Talk:Advanced Audio Coding

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Contents 1 2004-08-06 2 Introduction no place for detailed discussion of Apple/EMI announcement? 3 AAC protected by Patents? 4 Enhanced AAC? 5 Encoding Type Differences Amongst AAC Types 6 Quality 7 Other Players 8 Portable Devices 9 availability/popularity 10 2006-09-08 - FAAC and FAAD 11 2006-11-01 - Quality Again 12 2006-12-19 - "Summarize AAC at top of article please" 13 2006-12-13 - "Proprietary format" 14 Article Cleanup Co-Ordination Point 14.1 Discussion 14.2 Article is confusing? (2007-01-17) 14.3 Please post specific quality issues or clarfication requests on this page 14.4 AAC and MP3 comparison 15 Alt. players - XBMC

[edit] 2004-08-06

Good article otherwise, but "As anyone who has used several different MP3 encoders will tell you" isn't neccessarily true, is a bit colloqial and isn't really neccessary anyway. So I've taken it out. pomegranate 01:12, Aug 6, 2004 (UTC)

[edit] Introduction no place for detailed discussion of Apple/EMI announcement?

I think the introductory paragraph goes into far too much detail on the Apple/EMI announcement to offer music on the iTunes Music Store without DRM. I would like to see the EMI/Apple announcement detail removed and dealt with (as it already is) on the iTunes entry itself. It's a largish deletion though -- any objections to me deleting it? (Fredhoysted 4 Apr 07: 0540 UTC)

[edit] AAC protected by Patents?

Can anybody provide accurate information on whether AAC is patented? Mavros

See: http://www.vialicensing.com/

It most definately is. MPEG stuff is always heavily patented. This page presents it simply; I've added a link to it. User:Phil.a

[edit] Enhanced AAC?

Hi, I was reading an article about embedding chapters, images and urls in aac, a new possibility available in iTunes and new Ipods, perhaps someone could update the aac article ?`

There is info about it here ... http://www.makezine.com/blog/archive/2005/07/how_to_make_enh.html

- This article doesn't have anything to do with AAC, it's some iTunes specific stuff. "Enhanced AAC" would be HE-AAC/aacPlus.

- Agreed. AAC is an audio codec. That a particular file format (.m4a/.m4b) can contain both AAC audio and other material has nothing to do in an article about the AAC codec.

Hasn't AAC been improved to include Variable bit rate? --70.111.218.254 14:08, 23 December 2006 (UTC)

[edit] Encoding Type Differences Amongst AAC Types

Some information on the differences between:

-AAC -AAC+ -EAAC+ -AAC++

Information besides, this is better.

---

[edit] Quality

I'd like to see a section on AAC quality.

Like how do these compare:

128kbps AAC vs. 128 kbps MP3

128kbps AAC vs. 192 kbps MP3

192kbps AAC vs. 192 kbps MP3

128kbps AAC vs. 64 and 128 kbps OGG

etc.

— Ilyanep (Talk) 18:40, 25 March 2006 (UTC)

Thats not really feasible because there are so many different AAC and MP3 encoders, and so many different samples to use. At the moment, the two formats are essentially tied at 128k and above, with AAC becoming increasingly dominate at lower bitrates as the sheer technical advantage overwhelms MP3.

Current listening tests are showing a significant advantage towards AAC with the new nero encoder. General consensus seems to be that MP3 needs just under 1.5x the bitrate (more like 1.3-1.4x) for the same quality range in the 96-224kbits range. Above that it's hard to tell a difference anyway, so I'd take whatever results you see with a grain of salt, and obviously below that AAC wipes the floor with MP3. [hydrogenaudio.org] is a nice site if you aren't already aware of it (which is where these stats come from). On a side note, I added in a subsection on the new nero CLI encoder and cleaned up the list of media players that support it, everything supports it now really, so I replaced them with an entry for FAAD, one for mplayer because it's *nix and special, and a note about how everything supports it.

[edit] Other Players

The other players here is a little out of date. New versions of Real Player and MPlayer both include support for AAC encoded files.

[edit] Portable Devices

I can't find any evidence that indicates that the Sony Walkmen players mentioned in the article support AAC. Sony customer support even told me that they do not.

Don't know when comment was added but the Network Walman series does support AAC now. Wiki article on Walkman says so and also you can see here on Sony's own site for instance: http://support.sony-europe.com/DNA/Downloads/downloads.asp?l=en&c=WM&sc=NWH&f=FRM_NW_A1000

[edit] availability/popularity

"AAC was promoted as the successor to MP3 for audio coding at medium to high bit rates, though has yet to overtake the MP3 format or Microsoft's rival WMA format in terms of popularity or availability within the portable audio devices market."

I would be inclined to say that there may be more devices/programs that can play WMA than AAC, because of the popularity of iTunes and the iPod (market share numbers well in excess of 50%), AAC has overtaken the WMA format in terms of both popularity and availability within the portable market. Am I mistaken about it's prevalence?

[edit] 2006-09-08 - FAAC and FAAD

Currently, both FAAD and FAAC links in this article directly, or indirectly link back to this article! That's a bit pointless. I'd like to know more about either, but they arn't really mentioned/described anywhere on W. I'm fine with them being described in this artilce, but they certainly shouldn't link back to this article without a description. I don't know anything about this, so someone knowledgeable should add a ==Free Advanced Audio Coding/Decoding== section. Thanks! +mwtoews 01:35, 8 September 2006 (UTC)

[edit] 2006-11-01 - Quality Again

To the person who was concerned about quality, I havent found the exact bit rates you were looking for, but I have found an apple site which lists 3 comparisons done by dolby labs

• AAC compressed audio at 128 Kbps (stereo) has been judged by expert listeners to be “indistinguishable” from the original uncompressed audio source.*
• AAC compressed audio at 96 Kbps generally exceeded the quality of MP3 compressed audio at 128 Kbps. AAC at 128 Kbps provides significantly superior performance than does MP3 at 128 Kbps.*
• AAC was the only Internet audio codec evaluated in the range “Excellent” at 64 Kbps for all of the audio items tested in EBU listening tests.*
• Information provided by Dolby Labs.

Reference here http://www.apple.com/quicktime/technologies/aac/ Timmah01 05:55, 1 November 2006 (UTC)

Well, I'd have to disagree for classical music. I have to bump up the rate to at least 160 kbps for it to be "indistinguishable." And I certainly would not call it "excellent" at 64. That being said, it appears that other articles (Vorbis, WMA) have a "Listening Tests" or "Sound Quality" section. Perhaps something like that could be worked into this article. --W0lfie 18:38, 13 December 2006 (UTC)

Right now, the article compares AAC with just MP3, there should at least be a comparison with Ogg Vorbis too then, and perhaps other big players. --70.111.218.254 14:12, 23 December 2006 (UTC)

By what metric, exactly, is Ogg Vorbis a "big player"? I mean, I read slashdot and use linux (among other OSes) etc, so I am familiar with it, but I doubt almost any non-geeky people have a clue as to what it is, or why they should use it. If AAC is to be compared with other codecs it should probably be against ones that are used more widely than OV, and we'll need some serious references on it. - JustinWick 18:54, 17 January 2007 (UTC)

[edit] 2006-12-19 - "Summarize AAC at top of article please"

I came looking for a defination of what AAC actually is but couldn't find it. Can someone add an introduction to the article explaining what AAC before going into the heavy technical stuff? Philsy 11:32, 29 December 2006 (UTC)

[edit] 2006-12-13 - "Proprietary format"

Can somebody explain what this means: "Although AAC requires a patent license, contrary to popular belief, it is not a proprietary format." I'm not sure I understand how it can require patent license, but not be proprietary. Wouldn't the assignee of the patent also be the proprietor of the format? Maybe I don't understand the definition, but I thought that something was "proprietary software" any time there is a clear "owner" of it, and that owner puts restrictions on it. Somebody with more knowledge please correct/inform me.  :-) --W0lfie 18:38, 13 December 2006 (UTC)

I don't understand either. If it requires a license, it should be called "proprietary", even if streaming or broadcasting doesn't require a license...Sarenne 12:24, 24 February 2007 (UTC)

[edit] Article Cleanup Co-Ordination Point

Style Discussion Comment [2007-01-04] - IMHO having an automated bot promenently flag articles - yet provide no details of what the critera were - is not particularly helpful. Regarding the quote "You should use this section to discuss possible resolution of the problem and achieve consensus for action.": 'THE problem' implies a single, known problem; not a "list of possible problems". Besides the comments already on this discussion page (above), can any 'real human' provide some feedback on what specific problems (if any) there are with the content of this article? Editors could then use those issues for focusing any cleanup efforts... -Liberty 02:16, 5 January 2007 (UTC)

[edit] Article is confusing? (2007-01-17)

I don't seem to understand the problem with this article. The lead section has links to anything that a non-techie wouldn't know about, and the rest either is of little interest, or requires people to learn the subject before reading. I had no difficulty reading the entire article, and I'm sure anyone who took the time to learn the terms and become familiar with the field would have no problems either, as the English used is not overly complex. This isn't an Encylopaedia for Dummies - many math/science articles are hopeless to comprehend without at least a masters degree in the subject, and there's nothing wrong with that - some things are just hard. - JustinWick 18:57, 17 January 2007 (UTC)

[edit] Please post specific quality issues or clarfication requests on this page

Follow up to comments above; well, it's been a while, and there doesn't seem to be any specific feedback forthcoming. I'm removing the robot 'confusing' and 'cleanup' tags because they aren't helpful or needed (all wikipedia articles could be potentially confusing or may require "cleanup"; that's why wikipedia is editable). Specific issues/requests can be added to the bottom of this discussion page (in the way that wikipedia has always worked). - Liberty 22:12, 4 February 2007 (UTC)

[edit] AAC and MP3 comparison

The AAC improvements over MP3 section in the article does not explain in detail the way in which the high bit rate compression does the MP3 provides a lesser quality than AAC. In fact, I am highly skeptical about the argument pointed out in the article: "A natural side effect of the MP3 method is that it suffers a loss of information over time - bass frequencies which results in, often even to an untrained ear, distinguishable disfiguration of these frequencies." This particular argument was suggested in the article without further explanation and quote. I propose this particular section be suspended before any further clarification.

• I've removed that gibberish entirely. Unless there's something wrong with your storage medium, data does not change over time. As the data is not lost over time, MP3's quality cannot degrade over time as the text suggests. That is complete garbage written by someone who has no idea what they're talking about. -- Canar 03:36, 13 February 2007 (UTC)

Thank you!

[edit] Alt. players - XBMC

I really think the text after XBMC in the alternate player list needs to be reworded. It's derogatory towards the Xbox modding scene, and the fact that is uses other open source programs like Mplayer to play back video and audio (don't remember the audio player off the top of my head) makes it almost irrelevant towards the list. --AndrewNeo 23:35, 11 March 2007 (UTC)