[Flac] Re: FLAC: ERROR, MD5 signature mismatch

Harry Sack tranzedude at gmail.com
Wed Jul 25 12:35:24 PDT 2007 

2007/7/25, Harry Sack <tranzedude at gmail.com>:
>
>
>
> 2007/7/25, Harry Sack <tranzedude at gmail.com>:
> >
> > Hi
> >
> > I have downloaded a FLAC file somewhere and when trying to decode it to
> > WAV it gives the error message: ERROR, MD5 signature mismatch
> > So my question is now: are FLAC files that give the error message above
> > still decodable to WAV (and how can you do this, because flac.exedoesn't want to decode the file), even if there is a MD5 signature mismatch,
> > or is this not possible at all?
>
>
>
> An additional question: what happens if you re-encode a FLAC file, that
> gives the error message 'ERROR, MD5 signature mismatch' while trying to
> decode to WAV, to another FLAC file using a later version of the FLAC
> encoder? I tried this and it seems to work, but I'm wondering if the audio
> data is still the same in the new file as in the old file?  Or what happens
> in the re-encode process when such a input FLAC file is re-encoded to
> another FLAC file?
>


Here is the metaflac --list of the input and output FLAC file, the input
file is the file that gives the 'ERROR, MD5 signature mismatch' error when
decoding to WAV. The output file is the newly re-encoded FLAC file when
using the input file as an input to the FLAC encoder:

metaflac --list input_file.flac
METADATA block #0
  type: 0 (STREAMINFO)
  is last: false
  length: 34
  minimum blocksize: 1152 samples
  maximum blocksize: 1152 samples
  minimum framesize: 0 bytes
  maximum framesize: 4768 bytes
  sample_rate: 44100 Hz
  channels: 2
  bits-per-sample: 16
  total samples: 20527080
  MD5 signature: 5f00690064003d005000200020002000
METADATA block #1
  type: 4 (VORBIS_COMMENT)
  is last: false
  length: 287
  vendor string: Flake SVN
  comments: 11
    comment[0]: TITLE=Dido (Armin Van Buuren's Universal Religion Mix)
    comment[1]: ARTIST=Aria
    comment[2]: ALBUM ARTIST=DJ Tiësto
    comment[3]: ALBUM=Summerbreeze
    comment[4]: GENRE=General Trance
    comment[5]: DATE=2000
    comment[6]: DISCNUMBER=1/1
    comment[7]: PUBLISHER=Nettwerk
    comment[8]: COMMENT=Ripped by Winamp
    comment[9]: TRACKNUMBER=1
    comment[10]: ENCODED-BY=Winamp 5.34
METADATA block #2
  type: 1 (PADDING)
  is last: true
  length: 3826




******************************************************************************************

metaflac --list output_file.flac
METADATA block #0
  type: 0 (STREAMINFO)
  is last: false
  length: 34
  minimum blocksize: 4096 samples
  maximum blocksize: 4096 samples
  minimum framesize: 14 bytes
  maximum framesize: 14043 bytes
  sample_rate: 44100 Hz
  channels: 2
  bits-per-sample: 16
  total samples: 20527080
  MD5 signature: 4478d07a5f9acaae35cdef1f1753c764
METADATA block #1
  type: 3 (SEEKTABLE)
  is last: false
  length: 846
  seek points: 47
    point 0: sample_number=0, stream_offset=0, frame_samples=4096
    point 1: sample_number=438272, stream_offset=1010333, frame_samples=4096
    point 2: sample_number=880640, stream_offset=2027118, frame_samples=4096
    point 3: sample_number=1318912, stream_offset=3048483,
frame_samples=4096
    point 4: sample_number=1761280, stream_offset=4067062,
frame_samples=4096
    point 5: sample_number=2203648, stream_offset=5063693,
frame_samples=4096
    point 6: sample_number=2641920, stream_offset=6081493,
frame_samples=4096
    point 7: sample_number=3084288, stream_offset=7139986,
frame_samples=4096
    point 8: sample_number=3526656, stream_offset=8223226,
frame_samples=4096
    point 9: sample_number=3964928, stream_offset=9324016,
frame_samples=4096
    point 10: sample_number=4407296, stream_offset=10366547,
frame_samples=4096
    point 11: sample_number=4849664, stream_offset=11436008,
frame_samples=4096
    point 12: sample_number=5287936, stream_offset=12491977,
frame_samples=4096
    point 13: sample_number=5730304, stream_offset=13715044,
frame_samples=4096
    point 14: sample_number=6172672, stream_offset=14963345,
frame_samples=4096
    point 15: sample_number=6610944, stream_offset=16294043,
frame_samples=4096
    point 16: sample_number=7053312, stream_offset=17663068,
frame_samples=4096
    point 17: sample_number=7495680, stream_offset=19027520,
frame_samples=4096
    point 18: sample_number=7933952, stream_offset=20380473,
frame_samples=4096
    point 19: sample_number=8376320, stream_offset=21739699,
frame_samples=4096
    point 20: sample_number=8818688, stream_offset=23101828,
frame_samples=4096
    point 21: sample_number=9256960, stream_offset=24461617,
frame_samples=4096
    point 22: sample_number=9699328, stream_offset=25856237,
frame_samples=4096
    point 23: sample_number=10141696, stream_offset=27254435,
frame_samples=4096
    point 24: sample_number=10579968, stream_offset=28648219,
frame_samples=4096
    point 25: sample_number=11022336, stream_offset=30041445,
frame_samples=4096
    point 26: sample_number=11464704, stream_offset=31425625,
frame_samples=4096
    point 27: sample_number=11902976, stream_offset=32813313,
frame_samples=4096
    point 28: sample_number=12345344, stream_offset=34237869,
frame_samples=4096
    point 29: sample_number=12787712, stream_offset=35677126,
frame_samples=4096
    point 30: sample_number=13225984, stream_offset=37014200,
frame_samples=4096
    point 31: sample_number=13668352, stream_offset=38202707,
frame_samples=4096
    point 32: sample_number=14110720, stream_offset=39477479,
frame_samples=4096
    point 33: sample_number=14548992, stream_offset=40839121,
frame_samples=4096
    point 34: sample_number=14991360, stream_offset=42273932,
frame_samples=4096
    point 35: sample_number=15433728, stream_offset=43720347,
frame_samples=4096
    point 36: sample_number=15872000, stream_offset=45124682,
frame_samples=4096
    point 37: sample_number=16314368, stream_offset=46517446,
frame_samples=4096
    point 38: sample_number=16756736, stream_offset=47920614,
frame_samples=4096
    point 39: sample_number=17195008, stream_offset=49297279,
frame_samples=4096
    point 40: sample_number=17637376, stream_offset=50678518,
frame_samples=4096
    point 41: sample_number=18079744, stream_offset=52051262,
frame_samples=4096
    point 42: sample_number=18518016, stream_offset=53459833,
frame_samples=4096
    point 43: sample_number=18960384, stream_offset=54871690,
frame_samples=4096
    point 44: sample_number=19402752, stream_offset=56242030,
frame_samples=4096
    point 45: sample_number=19841024, stream_offset=57593260,
frame_samples=4096
    point 46: sample_number=20283392, stream_offset=58982958,
frame_samples=4096
METADATA block #2
  type: 4 (VORBIS_COMMENT)
  is last: false
  length: 310
  vendor string: reference libFLAC 1.2.0 20070715
  comments: 11
    comment[0]: TITLE=Dido (Armin Van Buuren's Universal Religion Mix)
    comment[1]: ARTIST=Aria
    comment[2]: ALBUM ARTIST=DJ Tiësto
    comment[3]: ALBUM=Summerbreeze
    comment[4]: GENRE=General Trance
    comment[5]: DATE=2000
    comment[6]: DISCNUMBER=1/1
    comment[7]: PUBLISHER=Nettwerk
    comment[8]: COMMENT=Ripped by Winamp
    comment[9]: TRACKNUMBER=1
    comment[10]: ENCODED-BY=Winamp 5.34
METADATA block #3
  type: 1 (PADDING)
  is last: true
  length: 3826


I hope somebody can tell me what happens in this situation with the audio
data. If you look at the MD5 signatures, they are not the same, but the
total samples is in both files 20527080. I know too little about FLAC to
understand what happens in the re-encode process in this situation.

I hope somebody can explain it too me!
thx

thx in advance!
>
> thx
> >
>
>
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