Hello evereybody; I am very confused and i hope that someone could help me. In fact i'm using an ADC 12bit to sample voice and then i encode the data using Speex. The problem is when i try to decode and replay the voice samples i got much noise. I think that the pb is iabout the conversion from 12bit unsigned to 16bit signed format which is required by speex codec. i have used the following code: signed_vakue16 = (unsigned_value12<<4)^0x8000; also i have tryed to convert the 12bit into 8bit and then transformat it into 16bit signed format: signed_vakue16 = ((unsigned_value12>>4)<<8)^0x8000; could anyone please give me more clarifiations, thanks best regards to all Seif _________________________________________________________________ Appelez vos amis de PC ? PC -- C'EST GRATUIT http://get.live.com/messenger/overview -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20080605/eb1d831c/attachment.htm