IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
True FLAC or fake one
ladyred
post Apr 9 2006, 00:46
Post #1





Group: Members
Posts: 2
Joined: 9-April 06
Member No.: 29303



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 huh.gif
Go to the top of the page
+Quote Post
Cosmo
post Apr 9 2006, 07:45
Post #2





Group: Members
Posts: 913
Joined: 10-January 05
Member No.: 18979



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 .
Go to the top of the page
+Quote Post
Latexxx
post Apr 9 2006, 08:44
Post #3


A/V Moderator


Group: Members
Posts: 858
Joined: 12-May 03
From: Finland
Member No.: 6557



QUOTE (Cosmo @ Apr 9 2006, 09:45 AM) *
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.
Go to the top of the page
+Quote Post
tgoose
post Apr 9 2006, 12:56
Post #4





Group: Members
Posts: 407
Joined: 12-April 05
Member No.: 21399



QUOTE (Cosmo @ Apr 9 2006, 07:45 AM) *
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.
Go to the top of the page
+Quote Post
kjoonlee
post Apr 9 2006, 13:31
Post #5





Group: Members
Posts: 2526
Joined: 25-July 02
From: South Korea
Member No.: 2782



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


--------------------
http://blacksun.ivyro.net/vorbis/vorbisfaq.htm
Go to the top of the page
+Quote Post
kritip
post Apr 9 2006, 13:48
Post #6





Group: Members
Posts: 531
Joined: 15-January 02
From: Warwickshire -- England
Member No.: 1036



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

This post has been edited by kritip: Apr 9 2006, 13:49
Go to the top of the page
+Quote Post
Mr_Rabid_Teddybe...
post Apr 9 2006, 14:06
Post #7





Group: Members
Posts: 1197
Joined: 3-September 03
From: Bergen, Norway
Member No.: 8667



QUOTE (kritip @ Apr 9 2006, 04:48 AM) *
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
Go to the top of the page
+Quote Post
LaserSokrates
post Apr 9 2006, 14:06
Post #8





Group: Members
Posts: 127
Joined: 9-March 06
From: NRW, Germany
Member No.: 28371



Take aucdtect then.
Edit: Ah, Mr_Rabid_Teddybear was slightly faster than I.

This post has been edited by LaserSokrates: Apr 9 2006, 17:54
Go to the top of the page
+Quote Post
kritip
post Apr 9 2006, 14:29
Post #9





Group: Members
Posts: 531
Joined: 15-January 02
From: Warwickshire -- England
Member No.: 1036



QUOTE (Mr_Rabid_Teddybear @ Apr 9 2006, 02:06 PM) *
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 smile.gif and serves me right for not looking harder last time I looked into it.

Cheers,

Kristian
Go to the top of the page
+Quote Post
ghost note
post Apr 9 2006, 14:40
Post #10





Group: Members
Posts: 40
Joined: 1-March 06
Member No.: 28164



Tell me, if I am mistaken, but if [url=http://www.accuraterip.comAccurateRip[/url] was applied, the
AccurateRip check results actuall are also able to reveal, if a flac, or file was sourced by an original-CD
or by any other non-original-CD source.
Go to the top of the page
+Quote Post
Never_Again
post Apr 9 2006, 15:15
Post #11





Group: Members (Donating)
Posts: 698
Joined: 31-March 04
From: NYC
Member No.: 13152



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.
Go to the top of the page
+Quote Post
EuMesmo
post Jun 30 2008, 06:02
Post #12





Group: Members
Posts: 21
Joined: 21-October 06
Member No.: 36610



QUOTE (ladyred @ Apr 8 2006, 20:46) *
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 huh.gif


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

Audiochecker Home.
Go to the top of the page
+Quote Post
djcarpediem
post Jul 1 2008, 09:18
Post #13





Group: Members
Posts: 1
Joined: 1-July 08
Member No.: 55121



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 DvorA├╔Č░k - Masterworks Disc 1.flac: *** Got error code 0:FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC


Antonin DvorA├╔Č░k - 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
Go to the top of the page
+Quote Post
Jany
post Oct 8 2010, 14:18
Post #14





Group: Members
Posts: 2
Joined: 8-October 10
Member No.: 84440



Ill show you how i detect fake FLAC smile.gif

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

FLAC vs MP3[320kbps]:


MP3[128kbps <lol>]:


After analyze fake flac you will see same specro like on source mp3.
TIP: Not always you will have 22,1KHz but that don't means its fake.
When i spectred full quality human sound solo, spectro is low xP
On website are good news, author will add multiple scan option smile.gif

This post has been edited by Jany: Oct 8 2010, 14:20
Go to the top of the page
+Quote Post
db1989
post Oct 8 2010, 14:43
Post #15





Group: Super Moderator
Posts: 5275
Joined: 23-June 06
Member No.: 32180



Why is the x-axis scale reversed?
Go to the top of the page
+Quote Post
Jany
post Oct 8 2010, 15:29
Post #16





Group: Members
Posts: 2
Joined: 8-October 10
Member No.: 84440



QUOTE (dv1989 @ Oct 8 2010, 14:43) *
Why is the x-axis scale reversed?


I don't know. I don't created that program tongue.gif
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 21st October 2014 - 04:19