Or Genre > 254 Then Genre = 12

GetMp3Tag.Genre = CInt(Genre)

Close FileNum

End Function

注意:MP3文件对音乐的风格进行了限制,共254种。Genre返回的只是MP3风格的序列号,具体还需要定位,在这里我把所有类型以常数形式列出,每个类型之间用"|"号隔开。

Private Const sGenreMatrix = "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|Alt. Rock|Bass|Soul|Punk|Space|Meditative|" + _

"Instrumental Pop|Instrumental Rock|Ethnic|Gothic|Darkwave|Techno-Industrial|Electronic|" + _

"Pop-Folk|Eurodance|Dream|Southern Rock|Comedy|Cult|Gangsta Rap|Top 40|Christian Rap|" + _

"Pop/Punk|Jungle|Native American|Cabaret|New Wave|Phychedelic|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|Blue Grass|" + _

"Avantegarde|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 Bass|Primus|Porn Groove|Satire|Slow Jam|Club|Tango|Samba|Folklore|" + _

"Ballad|power Ballad|Rhythmic Soul|Freestyle|Duet|Punk Rock|Drum Solo|A Capella|Euro-House|" + _

"Dance Hall|Goa|Drum & Bass|Club-House|Hardcore|Terror|indie|Brit Pop|Negerpunk|Polsk Punk|" + _

"Beat|Christian Gangsta Rap|Heavy Metal|Black Metal|Crossover|Comteporary Christian|" + _

"Christian Rock|Merengue|Salsa|Trash Metal|Anime|JPop|Synth Pop"

把以上代码写到一个模块中(.Bas),然后在窗体上加入5个TextBox和1个ComboBox控件,其中5个TextBox控件分别用来显示一首Mp3文件的以下信息:歌手、年代、唱片、评论、标题,ComboBox控件用来显示歌曲的风格。再放一个Command控件,其标题为“显示信息”,在它的Click事件中加入以下代码:

Private sub Command1_click()

Dim mp3Tag as Mp3tag

mp3tag = GetMp3Tag ("c:\Song.mp3")

Text1.Text = mp3tag.Artist

Text2.Text = mp3tag.Album

Text3.Text = mp3tag.Title

Text4.Text = mp3tag.Year

Text5.Text = mp3tag.Comments

Combo1.ListIndex = mp3tag.Genre

End Sub

在窗体的加载过程中加入如下代码:

Private Sub Form_Load()

Dim i As Integer,GenreArray() As String

GenreArray = Split(sGenreMatrix, "|")

For i = LBound(GenreArray) To UBound(GenreArray)

Combo1.AddItem GenreArray(i)

Next i

End Sub

以上代码在VB6 \Win2000中测试通过。

 
 
 
免责声明:本文为网络用户发布,其观点仅代表作者个人观点,与本站无关,本站仅提供信息存储服务。文中陈述内容未经本站证实,其真实性、完整性、及时性本站不作任何保证或承诺,请读者仅作参考,并请自行核实相关内容。
 
 
© 2005- 王朝網路 版權所有 導航