Bug 78746

Summary: tag data being read as audio data and so create noises
Product: [Unmaintained] mpeglib Reporter: bosselut
Component: generalAssignee: Stefan Westerfeld <stefan>
Status: RESOLVED DUPLICATE    
Severity: normal CC: wheeler
Priority: NOR    
Version: unspecified   
Target Milestone: ---   
Platform: Compiled Sources   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: Monica Mancini - Senza Fine.mp3
Sample MP3 file that has a sharp noise at the beginning with aRts.

Description bosselut 2004-03-30 17:00:39 UTC
Version:            (using KDE KDE 3.2.1)
Installed from:    Compiled From Sources
Compiler:          gcc (GCC) 3.3.2 (Mandrake Linux 10.0 3.3.2-6mdk) 
OS:          Linux

when mp3 file contains a lot of data in id3 tags like a picture, this cause some noises when the player start reading the file.
I think (i don't look at the code) the file is read as is(perhaps by a QDataStream) and no difference between audio data and tags data is made, so arts received those datas and play them.
This problem don't appear with XMMS and other apps whose don't use the kfile plugins.
Comment 1 Arnold Krille 2004-03-30 17:47:58 UTC
Thats a bug in mpeglib_artsplug then...
Comment 2 Arnold Krille 2004-03-30 17:53:02 UTC
More comment...

You wont hear the noise unless you have the previews activated. The audio-preview uses aRts to play the file. The aRts-part responsible for MP3-playback is mpeglib_artsplug.

If this is wrong, please correct me...

Could you provide a mp3 where such noise happens? Does it happen in noatun/juk/kaboodle too?

Arnold
Comment 3 Scott Wheeler 2004-03-30 18:02:26 UTC
Actually it's probably just that the tag contains a "false synch" -- i.e. 11 bits of ones that the decoder thinks is an MPEG frame header.  ID3v2 tags are supposed to use what's called an "unsynchronization scheme", but often they don't implement this.

So it's probably an issue of the tagging software not trying especially hard to avoid creating false synchs and mpeglib not trying especially hard to avoid false synchs...
Comment 4 bosselut 2004-03-30 18:42:54 UTC
Ok, i've search and found the most little mp3 with this problem.
This also  happens with noatun/juk and kaboodle but as i said in my bug 
report, this doesn't happen with xmms.
Cyril


Le mardi 30 Mars 2004 15:53, Arnold Krille a écrit :
 ------- You are receiving this mail because: -------
> You reported the bug, or are watching the reporter.
>
> http://bugs.kde.org/show_bug.cgi?id=78746
>
>
>
>
> ------- Additional Comments From arnold arnoldarts de  2004-03-30 17:53
> ------- More comment...
>
> You wont hear the noise unless you have the previews activated. The
> audio-preview uses aRts to play the file. The aRts-part responsible for
> MP3-playback is mpeglib_artsplug.
>
> If this is wrong, please correct me...
>
> Could you provide a mp3 where such noise happens? Does it happen in
> noatun/juk/kaboodle too?
>
> Arnold



Created an attachment (id=5468)
Monica Mancini - Senza Fine.mp3
Comment 5 bosselut 2004-03-30 18:50:29 UTC
There's no difference between programs used to set the tags, even mine (ktag) 
and i think i've respected the id3v2 api recommendations.
And as i said, there is no problem with XMMS and Amarok (i try it recently 
with all my problematics mp3s).
Cyril.


Le mardi 30 Mars 2004 16:02, Scott Wheeler a écrit :
> ------- You are receiving this mail because: -------
> You reported the bug, or are watching the reporter.
>
> http://bugs.kde.org/show_bug.cgi?id=78746
> wheeler kde org changed:
>
>            What    |Removed                     |Added
> ---------------------------------------------------------------------------
>- CC|                            |wheeler kde org
>             Summary|kfile mp3 plugin read id3   |tag data being read as
> audio
>
>                    |tags as audio data and so   |data and so create noises
>                    |create noises               |
>
> ------- Additional Comments From wheeler kde org  2004-03-30 18:02 -------
> Actually it's probably just that the tag contains a "false synch" -- i.e.
> 11 bits of ones that the decoder thinks is an MPEG frame header.  ID3v2
> tags are supposed to use what's called an "unsynchronization scheme", but
> often they don't implement this.
>
> So it's probably an issue of the tagging software not trying especially
> hard to avoid creating false synchs and mpeglib not trying especially hard
> to avoid false synchs...

Comment 6 Scott Wheeler 2004-03-30 20:51:41 UTC
JuK, Kaboodle and amaroK all use the same code for playing the stuff so you should see the same in all three...

I'm not sure what you're referring to as "the ID3v2 API" -- there is no "ID3v2 API" but rather an ID3v2 standard.  I was referring specifically to the standard for ID3v2.4, section 6.1:

http://www.id3.org/id3v2.4.0-structure.txt
Comment 7 bosselut 2004-03-30 21:02:16 UTC
i'm agree with you, it's strange but i don't have the problem with amarok. :|


Le mardi 30 Mars 2004 18:51, Scott Wheeler a écrit :
> ------- You are receiving this mail because: -------
> You reported the bug, or are watching the reporter.
>
> http://bugs.kde.org/show_bug.cgi?id=78746
>
>
>
>
> ------- Additional Comments From wheeler kde org  2004-03-30 20:51 -------
> JuK, Kaboodle and amaroK all use the same code for playing the stuff so you
> should see the same in all three...
>
> I'm not sure what you're referring to as "the ID3v2 API" -- there is no
> "ID3v2 API" but rather an ID3v2 standard.  I was referring specifically to
> the standard for ID3v2.4, section 6.1:
>
> http://www.id3.org/id3v2.4.0-structure.txt

Comment 8 Michael Pyne 2004-03-31 03:26:17 UTC
I have one song that has this problem.  I've clipped it to the first 32K that has that problem, and I'll attach it here.  It doesn't have this problem in mpg123, my car's MP3 player, or my DVD player.  It only does it in JuK, Kaboodle, and Noatun.  I will try removing the tags from it to see if that helps, I never tried that before.
Comment 9 Michael Pyne 2004-03-31 03:27:58 UTC
Created attachment 5470 [details]
Sample MP3 file that has a sharp noise at the beginning with aRts.

This is a 1 second clip that demonstrates the problem I have with aRts.  This
is the only song I have with this problem.
Comment 10 Michael Pyne 2004-03-31 03:34:27 UTC
Using JuK to change the tag (even to the same thing) caused it to play correctly.  So I'm not sure if the song is malformed, or if there is a problem with aRts.
Comment 11 Scott Wheeler 2004-03-31 03:38:07 UTC
On Wednesday 31 March 2004 3:34, Michael Pyne wrote:
> Using JuK to change the tag (even to the same thing) caused it to play 
> correctly. 
Comment 12 Allan Sandfeld 2004-07-16 13:26:28 UTC
The noice only happens with mpeglib_artsplugin. It might be that the song is also malformed, but akodelib plays it just fine.
Comment 13 Allan Sandfeld 2004-07-16 13:31:00 UTC
And it is a duplicate

*** This bug has been marked as a duplicate of 67800 ***