High Efficiency AAC
I've seen a few references to this but finally just read an explanation of what it is:
http://www.vialicensing.com/products/HE_AAC/
This sounds pretty impressive. Imagine getting 5.1 sound at the same 128kbps rate that the iPod supplies stereo. We don't all have flying cars yet but I'll be happy with a 5.1 iPod.
Has anyone been testing any beta versions of this? Is it as nice as they claim? Does it take a lot more computer power to decode?
Quote:
The High Efficiency AAC Profile (HE AAC) is a combination of the MPEG-4 AAC Low Complexity (LC) Object and the MPEG-4 Spectral Band Replication (SBR) Object; HE AAC can deliver coding gains of more than 40 percent compared to MPEG-4 AAC LC.
HE AAC enables the delivery of 5.1 surround sound at 128 kbps, consumer-grade stereo at 48 kbps, and excellent quality stereo at 32 kbps or below. The coding efficiency of HE AAC enables new opportunities for optimized audio at low bit rates that are unprecedented, for applications in digital broadcasting, mobile multimedia, and Internet services.
HE AAC also enhances the quality of AAC by enabling 96 kHz coding with a nominal bit rate of 128 kbps. Moreover, 96 kHz HE AAC bitstreams can be played in legacy AAC decoders with a 48 kHz result.
The High Efficiency AAC Profile (HE AAC) is a combination of the MPEG-4 AAC Low Complexity (LC) Object and the MPEG-4 Spectral Band Replication (SBR) Object; HE AAC can deliver coding gains of more than 40 percent compared to MPEG-4 AAC LC.
HE AAC enables the delivery of 5.1 surround sound at 128 kbps, consumer-grade stereo at 48 kbps, and excellent quality stereo at 32 kbps or below. The coding efficiency of HE AAC enables new opportunities for optimized audio at low bit rates that are unprecedented, for applications in digital broadcasting, mobile multimedia, and Internet services.
HE AAC also enhances the quality of AAC by enabling 96 kHz coding with a nominal bit rate of 128 kbps. Moreover, 96 kHz HE AAC bitstreams can be played in legacy AAC decoders with a 48 kHz result.
http://www.vialicensing.com/products/HE_AAC/
This sounds pretty impressive. Imagine getting 5.1 sound at the same 128kbps rate that the iPod supplies stereo. We don't all have flying cars yet but I'll be happy with a 5.1 iPod.
Has anyone been testing any beta versions of this? Is it as nice as they claim? Does it take a lot more computer power to decode?
Comments
HE AAC would be great for streaming audio around the house wired or wirelessly.
HE-AAC isn't designed for something as simple as an iPod - it's for HD level production.
This is great of Apple to support this. If they do use this as the new codec for iTMS, what will they do with all the music they have encoded in the current version of AAC?
Mike
Doublely unfortunate this is. iTMS could conceivably rip straight from studio DAT to higher than CD fidelity HE AAC.
Wow I'm impressed. I could literally see a 1GB flash memory working now that aacPlus could sound acceptable at say 48kbps.
Originally posted by dfiler
Doublely unfortunate this is. iTMS could conceivably rip straight from studio DAT to higher than CD fidelity HE AAC.
not unfortunate for itms though. imagine if they could say that a downloaded album from itms is HIGHER fidelity than listening to a store-bought cd.
Originally posted by Kickaha
HE-AAC isn't designed for something as simple as an iPod - it's for HD level production.
Not really, it's for <128 kbps encodings (internet-streaming etc)
LC-AAC will continue to be the standard above 128 kbps
Originally posted by Sopphode
Not really, it's for <128 kbps encodings (internet-streaming etc)
LC-AAC will continue to be the standard above 128 kbps
By golly, you're right. I got HE-AAC and HD-AAC confused.
The 5.1 surround is a totally separate idea, which I believe is already present in Tiger builds of quicktime (unlike HE-AAC). The only reason it gets mentioned is that 3 times as many sound channels needs 3x the bits so you need something like HE-ACC for 5.1 at 128kbps (i.e. an average of ~20kbps per channel).
I dunno, I'd hate to wear six speakers on my head... 5.1 on an iPod?? Hee.
They have surround sound headphones. Haven't used them personally though so not sure how well they actually work.
Originally posted by neutrino23
This could be a part of the rumored Flash iPod. If HE-AAC could provide reasonable fidelity at roughly three times the compression level of 128kbps songs then a 1GB iPod is more in line with the philosophy of the iPod (carry all or most of your music with you). If you are running or performing other activities you don't really need ultra high fidelity.
Yes, and this could be the "catch" and the "reason" for Apple to do a lower capacity (NOTE: I think the storage technology is irrelevant to most consumers) iPod (iPod Micro?)
Apple has been very astute at making products different enough (iPod and iPod Mini and iPod Photo) that sometimes it is hard to decide which one you want...oh heck I'll just get them all! ;-)
iPod Micro (or whatever) might use this new encoding (probably converted on the fly)...to allow more music to be stored.