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Topic: LAME equivalent in AAC world ? (Read 14625 times) previous topic - next topic

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  • [JAZ]
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LAME equivalent in AAC world ?
Reply #25
I have to apology since I added confusion in the aim of preventing confusion.

I still disagree. Why is the outer part of an image less important than the center part? If you look directly at the edges of an image, don't you want them to be artifact-free just like the center part?

Replace "center part" by "foreground" an "edges" by "background". Even JPEG may represent the background more blocky than the foreground.
Think of this as a redistribution of bits where more bits go to what the user may pay more attention to.


In posting #22 and #21 I highlighted in red the parts that made me - erroneously according to [JAZ] - fall for the "superset" explanation and I highlighted and posted them because I felt they might contradict [JAZ] when saying "That graphic does not try to say that HE-AAC is a superset of LC-AAC and that HE-AACv2 is a superset of HE-AAC.". That's all.


It is true that HE-AAC is a superset of LC-AAC by adding SBR, and HE-AACv2 is a superset of HE-AAC by adding Parametric Stereo.

It is true also that, since SBR and PS are parametric tools, and since the LC-AAC codec (when used with SBR and/or PS) works at a lower quality (half the samplerate for SBR, and in mono in the case of PS), the LC-AAC part is used without its full potential.

If one used LC-AAC only, it would be the same as taking a photograph with a professional camera.
Using HE-AAC would be like taking the photograph with a consumer camera, and then optimize it with a software program.

You cannot get the same quality, if your aim is getting the best one.

That's why the "HE" family is only targeted to low bitrates, and in those cases, being one of the best, if not the best codec.
  • Last Edit: 14 March, 2010, 05:29:48 AM by [JAZ]

  • chrizoo
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LAME equivalent in AAC world ?
Reply #26

I have to apology since I added confusion in the aim of preventing confusion.

it was certainly not your fault.

thanks for clearing it up, I think I know what you mean now.
Anyway, back to my readings ...

If you as me it's unfortunate that different companies use different terms for marketing reasons, further adding to the existing confusion.

Quote from: wikipedia link=msg=0 date=
HE-AAC is marketed under the trademark aacPlus? by Coding Technologies and under the trademark Nero Digital? by Nero AG. Sony Ericsson, Nokia and Samsung use AAC+ to label support for HE AAC v1 and eAAC+ to label support for HE-AAC v2 on their phones. Motorola uses AAC+ to indicate HE AAC v1 and "AAC+ Enhanced" to indicate HE AAC v2.
  • Last Edit: 14 March, 2010, 05:37:34 AM by chrizoo

  • chrizoo
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LAME equivalent in AAC world ?
Reply #27

  • Larson
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LAME equivalent in AAC world ?
Reply #28

  • TechVsLife
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LAME equivalent in AAC world ?
Reply #29

The FAQ in the wiki about AAC may clarify a few other things that you may not understand yet.
http://wiki.hydrogenaudio.org/index.php?title=AAC_FAQ

fyi note some important things are out of date in that aac faq.  For example, it says that only the nero encoder provides information for gapless playback, where itunes/qt also encodes and provides for gapless aac playback.
  • Last Edit: 20 March, 2010, 09:46:39 PM by TechVsLife

  • chrizoo
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LAME equivalent in AAC world ?
Reply #30
Judging from the image in post #6
and from
Quote
HE-AAC Profile (AAC LC with SBR) ... HE-AAC v2 Profile (AAC LC with SBR and Parametric Stereo)


I thought LC AAC + SBR + PS = HE v2 Profile

So why does MediaInfo say "LC profile" ?






  • chrizoo
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LAME equivalent in AAC world ?
Reply #31
since I cannot edit the post anymore, what  I meant is:

I thought
LC AAC = LC profile
LC AAC + SBR + PS = HE v2 profile

  • benski
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  • Developer
LAME equivalent in AAC world ?
Reply #32
Probably because it's assuming that there are only the 3 profiles from the original MPEG-2 spec, Main, LC and SSR.  HE is just an extension of LC.  In theory, one could make Main+SBR or SSR+SBR, although there are no legal profiles that allow this.

  • chrizoo
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LAME equivalent in AAC world ?
Reply #33

ok, that makes sense. There were lots of conflicting informations, but now everything fits together for me. Your answer was key to my comprehension, thank you.