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Topic: Distortions in AAC file purchased on iTunes (Read 3587 times) previous topic - next topic

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  • msvadi
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Distortions in AAC file purchased on iTunes
Hi all,

I've noticed a couple of audible distortions in an AAC track I bought on iTunes. I uploaded a small fragment of the track with distortions here: 53 FRAGMENT Sonata in A Minor, D. 821, 'Arpeggione '_ I. Allegro moderato.m4a. I wonder if these are compression artifacts or they were caused by something else?

I appreciate your help with this.

  • eahm
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Distortions in AAC file purchased on iTunes
Reply #1
"Our service is currently unavailable in your country.
Sorry about that."
  • Last Edit: 20 May, 2012, 10:46:55 PM by eahm

  • msvadi
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Distortions in AAC file purchased on iTunes
Reply #2
"Our service is currently unavailable in your country.
Sorry about that."



Sorry about that. I uploaded the same fragment also to Mediafire. I think it should work in the US too:

http://www.mediafire.com/?l8lip63v28y7r1c

  • eahm
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Distortions in AAC file purchased on iTunes
Reply #3
It seems an audio problem but I am not expert enough of that particular track and I can't for sure say it's not a key vibration sound.
  • Last Edit: 21 May, 2012, 01:52:32 AM by eahm

  • Nessuno
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Distortions in AAC file purchased on iTunes
Reply #4
Of course the only way to be sure would be a comparison with the lossless version, but to me it doesn't seem a compression artefact. It seems more an imperfection in the recording, or some kind of "mechanical" noise from the bow strokes, maybe the microphones were placed a little too near.

In my experience, trying to spot artefacts to ABX on AAC @256Kbps has instead leaded me to find a lot of similar imperfections in the original recordings!
... I live by long distance.

  • msvadi
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Distortions in AAC file purchased on iTunes
Reply #5
I see. Thanks for your replies!

  • Wombat
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Distortions in AAC file purchased on iTunes
Reply #6
To me it simply sounds like a string loosened on the Cello or whatever the bigger stringed instrument is.
Is troll-adiposity coming from feederism?

  • eahm
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Distortions in AAC file purchased on iTunes
Reply #7
The original one has the same sound as well, as I supposed it's just a key vibration sound.

http://dropcanvas.com/pnvin

EAC Log:
Code: [Select]
Exact Audio Copy V0.99 prebeta 5 from 4. May 2009

EAC extraction logfile from 6. January 2011, 1:50

Andras Schiff, Yuuko Shiokawa, Miklos Perenyi / Andras Schiff - Concertos & Chamber  Music - CD7 - Schubert

Used drive  : HL-DT-STDVDRAM GSA-4083N   Adapter: 1  ID: 0

Read mode               : Secure
Utilize accurate stream : Yes
Defeat audio cache      : Yes
Make use of C2 pointers : No

Read offset correction                      : 667
Overread into Lead-In and Lead-Out          : No
Fill up missing offset samples with silence : Yes
Delete leading and trailing silent blocks   : No
Null samples used in CRC calculations       : No
Used interface                              : Native Win32 interface for Win NT & 2000

Used output format              : User Defined Encoder
Selected bitrate                : 768 kBit/s
Quality                         : High
Add ID3 tag                     : No
Command line compressor         : C:\Program Files\Exact Audio Copy\FLAC\FLAC.EXE
Additional command line options : -6 -V -T "ARTIST=%a" -T "TITLE=%t" -T "ALBUM=%g" -T "DATE=%y" -T "TRACKNUMBER=%n" -T "GENRE=%m" -T "COMMENT=%e" %s -o %d


TOC of the extracted CD

     Track |   Start  |  Length  | Start sector | End sector
    ---------------------------------------------------------
        1  |  0:00.00 | 11:19.55 |         0    |    50979  
        2  | 11:19.55 |  4:18.52 |     50980    |    70381  
        3  | 15:38.32 |  9:15.08 |     70382    |   112014  
        4  | 24:53.40 | 15:07.15 |    112015    |   180054  
        5  | 40:00.55 |  9:56.65 |    180055    |   224819  
        6  | 49:57.45 |  6:40.05 |    224820    |   254824  
        7  | 56:37.50 |  9:04.25 |    254825    |   295649  


Range status and errors

Selected range

     Filename F:\Music\Schiff - Concertos & Chamber Music\Schiff - Concertos & Chamber  Music - CD7.wav

     Peak level 98.8 %
     Range quality 100.0 %
     Copy CRC CC05314A
     Copy OK

No errors occurred

End of status report
  • Last Edit: 21 May, 2012, 03:58:58 PM by eahm

  • msvadi
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Distortions in AAC file purchased on iTunes
Reply #8
The original one has the same sound as well, as I supposed it's just a key vibration sound.


Thank you very much! This is very helpful. I was considering contacting iTunes and asking them to fix the issue. Now I see that it's not their fault.

Distortions in AAC file purchased on iTunes
Reply #9
To me it simply sounds like a string loosened on the Cello or whatever the bigger stringed instrument is.
Agreed. It's Miklos Perenyi playing the cello. A great artist.