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Subject: Corrupt Recordings

Corrupt Recordings

From: Bluechip <csbluechip_at_gmail.com>
Date: 2005-12-28

Just noticed something that may be of interest. With reference to the dump
attached below:

Notice how there is a difference of 3 between the Xing-Hdr frame count and
the actual number of audio frames.

I'm guessing: 1 is the Xing Frame; another is the truncated frame on the
end; and the last is the [what is the word for "start is missing"?] frame
which is identified as 212 bytes of garbage.

I also postulate that the truncated and start'ated frames (from two
consecutive files, obviously) may be combined to reconstruct the corrupted
data ...but more files need to be analysed, not least of all to confirm my
suspicion that the garbage IS a start'ated MP3 frame.

For interest I have also included a file created from a CD by EAC/LAME (by
me) which shows that the Xing frame is NOT included in Xing's frame count.

Happy musing.

BC

------------------------------------------------------------------------------
Root:
D:\_DEV\ID3\

File:
R651909-211120.mp3

Stat: 09/Mar/2037 21:16:22 [ RW A ] 6776182
bytes

@0x00000000+0.0, 4096 - ID3 v2.3.0
Tag
!0x00001000+0.0, 211 - 211 bytes of unidentified data. All bytes:
0x00
@0x000010D3+0.0, 365 - Xing Xing/VBR header with LAME
extension
    [4] +000: Tag =
"Xing"
    [4] +004: Flags =
[...qtBF]
    [4] +02C: Frames =
11490
    [4] +030: Bytes =
6771510
!0x00001240+0.0, 212 - 212 bytes of unidentified
data
       +0000: 36 D3 D9 F7 55 F5 57 26 80 B2 6B C0 72 55 BC FE | 6+
UW& _k+ rU+_
       +0010: 2D 96 A6 52 A0 AD 47 14 3B 9E 63 7E B8 D9 D2 3B | -R
G. ;c~ +;
       +0020: 24 EA 5C DE 7F 86 B3 71 22 EF 14 89 67 67 25 BD | $\
q ". gg%
       +0030: AE E3 1A DA 1D EC 36 E5 33 36 7E 93 7A F5 9B BB | .+
.6 36~ z+
       +0040: 66 DF 9B 8B 6B 5B E4 B3 A0 5B C5 CB 98 A2 BA E6 | f_
k[ [+-
       +0050: 77 D3 1D 67 3F 8D 99 FB AF 39 B1 3D 27 76 7D 78 | w.g
?ֹ 9_= 'v}x
       +0060: BF 93 7B DF DE 5B 1B 94 5D 39 5F 5A 9B 9D 77 B9 | +{_
[. ]9_Z w
       +0070: 67 BD 80 00 00 00 00 00 00 00 00 00 00 00 00 00 | g.
.... .... ....
       +0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ....
.... .... ....
       +0090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ....
.... .... ....
       +00A0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ....
.... .... ....
       +00B0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ....
.... .... ....
       +00C0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ....
.... .... ....
       +00D0: 00 00 00 00 |
....
!0x00001314+0.0, 1 - 1 stray bit {0} [? ADC
error]
@0x00001314+0.1, 6770702 - 11487 MPEG audio
frames
!0x00676322+0.1, 595 - MPEG audio frame [Truncated. Expected
626]
!0x00676575+0.1, 7 - 7 stray bits {1110000} [? ADC
error]
@0x00676575+1.0, 0 - EOF Filesize: 0x00676576
(6776182)

------------------------------------------------------------------------------
Root: D:\_DEV\ID3\
File: RAll The Bits.mp3
Stat: 13/Mar/2005 20:06:46 [ RW A ] 1057221 bytes

@0x00000000+0.0, 4359 - ID3 v2.4.0 Tag
@0x00001107+0.0, 522 - Xing Info/CBR header with LAME extension
    [4] +000: Tag = "Info"
    [4] +004: Flags = [...QTBF]
    [4] +02C: Frames = 2014
    [4] +030: Bytes = 1052734
  [100] +034: TOC = 00 03 06 08 0B 0D 10 12 15 17 1A 1C 1F 21 24 26
        +044: 29 2B 2E 30 33 35 38 3A 3E 40 43 45 48 4A 4D 4F
        +054: 52 54 57 59 5C 5E 61 63 66 68 6B 6D 70 72 75 77
        +064: 7B 7D 80 83 85 88 8A 8D 8F 92 94 97 99 9C 9E A1
        +074: A3 A6 A8 AB AD B0 B2 B6 B8 BB BD C0 C2 C5 C7 CA
        +084: CC CF D1 D4 D6 D9 DB DE E0 E3 E5 E8 EA ED EF F3
        +094: F5 F8 FA FD
    [4] +098: Quality = 60
@0x00001311+0.0, 1052212 - 2014 MPEG audio frames
@0x00102145+0.0, 128 - ID3 v1.1 Tag
         +03: Title = "All The Bits"
         +21: Artist = "Van Morrison"
         +3F: Album = "At His Best, Volume 2 - ''Fr.."
         +5D: Year = "2000"
         +61: Comment = "Track 8"
         +7E: Track = 8
         +7F: Genre = 13 (Pop)
@0x001021C5+0.0, 0 - EOF Filesize: 0x001021C5 (1057221)

> No changes. Output file not written.
Received on Wed Dec 28 01:58:27 2005


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