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Hydrogenaudio AAC Listening Test Results
caffeine_monkey writes "Hydrogenaudio's AAC public listening test, previously posted on Slashdot, is now over and the results are in. The test compared five codecs at 128 kbps, including Psytel, Nero, Sorenson Squeeze, QuickTime, and FAAC. The winner? 'QuickTime is a clear winner, performing much better than the competition. Sorenson Squeeze, Psytel AACenc and Nero are tied, with Sorenson slightly higher than the others. Faac is clearly the worst.'"
From Apple's AAC page
Because of its exceptional performance and quality, Advanced Audio Coding (AAC) is at the core of the MPEG-4 and 3GPP specifications and is the new audio codec of choice for Internet, wireless, and digital broadcast arenas. AAC provides audio encoding that compresses much more efficiently than older formats such as MP3, yet delivers quality rivaling that of uncompressed CD audio.
AAC was developed by the MPEG group that includes Dolby, Fraunhofer (FhG), AT&T, Sony, and Nokia--companies that have also been involved in the development of audio codecs such as MP3 and AC3 (also known as Dolby Digital). The AAC codec in QuickTime 6 builds upon new, state-of-the art signal processing technology from Dolby Laboratories and brings true variable bit rate (VBR) audio encoding to QuickTime.
From Via Licensing
MPEG-4 AAC has been specified as the high-quality general audio coder for 3G wireless terminals. Apple Computer has incorporated MPEG-4 AAC into QuickTime 6 and iTunes 4, as well as the latest version of its award-winning iPod portable music player. The Digital Radio Mondiale system (the next-generation digital replacement for radio broadcasting under 30 MHZ) builds on the audio coding of MPEG-4 AAC. These exciting platforms represent the state of the art in audio coding--and Via Licensing is pleased to offer the MPEG-4 AAC Patent License Agreement.
The MPEG-4 AAC standard incorporates MPEG-2 AAC, forming the basis of the MPEG-4 audio compression technology for data rates above 32 kbps per channel. Additional tools increase the effectiveness of MPEG-2 AAC at lower bit rates, and add scalability or error resilience characteristics. These additional tools extend AAC into its MPEG-4 incarnation (ISO/IEC 14496-3, Subpart 4).
A copy of the MPEG-4 Audio standard can be purchased from the ISO online store (search for "14496-3").
Actually I do not agree with you at all. Comparing different encoders for a certain format is a complete test. In this particular case, the goal was to find out which AAC encoder is the best. The results answered that question.
As an Open-Source (and open standards) advocate it is easy to look at such a test and say "but Ogg/MP3/whatever is better anyways, they should have included them". Actually saying so leads nowhere at all.
If you want a comparison between Ogg, AAC, WMA and MP3, then do such a comparison. But this was not a test to find our which format/algorithm was the best, it was a test to find out which AAC encoder was the best, which is also what the test answered.
Not every test in the world should always include all and every variant of the test subject in question. Just because you're comparing the quality of carrots from different farmers, you shouldn't automatically be expected to include potatoes in the comparison just because there are people that prefer potatoes over carrots. If the test question was "which is the best vegetable", then omitting potatoes could be considered careless.
And, in very much the same way, if the test question is "which is the best AAC encoder", including MP3-or Ogg-encoders would be just as wrong.
That's my view, at least.
/Viktor...
As a musician myself, I can tell you that one of the most important aspects of a stereo to me is its ability to be manipulated with my toes. Makes transcribing music much easier.
"God is a comedian playing to an audience too afraid to laugh." -Voltaire
RTFA. This was onlyl the first step; next, HydrogenAudio will take the AAC winner (QuickTime) and compare it to what they consider the best encoders for the OGG Vorbis, WMA, MP3, etc.