Hi Jean-Marc, I have been a DSP man for 10 years, and i like speex. i want to do some thing that can help you to work out the fixed-point program of speex. In the recent release 1.1.6, there are fixed-point simulation in many files. I want to know what and how to help you. stereo.c, smallft.c, preprocess.c are not fixed-point yet. Can I start from these or? before your reply, i will take a close look on programs of speex. Best Regards, Jerry Wang YiDSP Consulting