The ICM_DRAW_START_PLAY message provides the start and end times of a play operation to a rendering driver.
This message does not return a value.
This message precedes any frame data sent to the rendering driver.
Units for lFrom and lTo are specified with the ICM_DRAW_BEGIN message. For video data this is normally a frame number. For more information about the playback rate, see the dwRate and dwScale members of the ICDRAWBEGIN structure.
If the end time is less than the start time, the playback direction is reversed.