what codec supports 24bit encoding ?

is there a codec/encoder that can compress 24 bits wave without converting to 16 bits ? (excluding lossless format) lame and vorbis seems treat input as 16 bits even without verifying. and also how about 96/192khz ?

MPC, DTS, and maybe AAC ... not sure about AAC But you could always convert the 24-bit WAV to 16-bit using SSRC as you are going to use lossy compression anyway. SSRC applies a dither algorithm so you should not loose much quality. If you use MPC be aware that the codec is currently only tuned for 44.1 and 48kHz sample rates; again SSRC will be able to help with this. [edit] added note about dither

Lame treat input as floating. So if you have 24bits input, use it, Lame won't convert it to 16 bits.

ogg.vorbsi supports up to 32bit float as input Psytel AAC encoder support 24bit but have som size limitations (the encoder. NOT the codec)