I use the main encoder with the defaults. I am converting divx to ntsc dvd elementary stream. I leave the defaults for the i and p frames. The i frame is 15 and the p frame is 5. When I use the tmpgenc dvdauthor program I get an error message stating the gop is too long and the dvd will be out of standard. What causes this? I think I know but I am not sure. The file I am converting to ntsc dvd elementary stream is 23.976 frames(ntsc film). I use the 3:2 pulldown progressive setting. When the source is 23.976 am I suppose to change the i frames to 12 and the p frames to 2? I tested it with 12 frames and the authoring program gave no error. Will the dvd still be compliant and will this effect the quality of it by reducing the i frames by 3 and the p frames by 3?