AAC FAQ - Revision history

178.83.188.253: /* Overview AAC FAQ */ fix typo

2017-01-07T11:45:25Z

Overview AAC FAQ: fix typo

← Older revision		Revision as of 11:45, 7 January 2017
Line 11:		Line 11:

	===What is the difference between LC (Low Complexity) and HE (High Efficiency)?===		===What is the difference between LC (Low Complexity) and HE (High Efficiency)?===
	These are two of the various Object Types in the MPEG4 Systems Standard. LC is the most popular Object Type with all encoders/decoders supporting it. Currently, Apple, Nero, Coding Technolgies, and Panasonic have incorporated the HE AAC standard into their encoders, which allows for higher quality sound at lower bitrates ~~then~~ the LC Object Type does (at the same bitrate). The HE Object Type is only used for music with a bitrate of less than ~80kbps.		These are two of the various Object Types in the MPEG4 Systems Standard. LC is the most popular Object Type with all encoders/decoders supporting it. Currently, Apple, Nero, Coding Technolgies, and Panasonic have incorporated the HE AAC standard into their encoders, which allows for higher quality sound at lower bitrates than the LC Object Type does (at the same bitrate). The HE Object Type is only used for music with a bitrate of less than ~80kbps.

	===What's the best AAC encoder?===		===What's the best AAC encoder?===

Bp: /* What's the best AAC encoder? */

2016-07-12T00:25:10Z

What's the best AAC encoder?

← Older revision		Revision as of 00:25, 12 July 2016
Line 14:		Line 14:

	===What's the best AAC encoder?===		===What's the best AAC encoder?===
			{{aac-encoders}}
	Deciding the best AAC encoder is difficult, because the quality of an encoding depends not only on the encoder implementation, but also on bitrate, audio content, playback equipment and conditions, and the subjective perceptual judgement of the listener at playback time.		Deciding the best AAC encoder is difficult, because the quality of an encoding depends not only on the encoder implementation, but also on bitrate, audio content, playback equipment and conditions, and the subjective perceptual judgement of the listener at playback time.

153.177.42.14: /* What's the best AAC encoder? */ removed outdated info and added new results.

2013-10-02T16:22:36Z

What's the best AAC encoder?: removed outdated info and added new results.

← Older revision		Revision as of 16:22, 2 October 2013
Line 18:		Line 18:
	Since it is very difficult to quantify the quality of an encoder, [[Listening Tests\|listening tests]] are used.		Since it is very difficult to quantify the quality of an encoder, [[Listening Tests\|listening tests]] are used.

	~~Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last~~ test] concluded that [~~http://www~~.~~nero~~.~~com/en/ Nero~~ AAC~~] was~~ the ~~best~~ AAC encoder, at 128kbps, on ~~classical samples~~, ~~at the time the test was conducted~~.		A public listening test conducted by rjamorim in mid-2004 comparing different codecs, at 128kbps, with several music styles and featuring several listeners concluded that [[iTunes]] (the only AAC codec included in the test) was better than other codecs - even VBR-enabled ones.

			The quality of any encoder is not linear with bitrates, and therefore these results may not be extrapolated to other higher or lower bitrates. It can also be said with great confidence that both the iTunes AAC encoder and the Nero AAC encoder are relatively 'mature' and should not fail badly (result in any obvious artifacts) on any particular sample at an average bitrate of 128kbps (i.e. Internet Profile for Nero AAC) or above (based on Roberto's listening tests, see bottom).

	~~On the other hand, a~~ public listening test conducted by ~~rjamorim~~ in ~~mid-2004~~ comparing ~~different codecs~~, at ~~128kbps~~, ~~with several music styles and featuring several listeners~~ concluded that [[~~iTunes~~]] (the ~~only AAC~~ codec ~~included in~~ the ~~test) was better than other~~ codecs ~~- even VBR-enabled ones~~.		A public listening test conducted by IgorC in July 2011 comparing Nero, QuickTime True VBR, QuickTime Constrained VBR, Fraunhofer IIS (via Winamp 5.62), Coding Technologies (via Winamp 5.61), ffmpeg's AAC, at 96kbps, concluded that [[QuickTime]] was the best codec among the 6 codecs. Fraunhofer IIS (via Winamp 5.62) came next. ffmpeg's AAC, considered experimental at the time of the test, came in dead last.

	~~The quality of any encoder is not linear with bitrates, and therefore these results can not be extrapolated to other higher or lower bitrates~~. ~~It can also be said with great confidence that both the iTunes~~ AAC ~~encoder and the Nero AAC encoder~~, ~~although still under development~~ at the ~~end~~ of ~~2006~~, ~~are relatively 'mature' and should not fail badly (result~~ in ~~any obvious artifacts) on any particular sample at an average bitrate of 128kbps (i.e. Internet Profile for Nero AAC) or above (based on Roberto's listening tests, see bottom)~~.

	Beyond that, only you can decide; you may want to conduct your own private [[Listening Tests\|listening tests]], or you may base your decision on other criteria besides audio quality. See the [[Audio format guide]] for more information.		Beyond that, only you can decide; you may want to conduct your own private [[Listening Tests\|listening tests]], or you may base your decision on other criteria besides audio quality. See the [[Audio format guide]] for more information.

87.114.111.131: Removed old rjamorim site linking.

2012-12-31T16:03:43Z

Removed old rjamorim site linking.

← Older revision		Revision as of 16:03, 31 December 2012
Line 20:		Line 20:
	Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last test] concluded that [http://www.nero.com/en/ Nero AAC] was the best AAC encoder, at 128kbps, on classical samples, at the time the test was conducted.		Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last test] concluded that [http://www.nero.com/en/ Nero AAC] was the best AAC encoder, at 128kbps, on classical samples, at the time the test was conducted.

	On the other hand, a public ~~[http://www.rjamorim.com/test/multiformat128/results.html~~ listening test] conducted by ~~[[User:rjamorim\|~~rjamorim]] in mid-2004 comparing different codecs, at 128kbps, with several music styles and featuring several listeners concluded that [[iTunes]] (the only AAC codec included in the test) was better than other codecs - even VBR-enabled ones.		On the other hand, a public listening test conducted by rjamorim in mid-2004 comparing different codecs, at 128kbps, with several music styles and featuring several listeners concluded that [[iTunes]] (the only AAC codec included in the test) was better than other codecs - even VBR-enabled ones.

	The quality of any encoder is not linear with bitrates, and therefore these results can not be extrapolated to other higher or lower bitrates. It can also be said with great confidence that both the iTunes AAC encoder and the Nero AAC encoder, although still under development at the end of 2006, are relatively 'mature' and should not fail badly (result in any obvious artifacts) on any particular sample at an average bitrate of 128kbps (i.e. Internet Profile for Nero AAC) or above (based on Roberto's listening tests, see bottom).		The quality of any encoder is not linear with bitrates, and therefore these results can not be extrapolated to other higher or lower bitrates. It can also be said with great confidence that both the iTunes AAC encoder and the Nero AAC encoder, although still under development at the end of 2006, are relatively 'mature' and should not fail badly (result in any obvious artifacts) on any particular sample at an average bitrate of 128kbps (i.e. Internet Profile for Nero AAC) or above (based on Roberto's listening tests, see bottom).
Line 40:		Line 40:
	* Known [[AAC implementations]].		* Known [[AAC implementations]].
	* Read the [[AAC guide]] to learn how to obtain AAC/[[MP4]] files out of [[WAV]] files and CDs.		* Read the [[AAC guide]] to learn how to obtain AAC/[[MP4]] files out of [[WAV]] files and CDs.
	* Detailed AAC comparisons can be found at ~~<s>[http://www.rjamorim.com/test/~~ Roberto's listening tests page~~]</s>~~.		* Detailed AAC comparisons can be found at Roberto's listening tests page.


	[[Category:Technical]]		[[Category:Technical]]
	[[Category:Codecs]]		[[Category:Codecs]]

109.149.14.19: /* Related Links */ rjamorim link (dead link), Strike Thru.

2012-10-25T19:45:59Z

Related Links: rjamorim link (dead link), Strike Thru.

← Older revision		Revision as of 19:45, 25 October 2012
Line 40:		Line 40:
	* Known [[AAC implementations]].		* Known [[AAC implementations]].
	* Read the [[AAC guide]] to learn how to obtain AAC/[[MP4]] files out of [[WAV]] files and CDs.		* Read the [[AAC guide]] to learn how to obtain AAC/[[MP4]] files out of [[WAV]] files and CDs.
	* Detailed AAC comparisons can be found at [http://www.rjamorim.com/test/ Roberto's listening tests page].		* Detailed AAC comparisons can be found at <s>[http://www.rjamorim.com/test/ Roberto's listening tests page]</s>.


	[[Category:Technical]]		[[Category:Technical]]
	[[Category:Codecs]]		[[Category:Codecs]]

Junh1024 at 09:52, 17 September 2011

2011-09-17T09:52:09Z

← Older revision		Revision as of 09:52, 17 September 2011
Line 11:		Line 11:

	===What is the difference between LC (Low Complexity) and HE (High Efficiency)?===		===What is the difference between LC (Low Complexity) and HE (High Efficiency)?===
	These are two of the various Object Types in the MPEG4 Systems Standard. LC is the most popular Object Type with all encoders/decoders supporting it. Currently, Nero, Coding Technolgies, and Panasonic have incorporated the HE AAC standard into their encoders, which allows for higher quality sound at lower bitrates then the LC Object Type does (at the same bitrate). The HE Object Type is only used for music with a bitrate of less than ~80kbps.		These are two of the various Object Types in the MPEG4 Systems Standard. LC is the most popular Object Type with all encoders/decoders supporting it. Currently, Apple, Nero, Coding Technolgies, and Panasonic have incorporated the HE AAC standard into their encoders, which allows for higher quality sound at lower bitrates then the LC Object Type does (at the same bitrate). The HE Object Type is only used for music with a bitrate of less than ~80kbps.

	===What's the best AAC encoder?===		===What's the best AAC encoder?===
	~~There is no~~ best AAC encoder ~~as such~~, because the quality of an encoding depends not only on the encoder implementation, but also on ~~bitrates~~, ~~sometimes on the specific~~ audio ~~sample being encoded~~, and ~~finally~~, on the subjective perceptual judgement of the listener at playback time ~~(which is also influenced by the equipment being used for playback)~~.		Deciding the best AAC encoder is difficult, because the quality of an encoding depends not only on the encoder implementation, but also on bitrate, audio content, playback equipment and conditions, and the subjective perceptual judgement of the listener at playback time.

	Since it is very difficult to quantify the quality of an encoder, [[Listening Tests\|listening tests]] are used.		Since it is very difficult to quantify the quality of an encoder, [[Listening Tests\|listening tests]] are used.

HotshotGG at 23:20, 10 June 2008

2008-06-10T23:20:39Z

← Older revision		Revision as of 23:20, 10 June 2008
Line 1:		Line 1:
			=Overview AAC FAQ=
	===Great, so you've given me all the technical stuff, but what is [[AAC]] really?===		===Great, so you've given me all the technical stuff, but what is [[AAC]] really?===
	[[AAC]] is the culmination of the current state of the art audio encoding techniques. It is designed		[[AAC]] is the culmination of the current state of the art audio encoding techniques. It is designed

Gigapod: /* What hardware players can play back AAC music? */

2006-11-26T20:23:46Z

What hardware players can play back AAC music?

← Older revision		Revision as of 20:23, 26 November 2006
Line 32:		Line 32:

	===What hardware players can play back AAC music?===		===What hardware players can play back AAC music?===
	There are also a few hardware players that can play back AAC audio. The most famous of these is the [[Apple iPod]] series of products, all of which feature AAC playback. A number of mobile (cell) phones also support unwrapped AAC (AAC not contained in the MP4 container). Recent Pioneer HT receivers can play back AAC files on a USB key or other mass-storage device.		There are also a few hardware players that can play back AAC audio. The most famous of these is the [[Apple iPod]] series of products, all of which feature AAC playback. A number of mobile (cell) phones also support unwrapped AAC (AAC not contained in the MP4 container). Recent Pioneer HT receivers can play back AAC files on a USB key or other USB mass-storage device.

	==Related Links==		==Related Links==

Gigapod: /* What's the best AAC encoder? */

2006-11-26T20:15:11Z

What's the best AAC encoder?

← Older revision		Revision as of 20:15, 26 November 2006
Line 23:		Line 23:
	The quality of any encoder is not linear with bitrates, and therefore these results can not be extrapolated to other higher or lower bitrates. It can also be said with great confidence that both the iTunes AAC encoder and the Nero AAC encoder, although still under development at the end of 2006, are relatively 'mature' and should not fail badly (result in any obvious artifacts) on any particular sample at an average bitrate of 128kbps (i.e. Internet Profile for Nero AAC) or above (based on Roberto's listening tests, see bottom).		The quality of any encoder is not linear with bitrates, and therefore these results can not be extrapolated to other higher or lower bitrates. It can also be said with great confidence that both the iTunes AAC encoder and the Nero AAC encoder, although still under development at the end of 2006, are relatively 'mature' and should not fail badly (result in any obvious artifacts) on any particular sample at an average bitrate of 128kbps (i.e. Internet Profile for Nero AAC) or above (based on Roberto's listening tests, see bottom).

	Beyond that, only you can decide; you may want to conduct your own private [[Listening Tests\|listening tests]], or you may base ~~yourself~~ on other ~~parameters~~ besides audio quality. See the [[Audio format guide]] for more information.		Beyond that, only you can decide; you may want to conduct your own private [[Listening Tests\|listening tests]], or you may base your decision on other criteria besides audio quality. See the [[Audio format guide]] for more information.

	===Do AAC encoded files play back gaplessly?===		===Do AAC encoded files play back gaplessly?===

Gigapod: /* What's the best AAC encoder? */

2006-11-26T20:14:02Z

What's the best AAC encoder?

← Older revision		Revision as of 20:14, 26 November 2006
Line 15:		Line 15:
	There is no best AAC encoder as such, because the quality of an encoding depends not only on the encoder implementation, but also on bitrates, sometimes on the specific audio sample being encoded, and finally, on the subjective perceptual judgement of the listener at playback time (which is also influenced by the equipment being used for playback).		There is no best AAC encoder as such, because the quality of an encoding depends not only on the encoder implementation, but also on bitrates, sometimes on the specific audio sample being encoded, and finally, on the subjective perceptual judgement of the listener at playback time (which is also influenced by the equipment being used for playback).

	Since it is very difficult to quantify the quality of an encoder, [[Listening Tests] listening tests] are used.		Since it is very difficult to quantify the quality of an encoder, [[Listening Tests\|listening tests]] are used.

	Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last test] concluded that [http://www.nero.com/en/ Nero AAC] was the best AAC encoder, at 128kbps, on classical samples, at the time the test was conducted.		Guruboolez's [http://www.hydrogenaudio.org/forums/index.php?showtopic=29924 last test] concluded that [http://www.nero.com/en/ Nero AAC] was the best AAC encoder, at 128kbps, on classical samples, at the time the test was conducted.
Line 23:		Line 23:
	The quality of any encoder is not linear with bitrates, and therefore these results can not be extrapolated to other higher or lower bitrates. It can also be said with great confidence that both the iTunes AAC encoder and the Nero AAC encoder, although still under development at the end of 2006, are relatively 'mature' and should not fail badly (result in any obvious artifacts) on any particular sample at an average bitrate of 128kbps (i.e. Internet Profile for Nero AAC) or above (based on Roberto's listening tests, see bottom).		The quality of any encoder is not linear with bitrates, and therefore these results can not be extrapolated to other higher or lower bitrates. It can also be said with great confidence that both the iTunes AAC encoder and the Nero AAC encoder, although still under development at the end of 2006, are relatively 'mature' and should not fail badly (result in any obvious artifacts) on any particular sample at an average bitrate of 128kbps (i.e. Internet Profile for Nero AAC) or above (based on Roberto's listening tests, see bottom).

	Beyond that, only you can decide; you may want to conduct your own private [[Listening Tests] listening tests], or you may base yourself on other parameters besides audio quality. See the [[Audio format guide]] for more information.		Beyond that, only you can decide; you may want to conduct your own private [[Listening Tests\|listening tests]], or you may base yourself on other parameters besides audio quality. See the [[Audio format guide]] for more information.

	===Do AAC encoded files play back gaplessly?===		===Do AAC encoded files play back gaplessly?===