Monitor the current playback position within the data block by using the waveOutGetPosition or the waveInGetPosition function and the MMTIME structure. Use the MMTIME structure to represent time in one or more different formats, including milliseconds, samples, a MIDI song pointer, or the Society of Motion Picture and Television Engineers (SMPTE) time formats. The wType member specifies the format used to represent time.
While calling this function, pass the MMTIME structure in the pmmt parameter.
If the device does not support the time format, the device driver specifies the time in an alternate time format and changes wType to the selected time format.
Most waveform audio devices support samples as the preferred time format. Thus, a waveform audio device usually describes its current position in a .wav file as the number of samples from the beginning of the waveform-audio file.