Hydrogenaudio Forums

Lossy Audio Compression => AAC => AAC - Tech => Topic started by: guruboolez on 2005-09-05 07:47:42

Title: HE-AAC v.1 & v.2 comparison
Post by: guruboolez on 2005-09-05 07:47:42
The very new Winamp “surround edition” (5.1) and its own encoding solution for low-bitrate is a good occasion to make a comparison between different HE-AAC encoders. Preliminary comments posted on this board were clearly enthusiastic, especially for aacPlus v.2 quality. I’d like to contribute to the evaluation of this new encoder and as usual to post a complete report of my personal listening test here.

From now I will be brief.



Samples:

I used 2 series of samples I already used in the past:
40 samples mixing “classical” (25 samples) and “various music” (15 samples) (serie used here (http://www.hydrogenaudio.org/forums/index.php?showtopic=35438) for all pools.
6 samples coming from DVD ripping (48000 Hz files transcoded from original AC3 files) (full serie already used here (http://www.hydrogenaudio.org/forums/index.php?showtopic=30547).

Encoders:

Coding Technologies “aacPlus v.2” : 48 kbps with SBR and Parametric Stereo
Coding Technologies “aacPlus v.2” : 64 kbps with SBR and “Stereo” (not parametric)
Helix “Producer” v. 11.0.0.1897 HE-AAC: 64 kbps with SBR
Nero Digital aacenc32 v.3.2.0.20 HE-AAC: 64 kbps with SBR

Software & Hardware setting:

Creative Audigy 2
ABC/HR for Java 0.5 alpha 5
faad 2.1 MPEG-4 AAC decoder

Important to note:

the test consists on pure ABCHR evaluation
offsets were removed and gain was always corrected (difference could reach 1.5 dB!)



[span style=\'font-size:14pt;line-height:100%\']OVERALL RESULTS[/span]

(http://audiotests.free.fr/tests/2005.09/AACHE/01/plots.png)

Code: [Select]
		WINAMP	WINAMP	HELIX	NERO
48 kbps 64 kbps 64 kbps 64 kbps

A02 3.3 3.5 3.5 2.5
E06 3.0 4.0 4.0 1.8
E15 3.0 5.0 4.8 4.3
E22 3.5 4.0 4.0 3.0
E26 2.7 3.0 3.0 2.0
E31 3.0 3.7 3.7 1.0
E40 3.0 3.5 3.5 2.5
E51 2.5 3.5 3.5 2.5
E53 1.5 2.5 2.5 1.8
S03 4.0 4.5 4.5 3.5
S08 2.5 3.5 3.5 1.5
S12 1.5 1.8 1.8 1.0
S17 3.0 2.5 2.5 1.0
S27 1.2 2.0 2.0 1.7
S38 3.0 3.5 3.5 1.5
S50 2.0 3.5 3.5 1.0
S54 2.5 3.0 3.0 2.0
V02 3.8 3.8 3.8 4.0
V07 3.9 3.7 3.7 3.0
V10 3.5 3.5 3.5 3.5
V15 2.0 3.0 3.0 2.0
V19 3.7 4.2 4.2 4.5
V20 3.0 3.5 3.5 1.0
V24 1.5 4.0 4.5 1.5
V27 3.5 2.0 2.0 1.0
---------------------------------------------
CLASSIC (MEAN) 2.80 3.39 3.40 2.20
---------------------------------------------

41_30sec 4.0 2.5 2.5 1.5
ATrain 3.0 3.5 3.5 1.5
DaFunk 3.5 4.2 4.0 1.5
death2 2.5 2.5 2.5 1.5
EnolaGay 2.3 3.0 3.0 1.0
experiencia 3.5 4.0 4.0 1.5
getiton 3.5 4.3 4.3 2.0
kraftwerk 2.0 1.8 2.5 1.0
LifeShatters 2.8 3.0 3.0 2.0
NewYorkCity 3.0 3.5 3.5 2.5
OrdinaryWorld 4.0 2.0 2.0 1.0
Quizas 3.5 4.0 4.0 1.5
rosemary 3.0 4.0 4.0 1.5
SinceAlways 4.0 2.5 2.5 1.0
trust 1.0 2.0 2.0 1.5
---------------------------------------------
VARIOUS (MEAN) 3.04 3.12 3.15 1.50
---------------------------------------------
Alien 4 3.5 4.0 4.0 1.5
Farinelli 4.5 4.8 4.8 2.0
Come Drink... 5.0 5.0 5.0 5.0
Ran 3.5 4.0 4.0 3.7
BlackAdder 3.0 3.2 3.2 1.0
Pulp Fiction 3.5 3.3 3.3 2.7
---------------------------------------------
DVD (MEAN) 3.83 4.05 4.05 2.65
---------------------------------------------

=============================================
46 SAMPLES 2.89 3.29 3.31 1.94
=============================================
ABCHR logs are available here (http://audiotests.free.fr/tests/2005.09/AACHE/01/AACHE_48_64_kbps.7z); I stopped to comment the notation after ~20 tests.



Helix & Winamp 64 kbps are highly similar. It might be possible to differentiate them with an ultra-careful listening, but my notation is only based on an attentive but fast evaluation. I suppose that Helix HE-AAC encoder is also coming from Coding Technologies. Apart quality, both have the same offset and a very similar gain (volume) deviation.

48 kbps HE-AAC with Parametric Stereo is inferior but not very far from 64 kbps HE-AAC with “regular” stereo coding (I guess it’s joint-stereo). It’s a very good performance I would say. At such low bitrate every bit is precious and by removing 16 kbps to a 64 kbps we could expect a huge drop in quality. But here, the quality stays close from the 64 kbps encodings (and is sometimes clearly better – see below).
I quickly noticed unusual issues with PS encodings. I can distinguish three different variants:
- weird and high-pitched noise
- stereo distortion: ping-pong effect (rare) and fake-stereo effect (reverberation, echo….)
- “equalizing issue” (unbalanced sound, often hollowed, lack of bass, flattened image, etc…), which is the most common problem I noticed.

Nero Digital AAC was the first publicly available HE-AAC encoder (released in summer 2003), but the latest version is now obviously outdated and not competitive anymore. On 46 samples this encoder finished last 36 times and first 2 times only! The quality is often really poor compared to all other contenders, including the 48 kbps encodings made with Coding Technologies/Winamp encoder.
Nero Digital usually suffers a lot from what I’m used to call “SBR artefacts”: a grainy sound, smeared impulse and also a lot of small but highly irritating noise packet/aggregation. I heard these issues for the first time with mp3PRO and found them again with the first (and only tested) HE-AAC (Nero Digital). Problems are audible even at the highest available bitrate: 96 kbps and also with forced 128 kbps. That’s why I always thought that all these issues were consubstantial to SBR technology. Now, by testing other HE-AAC implementation, I must completely change my mind. What I called “SBR defect” is rather a specific Nero Digital flaw. I don’t mean that Coding Technologies & Helix encoders are free of these problems: they’re all more or less perceptible (it really depends on the sample). In other words, there are still “SBR artefacts”. But both encoders have apparently a better control of the side effect of SBR. Pre-echo on strong impulse is also much stronger with Nero Digital (see Appendix) when compared to Helix/CT.
I’m now thinking to my 80 kbps listening test (http://www.hydrogenaudio.org/forums/index.php?showtopic=35438) I made on the beginning of the summer. I tested 185 samples with a HE-AAC implementation which appeared to be far from Vorbis aoTuV quality, and surprisingly similar to Apple LC-AAC and not that better than Lame MP3. I’m now pretty sure that Coding Technologies “aacPlus” would perform much better and could maybe compete with aoTuV at 80 kbps (for 64 & 48 kbps, I fear that it would be hard for aoTuV to stay competitive against the SBR beast)… I read somewhere that Nero 7 is announced for October. I guess that the new generation of Nero Digital HE-AAC will be released with the new Nero package and I’m sure that Ivan had built a competitive encoder.

 


[span style=\'font-size:14pt;line-height:100%\']DETAILED RESULTS[/span]


(http://audiotests.free.fr/tests/2005.09/AACHE/01/plotsx3.png)

classical group : parametric stereo doesn’t work very well with several samples tested here. The 64 kbps are clearly more enjoying (but are of course bigger). Nero Digital didn’t perform very well, but at least it’s not so far from 48 kbps PS encodings. The Winamp/Helix duo gets a better note with “classical” samples than with “various music” ones. This is another surprise for me: I really expected from SBR to work (much) better with louder music.

various music group : Parametric Stereo is working very well here, and at 48 kbps the results are very close to 64 kbps encodings without PS. But a closer analysis reveals that these good results are contrasted. Most often 48-PS encodings are worse than 64-JS; not too worse but worse. But with three samples 48-PS encodings are better than 64-JS: not only better but much better (to my ears – see Appendix for illustration). The incriminated samples are 41-30, OrdinaryWorld & SinceAlways. What happens? The Parametric Stereo encodings are free of nasty artefacts audible with 64-JS, located on cymbals mostly, and which consists on aggressive and sandy noise (except for 41-30 which has another problem).
Second surprise: Nero Digital results, worse again compared to competitors, but also worse with “various music”. Nero Digital was used to have problems with classical music; here it’s the opposite. Most often encodings produced by latest Nero Digital encoder are simply unlistenable. These unbalanced results in favour of “classical” samples are confirming the results I got after the 80 kbps LT I made this summer.

DVD transcoding : there are too few samples to make any strong conclusions. First comment: notations are higher (for all four encoders) with this group of sample. This could be partially explained by the presence of one mono-encoding which sounded transparent with all encoders (which obtained as consequence 5 points for this sample). Helix & Winamp quality at 64 kbps are really excellent. I’m not fond of DVD ripping but I think I will consider HE-AAC again (I was very disappointed by my previous tests, all made with Nero…). Nero Digital performs less badly than with music encoding, but is still far from all other competitors, including the 48 kbps “aacPlus” encoder. It confirms my previous experience with HE-AAC and DVD ripping: poor. The usual artefacts of Nero are also audible, altering voice as well as music.



[span style=\'font-size:14pt;line-height:100%\']APPENDIX[/span]

three different statistical analysis of the complete results are available here:
http://audiotests.free.fr/tests/2005.09...ots_mixedx3.png (http://audiotests.free.fr/tests/2005.09/AACHE/01/plots_mixedx3.png)


Illustration of Nero Digital ultra-smearing issues with Kraftwerk.wav sample:

http://audiotests.free.fr/tests/2005.09...1/kraftwerk.gif (http://audiotests.free.fr/tests/2005.09/AACHE/01/kraftwerk.gif)
http://audiotests.free.fr/tests/2005.09...ftwerk_Helix.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/kraftwerk_Helix.wv)
http://audiotests.free.fr/tests/2005.09..._NeroDigital.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/kraftwerk_NeroDigital.wv)


Illustration of Nero Digital grainy sound with S50.wav sample:

http://audiotests.free.fr/tests/2005.09/AACHE/01/S50.gif (http://audiotests.free.fr/tests/2005.09/AACHE/01/S50.gif)
http://audiotests.free.fr/tests/2005.09...01/S50_Helix.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/S50_Helix.wv)
http://audiotests.free.fr/tests/2005.09..._NeroDigital.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/S50_NeroDigital.wv)

Illustration of Nero Digital grainy sound (other samples):

http://audiotests.free.fr/tests/2005.09...01/E06_Helix.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/E06_Helix.wv)
http://audiotests.free.fr/tests/2005.09..._NeroDigital.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/E06_NeroDigital.wv)
http://audiotests.free.fr/tests/2005.09...semary_Helix.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/rosemary_Helix.wv)
http://audiotests.free.fr/tests/2005.09..._NeroDigital.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/rosemary_NeroDigital.wv)


Illustration of Parametric Stereo distortions (three samples):

http://audiotests.free.fr/tests/2005.09...ereo_issues.zip (http://audiotests.free.fr/tests/2005.09/AACHE/01/parametric_stereo_issues.zip)
Try also rosemary.wav (beginning)


Illustration of SBR “sand” reduction with PS encodings:

http://audiotests.free.fr/tests/2005.09...ld_Winamp_48.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/OrdinaryWorld_Winamp_48.wv)
http://audiotests.free.fr/tests/2005.09...ld_Winamp_64.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/OrdinaryWorld_Winamp_64.wv)
http://audiotests.free.fr/tests/2005.09...ys_Winamp_48.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/SinceAlways_Winamp_48.wv)
http://audiotests.free.fr/tests/2005.09...ys_Winamp_64.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/SinceAlways_Winamp_64.wv)
http://audiotests.free.fr/tests/2005.09...27_Winamp_48.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/V27_Winamp_48.wv)
http://audiotests.free.fr/tests/2005.09...27_Winamp_48.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/V27_Winamp_48.wv)


Illustration of a minor artefact audible with Winamp and not with Helix:

(http://audiotests.free.fr/tests/2005.09/AACHE/01/Helix_Winamp_blip.png)
http://audiotests.free.fr/tests/2005.09..._blip_Winamp.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/Kraftwerk_blip_Winamp.wv)
http://audiotests.free.fr/tests/2005.09...k_blip_Helix.wv (http://audiotests.free.fr/tests/2005.09/AACHE/01/Kraftwerk_blip_Helix.wv)


P.S. All uploaded samples are already decoded (in order to any avoid biased evaluation due to possible playback with non-SBR compatible AAC decoders). They’re consequently very short – maybe too short to be convincing. Try if possible to download the full samples and to encode them with the required settings.
Title: HE-AAC v.1 & v.2 comparison
Post by: kl33per on 2005-09-05 08:34:34
Again, wow guru.  I don't know how you find time to do this, but thank you.
Title: HE-AAC v.1 & v.2 comparison
Post by: guruboolez on 2005-09-05 08:40:43
Quote
Again, wow guru.  I don't know how you find time to do this, but thank you.
[a href="index.php?act=findpost&pid=325098"][{POST_SNAPBACK}][/a]

That's simple: a sleepless night before joining my workplace (http://forum-images.hardware.fr/icones/smilies/sleep.gif)
Title: HE-AAC v.1 & v.2 comparison
Post by: dand on 2005-09-05 08:47:53
Guru, great work again!
It's strange how you missed HE-AAC encoder from CodingTechnologies in your 80 kbps test. Since CT standardized SBR as technology, it was obvious that it will take time until someone else develops a HE encoder close in quality to CT's. Even Nero, who started first a couple of years ago, didn't get there yet. Also, as SBR is pretty complicated, there won't be too many new HE implementations, at least I don't expect much in the near future, companies will just licence it from CT (as is the case now).
Title: HE-AAC v.1 & v.2 comparison
Post by: guruboolez on 2005-09-05 09:20:32
Quote
It's strange how you missed HE-AAC encoder from CodingTechnologies in your 80 kbps test. Since CT standardized SBR as technology, it was obvious that it will take time until someone else develops a HE encoder close in quality to CT's.
[a href="index.php?act=findpost&pid=325101"][{POST_SNAPBACK}][/a]

Was it really obvious that CT implementation should be considered as better than Nero? On this board, I can't remember anyone making such test or even such assumption. Remember Sebastian Mares and his project to organize a collective listening test at 64 kbps: he considered Nero Digital and the upcoming Apple's implementation as the two most interesting ones. Most people on this board (including me) were convinced that Nero Digital is a better encoding solution (compared to CT).
That's why I didn't consider Coding Technologie for my test (I regret it, believe me...).
Title: HE-AAC v.1 & v.2 comparison
Post by: optimus on 2005-09-05 09:25:24
Very nice article! I really learned something!
Title: HE-AAC v.1 & v.2 comparison
Post by: Ivan Dimkovic on 2005-09-05 10:40:32
I just want to inform you all that the new HE-AAC encoder from Nero is being finalized as we speak (current version uses very outdated SBR tools) - and it will be a huge (and I mean huge  improvement (as already found out by internal tests) over the current version that Guru tested.

So please stay tuned
Title: HE-AAC v.1 & v.2 comparison
Post by: bond on 2005-09-05 12:24:45
wow very interesting! thx a lot guru!

seems we need to get a closer eye on the afaik freely available helix aac encoder!

also its great to see how close 48kbps ps-aac comes close to 64 he-aac with ac3 sources!
Title: HE-AAC v.1 & v.2 comparison
Post by: Garf on 2005-09-05 12:37:24
I am pretty sure Helix AAC is just the same as aacPlus (CT), and the results show this as well.
Title: HE-AAC v.1 & v.2 comparison
Post by: Gecko on 2005-09-05 12:59:51
Quote
I am pretty sure Helix AAC is just the same as aacPlus (CT), and the results show this as well.

Quote
Apart quality, both have the same offset and a very similar gain (volume) deviation

Judging from that last bit, they are not identical. I'd guess different versions.

Thanks for the test, guruboolez!
Title: HE-AAC v.1 & v.2 comparison
Post by: IgorC on 2005-09-05 14:38:49
This test was very informative for me.
were AC3 samples 48 khz or 44.1 khz?

And what about db HE-AACv2. It has some issue with 44.1 khz but at least it works fine with AC3 48 khz.

I also noticed that on some samples parametric stereo of Winamp 5.1 and db HE-AAC2 sound worth than simple stereo.  Maybe that's why Nero is delaying their HE-AAC2 due to unstability of parametric strereo.

Test was quite short. But anyway thank you 
Title: HE-AAC v.1 & v.2 comparison
Post by: guruboolez on 2005-09-05 14:42:33
Quote
were AC3 samples 48 khz or 44.1 khz?

48000 KHz.
[a href="index.php?act=findpost&pid=325163"][{POST_SNAPBACK}][/a]
Title: HE-AAC v.1 & v.2 comparison
Post by: Garf on 2005-09-05 14:56:03
Quote
Maybe that's why Nero is delaying their HE-AAC2 due to unstability of parametric strereo.
[a href="index.php?act=findpost&pid=325163"][{POST_SNAPBACK}][/a]


You can tune PS and SBR for ages. Actually, just LC AAC is probably far from it's end yet, either.

But yes, it's tempting to just keep tuning... :-P
Title: HE-AAC v.1 & v.2 comparison
Post by: bond on 2005-09-05 16:24:17
it seems coding technologies released the sourcecode for their ps-aac encoder as opensource for the 3gpp reference encoder here:
http://www.3gpp.org/ftp/Specs/html-info/26410.htm (http://www.3gpp.org/ftp/Specs/html-info/26410.htm)

now my questions:
- is it sure that the 3gpp reference is from coding technologies?
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?

would be happy if someone knows an answer to this
Title: HE-AAC v.1 & v.2 comparison
Post by: dand on 2005-09-05 16:30:56
Quote
- is it sure that the 3gpp reference is from coding technologies?

Definitely yes.
Quote
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?

Probably with minor differences.
Title: HE-AAC v.1 & v.2 comparison
Post by: Garf on 2005-09-05 16:34:27
Quote
Quote
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?

Probably with minor differences.
[a href="index.php?act=findpost&pid=325196"][{POST_SNAPBACK}][/a]


Some experimenting will quickly tell they're "not so minor" IMHO...
Title: HE-AAC v.1 & v.2 comparison
Post by: bond on 2005-09-05 16:38:11
well i also read it here and there, but any proof that they are (not) the same or that its from coding technologies?

apart from that: the helix he-aac codec is indeed from coding technologies as has been stated by karl_lillevold here:
http://forum.doom9.org/showthread.php?t=68245 (http://forum.doom9.org/showthread.php?t=68245)
Title: HE-AAC v.1 & v.2 comparison
Post by: dand on 2005-09-05 16:38:29
Quote
Quote
Quote
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?

Probably with minor differences.
[a href="index.php?act=findpost&pid=325196"][{POST_SNAPBACK}][/a]


Some experimenting will quickly tell they're "not so minor" IMHO...
[a href="index.php?act=findpost&pid=325198"][{POST_SNAPBACK}][/a]

Maybe... Where do I get their commercial version?
Title: HE-AAC v.1 & v.2 comparison
Post by: Garf on 2005-09-05 16:59:31
Quote
Quote
Quote
Quote
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?

Probably with minor differences.
[a href="index.php?act=findpost&pid=325196"][{POST_SNAPBACK}][/a]


Some experimenting will quickly tell they're "not so minor" IMHO...
[a href="index.php?act=findpost&pid=325198"][{POST_SNAPBACK}][/a]

Maybe... Where do I get their commercial version?
[a href="index.php?act=findpost&pid=325201"][{POST_SNAPBACK}][/a]


I am really the *worst possible* person to ask that. You should really buy Nero instead 
Title: HE-AAC v.1 & v.2 comparison
Post by: slippyC on 2005-09-05 17:01:06
Guru, thanks for tests.
Title: HE-AAC v.1 & v.2 comparison
Post by: Oki on 2005-09-05 17:15:29
Quote
Quote
Quote
Quote
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?

Probably with minor differences.
[a href="index.php?act=findpost&pid=325196"][{POST_SNAPBACK}][/a]


Some experimenting will quickly tell they're "not so minor" IMHO...
[a href="index.php?act=findpost&pid=325198"][{POST_SNAPBACK}][/a]

Maybe... Where do I get their commercial version?
[a href="index.php?act=findpost&pid=325201"][{POST_SNAPBACK}][/a]
Sorenson Squeeze 4.1 is using the commercial CT's HE-AAC encoder. I do not know if it is the HE-AAC v2 or just v1 encoder.
Title: HE-AAC v.1 & v.2 comparison
Post by: bond on 2005-09-05 17:20:09
as mentioned by guruboolez the coding technologies encoder is available in winamp5
Title: HE-AAC v.1 & v.2 comparison
Post by: shrinkmail on 2005-09-05 20:05:22
Thank you, Guru. For the last three days i have beeing going through your tests, and i have found them all edifying.
Qs: So at the current state of development, what would be the use of HE-AAC v2 for an audiophile, and if so what bitrate would be transparent? Again, one can't possibly use Winamp for secure rips...
Title: HE-AAC v.1 & v.2 comparison
Post by: nyaochi on 2005-09-05 20:46:46
Your articles are always something exciting for me. Thanks a lot, guruboolez.

Quote
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=325192")

As far as I tried, the source code does not support 44.1kHz input. We can change the parameters to support 44.1kHz though (see [a href="http://forum.dbpoweramp.com/showthread.php?t=7107&page=2&pp=15]this thread[/url]). PS will be activated when the target bitrate is 32kbps or lower. 44.1kHz 48kbps SBR (w/o PS) that I tried with this source code was actually good.

I found many parameters in the source code waiting for someone to tune...
Title: HE-AAC v.1 & v.2 comparison
Post by: bond on 2005-09-05 20:57:04
Quote
Quote
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=325192")

As far as I tried, the source code does not support 44.1kHz input. We can change the parameters to support 44.1kHz though (see [a href="http://forum.dbpoweramp.com/showthread.php?t=7107&page=2&pp=15]this thread[/url]). PS will be activated when the target bitrate is 32kbps or lower. 44.1kHz 48kbps SBR (w/o PS) that I tried with this source code was actually good.

I found many parameters in the source code waiting for someone to tune...
[a href="index.php?act=findpost&pid=325247"][{POST_SNAPBACK}][/a]

thx for the info!

is there any technical reason for this exclusion of 44.1?
Title: HE-AAC v.1 & v.2 comparison
Post by: Garf on 2005-09-05 20:59:19
Quote
Qs: So at the current state of development, what would be the use of HE-AAC v2 for an audiophile, and if so what bitrate would be transparent?
[a href="index.php?act=findpost&pid=325239"][{POST_SNAPBACK}][/a]


HE-AAC (and HE-AAC v2) are essentially useless for "transparent" encodes.
Title: HE-AAC v.1 & v.2 comparison
Post by: nyaochi on 2005-09-05 21:25:14
Quote
is there any technical reason for this exclusion of 44.1?
[a href="index.php?act=findpost&pid=325251"][{POST_SNAPBACK}][/a]

I don't think so. I presume that the source code is only for reference purpose. I found the code for 44.1kHz in many places. But the mapping table to determine encoding parameters for given sample rate, stereo mode, and bitrate does not have entries for 44.1kHz. We can easily add 44.1kHz support by copy-and-pasting entries for 48kHz.
Title: HE-AAC v.1 & v.2 comparison
Post by: nyaochi on 2005-09-05 21:32:58
And I found an interesting sample that exposes a clear flaw of 48kbps (SBR+PS).

"Wish I" in album "Finally Woken" by Jem.

original (http://nyaochi.sakura.ne.jp/samples/WishI.ape)
aacPlus v2 48kbps (SBR+PS) (http://nyaochi.sakura.ne.jp/samples/WishI-48kSBRPS.aac)
aacPlus v2 48kbps (SBR) (http://nyaochi.sakura.ne.jp/samples/WishI-48kSBR.aac)

I was astonished to listen to the SBR+PS sample. It eliminates the sub melody (played by the classic guitar?) from the right channel too much that it's like a different session. I don't complain of other artifacts for this bitrate, but it's not acceptable for me that an encoder changes the volue valance so drastically. SBR without PS sample does not suffer from this problem. We may have to be familar with the original sample to notice this kind of problems.
Title: HE-AAC v.1 & v.2 comparison
Post by: bond on 2005-09-05 21:38:20
Quote
Quote
is there any technical reason for this exclusion of 44.1?
[a href="index.php?act=findpost&pid=325251"][{POST_SNAPBACK}][/a]

I don't think so. I presume that the source code is only for reference purpose. I found the code for 44.1kHz in many places. But the mapping table to determine encoding parameters for given sample rate, stereo mode, and bitrate does not have entries for 44.1kHz. We can easily add 44.1kHz support by copy-and-pasting entries for 48kHz.
[a href="index.php?act=findpost&pid=325255"][{POST_SNAPBACK}][/a]
sounds evil, i guess this also answers the question whether this reference code is the same as the commercial one sold by coding tech 
Title: HE-AAC v.1 & v.2 comparison
Post by: Loke on 2005-09-05 23:16:40
hmm...
In the AAC+ v1 & v2 encoder from Coding Technologies isn't the LC-AAC part of it made by fraunhofer?

I seem to remember this was the case with their mp3PRO-encoder, when it came 4 years ago. It was a normal lowbitrate mp3-stream, with additional information for the high frequencies (SBR).
The lowrate mp3 part was made with a fraunhoferencoder, while SBR-part was made by CT.

Is this true?

Now winamp's got two AAC encoders; one by Dolby, and now one made by CT.
Title: HE-AAC v.1 & v.2 comparison
Post by: Enig123 on 2005-09-06 03:17:41
The HE-AAC encoder included in Helix can encode to bitrate up to 128kb. I wonder if HE will help in such bitrate.

Also it was reported somewhere in doom9's forum Helix's LC-AAC encoder performes very well @ bitrate of 192 kb. Would someone test it at such high bitrate?
Title: HE-AAC v.1 & v.2 comparison
Post by: Digisurfer on 2005-09-06 04:02:03
This was an exciting test, thanks Guru! I'm really looking forward to seeing how Nero's soon to be released aacPlusv2 encoder stacks up after seeing this test. It's been a while since I first started taking an interest in HE-AAC, but a year later it's starting to look like things are finally beginning to heat up. Now to get all the audio player and tagger developers on the same page as far as support goes.

Edit: Would be cool if mp3pro was thrown into with aacPlusv2 tests if there is another one in the future.
Title: HE-AAC v.1 & v.2 comparison
Post by: yourtallness on 2005-09-06 08:36:44
Quote
The HE-AAC encoder included in Helix can encode to bitrate up to 128kb. I wonder if HE will help in such bitrate.

Also it was reported somewhere in doom9's forum Helix's LC-AAC encoder performes very well @ bitrate of 192 kb. Would someone test it at such high bitrate?
[a href="index.php?act=findpost&pid=325298"][{POST_SNAPBACK}][/a]


Are the Helix LC and HE AAC encoders freely available for download?
If yes, could someone provide a download link for the latest version?

And another question: does anyone know of an AAC-capable mobile
phone that can play back HE AAC streams? I'm planning to buy the
SonyEricsson W800 Walkman phone and would like to know if HE AAC
is supported.

Thanks
Title: HE-AAC v.1 & v.2 comparison
Post by: bond on 2005-09-06 08:41:44
Quote
Are the Helix LC and HE AAC encoders freely available for download?
If yes, could someone provide a download link for the latest version?

https://helix-producer.helixcommunity.org/downloads.htm (https://helix-producer.helixcommunity.org/downloads.htm)
Title: HE-AAC v.1 & v.2 comparison
Post by: yourtallness on 2005-09-06 09:56:45
Should I download the Command Line Application or the SDK?

I can't find the version Guruboolez used (v.11).
Title: HE-AAC v.1 & v.2 comparison
Post by: dimzon on 2005-09-06 10:33:56
Quote
Should I download the Command Line Application or the SDK?

I can't find the version Guruboolez used (v.11).
[a href="index.php?act=findpost&pid=325348"][{POST_SNAPBACK}][/a]

looking for it too...
Title: HE-AAC v.1 & v.2 comparison
Post by: kurtnoise on 2005-09-06 10:44:10
Quote
Should I download the Command Line Application or the SDK?

I can't find the version Guruboolez used (v.11).
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=325348")


[a href="https://helixcommunity.org/beula/download/]https://helixcommunity.org/beula/download/[/url] . register needed but it's free.. 

CLI is enough but keep in mind that the AAC stream is embedded in the rm container. However, Guru uses an other way...  The AAC streams are directly embedded in mp4 file.
Title: HE-AAC v.1 & v.2 comparison
Post by: dimzon on 2005-09-06 11:40:16
Quote
Quote
Should I download the Command Line Application or the SDK?

I can't find the version Guruboolez used (v.11).
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=325348")


[a href="https://helixcommunity.org/beula/download/]https://helixcommunity.org/beula/download/[/url] . register needed but it's free.. 

CLI is enough but keep in mind that the AAC stream is embedded in the rm container. However, Guru uses an other way...  The AAC streams are directly embedded in mp4 file.
[a href="index.php?act=findpost&pid=325353"][{POST_SNAPBACK}][/a]

Can anybody provide command line sample?
Title: HE-AAC v.1 & v.2 comparison
Post by: bond on 2005-09-06 12:01:39
i think the helix encoder can output mp4 too, not sure
Title: HE-AAC v.1 & v.2 comparison
Post by: Enig123 on 2005-09-06 12:30:22
The following information is originally from doom9's forum. I just forget the exact url. In this way make Helix Producer can output aac stream in mp4 container directly.

Code: [Select]
Codec Bitrate Label                 4cc flavor  Compatibility *)
48 Kbps Stereo - RA 10 with aacPlus racp  3     RealPlayer 10
32 Kbps Stereo - RA 10 with aacPlus racp  4     RealPlayer 10

64 Kbps Stereo - RA 10 with aacPlus racp  0     RealOne
96 Kbps Stereo - RA 10 with aacPlus racp  1     RealOne
128Kbps Stereo - RA 10 with aacPlus racp  2     RealOne


Keng!
11th June 2005, 07:45

From your RealPlayer folder <C:\Program Files\Real\RealPlayer\producer>, copy both [mp4wrtr.dll] in <plugins> folder & [hxfilewriter.dll] in <tools> folder to Helix DNA Producer directory, [mp4wrtr.dll] in <plugins> folder & [hxfilewriter.dll] in <tools> folder.

Now create an audience file: audio.rpad

<?xml version="1.0"?>
<audience>
<streams>
<audioStream>
<pluginName type="string">rn-audiocodec-realaudio</pluginName>
<codecName type="string">raac</codecName>
<codecFlavor type="uint">1</codecFlavor>
<streamContext type="bag">
<presentationType type="string">audio-only</presentationType>
<audioMode type="string">music</audioMode>
</streamContext>
</audioStream>
</streams>
</audience>

Then launch producer with following commandline:
    Producer.exe -i CDImage.wav -o CDImage.m4a -ad audio -dv -dt

Also work for .mp4 extension!

This is useful if you rip your AudioCD with Foobar2000 or CDex!
The commandline for Foorbar2000 should like this:
-i %s -o %d -ad audio -dv -dt
Remember to use mp4/m4a in the extension box!
So, no more mka -> aac -> mp4!
Title: HE-AAC v.1 & v.2 comparison
Post by: Assault on 2005-09-06 14:19:35
@ Enig123

I've just tried encoding a wav file to an he-aac file but I only get an lc-aac file with 64kbps and a sampling rate of 32khz with your audience file (raac flavor 0) . Do you know the codec type and flavor I have to use to get an he-aac file? I tried racp flavor 0 but without success. Thanks for your help!

EDIT: Problem solved. I found racp.dll on https://helixcommunity.org/beula/download/ (https://helixcommunity.org/beula/download/) and now it works fine with racp flavor 0.
Title: HE-AAC v.1 & v.2 comparison
Post by: JohnV on 2005-09-06 19:48:20
Quote
I read somewhere that Nero 7 is announced for October. I guess that the new generation of Nero Digital HE-AAC will be released with the new Nero package and I’m sure that Ivan had built a competitive encoder.

Yeah, a bit bad time for us (or for you) for this test. The Nero Digital audio encoder you are testing here is now very much outdated.
During the last weeks, AAC-HE and PS have received very significant quality updates.
When we release the new one pretty soon, remember to redo this test.
Title: HE-AAC v.1 & v.2 comparison
Post by: rjamorim on 2005-09-07 00:08:15
Awesome test, as always, my friend.

You seem to be getting a taste for debunking age-old prejudices
Title: HE-AAC v.1 & v.2 comparison
Post by: optimus on 2005-09-07 15:25:25
I've just integrated Helix Encoder support (as well as Winamp AAC+ encoder) in my MEnc, with all info I got in this thread, check it out here (http://www.hydrogenaudio.org/forums/index.php?showtopic=36870).

(http://base.3322.org/ftp/pics/menc-helix.png)

Download it here.
This includes:
MEnc executable
MPlayer (latest CVS version)
Helix Producer (stripped for audio encoding only and added aacplus audience files)
Winamp AAC+V2 encoder
Lame MP3 encoder (latest CVS version)
Title: HE-AAC v.1 & v.2 comparison
Post by: dand on 2005-09-13 09:02:00
Quote
Quote
Quote
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?

Probably with minor differences.
[a href="index.php?act=findpost&pid=325196"][{POST_SNAPBACK}][/a]


Some experimenting will quickly tell they're "not so minor" IMHO...
[a href="index.php?act=findpost&pid=325198"][{POST_SNAPBACK}][/a]

Garf, what are the main differences (spare us a time...)?
Title: HE-AAC v.1 & v.2 comparison
Post by: Oki on 2005-09-13 09:07:01
Quote
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?
Quote
Probably with minor differences.[a href="index.php?act=findpost&pid=325196"][{POST_SNAPBACK}][/a]
Quote
Some experimenting will quickly tell they're "not so minor" IMHO...
[a href="index.php?act=findpost&pid=325198"][{POST_SNAPBACK}][/a]
Quote
Garf, what are the main differences (spare us a time...)?[a href="index.php?act=findpost&pid=326576"][{POST_SNAPBACK}][/a]

The main differences should be speed optimizations and more options in the commercial one. I do not hear big differences in quality.

Regards,
Oki
Title: HE-AAC v.1 & v.2 comparison
Post by: SirGrey on 2005-09-13 12:35:58
Interesting...
Nero lost to CT this time. Life is full of surprises 
Thanks a lot for your efforts, Guruboolez !!!
Title: HE-AAC v.1 & v.2 comparison
Post by: moozooh on 2005-09-13 21:40:29
Cause Nero is simply outdated. We'll see the real winner when the long-awaited new version comes out.
Title: HE-AAC v.1 & v.2 comparison
Post by: Garf on 2005-09-14 09:18:54
Quote
Quote
- is the 3gpp reference the same or a different encoder than the one coding technologies sells?
Quote
Probably with minor differences.[a href="index.php?act=findpost&pid=325196"][{POST_SNAPBACK}][/a]
Quote
Some experimenting will quickly tell they're "not so minor" IMHO...
[a href="index.php?act=findpost&pid=325198"][{POST_SNAPBACK}][/a]
Quote
Garf, what are the main differences (spare us a time...)?[a href="index.php?act=findpost&pid=326576"][{POST_SNAPBACK}][/a]

The main differences should be speed optimizations and more options in the commercial one. I do not hear big differences in quality.

Regards,
Oki
[a href="index.php?act=findpost&pid=326577"][{POST_SNAPBACK}][/a]


I actually did mean quality. Can you try some PS problem clips? I might have had an older/newer encoder so sorry if I messed up.
Title: HE-AAC v.1 & v.2 comparison
Post by: Oki on 2005-09-14 09:32:19
Quote
I actually did mean quality. Can you try some PS problem clips? I might have had an older/newer encoder so sorry if I messed up.[a href="index.php?act=findpost&pid=326773"][{POST_SNAPBACK}][/a]
If you make those clips available to us I am sure we could test them. I am not the best artifact hunter over here but i can help anyway. Guruboolez has proven habilities for this and it can be interesting to compare the CT's reference 3GPP rel6 audio codec against their commercial one.

Regards,
Oki
Title: HE-AAC v.1 & v.2 comparison
Post by: Gabriel on 2005-09-14 10:02:41
I also think that the commercial CT encoder should be different from the 3gpp reference code, because there is no tonality estimation in the 3gpp code.

It would be a little strange for CT to not have any tonality estimation in its commercial encoder.
Title: HE-AAC v.1 & v.2 comparison
Post by: dand on 2005-09-15 09:05:52
Quote
I also think that the commercial CT encoder should be different from the 3gpp reference code, because there is no tonality estimation in the 3gpp code.

It would be a little strange for CT to not have any tonality estimation in its commercial encoder.
[a href="index.php?act=findpost&pid=326781"][{POST_SNAPBACK}][/a]

Are you sure?
As I look at the 3GPP TS 26.404 and the source code also, I see "the tonality is derived from the prediction gain of a second order linear prediction...", etc. etc. As a matter of fact, without tonality detection most other modules would be seriously crippled, namely noise estimation, sines detection and inverse filtering, which would probably make this encoder useless - and it isn't useless at all.
Title: HE-AAC v.1 & v.2 comparison
Post by: Gabriel on 2005-09-15 11:12:41
Quote
Are you sure?
As I look at the 3GPP TS 26.404 and the source code also, I see "the tonality is derived from the prediction gain of a second order linear prediction...", etc. etc.

This is for the SBR part, not the base part.

From 26.403 (AAC part):
Quote
No difference is made between tonal and noisy components in the signal. Therefore the "worst case" is assumed, i.e. the signal is tonal for the complete frequency range.
Title: HE-AAC v.1 & v.2 comparison
Post by: dand on 2005-09-15 13:54:31
Quote
Quote
No difference is made between tonal and noisy components in the signal. Therefore the "worst case" is assumed, i.e. the signal is tonal for the complete frequency range.


Sorry, didn't look at the core AAC.

Now that we know the core AAC is crippled (which makes whole 3GPP encoder crippled), it would be ok to know if SBR part is fully functional...
Title: HE-AAC v.1 & v.2 comparison
Post by: ckjnigel on 2005-09-15 18:59:50
Most importantly, I'd like to know if one will have to install the whole new Nero 7 just to use the improved AAC+ for which Ivan Dimkovic has been providing drumrolls. ( I'm darkly suspicious of any software that's compatible with Blu-Ray.)
I had wondered why some of the top posters have been quiet in encoding quality disccussion/debate, but it seems they must have been gagged by beta tester non-disclosure agreements.
I also am wondering how the proprietary elements that Coding Technologies and Ahead put into their encoder applications will affect willingness of hardware manufacturers to create portable devices that can play the files.  If the iPod Nano could play the files, I'd surely have bought one right away, since one could get not far shy of 200 hours good quality music on the 4Gb model.
Title: HE-AAC v.1 & v.2 comparison
Post by: Gabriel on 2005-09-15 19:10:36
Quote
I also am wondering how the proprietary elements that Coding Technologies and Ahead put into their encoder applications will affect willingness of hardware manufacturers to create portable devices that can play the files.

SBR and PS are not proprietary elements, just plain mpeg-4 standard.
Title: HE-AAC v.1 & v.2 comparison
Post by: dimzon on 2005-09-20 18:43:49
guruboolez
Can you add this (http://sr1.mytempdir.com/161140) encoder for comparision @ 48000Hz?
Title: HE-AAC v.1 & v.2 comparison
Post by: Ivan Dimkovic on 2005-10-02 22:05:31
Quote
Gabriel
It would be a little strange for CT to not have any tonality estimation in its commercial encoder.


Hmm I wouldn't be that surprised - I think Dolby's AAC encoder described in their AES paper didn't use tonality esitmation as well, and I know for a fact that couple of other commercial LC-AAC encoders do not use tonality estimation  I cannot reveal names, of course    Not having a tonality estimation might not be so problematic especially at the very low bit rate CBR - where maintaining stable NMR and avoiding spectral holes is much more important than avoiding artifacts of a problematic harmonic structures (hello pitchpipe) - and for high bitrates, you could overcode anyway (like Dolby is doing in A52 specification, or as described in fast AAC AES paper).

Also, 3GPP reference code obviously misses some things from what I saw, for example TNS encoding,  uses fixed multiplication of the post-TNS thresholds (factor 0.25), while in the specs it is clearly called "a table" - and, well, some more.

Also - quality difference clips between CT (commercial) and 3GPP - just try Waiting.wav @48 kbps, 48 khz with CT encoder and 3GPP reference source (I am talking about HE-AAC , not v2 with PS)  - and check the amount of stereo reduction (which is being done to improve the LC SNR on the expense of stereo image) - while 3GPP code almost completely downmixes LC part to mono - CT maintains better spatial image (not perfect, though, but much better) - which means it had more SNR available so it didn't need to reduce stereo image that much (or the 3GPP reference code algo is broken).

There are many more - i.e.  with castanets.wav you can clearly hear typical short block distortions @48 kbps (HE, too) at the end of the "fast" castanets clip - while they are not there with CT's commercial encoder, etc..  etc...

Quote
Most importantly, I'd like to know if one will have to install the whole new Nero 7 just to use the improved AAC+ for which Ivan Dimkovic has been providing drumrolls. ( I'm darkly suspicious of any software that's compatible with Blu-Ray.)


Unfortunately, I cannot tell you that. What is sure, at the moment, the new encoder will be available with N7 web release - and about its future and possible other applications, no more public info is available at this moment.

Quote
ckjnigel
I also am wondering how the proprietary elements that Coding Technologies and Ahead put into their encoder applications will affect willingness of hardware manufacturers to create portable devices that can play the files.


You can be pretty sure that HE-AAC encoders (at least for Nero I can be 101% sure, and for CT I have no reason to doubt it is also the case) do not put anything proprietary in the elementary bitstream - which is what it is needed to be decoded by the ISO decoders ;-)  There are proprietary algorithms, of course - but all of them produce standard compatible MPEG-4 streams.
Title: HE-AAC v.1 & v.2 comparison
Post by: jwaldi on 2005-10-04 21:44:54
Where from to download program "Helix Producer v11" ? Because I on net nowhere can find this version...
Title: HE-AAC v.1 & v.2 comparison
Post by: kurtnoise on 2005-10-04 23:54:41
https://helixcommunity.org/beula/download/ (https://helixcommunity.org/beula/download/)

registration needed but it's free.
Title: HE-AAC v.1 & v.2 comparison
Post by: cartman on 2005-10-27 18:48:17
Nice work guruboolez . Cheers
Title: HE-AAC v.1 & v.2 comparison
Post by: sven_Bent on 2005-10-27 20:23:57
could we put helix encoder on rarewares ?
Title: HE-AAC v.1 & v.2 comparison
Post by: cartman on 2005-10-27 20:29:40
Quote
could we put helix encoder on rarewares ?
[a href="index.php?act=findpost&pid=337659"][{POST_SNAPBACK}][/a]


You can't redistribute helix aac codec anyway so you will have to register to download.
Title: HE-AAC v.1 & v.2 comparison
Post by: IgorC on 2005-10-28 15:47:39
I didn't find a bitrate (or final size)  table. I noticed that Helix produce slighlty bigger files than other encoders. For  some people it's not important the difference on some kilobytes. But I work with limited space of memory. Especially for encodes for audiotrack of home videos file to fit one CD for example
Title: HE-AAC v.1 & v.2 comparison
Post by: guruboolez on 2005-10-28 16:14:28
Quote
I didn't find a bitrate (or final size)  table. I noticed that Helix produce slighlty bigger files than other encoders. For  some people it's not important the difference on some kilobytes. But I work with limited space of memory. Especially for encodes for audiotrack of home videos file to fit one CD for example
[a href="index.php?act=findpost&pid=337863"][{POST_SNAPBACK}][/a]

All encodings were done in CBR mode. Size is approximately the same for both implementation (if not, the MP4 container could be optimized in order to reduce the difference: a tool like foobar2000 can do it).

All files are deleted; I can't therefore post the bitrate table (useless in this case I'd say).
Cheers.
Title: HE-AAC v.1 & v.2 comparison
Post by: optimus on 2006-01-25 07:00:12
Hi, every one. Just to say that MediaCoder (http://mediacoder.sourceforge.net/) now natively supports 3gpp AAC+ encoder (supports 44.1Khz). There is a little bit performance gain after I optimized the compiler options (enabled SIMD).
Title: HE-AAC v.1 & v.2 comparison
Post by: rootkit on 2006-05-28 15:27:17
How could you test the CT encoder?
did you bought the SDK?
Title: HE-AAC v.1 & v.2 comparison
Post by: rjamorim on 2006-05-28 15:45:50
How could you test the CT encoder?
did you bought the SDK?


You can get the CT encoder on Winamp, Real Player, etc, etc.
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