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Topic: iTunes Encodes vs. Amazon (Spectrograms) (Read 8001 times) previous topic - next topic

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  • dhromed
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iTunes Encodes vs. Amazon (Spectrograms)
Reply #25
I said that which Amazon's encoder saw fit to throw out was within the range of human hearing.

It's not quite a clear-cut as that. It's not comparable to a cropped image.

I know I can't hear the stuff that was cut off of in the mp3 file.


Would you also say that ultraviolet and infrared are "missing" from paintings and photographs?

Or maybe: "which file theoretically would better represent the source to all humans?"

The one without the high frquences, most likely.

iTunes Encodes vs. Amazon (Spectrograms)
Reply #26
I really wasn't clear as to how these spectrographs weren't somehow helpful in comparing encodes.

Nearly every reply has been helpful (to me) since my last. Thanks. I felt 2Bdecided's explanation pretty much convinced me that I shouldn't be looking at these graphs and expecting as much as I was by way of meaningful comparison.

I apologize for not being on the same page as most of you. Hopefully now I am. (This really isn't worth me getting upset over and it wasn't my intention.)
The Loudness War is over. Now it's a hopeless occupation.

  • dhromed
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iTunes Encodes vs. Amazon (Spectrograms)
Reply #27
This really isn't worth me getting upset over



  • Canar
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iTunes Encodes vs. Amazon (Spectrograms)
Reply #28
I apologize for not being on the same page as most of you. Hopefully now I am.
There is no need to apologize, though the sentiment is welcome. Helping people understand this stuff is one of the main points of this forum. I'm glad to see you're starting to understand.
1. Attack the argument, not the arguer.
2. Assume good faith.

  • mjb2006
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iTunes Encodes vs. Amazon (Spectrograms)
Reply #29
Just because there are high frequencies, it does not mean that they are the same as in the original.

I believe this is especially true for the AAC(-LC) file. It probably uses Perceptual Noise Substitution (PNS) to generate noise at decoding time. I wouldn't be surprised if most of those uppermost frequencies are from this effect. Maybe someone with knowledge of Apple's encoder can confirm?
  • Last Edit: 14 May, 2012, 08:18:18 PM by mjb2006

  • lvqcl
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iTunes Encodes vs. Amazon (Spectrograms)
Reply #30
Given the cons of using these tools (read: iPod can't decode it properly) it is probably not a good idea to enable them.


So at least in 2007 Apple encoder didn't use PNS