Positive integers indicate forward rates and negative integers indicate reverse rates. Your application can change the preferred playback rate by calling the SetMoviePreferredRate function, which is described in the previous section. You can change the current playback rate of a movie by calling the SetMovieRate function, which is described on SetMovieRate . The SetMoviePreferredVolume function allows your application to set a movie's preferred volume setting. Volume values range from -1.0 to 1.0.
Negative values play no sound but preserve the absolute value of the volume setting.
Your application can obtain the preferred volume setting by calling the GetMoviePreferredVolume function, which is described in the next section. You can change a movie's current volume by calling the SetMovieVolume function, which is described on SetMovieVolume . A movie's tracks may have their own volume settings. Use the SetTrackVolume function, described on SetTrackVolume , to set the volume of an individual track. A track's volume is scaled by the movie's volume to produce the track's final volume.