MP3 id3 tag v2

[P.curtis]

Does anyone have a working example of how to get MP3 tags. I'm interested in duration and title.
Thanks in advance.

[winni]

Hi!

The implementation of Tags in version 2 a bunch of idiotic relations.
The only good solution I know is the tag plugin of BASS:

http://www.un4seen.com/

Tag V1 is simple.
I can search for my code if you need it.

Winni

[Fred vS]

Hello.

Code: Pascal  [Select][+][-]

1. var
2.   F: file;
3.   title, album, date, comment, tag : string;
4.   genre : integer;
5.   BufferTag: array[1..128] of char;
6. ...
7.  
8.  AssignFile(F, '/dirrectory/of/filename.mp3');
9.    FileMode:=fmOpenRead + fmShareDenyNone;
10.    Reset(F, 1);
11.    Seek(F, FileSize(F) - 128);
12.    BlockRead(F, BufferTag, SizeOf(BufferTag));
13.    CloseFile(F);
14.  
15.   title := copy(BufferTag, 4, 30);
16.   artist := copy(BufferTag, 34, 30);
17.   album := copy(BufferTag, 64, 30);
18.   date :=  copy(BufferTag, 94, 4);
19.   comment := copy(BufferTag, 98, 30);
20.   tag :=  copy(BufferTag, 1, 3);
21.   genre := ord(BufferTag[128]);
22.  

For duration it is more tricky, you may use like wini said Bass.
And if you want a free open source solution, maybe take a look at uos.

[lucamar]

See this thread:
Recomendations for audio metadata
Lots of recommendations there, though I ended up using a TProcess and parsing the output of soxi

@Fred vS: That will only work to retrieve v1 tags ... and doesn't even check whether they are there! Also it makes too many assumptions about the length and presence of each tag.

[Fred vS]

@lucanar, afaik, a mp3 that has v2 (tag info at begin of file) has also v1 (tag info at end).

But yes, it can give the title but not the length.

uos does what you need.

[Awkward]

if you don't want to search and use old (since D3 i think) Audo Tools Library (if i remember right), you can check https://www.3delite.hu/Object Pascal Developer Resources/id3v2library.html
Tags Library there have sources and examples dor other tag formats too

[lucamar]

@lucanar, afaik, a mp3 that has v2 (tag info at begin of file) has also v1 (tag info at end).

Not necessarily, though it's rather common. The real question, though, is that the OP asked specifically for ID3v2 tags.

[Fred vS]

> The real question, though, is that the OP asked specifically for ID3v2 tags

Ok, ok, so it is exactly the same principle, but from begin of file.

If you read the first 3 bytes, and they are equal to "ID3", then skip to the 7th byte, then read the header size.

[winni]

Hi!

That's the way to get ID3 Tags version 1:

Code: Pascal  [Select][+][-]

1. TYPE
2. TAG_ID3 = record   // 128 byte
3.     id: Array[0..2] of AnsiChar;
4.     title: Array[0..29] of AnsiChar;
5.     artist: Array[0..29] of AnsiChar;
6.     album: Array[0..29] of AnsiChar;
7.     year: Array[0..3] of AnsiChar;
8.     comment: Array[0..29] of AnsiChar;
9.     genre: Byte;
10.   end;
11.  
12. Function ReadTagID3Tag (fname : String; var Tag: TAG_ID3 ): boolean;
13. var phyle : File of byte;
14.       ok : Boolean;
15.  
16. begin
17. fillchar(tag,sizeof(tag),0);
18. ok := false;
19. if LazFileUtils.FileExistsUTF8(fname) then
20.   begin
21.   {$I-}
22.   assign (phyle,Fname);
23.   reset (phyle);
24.   seek(phyle, fileSize(phyle) -sizeof(tag));
25.   blockread(phyle,tag,sizeof(tag));
26.   closeFile (phyle);
27.   {$I+}
28.   ok := tag.id = 'TAG';
29. result := ok;
30. end;
31.  
32. ......
33. var artist : string;
34. .....
35. artist := string(tag.artist);
36. ..
37.  
38.  

The genre byte points to al list of around 200 genre strings.
I add an include file with the genres in the attachment.


Winni

PS.: Had to rename it to '*txt' to get through the "sophisticated" forum filter

[Fred vS]

> That's the way

Yes (and I dont see any difference with my previous code).

[Fred vS]

If you read the first 3 bytes, and they are equal to "ID3", then skip to the 7th byte, then read the header size.

About the length stored in id3 tag v2, it is a "synchsafe integer".

[Fred vS]

The best ot the best id3 tag v2 Pascal Open Source reader-editor is, imho, the one from OvOPlayer:

https://github.com/varianus/ovoplayer

With his own, independent, tag v2 decoder in Pascal source (WOW):
https://github.com/varianus/ovoplayer/tree/master/src/ovotag

It can deal also with picture.

[P.curtis]

Fred VS, OVOPlayer looks good.......

[Fred vS]

Fred VS, OVOPlayer looks good.......

Imho, OvOPlayer is the tenor of what has be done with Lazarus for audio players.

Like LazPaint who is the reference in graphic application.
 

[stephanos]

Dear All

I have a similar need and am exploring BASS.  Can Fred vS or anyone clarify what UOS is: "uos does what you need."

It is not a link and a google search here from the UK does not reveal anything

Thanks and wait to hear