Normalize gived me an acces violation. :( i tested it only one time, so it could be an user issue. when i speaked of MMX, it was only for the loading of the samples. it takes too much time. maybe MMXing would help.what do you think. BTW, when do you add floting-point samples in avisynth ?? I heard there would be YUV12 in next version of avisynth too. How exactly would it be done ? I'd really like deinterleaved (or 128 bit interleaved) YUV data.