If a video cannot be played without being jerky, the computer performance may be too low. The following options are available::
Use Intermediate Video Date. They allow bypassing of Windows routines and demand only moderate performance. See Optimization through Intermediate Video Data.
Do without pitching. Playing videos at varying speed, i.e. when they are compressed or expanded, requires more computer performance as the playback mode has to be changed. See Video Object Properties.
Create a video using a smaller picture size and/or lower frame rate. See Tips for video rendering.
Use a codec with lower CPU usage, e.g. WMV or MPEG-2. See also MPEG-2, H.264 or WMV format?