What is ATRAC?

[aznmist]

http://www.memorystick.com/en/lifes...sic/tech03.html

I know it's a audio compression technology but wanted to know how quality is affected by it. I know MDs use ATRAC technology, but is it only used when MDLP is activated? Does quality degrade a lot when it is in use?

 

[casio3476]

atrac is an encoding scheme used by sony with its minidisc products. Im actually doing a bit of research about how it physically encodes thes files, but a lot of the information i am finding is over my head.

Atrac is used in every mode (stereo, mono, lp2,lp4)

here is an overview of the entire ATRAC system. If anyone can make sense of this, or point me in a direction where I can learn the basics on "physchoacoutstic principles" and such


Adaptive Transform Acoustic Coding


also if anyone knows where i can learn the encoding principles behind MP3, wma, ogg, and others feel free to share them


as far a quality degredation, i can not tell a stereo encoded minidisc from a CD, in lp2 mode the resulting file sounds similar to an mp3 at ~140k and in lp4 mode the sound degredation is severe, equvalent to an mp3 encoded at less than 100k (its acceptable for microphone recordings and the radio though)

 

[PowerMacG5]

Originally posted by: casio3476
atrac is an encoding scheme used by sony with its minidisc products. Im actually doing a bit of research about how it physically encodes thes files, but a lot of the information i am finding is over my head. Atrac is used in every mode (stereo, mono, lp2,lp4) here is an overview of the entire ATRAC system. If anyone can make sense of this, or point me in a direction where I can learn the basics on "physchoacoutstic principles" and such Adaptive Transform Acoustic Coding also if anyone knows where i can learn the encoding principles behind MP3, wma, ogg, and others feel free to share them as far a quality degredation, i can not tell a stereo encoded minidisc from a CD, in lp2 mode the resulting file sounds similar to an mp3 at ~140k and in lp4 mode the sound degredation is severe, equvalent to an mp3 encoded at less than 100k (its acceptable for microphone recordings and the radio though)

I have never had a problem recording in lp4 mode. I can not here a difference between lp2. As far as mp3 encoding goes, in my limited knowledge of it, I believe the way it drastically reduces size is by removing the information we cannot hear.