Hi, Kiste, > Oh, when you play them in mplayer, all codec information will be written? > to the console. No need to ask someone, I think. I tried your suggestion.? I viewed the codec information of one of the input wmv's in mplayer.? I also tried viewing the codec info of the stitched wmv. To my surprise, the stitched wmv file played in mplayer with audio!!!? I tried the rest of the sample stitched files and they all played with audio in mplayer.? How come the files don't play with audio in Windows Media Player 10? Anthony