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  • ladyred
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True FLAC or fake one
Hi there,

Does anyone know of a program that can verify the integrity of a flac?

How can I tell if it is a real FLAC or an mp3 file that has been converted into a FLAC?

Is there a program out there that will do this?

Thanks 

  • Cosmo
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True FLAC or fake one
Reply #1
A FLAC file who's source was originally an mp3 file is still, technically, a "real" FLAC file. So it's not really the integrity of the FLAC file that you want to check (in technical terms), it's the audio data contained within.

There is only one program that I know of that can make a reasonably educated guess at whether music has been transcoded from a lossy source like mp3. Tau_Analyzer. But if I recall correctly, you probably can't scan FLAC files directly with it.

Most of the time it's pretty easy to tell if an audio sample has originated from a lossy/mp3 source, just by looking at a the frequency spectrum. Lossy file compression like mp3 usually employs lowpass filtering at a frequency well below that of true CD audio. And the effect of such lowpass filtering remains apparent even after it has been transcoded. See: http://www.audiohub.org/get/fa/fa.htm + http://www.audiohub.org/get/fa/sa.htm .

  • Latexxx
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True FLAC or fake one
Reply #2
Most of the time it's pretty easy to tell if an audio sample has originated from a lossy/mp3 source, just by looking at a the frequency spectrum. Lossy file compression like mp3 usually employs lowpass filtering at a frequency well below that of true CD audio. And the effect of such lowpass filtering remains apparent even after it has been transcoded. See: http://www.audiohub.org/get/fa/fa.htm + http://www.audiohub.org/get/fa/sa.htm .

That isn't very reliable method. For some reason there are original cds come with a 16 kHz lowpass and according to cd specs the band between 20 kHz and 22.05 kHz should contain no meaningful information.

  • tgoose
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True FLAC or fake one
Reply #3
There is only one program that I know of that can make a reasonably educated guess at whether music has been transcoded from a lossy source like mp3. Tau_Analyzer. But if I recall correctly, you probably can't scan FLAC files directly with it.

True enough, but the simple way to get around this is to burn the FLAC to an ISO file, then mount it with something like Daemon Tools. I'm pretty sure that works fine.

  • kjoonlee
  • [*][*][*][*][*]
True FLAC or fake one
Reply #4
Eh? Why not just decode to .wav? If you're smart enough to burn an ISO, you're smart enough to use the command-line, IMHO.

flac -d input.flac

  • kritip
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True FLAC or fake one
Reply #5
Because it only reads from a CD, therefore you have to either burn them to an actual disc, or mount them as a virtual drive.

Kristian

//edit refering to Tau Analyzer of course
  • Last Edit: 09 April, 2006, 08:49:06 AM by kritip

True FLAC or fake one
Reply #6
Because it only reads from a CD, therefore you have to either burn them to an actual disc, or mount them as a virtual drive.

Kristian

//edit refering to Tau Analyzer of course

auCDtect works directly on wav files.
"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
       - Oceania Association of Autonomous Astronauts

True FLAC or fake one
Reply #7
Take aucdtect then.
Edit: Ah, Mr_Rabid_Teddybear was slightly faster than I.
  • Last Edit: 09 April, 2006, 12:54:12 PM by LaserSokrates

  • kritip
  • [*][*][*][*][*]
True FLAC or fake one
Reply #8
auCDtect works directly on wav files.


Ah, i was aware of that, but for some reason thought it was not developed anymore, and Tau Analyzer had superceded it. Upon looking further it appears i was totally wrong about that, and it is what Tau Analyzer is based upon? Good news  and serves me right for not looking harder last time I looked into it.

Cheers,

Kristian

  • ghost note
  • [*]

  • Never_Again
  • [*][*][*][*][*]
  • Members (Donating)
True FLAC or fake one
Reply #10
You would have to burn an Audio CD from those files first to use AccurateRip. Then if AccurateRip reports the results as accurate, the source was lossless. However, if your results don't match those in the AccurateRip database, it could mean anything from a different CD pressing to the wrong write offset to lossy source.

  • EuMesmo
  • [*]
True FLAC or fake one
Reply #11
Hi there,

Does anyone know of a program that can verify the integrity of a flac?

How can I tell if it is a real FLAC or an mp3 file that has been converted into a FLAC?

Is there a program out there that will do this?

Thanks 


There's a GUI for Tauanalyzer that decodes to wav directly.

Audiochecker Home.

True FLAC or fake one
Reply #12
I am having trouble decoding a flac file and I can't get it to work with many programs
flac, cog, etc.

I got an error message when I tried to decode it...


flac 1.1.0, Copyright © 2000,2001,2002,2003 Josh Coalson
flac comes with ABSOLUTELY NO WARRANTY.  This is free software, and you are
welcome to redistribute it under certain conditions.  Type `flac' for details.

Antonin Dvorák - Masterworks Disc 1.flac: *** Got error code 0:FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC


Antonin Dvorák - Masterworks Disc 1.flac: ERROR while decoding metadata
                                              state = 4:FLAC__STREAM_DECODER_END_OF_STREAM

can anyone tell me what this means?
do i have a corrupted flac?

or just some program that can't decode it? it looks russian....I think......or czech....as the last characters are not coming up properly....could this be the issue?

anyway...thanks

dj

  • Jany
  • [*]
True FLAC or fake one
Reply #13
Ill show you how i detect fake FLAC

Software: Spectro [FLAC is supported]
Homepage: http://spectro.enpts.com/

FLAC vs MP3[320kbps]:
  • Last Edit: 08 October, 2010, 09:20:54 AM by Jany

  • db1989
  • [*][*][*][*][*]
  • Global Moderator
True FLAC or fake one
Reply #14
Why is the x-axis scale reversed?

  • Jany
  • [*]
True FLAC or fake one
Reply #15
Why is the x-axis scale reversed?


I don't know.  I don't created that program