v.packy_uv v.packy_uv takes 2 gray scale streams and combines them into an yuv image. v.packy_uv takes 2 gray scale streams and combines them into an yuv image. The first stream is the y values. The second stream contains the u and v values (alternating u then v then u) each at 1/2 the resolution of the y components. The yyyy stream and the uvuv streams are packed into a yuyvyuyv stream (normal yuv) N.B. the u and v streams are assumed to be signed. 0 - 127 are positive values and 128 - 255 are actually -128 to -1. (Note that this is different from the pseudo-signed images like those from v.motion (signed mode) where 0 - 127 are really negative and 128 - 255 are positive. To convert an unsigned or pseudo-signed int8 stream to a signed int8 stream or vice versa, you can use a v.xor 128 object.

from the library : softVNS Format : External Environment : jitter / max commercial Max 4.x http://homepage.mac.com/davidrokeby/softVNS.html