Prepares the loaded sound for a playback session where the usage of a scrolling waveform may be needed.
In order to optimize system resources, when pre-loading is disabled (default situation), the stream to play is only loaded when specifically requested through a call to the PlaySound or PlaySoundRange methods and automatically discarded from memory after a call to the StopSound method or when the end of the song is reached. In this situation it's not possible to visually set an initial position through a scrolling waveform until the loaded sound is not in playback. By enabling pre-load through this method, the sound stream is immediately available in memory after a recording or editing session so could set an initial position for playback directly into a scrolling waveform as seen inside the SoundEditor sample.
As a further feature, when pre-load is enabled there is the possibility to distinguish if the sound playback is stopped through the GetPlaybackStatus method..
For details about creating a scrolling waveform, refer to the section "Mode 3: Rendering on a graphic Device Context (HDC)" of the How to use the Waveform Analyzer tutorial.