Granted no portables can decode it right now, but is there a sound quality disadvantage to encoding 64kpbs files using HE rather than LC?

I'm asking cause at one point it was said that low-bit mp3PRO files (also using SBR) sounded worse when played back without SBR decoding than regular MP3s.

Does the same hold for HE-AAC (AACplus)?

If not, I'm going to build my library in HE anticipating the day that iPod supports it.

Thanks.

HE AAC is great for streaming (when many apps start supporting it) and playback at low bitrates. The sound quality can't be beat for that. But for archiving your audios or making an audio library, I don't recommend using it for that. Also you need an SBR (HE AAC) compatible player and so does the recipient of your stream/files or else they will only heard the "lower portion" of the audio (non-SBR part).

If you have Nero 6, you will see that HE AAC is only used at 80kbps or below bitrates. For standard stereo 44.1kHz files, the "rule of thumb" is to use HE AAC for 80k or less and use AAC LC for 96kBps of above bitrates. I had to learn this the hard way.

AAC LC will always be better quality for audiophiles and those desiring higher quality audio. HE AAC is more for portable players, streaming or where size/bitrate is a key factor.

2. Still no hardware support for HE
2. It is not free

True there is no hardware support for HE AAC, but the AAC LC and HE AAC files themselves require no royalties for distributing, streaming or using them.

Both AAC LC and HE AAC require patent royalties to be paid to Via Licensing. See the thread about this at:
http://www.hydrogenaudio.org/forums/index....howtopic=18380&

But the rates for HE AAC over plain AAC LC are not that much higher for software developers wanting to include HE AAC support. In fact HE AAC patent licensing rates are cheaper than MP3 patent licensing rates! Plus no need to pay streaming or other fees for AAC/HE AAC like you have to pay for using MP3 files.

Here is more about HE AAC from the ViaLicensing.com web site:

High Efficiency AAC (HE AAC) is the combination of MPEG-4 AAC and MPEG Spectral Band Replication (SBR) technology, resulting in coding gains of more than 40 percent compared to standard MPEG-4 AAC.

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.

HE AAC achieves its performance by regenerating, rather than coding, high frequency signal components. The high quality of the regeneration process is achieved through the use of modern transposition technology, steered by a small amount of control data. The control data is transmitted in the AAC bitstream, along with the standard AAC data for the low frequency part of the signal.

One would assume playing back an HE-AAC file on a non-HE-AAC compatible player would result in worser quality since the audio is encoded at half the sampling rate (22 kHz for 44 kHz audio) and that is what you will be playing. It is perhaps less of a problem for AAC than it is for mp3pro, since we can all agree that an mp3 at 22 kHz and a bitrate of around 64 kbps tends to sound rather inferior.

I can't wait til Nero comes out with the new HE-AAC, adding there new stereo type algo in the mix. Will be pretty cool to see how low you can go and still have a decent sounding file.

I know alot of you folks on this board are more interested in slighly higher bitrates with lossless quality. The thing we all have in common is trying to get the lowest file size possible to achieve what our goals are though.


I haven't ever listened to HE-AAC with headphones or it might change how I feel about it, but if I only listen to it without critiquing it against the original sample; then I'm happy with what it produces. I'm not looking for lossless, I'm just looking for good sound that is non-metalic/non-robotic sounding of course at the lowest filesize possible.

One other thing, the lack of portable support is really irking me. Right now I have alot of tunes in MP3Pro format, which isn't bad for what I want it for(RCA has a couple of players that support it).

A note to the original poster. The main thing that seems to be unfavorable right now about HE-AAC is that it is still in it's infancy. If you take a look at a few of the more recent posts from the devs of Nero you will see that they feel there is much improvement to still be made in HE-AAC. As the guys above me said I wouldn't use it for Archiving for quality purposes, only for what it can give you at it's size(best bang for smallest amount of space).

Well, the HE technology was standardized less than an year ago. It'll take some time until it becomes popular and player manufacturers become interested in adding support.

Not long ago I was checking up on some of the Philips portable players. If you look at some of the older details on some of them you will see that they supported AAC, of course they want support HE-AAC(I'm sure you already know all this). Anyway, me and one of the folks ended up writing each other back and forth a few times(supprisingly seemed like a pretty knowledgable person too). It came down to them telling me that they didn't know if they would support AAC in it's upgradable players.

If any of these companies would just comit to saying they will support AAC and some of it's variants in the future I would buy a portable player from them. It just doesn't seem like it is that hard to implement these codecs into their players. Like I said in another post I posted here awhile back, I do not care if I have to pay for the upgraded codecs; please just offer them.

Why do you think these hardware manufactures are slacking so bad? Is it laziness or is it all part of some sort of cycle to get the most money out of folks(meaing holding technology back so folks will have to upgrade to other hardware for more profit)?

I never thought I'd actually be defending (sort of) corporations, but I'm less inclined to think that the lackluster introduction of AAC into the portable hardware scene is entirely attributable to greedy companies.

I'm not much of an expert around here (not much? Who am I kidding, I'm as green as they come...) but honestly, most consumers are not fickle. When they buy something, they want to be secure in their investment, and to be sure it will last them for a long time. Now that the mp3 format is widespread, it's going to be a while before the industry can shift to a higher quality codec.

Remember how long it took for mp3 to become widespread? I came across my first mp3 back in 1997, and two years later, I overheard a conversation that went something like, "Hey! Have you heard about this new thing called mp3?"

My point is, at this point in time, companies know consumers are not going to instantly respond to a new audio format if they introduce it because the consumers still think mp3 is in its hey-day. That of course means lower sales, and lost profits (and that's where the greed comes in). So, I think it's a two-fold problem. Unless we see a calculated intiative to educate the public as to why it's important not to get too comfortable with mp3, I think AAC is going to have trouble breaking into the industry (significantly, that is).

I am big supporter of AAC, so I hope this is all wrong.

As for players supporting HE AAC - my Siemens DRM Music Player (flash - based) does (as well as mp3 and LC AAC).

Player is also sold in UK & Europe as "O2 DMP"

http://www.o2.co.uk/music?ref=hpmod2img

Ignore all the "download music through your phone" blurb