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  • Oki
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How far will AAC plus go?
Reply #25
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SBR and PS  algorithms were developed by Coding Technologies and your link points to a competitor. A competitor such as FhG will not give you good numbers on their technology (Remember that Coding Technologies was a spin off of FhG) since they do not have the latest developments on SBR implemented in their products.
LOL. They are not competitors, they have worked as partners since CT spun off! Guess who made the underlying MP3 and AAC encoders in MP3pro and HE AAC? If FhG really regarded CT as a fierce competitor, they would tell them to screw off and go find another encoder.[{POST_SNAPBACK}][/a]

CT used the FhG algorithms as the core codec because of an obvious reason: it was a well known code for CT engineers since they were very involved in the developement of those implementations when they were part of FhG.
CT has better relations with far more powerful companies like Philips and Matsushita. FhG and CT are competitors, I never said that they were fierce competitors, that sounds like if they were enemies!!!! They will always be partners because of licensing issues, but nothing more than that. You can see that they are not that close, we have an example of that in the response for the call for proposal on MPEG Surround. FhG and CT were not together, One joined with Agere and the other one with Philips.

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Simply their SBR know-how is not mature enough.
This is bullshit. Their SBR know-how is just as good as CT's. Why wouldn't CT want a partner as powerful and influential as FhG? Sure, FhG would make more profit in selling DSP implementations. But CT would have their IP licensing income guaranteed.[a href="index.php?act=findpost&pid=321733"][{POST_SNAPBACK}][/a]

As I said before, CT already has bigger partners like Philips but the situation is not related to partnerships. The scene is very simple, the LP-SBR technique developed by CT is too recent to be already assimilated by the rest of the partners of the MPEG like FhG, Ahead, etc, remember that it is even newer than aaPlus v2, not yet supported by any FhG embedded implementations. But it is a question of time, I am completely sure that FhG and many others will incorporate LP-SBR decoding in their hardware solutions in a near future, and MPEG Parametric Stereo as well.

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FhG is giving you the computational complexity of High Quality SBR, this makes HE-AAC 30% more complex than AAC-LC but Coding Technologies released a Low Power SBR algorithm with 30% less computational complexity. Subjective quality test results demostrated that there was no statistical difference between HQ-SBR and LP-SBR when they are incorporated into AAC decoders and CT implementations use CT's latest and more advanced method, being chosen as a standard by 3GPP. That leave AAC-LC and HE-AAC (using the new LP-SBR algorithm) at the same level of complexity.
Got proof of that? That is really hard to swallow based on most people's experience..[a href="index.php?act=findpost&pid=321733"][{POST_SNAPBACK}][/a]

It is not that hard, you just have to read the papers from the [a href="http://www.aes.org/events/116/papers/G.cfm]Audio Engineering Society[/url] or the information about embedded aacPlus v2 decoder implementations from Coding Technologies. Find the Subjective quality test results between HQ-SBR and LP-SBR here.

Regards,
Oki

Edit: fast typing error, Ateme replaced by Agere (thanks to Gabriel [a href="index.php?act=findpost&pid=321990"][{POST_SNAPBACK}][/a] and Ivan [a href="index.php?act=findpost&pid=321991"][{POST_SNAPBACK}][/a]).
  • Last Edit: 23 August, 2005, 08:33:05 AM by Oki

  • guruboolez
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How far will AAC plus go?
Reply #26
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[...]
I will use real values for estimating the power consumtion of AAC compared to OGG:
[...] the relative difference in power consumption is (Tmp3/Togg - 1) x 100 % = 45% But the power load of MP3 decoding is not that much, most of the power is taken by the hard drive.
[...]
this is 18 times more power for ogg than for MP3!!!!
[...]
This numbers make perfect sense (...)
Concluding, 
1st: Wogg ~= 18 x Waac;
2nd: Waac ~= Wmp3 in the newest implementations.
[a href="index.php?act=findpost&pid=321716"][{POST_SNAPBACK}][/a]

 
If this number really makes sense, flash memory players [no hard drive] would offer ~18x less battery life than MP3. This is insane! From what I read by some people, battery life dropped by ~30% (depending on the model) which could, of course, be really annoying.

  • Ivan Dimkovic
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How far will AAC plus go?
Reply #27
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As I said before, CT already has bigger partners like Philips but the situation is not related to partnerships. The scene is very simple, the LP-SBR technique developed by CT is too recent to be already assimilated by the rest of the partners of the MPEG like FhG, Ahead, etc, remember that it is even newer than aaPlus v2, not yet supported by any FhG embedded implementations. But it is a question of time, I am completely sure that FhG and many others will incorporate LP-SBR decoding in their hardware solutions in a near future, and MPEG Parametric Stereo as well.


Mind you that Ahead (today Nero) had LP-SBR implementation for quite some time - almost as long as the regular HP-SBR implementation, definitely more than one year 

If I remember correctly - but I might be wrong, LP-SBR patents are coming from another company?

HE-AAC v2 like we call it is also supported by Nero - we will release the encoder very soon - and people from HA were seeing it long time ago during the first beta tests.
  • Last Edit: 23 August, 2005, 04:48:00 AM by Ivan Dimkovic

  • Gabriel
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How far will AAC plus go?
Reply #28
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FhG and CT were not together, One joined with Ateme and the other one with Philips.

Sorry, not yet Ateme 

  • Ivan Dimkovic
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How far will AAC plus go?
Reply #29
I think the right word is Agere

  • Oki
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How far will AAC plus go?
Reply #30
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Mind you that Ahead (today Nero) had LP-SBR implementation for quite some time - almost as long as the regular HP-SBR implementation, definitely more than one year [{POST_SNAPBACK}][/a]
Hopefully we will see your embedded technology in portable devices in a near future, It will be a big step forward for Nero. 
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If I remember correctly - but I might be wrong, LP-SBR patents are coming from another company?[a href="index.php?act=findpost&pid=321980"][{POST_SNAPBACK}][/a]
You are almost right, LP-SBR was initially developed by Matsushita Electric Industrial (Panasonic) but implemented along with CT and NEC. Technology and intellectual property for low-power SBR was contributed by all three companies but Coding Technologies is the licensing agent for LP-SBR in HE-AAC according to CT, NEC and MEI joint [a href="http://www.nec.co.jp/press/en/0212/1202.html]press release.[/url]
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HE-AAC v2 like we call it is also supported by Nero - we will release the encoder very soon - and people from HA were seeing it long time ago during the first beta tests.[a href="index.php?act=findpost&pid=321980"][{POST_SNAPBACK}][/a]
Soon when? We all are waiting for your solution to be released.

Regards,
Oki

  • Ivan Dimkovic
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How far will AAC plus go?
Reply #31
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Mind you that Ahead (today Nero) had LP-SBR implementation for quite some time - almost as long as the regular HP-SBR implementation, definitely more than one year
Hopefully we will see your embedded technology in portable devices in a near future, It will be a big step forward for Nero.


Actually ShowTime Mobile will be a first Nero product where this technology is widely deployed. Should have a good impact on a battery life

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If I remember correctly - but I might be wrong, LP-SBR patents are coming from another company?[{POST_SNAPBACK}][/a]
You are almost right, LP-SBR was initially developed by Matsushita Electric Industrial (Panasonic) but implemented along with CT and NEC. Technology and intellectual property for low-power SBR was contributed by all three companies but Coding Technologies is the licensing agent for LP-SBR in HE-AAC according to CT, NEC and MEI joint [a href="http://www.nec.co.jp/press/en/0212/1202.html]press release.[/url]

Thanks, now it is much more clear.

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HE-AAC v2 like we call it is also supported by Nero - we will release the encoder very soon - and people from HA were seeing it long time ago during the first beta tests.[a href="index.php?act=findpost&pid=321980"][{POST_SNAPBACK}][/a]
Soon when? We all are waiting for your solution to be released.

I cannot promise the exact date, but after the quite some time, the things are being finalized - The new encoder is under heavy internal tests now, and being optimized for performance - it will bring improvements, as far as the very low bit rate goes, and also it will have Parametric Stereo.
  • Last Edit: 23 August, 2005, 05:41:20 AM by Ivan Dimkovic

  • Oki
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How far will AAC plus go?
Reply #32
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If this number really makes sense, flash memory players [no hard drive] would offer ~18x less battery life than MP3. This is insane! From what I read by some people, battery life dropped by ~30% (depending on the model) which could, of course, be really annoying.
[a href="index.php?act=findpost&pid=321964"][{POST_SNAPBACK}][/a]

Portable Audio devices with hard drives use a cache for storing the music when playing, so the HD is not working 100% of the time, only a little fraction of the time when filling the memory with the HD data, so similar conclusions could be achieved for flash memory players.

The impact in battery life when moving from MP3 to OGG is not 18 times because there are other modules that load the battery. A typical power amplifier in a portable device takes around 0.6W from the battery and the display driver and panel is taking similar values and you always need a memory driver/bus. Some manufacturers are removing displays but you could never remove the basic modules. This fixed power consumption makes negligible the difference in battery life between MP3 and AAC decoding in the iPod Shuffle.

Basically, bigger fixed consumption means a lot less difference in battery life impact between different decoding algorithms.

Regards,
Oki
  • Last Edit: 23 August, 2005, 08:40:50 AM by Oki

  • Althalus
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How far will AAC plus go?
Reply #33
Thank you Oki for your contribution in this thread.
It has been very informational.

  • Oki
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How far will AAC plus go?
Reply #34
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Thank you Oki for your contribution in this thread.
It has been very informational.
[a href="index.php?act=findpost&pid=321998"][{POST_SNAPBACK}][/a]
You are welcome.

  • Oki
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How far will AAC plus go?
Reply #35
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That's the satellilte broadcast, not the internet stream.  Why don't you pay attention to what I am talking about before trying to correct me?[{POST_SNAPBACK}][/a]
I am  sorry. XM Satellite Radio is broadcasting in [a href="http://www.xmradio.com/corporate_info/fast_facts_sound.html]HE-AAC[/url] and XM Radio Online is streaming in WMA v2.

  • Cartoon
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How far will AAC plus go?
Reply #36
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The ADSP is a cisc processor - (ARM is risc?), and is able to handle 3 operations per instruction cycle (a multiply, add and move for example)


Performing more than one instruction per cycle is called superscalar, not CISC. CISC CPU's can generally take more than one cycle to finish an instruction (but the instruction can be a complex one), RISC CPU's contains fewer, simpler instructions and will always only use one cycle per instruction.

Both the RISC and CISC terms are irrelevant in modern CPU's, as the instruction set is not the real machinecode anymore.

Anyway, comparing MIPS and Megaherz is dangerous 

  • dand
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How far will AAC plus go?
Reply #37
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Do not worry, HE AAC will be the MP3 format of the future. When? soon, very soon.

This is misleading.

HE AAC targets different audience than MP3. It will never replace MP3 at the segment where vast majority of people use MP3 - for transparent or near transparent encoding. HE isn't designed to achieve transparency, but to improve quality at low bitrates. These two codecs don't play in the same league.

Same holds for HE AAC vs. normal AAC.

  • Oki
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How far will AAC plus go?
Reply #38
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Do not worry, HE AAC will be the MP3 format of the future. When? soon, very soon.
This is misleading.

HE AAC targets different audience than MP3. It will never replace MP3 at the segment where vast majority of people use MP3 - for transparent or near transparent encoding. HE isn't designed to achieve transparency, but to improve quality at low bitrates. These two codecs don't play in the same league.

Same holds for HE AAC vs. normal AAC.[a href="index.php?act=findpost&pid=322754"][{POST_SNAPBACK}][/a]
I remember the quality and speed of the very first MP3 reference encoder, it took me 4 minutes to compress 40 seconds. MP3 technology has improved a lot in speed and quality and I am sure that AAC and the rest of the related technologies such as SBR, PS and SAC will evolve as MP3 did once.

If you extrapolate the recent improvements in quality of the HE-AAC encoders and taking into account that MP3 improved a lot, I am sure that HE-AAC @ 64kbps will have the same quality than MP3 @ 128kbps, the most used bitrate in MP3. It is true that MP3 is now used in a wide range of bitrates, mostly from 96 to 192kbps, but HE-AAC v2 (including HE-AAC for medium btrates) and AAC-LC cover the whole range and even more, since it supports multichannel audio, low bitrates, error resilence, etc...

Anyway, you are completely right when pointing that HE-AAC can never be considered transparent, even with high bit rates. But there are a lot of people over there considering that 96Kbps MP3 or 80Kbps WMA is more than enough. Those will always have 48kbps HE-AAC.

And do not forget streaming...

Regards,
Oki

  • dnewhous
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How far will AAC plus go?
Reply #39
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If you extrapolate the recent improvements in quality of the HE-AAC encoders and taking into account that MP3 improved a lot, I am sure that HE-AAC @ 64kbps will have the same quality than MP3 @ 128kbps, the most used bitrate in MP3.
Regards,
Oki
[a href="index.php?act=findpost&pid=322775"][{POST_SNAPBACK}][/a]


It already does.  For internet radio, 64 kbps HE-AAC is much better than 128 kbps WMA.

  • Digisurfer
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How far will AAC plus go?
Reply #40
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If you extrapolate the recent improvements in quality of the HE-AAC encoders and taking into account that MP3 improved a lot, I am sure that HE-AAC @ 64kbps will have the same quality than MP3 @ 128kbps, the most used bitrate in MP3.
Regards,
Oki
[a href="index.php?act=findpost&pid=322775"][{POST_SNAPBACK}][/a]


It already does.  For internet radio, 64 kbps HE-AAC is much better than 128 kbps WMA.
[a href="index.php?act=findpost&pid=323115"][{POST_SNAPBACK}][/a]

Oki said MP3 though, not WMA, and  there is a fairly big difference between the two in my humble opinion. Honestly, WMA isn't all that hard to beat no matter the bitrate. I agree with Oki though. With enough time, 64k HE-AAC will probably be as good as 128k MP3. I'm really looking forward to testing Nero's HE-ACC+PS encoder when it arrives, and I'm especially looking forward to radio stations moving away from MP3Pro, especially for orchestral stuff.

  • FrzzMan
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How far will AAC plus go?
Reply #41
Thank you Oki, this is one of the most valuable thread of HA I've ever read. Thank you very much...

But, about the future of AAC, I doubt it will replace MP3 any day, at least it's not as soon as you think

AAC will play great part in mobile devices, streaming... but in other sectors, where low bit-rate is not critical, AAC maybe won't have its future brighter, hopefully some lossless codec will...

  • Oki
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How far will AAC plus go?
Reply #42
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Thank you Oki, this is one of the most valuable thread of HA I've ever read. Thank you very much...

But, about the future of AAC, I doubt it will replace MP3 any day, at least it's not as soon as you think

AAC will play great part in mobile devices, streaming... but in other sectors, where low bit-rate is not critical, AAC maybe won't have its future brighter, hopefully some lossless codec will...[a href="index.php?act=findpost&pid=323362"][{POST_SNAPBACK}][/a]
Thank you FrzzMan, but IMHO I am far from being a guru, just an average signal processing lover.

In a furure where AAC (and family) and 5.1ch will be the standard in DVB, DAV, DVD2 (HD-DVD or Blu-ray) and 3G telephones; In a world where all the consumer devices support this encoding, who is going to use the "old" MP3 format with their inherent disadvantages when you have more quality for the same file size? MP3 will be supported just for backward compatibility.

For HQ audio you can always use AAC with a high bitrate and for lossless compression you will have MPEG ALS and SLS, the MPEG standards in lossless audio. Remember that all of them share the same container: MP4 for even more compatibility.

Regards,
Oki
  • Last Edit: 29 August, 2005, 03:54:08 AM by Oki

How far will AAC plus go?
Reply #43
Winamp 5.1 supports aac+ (HE-AAC) It was "leaked" (if you can call it that as people were downloading it from winamps site.)  There are a number or online radio stations streaming using this method, so the support is growing.

Anyway...

  • ckjnigel
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How far will AAC plus go?
Reply #44
Winamp 5.1 beta 3 (recalled -- unauthorized on filehippo.com )
provides AACPlus Encoder v. 1.1 from Coding Technologies.  Options are for AAC+ versions 1 and 2 at rates from 8 to 128 kbps and 32,000 and 44,100 hz.
  • Last Edit: 31 August, 2005, 03:47:08 AM by ckjnigel

  • ckjnigel
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How far will AAC plus go?
Reply #45
I just ripped directly to AAC+ my first files using the new Winamp. I was surprised that Winamp gives them the AAC suffix, but I prefer that to MP4 which may be mistaken for video. They played fine with XMPlay on PC and BetaPlayer on Pocket PC.
It's hella faster and easier than EAC to FLAC, retaining WAV, then using Magix MP3 Maker 10 Deluxe to convert from WAV -- that program recognizes no lossless.  But, EAC gets tag information from freedb rather than Gracenote, so that provides opportunities for two sources of inaccurate, idiotically arranged ID3 information which can then be time-consumingly revised.
It would be mighty nice if somebody figured how to direct EAC to use the Coding Technologies encoder in Winamp 5.1 .

  • d-b
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How far will AAC plus go?
Reply #46
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This a basic abstract about the AAC family:

AAC = MPEG2 AAC ~= MP3 + TNS + TP (It is not an upgrade of MP3 since it is not backward compatible but uses all MP3's features in a better way).

MPEG4 AAC = MPEG2 AAC + LTP + PNS
There are several profliles depending on the decoding/encoding complexity, required power, delay, error resilience characteristics, etc... The most used one in the PC arena is the AAC LC (Low Complexity) = MPEG4 AAC without LTP.

HE-AAC = SBR + AAC LC
Coding Technologies, developers of SBR, named this coding aacPlus™, also known as AAC+, HE-AAC, AACP, AAC-LC+SBR, etc...

HE-AAC v2= PS + HE-AAC
Coding Technologies, developers of the MPEG Parametric Stereo, named this coding aacPlus™ v2 as a new revision of the previous release. It is also known as AAC++, EAAC+, Enhanced HE-AAC, EAACP, HE-AAC+PS, etc... Recently it was standarized by ISO as HE-AAC v2.

S-AAC...(Just guessing, not yet released)
Since MPEG is focusing in multichannel, the next standard will be something based in the Spatial Audio Coding tool standarized as MPEG Surround, that allows to do someting similar to PS but aimed to 5.1ch or 7.1ch content. This could be named as S-AAC, AAC Surround or AACS, Surround HE-AAC, [Put your favorite name here]. There isn't an official name for it yet.



That was a lot of information about AAC - but I am still not sure what to use if I want to compress music with a quality similar to lame -alt-preset standard ?

I understand that you can't give an exact answer but an approximation would be great.

Is HE-AAC optimized for low bitrates?

Another question, are any of all these formats incompatible with iTunes/iPods? Or do they lose quality when used with iTunes/iPods (possible they might have some non-standard »magic addition»), that is, they play but it does not sound as good as it could?

  • Oki
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How far will AAC plus go?
Reply #47
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That was a lot of information about AAC - but I am still not sure what to use if I want to compress music with a quality similar to lame -alt-preset standard ?

I understand that you can't give an exact answer but an approximation would be great.[{POST_SNAPBACK}][/a]

An equivalent quality can be achieved with a good [a href="http://www.hydrogenaudio.org/forums/index.php?showtopic=36870&view=findpost&p=325555]HE-AAC encoder[/url] (Winamp's pluging from Coding Technologies or Helix are the best so far). HE-AAC v2 is good too if you are listening to the music in a noisy environment or at low level. Guruboolez has done several tests with different encoders here. If you need more quality, iTunes AAC-LC encoder is a valid option but at a lot more bitrate than HE-AAC.

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Is HE-AAC optimized for low bitrates?[a href="index.php?act=findpost&pid=325696"][{POST_SNAPBACK}][/a]
It depends on what are you considering low bitrates. The "sweet-point" (you can consider that the point where quality/bitrate is maximum) of HE-AAC is achieved at a lower bitrate than AAC-LC and at a higher bitrate than HE-AAC v2. It all depends on your needs and requirements.

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Another question, are any of all these formats incompatible with iTunes/iPods? Or do they lose quality when used with iTunes/iPods (possible they might have some non-standard »magic addition»), that is, they play but it does not sound as good as it could?[a href="index.php?act=findpost&pid=325696"][{POST_SNAPBACK}][/a]
iPod can play only AAC-LC. HE-AAC v1 and v2 are not yet supported but they will be supported very soon. Maybe you can play an HE-AAC encoded file but it will sound VERY bad since it is not decoding the SBR spectrum or the parametric stereo.

Regards,
Oki

  • Gabriel
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How far will AAC plus go?
Reply #48
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An equivalent quality can be achieved with a good HE-AAC encoder (Winamp's pluging from Coding Technologies or Helix are the best so far)

He asked about similar quality to lame --preset standard.
I think that current HE-AAC do not reach this quality. In this case AAC-LC should be used instead.

  • d-b
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How far will AAC plus go?
Reply #49
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Do not worry, HE AAC will be the MP3 format of the future. When? soon, very soon. One of the most important reasons is that most cell phones will have a lot of memory or flash card support and they will be able to play AAC+ and even AAC++ audio thus taking most of the market share of the current portable audio solutions.
[a href="index.php?act=findpost&pid=320831"][{POST_SNAPBACK}][/a]



But is HE-AAC really a hifi-format like mp3 at higher bit rates can be? If it's optimized for streaming I guess avoiding stuttering is prioritized to transparency, isn't it?