Why can't I rewind and fast foward..

.Wmv files and some .mpeg files??? Everytime I try, they stop playing and go ALL the way back to the start. The only way I can rewind and fast foward is to open them in Soundforge. Is this a codec problem???

No, it just means the file hasn’t been indexed and is meant for streaming only. You can view it in one sitting, but you can’t jump to a specific point. That’s what the person who encoded it intended. It’s usually done for streaming file types or to shrink files to a max (indices are like keyframes and take a bit of space).

P.S: I suspect the mpeg files who behave that way are just renamed wmv’s. To be sure feed them into avicodec and see if the file type says “ASF”.