Go Back   MacRumors Forums > Special Interests > Digital Audio

Reply
 
Thread Tools Search this Thread Display Modes
Old Sep 8, 2012, 09:47 AM   #1
photogpab
macrumors 6502
 
Join Date: Jun 2010
spotting fake FLACs?

any program I can use to spot fake flac or lossless files?

a few people mentioned audio checker but i dont think its available on mac.
photogpab is offline   0 Reply With Quote
Old Sep 9, 2012, 04:14 PM   #2
Blackberryroid
Banned
 
Join Date: Aug 2012
Location: /private/var/vm/
I do not listen to FLACs, I listen to ALACs, which is lossless but it's for iTunes, iPhone and iPod so I wouldn't have to worry about converting it to low quality MP3.

The best way to spot fake FLACs is to check their bit-rate. If it's below 500, you got the fake one. Typically, FLACs are 1000+ kb/s, but some are also 600 KB/s.
Blackberryroid is offline   0 Reply With Quote
Old Sep 10, 2012, 11:06 AM   #3
bwhli
macrumors Demi-God
 
Join Date: Jan 2012
Location: Boston, MA
Quote:
Originally Posted by photogpab View Post
any program I can use to spot fake flac or lossless files?

a few people mentioned audio checker but i dont think its available on mac.
You can run it through a spectrum analyzer. If it has a brickwall on the high frequencies, it's probably not true lossless. Lots of lossy compression codecs take out the high frequencies.
__________________
@bwhli
bwhli is offline   0 Reply With Quote
Old Sep 10, 2012, 01:02 PM   #4
ChrisA
macrumors G4
 
Join Date: Jan 2006
Location: Redondo Beach, California
Quote:
Originally Posted by photogpab View Post
any program I can use to spot fake flac or lossless files?

a few people mentioned audio checker but i dont think its available on mac.
The for-sure method isto compare the decompressed FLAC to the WAV file you got from the CD. Subtract the two files in an audio editor.

Lacking the CD, the best way to check is to convert to WAV and then look at the file with something like Adobe Audition or some other analisys tool. An FFT plot would tell you quite a lot.

A quick way is to simply look at the file size compared to other FLAC files of the same music genre and length. A"fake" will be shorter. Seeing the short file then you check it using above methods

But on the other hand if your ears can't tell by just listening why would you care? I assume if you don't know the history of the file you got it as a free download, why complain about the quality of stolen music?
ChrisA is offline   2 Reply With Quote
Old Sep 10, 2012, 01:10 PM   #5
blueroom
macrumors 603
 
blueroom's Avatar
 
Join Date: Feb 2009
Location: Toronto, Canada
Quote:
Originally Posted by ChrisA View Post
But on the other hand if your ears can't tell by just listening why would you care? I assume if you don't know the history of the file you got it as a free download, why complain about the quality of stolen music?
Ahh thanks, I couldn't figure out how you could have a fake FLAC.
__________________
My iOS devices are not jailbroken.
Bill
My Blog
blueroom is offline   3 Reply With Quote
Old Sep 10, 2012, 05:43 PM   #6
AzN1337c0d3r
macrumors 6502
 
Join Date: Sep 2010
Quote:
Originally Posted by ChrisA View Post
But on the other hand if your ears can't tell by just listening why would you care? I assume if you don't know the history of the file you got it as a free download, why complain about the quality of stolen music?
Lossless formats aren't typically used directly for audio reproduction you know...

The idea is to preserve a bit-perfect copy of the original so that when you encode it, you'll be preserving as much of the original signal as possible.
__________________
rMBP (10.8), 2.6 GHz, 8 GB RAM, 512 GB SSD
Hackintosh (10.7.4), 4.6 GHz i7-3930K, 32 GB RAM, 3xHD7970, 2x240GB Vertex 3 RAID 0 SSD, 2x600GB Velociraptor 10KRPM, Drobo S 5x2TB, 2x HP LP3065 30-inch.
AzN1337c0d3r is offline   1 Reply With Quote
Old Nov 26, 2012, 01:54 AM   #7
buklau
macrumors newbie
 
Join Date: May 2010
This method isn't rigorous at all, but sometimes you can 'spot' compression in the audio spectrum, with AAC I believe it looked like lots of little blocks or squares punched out where you would expect it to be continuous, usually in the very high frequencies.
buklau is offline   1 Reply With Quote
Old Nov 26, 2012, 01:58 AM   #8
alphaod
macrumors Core
 
alphaod's Avatar
 
Join Date: Feb 2008
Location: 上海 (Shanghai)
I don't understand the fake FLAC business. If you're ripping your own music, how the world would it be fake unless you used the wrong source.

If you're buying music online (like HDTracks), I've never had issues with their music.
__________________
Mac Pro | Mac mini | 15" MacBook Pro | iPad Air | iPhone 6
alphaod is offline   0 Reply With Quote
Old Nov 27, 2012, 07:49 PM   #9
bwhli
macrumors Demi-God
 
Join Date: Jan 2012
Location: Boston, MA
Quote:
Originally Posted by alphaod View Post
I don't understand the fake FLAC business. If you're ripping your own music, how the world would it be fake unless you used the wrong source.

If you're buying music online (like HDTracks), I've never had issues with their music.
Some people download FLACs from "free" sources.
__________________
@bwhli
bwhli is offline   1 Reply With Quote
Old Nov 28, 2012, 07:20 AM   #10
shigzeo
macrumors 6502a
 
shigzeo's Avatar
 
Join Date: Dec 2005
Location: Japan
Send a message via Skype™ to shigzeo
Quote:
Originally Posted by bwhli View Post
You can run it through a spectrum analyzer. If it has a brickwall on the high frequencies, it's probably not true lossless. Lots of lossy compression codecs take out the high frequencies.
This is probably the best answer in this thread. FLAC can be re-encoded to any bitrate, so looking at that alone will leave you with more questions than anything. Running a spectrum analyser will give you a visual comparison of the data inside.

We all know that listening to the files (especially if one is in doubt) will not do the trick: ears are too easily fooled. Half a decibel louder and suddenly: it sounds better.
__________________
TouchMyApps All Things iPhone for Those Who Like to Touch
Ω image - headphone and desktop audio photography
shigzeo is offline   0 Reply With Quote
Old Feb 25, 2013, 10:56 AM   #11
SHAL0MINTHEH0ME
macrumors newbie
 
Join Date: Feb 2013
Quote:
Originally Posted by shigzeo View Post
This is probably the best answer in this thread. FLAC can be re-encoded to any bitrate, so looking at that alone will leave you with more questions than anything. Running a spectrum analyser will give you a visual comparison of the data inside.

We all know that listening to the files (especially if one is in doubt) will not do the trick: ears are too easily fooled. Half a decibel louder and suddenly: it sounds better.
Unfortunately this isn't a fail safe. I did a few tests as I have a few ALACs that I did not rip myself (cough), and I wanted to verify their authenticity. I ran a few suspect and a few confirmed ALAC files through a spectrum analyzer, as well as a few MP3s. All of the MP3 files had the visual cut-off you are referring to. Some of the ALAC files did as well. Some visually did not. I thought, "Great the cut off files are fake!", until I took some CDs that I had and created ALAC files straight from them myself. Lo and behold, they had the same frequency cut-offs that the MP3 files did. Apparently whether or not the files have those frequencies can be caused just as much from the source as the encoding method.

Bummer. Too much compression in the CD mastering process maybe?

I guess the only way to really tell is to directly compare the source cd with the ripped file.

Caveat emptor: I am not an audio pro, but I did stay at a Holiday Inn Express last night.
SHAL0MINTHEH0ME is offline   0 Reply With Quote
Old Feb 25, 2013, 12:14 PM   #12
gannonsamuel
macrumors member
 
Join Date: Aug 2012
i would argue that if you're needing a program to tell you before you notice it probably doesn't matter.

it should stick out as sounding like an mp3, if it doesn't, or you're not hearing a difference without a program telling you it's an mp3 conversion then, why care?
gannonsamuel is offline   0 Reply With Quote
Old Feb 25, 2013, 02:56 PM   #13
SHAL0MINTHEH0ME
macrumors newbie
 
Join Date: Feb 2013
Quote:
Originally Posted by gannonsamuel View Post
i would argue that if you're needing a program to tell you before you notice it probably doesn't matter.

it should stick out as sounding like an mp3, if it doesn't, or you're not hearing a difference without a program telling you it's an mp3 conversion then, why care?


I don't disagree with your point. Most MP3s do stand out. I've got a good enough setup that I can easily tell, especially when comparing side by side. Unfortunately I don't know if I can tell 100% of the time without a comparison. I just want to know, you know?
SHAL0MINTHEH0ME is offline   0 Reply With Quote
Old Feb 25, 2013, 03:30 PM   #14
gannonsamuel
macrumors member
 
Join Date: Aug 2012
Quote:
Originally Posted by SHAL0MINTHEH0ME View Post
I just want to know, you know?
Fair enough, I would see if you can check with your source of the files then.
gannonsamuel is offline   0 Reply With Quote
Old Feb 25, 2013, 06:47 PM   #15
Mr. Retrofire
macrumors 601
 
Mr. Retrofire's Avatar
 
Join Date: Mar 2010
Location: www.emiliana.cl
Quote:
Originally Posted by photogpab View Post
any program I can use to spot fake flac or lossless files?
I use my ears, good headphones and the correct equalizer settings.

----------

Quote:
Originally Posted by bwhli View Post
Some people download FLACs from "free" sources.
Really?

;-)
__________________

“Only the dead have seen the end of the war.”
-- Plato --
Mr. Retrofire is offline   0 Reply With Quote
Old Feb 27, 2013, 05:27 PM   #16
shigzeo
macrumors 6502a
 
shigzeo's Avatar
 
Join Date: Dec 2005
Location: Japan
Send a message via Skype™ to shigzeo
Quote:
Originally Posted by SHAL0MINTHEH0ME View Post
Unfortunately this isn't a fail safe. I did a few tests as I have a few ALACs that I did not rip myself (cough), and I wanted to verify their authenticity. I ran a few suspect and a few confirmed ALAC files through a spectrum analyzer, as well as a few MP3s. All of the MP3 files had the visual cut-off you are referring to. Some of the ALAC files did as well. Some visually did not. I thought, "Great the cut off files are fake!", until I took some CDs that I had and created ALAC files straight from them myself. Lo and behold, they had the same frequency cut-offs that the MP3 files did. Apparently whether or not the files have those frequencies can be caused just as much from the source as the encoding method.

Bummer. Too much compression in the CD mastering process maybe?

I guess the only way to really tell is to directly compare the source cd with the ripped file.

Caveat emptor: I am not an audio pro, but I did stay at a Holiday Inn Express last night.
No a spectrum analyser will not tell you what file is uncompressed and of higher intrinsic quality (without size compression or inflation) but will show how much dynamic range is lost due to dynamic compression to emphasise loudness.

----------

Quote:
Originally Posted by SHAL0MINTHEH0ME View Post
I don't disagree with your point. Most MP3s do stand out. I've got a good enough setup that I can easily tell, especially when comparing side by side. Unfortunately I don't know if I can tell 100% of the time without a comparison. I just want to know, you know?
Again, it isn't so easy. It has not been proven one way or another that users CAN hear a difference unless the files are very very poorly recorded. New algorithms are good enough even at 128 that I doubt most 'golden ears' could tell a difference if the volumes of both songs were perfectly matched.

The ear is very very easily tricked.

And doing the test yourself, unless it is a blind ABX, is meaningless. Even then, there are too many questions raised. I'd say, if in a blind test with 100% matching volumes, you fail to suss which is which in more than 1/3 of the phases, it doesn't matter. Such tests require specific pieces of software, not a random play in iTunes and absolutely must be volume matched. I suggest having someone with you to keep you straight.

Often, 'good' systems are even more prone to lies. Why? Good, expensive systems introduce their own flavour - that is, unless you invest in a system that aims for bit accuracy. Those systems don't usually cost that much. Benchmark is much cheaper than Antelope and Antelope DACs are still cheap in the grand scheme of things.

Hell, an ODAC should do it and it is cheap. Feed it to a truthful system (Good monitoring headphones like Beyer DT770 may be better in this case, than speakers).

I meet 'golden ears' all the time. And they are often the easiest to fool as they want to believe anything. It's the normal folk who tend to spot truth faster as they are in essence, doubters.
__________________
TouchMyApps All Things iPhone for Those Who Like to Touch
Ω image - headphone and desktop audio photography
shigzeo is offline   0 Reply With Quote
Old Feb 27, 2013, 05:48 PM   #17
jon3543
macrumors 6502
 
Join Date: Sep 2010
Quote:
Originally Posted by shigzeo View Post
Again, it isn't so easy. It has not been proven one way or another that users CAN hear a difference unless the files are very very poorly recorded. New algorithms are good enough even at 128 that I doubt most 'golden ears' could tell a difference if the volumes of both songs were perfectly matched.
From my post the other day:

*****
http://forums.macrumors.com/showthre...7#post16873587

Besides using foobar ABX or equivalent, the two files to be compared must be derived from the same mastering, and preferably the exact same source (one from the other obviously counts); otherwise, you may be testing for differences in mastering, not encoding, and differences in mastering can be genuinely profound and trivial for anyone to ABX.

There is an infinite amount of nonsense in discussions about these things. Here is a fairly detailed slideshow of a scholarly presentation that used high-end equipment under ideal conditions:

http://www.music.mcgill.ca/~hockman/...tation2009.pdf

Its conclusion were:
  • Trained listeners can hear differences between CD quality and mp3 compression (96-192 kb/s) and prefer CD quality.
  • Trained listeners can not discriminate between CD quality and mp3 compression (256-320 kb/s) while expert listeners could.
  • Ability to discriminate depends on listeners’ expertise and musical genre.
  • Artifacts can be verbalized and do not depend on musical genre.

I think AAC is a lot better than MP3 at low bitrates, judging by my threshold for hearing artifacts in various "killer samples", which disappear for me at AAC 128 Kbps but persist in LAME 3.98 MP3 up to 192 Kbps and a little beyond. I've also found transcoding high bitrate MP3s to AAC to be much more transparent than going MP3->MP3, which introduces obvious artifacts after one generation. If you want to read a lot of subjective crazy talk including things like cable directionality, try the stevehoffman.tv forums. For people who value blind listening tests, try hydrogenaudio.org.
*****

Quote:
I meet 'golden ears' all the time. And they are often the easiest to fool as they want to believe anything.
Yep. And when I said I could hear artifacts in some killer samples at 192 Kbps MP3, that says nothing about most music, which I find transparent at that level. While most of my library is lossless, I always have iTunes transcode to 128 Kbps AAC when syncing to my 64 GB Touch. There are apps for ABXing directly on the Touch, and I've found there is no reason to encode at a higher rate for how I use my Touch. There might be brief, infrequent moments of non-transparency that I might notice under ideal conditions and with higher quality equipment that I normally use, but it would be stupid to sacrifice a ton of storage out of fear of that.
jon3543 is offline   0 Reply With Quote
Old Feb 27, 2013, 08:45 PM   #18
jon3543
macrumors 6502
 
Join Date: Sep 2010
Quote:
Originally Posted by photogpab View Post
any program I can use to spot fake flac or lossless files?

a few people mentioned audio checker but i dont think its available on mac.
If you have a whole album in lossless format, many can be verified against AccurateRip with CueTools or foobar2000 on the PC. A minority (10%?) require the .cue file in order to verify.
jon3543 is offline   0 Reply With Quote
Old Feb 28, 2013, 10:15 AM   #19
SHAL0MINTHEH0ME
macrumors newbie
 
Join Date: Feb 2013
Quote:
Originally Posted by shigzeo View Post
No a spectrum analyser will not tell you what file is uncompressed and of higher intrinsic quality (without size compression or inflation) but will show how much dynamic range is lost due to dynamic compression to emphasise loudness.

----------



Again, it isn't so easy. It has not been proven one way or another that users CAN hear a difference unless the files are very very poorly recorded. New algorithms are good enough even at 128 that I doubt most 'golden ears' could tell a difference if the volumes of both songs were perfectly matched.

The ear is very very easily tricked.

And doing the test yourself, unless it is a blind ABX, is meaningless. Even then, there are too many questions raised. I'd say, if in a blind test with 100% matching volumes, you fail to suss which is which in more than 1/3 of the phases, it doesn't matter. Such tests require specific pieces of software, not a random play in iTunes and absolutely must be volume matched. I suggest having someone with you to keep you straight.

Often, 'good' systems are even more prone to lies. Why? Good, expensive systems introduce their own flavour - that is, unless you invest in a system that aims for bit accuracy. Those systems don't usually cost that much. Benchmark is much cheaper than Antelope and Antelope DACs are still cheap in the grand scheme of things.

Hell, an ODAC should do it and it is cheap. Feed it to a truthful system (Good monitoring headphones like Beyer DT770 may be better in this case, than speakers).

I meet 'golden ears' all the time. And they are often the easiest to fool as they want to believe anything. It's the normal folk who tend to spot truth faster as they are in essence, doubters.
I don't think that anyone here is claiming to have "golden ears", but I certainly do think that there is a marked difference between (some?) mp3s and lossless files. I still have songs from back when "torrenting" was simply browsing your college network for songs to play with winamp. When replacing these songs with lossless rips, there's an audible difference in the quality. I don't think any mp3 I had was over 192kbps; most under 160.

Of course I am probably comparing the worst-case scenario to the best-case, but never-the-less I stand by the idea that there's an audible difference to be heard.

I also buy direct from an artist when there's a high-quality (32bit wav!) download available. On top of buying direct, I know I'm getting the best possible quality in the off chance that sometime, maybe, I'll have the system and ear to reproduce the files. Plus, as these files will be backups, I'll have a perfect source to rip smaller versions from when needed.
SHAL0MINTHEH0ME is offline   0 Reply With Quote
Old Feb 28, 2013, 11:15 AM   #20
PBG4 Dude
macrumors 65816
 
Join Date: Jul 2007
Didn't realize FLAC had been taken over by pirates. That's usually how Grateful Dead shows are encoded and it's legal to download their music. Other bands are cool with live shows being traded as well.
PBG4 Dude is offline   0 Reply With Quote
Old Mar 1, 2013, 05:03 PM   #21
Julien
macrumors 601
 
Join Date: Jun 2007
Location: Atlanta
Quote:
Originally Posted by PBG4 Dude View Post
Didn't realize FLAC had been taken over by pirates.....
FLAC is open source and can be used (taken over) by the pope or Kim Jong-il.
Julien is offline   0 Reply With Quote
Old Mar 2, 2013, 05:59 PM   #22
shigzeo
macrumors 6502a
 
shigzeo's Avatar
 
Join Date: Dec 2005
Location: Japan
Send a message via Skype™ to shigzeo
Quote:
Originally Posted by SHAL0MINTHEH0ME View Post
I don't think that anyone here is claiming to have "golden ears", but I certainly do think that there is a marked difference between (some?) mp3s and lossless files. I still have songs from back when "torrenting" was simply browsing your college network for songs to play with winamp. When replacing these songs with lossless rips, there's an audible difference in the quality. I don't think any mp3 I had was over 192kbps; most under 160.

Of course I am probably comparing the worst-case scenario to the best-case, but never-the-less I stand by the idea that there's an audible difference to be heard.

I also buy direct from an artist when there's a high-quality (32bit wav!) download available. On top of buying direct, I know I'm getting the best possible quality in the off chance that sometime, maybe, I'll have the system and ear to reproduce the files. Plus, as these files will be backups, I'll have a perfect source to rip smaller versions from when needed.
I don't check this thread or MR forums often enough as I live in another forum called headfi. Need to start a more permanent spot here.

Files from back then will be encoded from those days. The poster above who responded at length to me is right: there are profound differences between encoding samples. Today's AAC files at low bit rates such as 128 are better than yesterday's MP3 files at 320. But today's MP3 is very very good. I heard samples that were coded at 1997 MP3 encoding that sounded awful.

As mentioned above: files from the same CD could be ripped at same volumes, diff. bitrates, different engines (volume must be lossless though). A different mastering year or equipment can make a heap of difference; simply putting any old FLAC vs any old AAC isn't going to be fair - for one or the other as there are so many variables.

Everything the same, I've not met a single person that could reliably tell the difference past 192kbps despite hugging their STAX and associated gear to their hearts. I admit that I cannot reliably tell between all-variables-equal encodings using the latest/best software.
__________________
TouchMyApps All Things iPhone for Those Who Like to Touch
Ω image - headphone and desktop audio photography
shigzeo is offline   0 Reply With Quote

Reply
MacRumors Forums > Special Interests > Digital Audio

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Similar Threads
thread Thread Starter Forum Replies Last Post
Mac Spotting eyoungren PowerPC Macs 17 Mar 1, 2014 07:32 PM
Resolved: Spotting high density ram fenjen MacBook Pro 10 Jul 28, 2013 12:50 PM

Forum Jump

All times are GMT -5. The time now is 03:29 AM.

Mac Rumors | Mac | iPhone | iPhone Game Reviews | iPhone Apps

Mobile Version | Fixed | Fluid | Fluid HD
Copyright 2002-2013, MacRumors.com, LLC