Since I tried to code Matrix Reloaded, when I tried to open the avisynth project made with GKnot in VirtualDubMod or make a preview of the video with W. Media player (always) appeared the following error: "Couldn't locate decompressor for format 'YV12' (unknown). VirtualDub requires a Video for Windows compatible codec to decompress video. DirectShow codecs, such as those used by windows media player aren't suitable. Only direct stream copy is available for this video" So I couldn't/can't process the video neither compress it. What should I do? 1) Download the latest version of Windows Media Player? 2) Download a pack of codecs that can decompress this format 'YV12'? 3) Re-install windows???? - because this is the first time that appears this message and with other movies I coded before without no problem, now reports me that error - 'not found a codec for YV12' 4) Could it come because I recently uninstalled TMPEG-encoder, and perhaps, somehow mpeg codec dissapeared misteriously o_O? Thanks go to everybody that can solve this ENORMOUS problem :eek: