Apple AAC: Difference between revisions
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'''QuickTime AAC''' is known to be one of the highest quality medium-bitrate [[CBR]] and [[VBR]] LC | '''QuickTime AAC''' is known to be one of the highest quality medium-bitrate [[CBR]] and [[VBR]] LC | ||
[[AAC]] encoders and is also another commercial | [[AAC]] encoders and is also another commercial AAC implementation. The current version of Quicktime supports [[Multichannel]] encoding up to 8 channels, and HE-AAC v1 with [[SBR]]. | ||
Although this is a comercial implementation and part of the QuickTime Pro package, VBR and CBR modes (with a maximum [[sampling rate]] of 44.1khz for iTunes 10+ and 48khz for iTunes 9-) are available for free | Although this is a comercial implementation and part of the QuickTime Pro package, VBR and CBR modes (with a maximum [[sampling rate]] of 44.1khz for iTunes 10+ and 48khz for iTunes 9-) are available for free | ||
through [http://www.apple.com/itunes/ iTunes ] | through [http://www.apple.com/itunes/ iTunes ] | ||
Third-party interfaces such as [http://sites.google.com/site/qaacpage/ qAAC] expose more modes such as TVBR (equivalent to quality modes in other encoders) and CVBR ("constrained VBR") | Free Third-party interfaces such as [http://sites.google.com/site/qaacpage/ qAAC] expose more modes such as TVBR (equivalent to quality modes in other encoders) and CVBR ("constrained VBR") | ||
Multichannel channel mapping is buggy but can be | Multichannel channel mapping is buggy but can be remedied by installing an older version of Quicktime (7.68-) | ||
In recent tests for [http://listening-tests.hydrogenaudio.org/igorc/results.html 64kbps HE-AAC] and [http://listening-tests.hydrogenaudio.org/igorc/aac-96-a/results.html 96kbps LC-AAC] Quicktime has consistently come out near the top. | |||
In 2009, the core AAC encoding algorithm was updated with "higher fidelity". The bitrate distribution algorithm was also changed. | |||
More information can be found at the [http://www.apple.com/quicktime Apple Quicktime Website] | More information can be found at the [http://www.apple.com/quicktime Apple Quicktime Website] | ||
{{stub}} | {{stub}} | ||
Revision as of 06:19, 17 September 2011
QuickTime AAC is known to be one of the highest quality medium-bitrate CBR and VBR LC AAC encoders and is also another commercial AAC implementation. The current version of Quicktime supports Multichannel encoding up to 8 channels, and HE-AAC v1 with SBR.
Although this is a comercial implementation and part of the QuickTime Pro package, VBR and CBR modes (with a maximum sampling rate of 44.1khz for iTunes 10+ and 48khz for iTunes 9-) are available for free through iTunes
Free Third-party interfaces such as qAAC expose more modes such as TVBR (equivalent to quality modes in other encoders) and CVBR ("constrained VBR")
Multichannel channel mapping is buggy but can be remedied by installing an older version of Quicktime (7.68-)
In recent tests for 64kbps HE-AAC and 96kbps LC-AAC Quicktime has consistently come out near the top.
In 2009, the core AAC encoding algorithm was updated with "higher fidelity". The bitrate distribution algorithm was also changed.
More information can be found at the Apple Quicktime Website
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