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Topic: Snow Leopard AAC improvements.. (Read 73723 times) previous topic - next topic
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Snow Leopard AAC improvements..

OS X 10.6 "Snow Leopard" is out today and sports some changes to the AAC encoder. From what I've seen so far, the 'true' VBR mode settings give different bitrates than the previous version, where q127 files now end up being >320kbps most of the time. It seems ~q90 is the equivalent to the old q127. I'm not sure if there are any major quality improvements to the encoder though.

HE-AAC support is now included too, but not yet in iTunes.. Hopefully it's set to be included in the next version of iTunes, which according to rumors will be released in a couple of weeks. That's probably when Windows users will get the new encoder too.

It'd be fun to see some listening tests on both the new HE encoder and also the regular one to see how it compares to QT 7.6.2..

Snow Leopard AAC improvements..

Reply #1 –
interesting,can't wait to try it out!

Snow Leopard AAC improvements..

Reply #2 –
Does the iPod App from the iPhone support HE-AAC?

Snow Leopard AAC improvements..

Reply #3 –
The new XLD version that just came out supports it already!

I have played around with it a little bit and made some interesting observations:

The new Quicktime includes the first AAC encoder that masters the infamous Emese sample transparently! For my ears at least. Nero was never able to handle it even at the highest bit rates and also LAME and Vorbis have always failed badly. This only works at the highest setting of Q127; at Q122 with only slightly less bit rate I can ABX it instantly, which is kind of strange. ABR 320 is also transparent.

Snow Leopard AAC improvements..

Reply #4 –
I hope that Apple finally opens up true VBR AAC encoding to iTunes.  I would have tested out their true VBR AAC encoder more if it wasn't such a pain to encode on Windows.  I am interested to see how it stacks up against Nero AAC as I have always been forced to use their VBR_constrained setting.  I wouldn't hold my breath for HE-AAC support in iTunes or on iPods though.  Apple seems intent on allowing users to access high bitrates.  After all, the iTunes Plus encoding standard (256kbps, VBR_constrained, "high quality" setting) is now the default ripping/encoding setting in iTunes.  HE-AAC support would benefit iPod shuffle and iPod nano users as their players have limited capacities (I consider 16GB and less to be limited especially whenever there are 120GB players floating around for only $40-$50 more).  We will see what Apple does once their September iPod event rolls around.  The current rumor is that it will happen on the 9th of September but Apple hasn't confirmed anything and likely won't until next week.

Snow Leopard AAC improvements..

Reply #5 –
The new Q127 might be a good candidate for my collection. Still I would consider a >300kbps average a huge waste and would not want that. So I checked if there's at least some degree of economical sanity left in this mode and fed it an old shellac recording, that used to average at ~101kbps with the old Q127. It comes out at ~155kbps now, which is a waste since the 101kbps was already perfectly transparent, but at least demonstrates that the new Q127 mode does not stubbornly push >300kbps bit rates. I'll post some new collection averages later.

Snow Leopard AAC improvements..

Reply #6 –
Quote from: rpp3po on
The new Quicktime includes the first AAC encoder that masters the infamous Emese sample transparently! For my ears at least. Nero was never able to handle it even at the highest bit rates and also LAME and Vorbis have always failed badly.

Last time I tried Vorbis Aotuv at 192 kbits it did better job than any other encoder for emese sample.

Snow Leopard AAC improvements..

Reply #7 –
Quote from: kornchild2002 on
HE-AAC support would benefit iPod shuffle and iPod nano users as their players have limited capacities (I consider 16GB and less to be limited especially whenever there are 120GB players floating around for only $40-$50 more).

I wouldn't use HE-AAC even if I'd have only 1GB DAP.  The quality drop is too big.
At least LC-AAC 96 kbit/s with true VBR+best settings.
I don't think people would sacrifice quality that much. I've already done some test around new HE-AAC encoder. For my ears it's better than Nero at 64 kbit/s.

Apple claims that new HE-AAC encoder at 64kbit/s is comparable with LC-AAC 96kbit/s.
Of course, it's not true.

Snow Leopard AAC improvements..

Reply #8 –
Quote from: IgorC on
Last time I tried Vorbis Aotuv at 192 kbits it did better job than any other encoder for emese sample.


Better or transparent? With "failed badly" I meant the inability to reach transparency at any bit rate. I have never actually tried the Aotuv flavor, though.

Snow Leopard AAC improvements..

Reply #9 –
Quote from: IgorC on
I don't think people would sacrifice quality that much. I've already done some test around new HE-AAC encoder. For my ears it's better than Nero at 64 kbit/s.


From my 6+ years on a different set of iPod related forums, people don't care.  Most people open iTunes, plop in a CD, rip it, and copy the tracks to their iPod.  They also use the supplied earbuds with their iPod.  They don't care about adjusting the bitrate, which audio format to use, etc.  These are the types of people that probably can't discern a difference between a 64kbps HE-AAC file and the source lossless material.  After all, 128kbps (iTunes AAC, Nero AAC, Lame mp3) is transparent to them.  Couple that with the supplied iPod earbuds and noisy environments, that makes 64kbps HE-AAC actually sound pretty tempting.  Most people want to fit more songs on their iPods over sacrificing space with higher quality.  The forums contained a bunch of posts complaining about how their newly ripped songs won't fit on their iPod.  In other words, after Apple made 256kbps VBR the new ripping standard setting in iTunes, people were complaining that their iPods ran out of space much faster than before (when 128kbps "CBR" was the standard).  Either that or people will just crank the setting up to 320kbps and move on.  There really are only a handful of people that take the time to conduct blind ABX tests and mess around with the iTunes CD import/encoding settings (aside from going all the way up to 320kbps).

That is why I feel that a good chunk of people may benefit from HE-AAC.  They will be able to encode down to 64kbps and fit more on their iPod nano (the most successful of the iPod line).  Now, whether or not these people take the time to educate themselves is a different matter.  I am a little disappointed to see Apple playing the numbers game.  Microsoft did that back when they updated WMA (way back during the Windows ME/2000 days) and said that a 64kbps WMA file was equal to a 128kbps mp3 file.

Snow Leopard AAC improvements..

Reply #10 –
I'm expecting my copy of SL to arrive sometime later this afternoon, so I'm looking forward to getting to test out these new improvements (or at least, the higher quality settings available now)... until then, where would be the best place to find a quality vs. average bitrate breakdown for this latest Quicktime version?  I was used to -q 120 yielding files with an average bitrate of ~160kbps before, so I'm curious what setting I'd need to use now to get an equivalent average bitrate.

(will post my results later today after I've had a chance to test out the new encoder for a bit... can't wait, I already noticed the addition of HE-AAC to XLD's options with the latest update, so this should be interesting  )
Archive- FLAC (-v 8)
Portable- QuickTime AAC (True VBR/-q 77)

Snow Leopard AAC improvements..

Reply #11 –
OT: What does the OS have to do with the capabilities or the version of an encoder?

Snow Leopard AAC improvements..

Reply #12 –
For "Snow Leopard", read "QuickTime X"; I don't think the latter's available separately yet.

Snow Leopard AAC improvements..

Reply #13 –
My whole collection (Jazz, Classical, Rock, Electronic) average with the new Q127 setting turned out to be 302 kbps. That's way too high for my taste. I won't use it as default.

It's nice to see Quicktime being capable of handling Emese. Still 99% of my collection were perfectly transparent with the old Q127 setting at ~190kbps average. Substantially increasing the bit rate for 99% of my collection just to make 1% transparent eventually doesn't make sense to me.

Maybe they succeed at making the encoder smarter in the future. I think transparency could be maintainable at <=200kbps averages when the encoder is smart enough to scale up high enough, when needed, for samples as Emese.

PS: I think Quicktime X is just the new Player. The new tracks say they were encoded with Quicktime 7.6.3.

Snow Leopard AAC improvements..

Reply #14 –
Quote from: rpp3po on
Better or transparent? With "failed badly" I meant the inability to reach transparency at any bit rate. I have never actually tried the Aotuv flavor, though.

Transparency level  is unique for each person. In my case  Aotuv was transparent on 192 kbit/s for emese sample while rest of encoders weren't.

Snow Leopard AAC improvements..

Reply #15 –
Quote from: Fandango on
OT: What does the OS have to do with the capabilities or the version of an encoder?


As per one of the Apple devs:

Quote from: skuo on
Hmm, maybe I can clarify something.

First of all, Apple AAC codec along with other audio codecs are shipped as a component in Mac OS X, i.e., /System/Library/Components/AudioCodecs.component. Hence, its updates or releases are always tied up with those of Mac OS X. QuickTime and iTunes are just applications using the same AAC codec in Mac OS X. Their updates don't have a direct relationship with AAC codecs'. With the help of the SDK shipped with Mac OS X, everyone can develop his/her own applications using APIs to access Apple AAC codec, just like QuickTime or iTunes does. People can also use the command line tool, afconvert (built from /Developer/Examples/CoreAudio/Services/AudioFileTools/AudioFileTools.xcodeproj) to freely access the AudioCodecs (including AAC of course) to encode their favorite tracks.

Snow Leopard AAC improvements..

Reply #16 –
Quote from: kornchild2002 on
From my 6+ years on a different set of iPod related forums, people don't care.  Most people open iTunes, plop in a CD, rip it, and copy the tracks to their iPod.  They also use the supplied earbuds with their iPod.  They don't care about adjusting the bitrate, which audio format to use, etc.  These are the types of people that probably can't discern a difference between a 64kbps HE-AAC file and the source lossless material.  After all, 128kbps (iTunes AAC, Nero AAC, Lame mp3) is transparent to them.  Couple that with the supplied iPod earbuds and noisy environments, that makes 64kbps HE-AAC actually sound pretty tempting.  Most people want to fit more songs on their iPods over sacrificing space with higher quality.  The forums contained a bunch of posts complaining about how their newly ripped songs won't fit on their iPod.  In other words, after Apple made 256kbps VBR the new ripping standard setting in iTunes, people were complaining that their iPods ran out of space much faster than before (when 128kbps "CBR" was the standard).  Either that or people will just crank the setting up to 320kbps and move on.  There really are only a handful of people that take the time to conduct blind ABX tests and mess around with the iTunes CD import/encoding settings (aside from going all the way up to 320kbps).

That is why I feel that a good chunk of people may benefit from HE-AAC.  They will be able to encode down to 64kbps and fit more on their iPod nano (the most successful of the iPod line).

But those clueless/careless average Joes would have to update their firmware to enable HE-AAC support. You understand that's impossible for that kind of people, don't you?

Second reason why people wouldn't use HE-AAC for iPods is that there is only ~5% people using LC-AAC at low bitrate (=<80-90 kbit/s).  Rest of people who use LC-AAC >90 kbit/s won't jump to 64-80 kbit/s. http://www.hydrogenaudio.org/forums/index....showtopic=72265 . If you analyze some numbers around bitrates over internet  more than 95% didn't go lower than 128 kbit/s.

HE-AAC is a big NO-GO for music content on DAP. Its application is for low bandwidth.

Snow Leopard AAC improvements..

Reply #17 –
I'm also wondering what Apple's plans for HE-AAC could be. They usually don't bring out stuff like this just for the cause of it.

Steve Job's next big "one more thing", after he has demonstrated the new "iPad" device, could be something like free 64/96 kbps HE-AAC streaming of the whole iTunes catalog with each one of those. With the usual upgrade option to iTunes Plus quality for $.99 each.

It would be the next logical step. Low quality music is available freely on the internet (legally & illegally), so why not make it also free on iTunes (or a low cost flat-rate) and use it as a comfortable sales channel for high quality tracks including HQ tags & digital artwork?

Snow Leopard AAC improvements..

Reply #18 –
Quote from: rpp3po on
I'm also wondering what Apple's plans for HE-AAC could be. They usually don't bring out stuff like this just for the cause of it.

I can't find now link to news but I read that Apple adopt HE-AAC for radio streams, RSS and maybe postcards.

Quote from: rpp3po on
Steve Job's next big "one more thing", after he has demonstrated the new "iPad" device, could be something like free 64/96 kbps HE-AAC streaming of the whole iTunes catalog with each one of those. With the usual upgrade option to iTunes Plus quality for $.99 each.

Apple HE-AAC is only up to 80 kbit/s. Not 96 kbit/s. Averagely at 96 kbit/s HE-AAC isn't better than LC-AAC.

Snow Leopard AAC improvements..

Reply #19 –
Quote from: rpp3po on
I'm also wondering what Apple's plans for HE-AAC could be. They usually don't bring out stuff like this just for the cause of it.

How about finally offering the option to use iTunes to listen to all those internet radio stations streaming in HE-AAC? It is quite annoying having to launch a separate application just to listen to some stations.
Every night with my star friends / We eat caviar and drink champagne
Sniffing in the VIP area / We talk about Frank Sinatra
Do you know Frank Sinatra? / He's dead

Snow Leopard AAC improvements..

Reply #20 –
I don't know any, are there many?

Snow Leopard AAC improvements..

Reply #21 –
Quote from: rpp3po on
I don't know any, are there many?

What do you mean, internet radio stations using HE-AAC? If I had to guess I'd say thousands. Tuner2 is a good start if you want to find them.

One of my favourites is Soma.FM's Secret Agent. I have to start up RealPlayer to listen to it  with this link. I would much prefer if I could just use iTunes for it, just as I can for stations that still use MP3 streams (which are often too low-bandwidth for MP3 to sound half-decent). Internet radio stations have a good reason to use as little bandwidth as possible per individual stream which means HE-AAC is a welcome alternative to MP3. Good quality at a considerably lower bitrate.
Every night with my star friends / We eat caviar and drink champagne
Sniffing in the VIP area / We talk about Frank Sinatra
Do you know Frank Sinatra? / He's dead

Snow Leopard AAC improvements..

Reply #22 –
I know Soma, but they also serve good quality 128kbps MP3. I wouldn't want to trade that for synthesized low bit rate HE-AAC. Are there really many stations you could not receive without HE-AAC support in iTunes?

Snow Leopard AAC improvements..

Reply #23 –
Quote from: rpp3po on
The new Quicktime includes the first AAC encoder that masters the infamous Emese sample transparently!


Kind of off topic, but the original topic is from 2007 and I'd hate to bump it. Where can I find this infamous "Emese" sample?