Ivan Dimkovic: PsyTEL AAC Developer

PNS is not handled well with current public versions of FAAD. Menno and I
have just talked about the issue, and this will be fixed soon. Anyway, PNS
needs "tweaking", for example I use following switch for 64 kbps, 44100
mode:

aacenc -br 64 -c 11500 -pns -psf 7000 -if somefile.wav

Some switches control PNS:

-ptt
    PNS switch threshold (for some test samples it needs to be at least
    0.6, default is 0.5)

-psf
    PNS start frequency, default is 4 kHz - under this frequency PNS might
    seriously degrade signal

PNS will need more tweaking, of course.

Note: PNS is not a magic wand, or a bandwidth extension (like SBR used in
MP3Pro or PlusV) - so the results at 64 kbps can't be spectacular. MPEG
commitee is working on incorporation of bandwidth extension tool (probably
SBR) so we all are looking forward to see new MPEG-4 profile with SBR.

Please use -profile 0 with PNS... I recommend Profile 0 always.