It is used in memory stick walkman and the like, the speech compression technology which SONY developed. Those which improvethe ATRAC technology of the same company.The SONY product focusing on,music transmission serviceand MDLP etc. it is adopted.The data quantity after the compressing from 1 of 4 parts becomes 1 of 20 parts depending upon bulk compressibility.I fthe
sound quality like CD it is assumedthat it becomes furthermore 1 of the half 10 parts of ATRAC.With ATRAC3,it dividesATRAC similar and the aural signal into four frequency zoneswiththe bandwidth division filter. After that, fromthe time based data string it converts to the frequency based data string Modified DCT
with, it compresses encodes. ... At that time, making use of the quality of hearing of the human, the quantity of the data which is encoded without Impairing the sound quality by between pulling the data of front and back of the componentandthe big sound which are difficult to be audible, is decreased. ATRAC3 has made effective compressionpossible by raising the distinction precision of at this thinning in2times that ATRAC. The foundation of these principles after that is the sameasthe speech compressionof MP3and the like which appears. With the SDMI project which is promotedby music industry, while protective copyright technical specification in order to do the circulation of the music data is decided, but the fact that you adopt ATRAC3 as one of compressed systems is examined. |
