[X] Mp3tag identifies some MP3 files as MP2 and reports incorrect durations


#1

Mp3tag identifies some MP3 files as MP2 and reports incorrect track durations.

I have uploaded an archive with problematic MP3 files:
http://www.sendspace.com/file/xjibch

They all are MP3 128 kbps 44100Hz

The correct durations are

  1. In Chains (6:46)
  2. Hole To Feed (3:55)
  3. Wrong (3:10)
  4. Fragile Tension (4:08)
  5. Little Soul (3:30)
  6. In Sympathy (4:53)
  7. Peace (4:25)
  8. Come Back (5:13)
  9. Spacewalker (1:49)
  10. Perfect (4:34)
  11. Miles Away / The Truth Is (4:09)
  12. Jezebel (4:39)
  13. Corrupt (5:01)

For some unknown reason, MP3TAG identifies some of the files as Mpeg1 Layer2 or Mpeg2 Layer3 and reports totally incorrect durations:

Image:

As you see, for example 09 Spacewalker.mp3 has become a 416 kbps 32000 Hz file with duration = 00:34 (instead of 01:49).
And 08 Come Back.mp3 is displayed as 24 kbps 16000 Hz file with duration = 27 minutes (instead of actual 05:13)

Mp3tag - File Overview

16.11.2012
Title Genre Duration Filename Codec Bitrate Samplerate
In Chains 06:47 01 In Chains.mp3 MPEG 1 Layer III 128 44100
Hole To Feed Blues 03:49 02 Hole To Feed.mp3 MPEG 1 Layer I 128 44100
Wrong 03:11 03 Wrong.mp3 MPEG 1 Layer III 128 44100
Fragile Tension 09:27 04 Fragile Tension.mp3 MPEG 2 Layer III 56 22050
Little Soul 01:24 05 Little Soul.mp3 MPEG 1 Layer II 320 44100
In Sympathy 11:07 06 In Sympathy.mp3 MPEG 1 Layer II 56 32000
Peace 04:25 07 Peace.mp3 MPEG 1 Layer III 128 44100
Come Back 27:36 08 Come Back.mp3 MPEG 2 Layer III 24 16000
Spacewalker 00:34 09 Spacewalker.mp3 MPEG 1 Layer I 416 32000
Perfect 01:50 10 Perfect.mp3 MPEG 1 Layer I 320 44100
Miles Away / The Truth Is 01:23 11 Miles Away-The Truth Is.mp3 MPEG 1 Layer I 384 44100
Jezebel 04:39 12 Jezebel.mp3 MPEG 1 Layer III 128 44100
Corrupt 05:01 13 Corrupt.mp3 MPEG 1 Layer III 128 44100

build on 16.11.2012 with Mp3tag v2.53 - the universal Tag Editor www.mp3tag.de


Play length / duration / CBR / VBR
Wavelab kann die MP3Tag Datei nicht öffnen
#2

That is a problem with the files, not a bug in Mp3tag

Scan the files with MP3val and you will see "WARNING: MP3 stream error, resynchronized successfully" for each file.

Sometimes, that means the audio information is corrupt. But if you remove all the tags and rescan, the warning is changed to "WARNING: Garbage at the beginning of the file". That indicates to me that the audio information is intact and that the tags were messing up the file. See the MP3val documentation.

If you click "Repair all files with problems" in MP3val, the garbage will be removed and Mp3tag will show the correct information.

The files can be repaired without stripping the tags, but I don't do that because I don't understand "offsets" or the file structure or how to use a hex editor, which might be used to pinpoint the stream error. If the tags are stripped but the warning does not change, I assume the audio data is corrupt. MP3val will "correct" all stream errors, and that may create a click if information is deleted from the middle of the audio information.

If the problem files are VBR, you will probably need to use VBRfix (Moonbase version).



#3

Hi ryerman

You say the files are corrupt... But why WinAmp, XmPlay and some other players identify the files (mpeg version & layer, durations, etc.) correctly ?

I have tried another 'MP3 info' program on these files ( l2001.exe for DOS :slight_smile: ) and got the following info:

  1. Come Back (5:13)

MPEG Audio data found:
MPEG 1 Layer III 44100 Hz Stereo 128 kbps PADDING = 8 bits
Frame Size= 417 (418) bytes Number of frames: 11998 Total Size: 5014675
CRC16=YES Emphasis=NONE Audio data starts at filepos: 52142

  1. Spacewalker (1:49)

MPEG Audio data found:
MPEG 1 Layer III 44100 Hz Stereo 128 kbps PADDING = 8 bits
Frame Size= 417 (418) bytes Number of frames: 4202 Total Size: 1756265
CRC16=YES Emphasis=NONE Audio data starts at filepos: 52146

As you see, on both files MP3 data starts after 50 Kb!
The first 50 Kb of the files contain some tag data, probably album artwork (thumbnail of the front cover)

I have tried "l2001.exe for DOS" on other tracks from this pack of MP3s, the ones that are correctly processed by MP3tag:

  1. Corrupt (5:01)

MPEG Audio data found:
MPEG 1 Layer III 44100 Hz Stereo 128 kbps PADDING = 8 bits
Frame Size= 417 (418) bytes Number of frames: 11543 Total Size: 4824503
CRC16=YES Emphasis=NONE Audio data starts at filepos: 52139

Well, this file also has a 50 kb of tag data at the beginning, but it's processed correctly.

Ok, then my guess is - MP3tag founds false MPEG frames in the file (probably some sequences of bytes in the tags of these MP3s look like MPEG frame headers).

So I can only ask the developer of MP3tag - please run MP3tag in Debug mode on these files and please see what's wrong.


#4

Hi testuser01,

In the meantime, you could use my suggestion (MP3val) to see what's wrong and to fix the files.
Read the MP3val documentation to see an explanation for why some players don't report incorrect information.
http://mp3val.sourceforge.net/


#5

foobar2000 can repair damaged MP3 files.
See file context menu "Utilities/Rebuild MP3 stream".
See file context menu "Utilities/FIX VBR MP3 header".

DD.20121116.1823.CET


[X] Error in duration