> > Hi > > I am a student doing a University project. I am trying to add MS > stereo to the dist10 code so it will be useful if I know where the > tonality index c(w) is called and saved. I am trying to use it for > MS threshold calculations. Just a little curious about the > psymodel.c functions L3psycho_anal_ns and L3psycho_anal. Counldn't > really understand the psychoacoustics model 2 of dist10. In dist10, > there is only one call for psycho analysis. What are the differences > between these 2 function calls? They look quite similar to me > especially the agruments that are being called from encoder.c. Will > appreciate all help. >
One of the biggest differences between l3psycho_anal_ns and l3psyco_anal is exactly what you are asking about - how the estimate the tonality index. One is a tweaked and cleaned up version of the MPEG1/2 recommendation: the predictiictability of the energy in each band over several granules. I believe it comes from thesis work of one of the creators of MP3. The other is based on how peaked the spectrum is, and uses data just from a single granule. Naoki wrote it based on data in Zweicker's book. Keep in mind that all the models are very crude estimates, and the output should be considered as a rough guide to the noise shaping algorthims rather than absolute truth. Mark _______________________________________________ mp3encoder mailing list [EMAIL PROTECTED] http://minnie.tuhs.org/mailman/listinfo/mp3encoder