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Thu, 2009-07-02 20:50 — admin

Audio

Codec

AAC

The best codec for audio compression is MPEG-4 aacPlus v2, also called HE-AAC or simply AAC. It is extremely efficient for high quality audio and gives the best results among all codecs even at low bitrates. It uses SBR and PS to make a very good use of bandwith.
To rip a CD into AAC, it takes about 5 minutes and 20MB for a whole CD. AAC at 48 kbps is as good as mp3 at 128 kbps and as good as a CD.
To rip a CD and encode it in AAC, there are few good softwares:

  1. Easy CD-DA extractor: very rapid, parametrization, good interface
  2. Winamp: good, retrieve titles from internet DBgrace, but makes errors (my experience).
  3. Nero CD ripping, dbpoweramp, others (http://www.download.com/Audio-Video-Software/2001-2025_4-0.html?tag=dir)

Best codecs:

  1. aacPlus v2
  2. MP3pro
  3. OGG Vorbis
  4. MP3

References:
http://www.codingtechnologies.com/products/aacPlus.htm

aacPlus withe paper.
http://www.codingtechnologies.com/products/assets/CT_aacPlus_whitepaper.pdf

http://en.wikipedia.org/wiki/HE-AAC

Summary from wikipedia
Perceived quality

It is sometimes claimed that a 48- or 64-kilobit per second|kbit/s HE-AAC stream, when decoded to audio, will produce similar quality output to MP3 at 128 kbit/s. HE-AAC generally outperforms other popular codecs on non time-critical audio materials light music in the 32–64 kbit/s range. Its main competition for delivering acceptable quality at these bitrates comes from MP3pro, which also employs SBR.

Decoders that do not support SBR will simply play back the LC-AAC part of the audio, generally resulting in significantly reduced quality, since it is typically half the sampling rate therefore the audio bandwidth.

== Support ==
HE-AAC is supported in the open source FAAD/FAAD2 decoding library (and all players incorporating it), Winamp, foobar2000, and Sony's latest SonicStage version 4.

HE-AAC is also used by AOL Radio clients to deliver high-fidelity music at low bitrates.

As of 2007, neither iTunes, nor iPod supports HE-AAC. Only MPEG 2 AAC (MPEG 2 Audio - part 3) is supported so the only players for Mac OS X are VLC (without metadata/title streaming) and Songbird.

Ahead Nero has released a free of charge command line HE-AAC encoder, and also support HE-AAC inside the Nero software suite.

The 3GPP consortium released source code of a reference HE-AACv2 encoder that appears to be quite competitive regarding quality <ref>http://www.mp3-tech.org/tests/aac_48/results.html</ref>. No community-supported Free Software encoder is available yet.

CD ripping

I recommend using Easy CD-DA Extractor, or winamp or DBpowerAMP or audiograbber.

Reference:
The top softwares for Win/Mac: http://www.download.com/sort/3120-20_4-0-1-4.html?qt=cd+ripping&ca=20