mvGetActualFrameRate(3dm)

NAME
     mvGetActualFrameRate - Obtain playback frame rate information for a movie


SYNOPSIS
     #include <dmedia/movieplay.h>


     DMstatus mvGetActualFrameRate(MVid movieid, double *ratereturn);


DESCRIPTION
     mvGetActualFrameRate(3dm) returns the frame rate which the Movie Playback
     Library has actually achieved for the specified movie, computed over the
     last second of playback.

     The return value of mvGetActualFrameRate(3dm) is always equal to or less
     than the movie's current speed.  The movie's current speed is its natural
     frame rate, as stored in the movie file, multiplied by the absolute value
     of the play speed setting.  (The return value of
     mvGetActualFrameRate(3dm) is always >= 0 regardless of the movie's
     current direction or loop mode).  To change the play speed setting for a
     movie, use mvSetPlaySpeed(3dm).

     If your application needs more detailed information about the rate of
     movie playback, you should check the timestamp information associated
     with movie frame events.  To do this, use the mvGetEventFD(3dm),
     mvSetSelectEvents(3dm), and mvNextEvent(3dm) calls.

     You may call mvGetActualFrameRate(3dm) on a movie regardless of whether
     or not the movie is playing.

     You should only call this function for a specified movie while it is
     bound (see mvBindOpenGLWindow(3dm)).

     If you call mvGetActualFrameRate(3dm) before the first second of playback
     has elapsed, it will return DM_FAILURE, set the current errno to
     MV_OUT_OF_CONTEXT, and leave the value pointed to by ratereturn
     unchanged.  The same is true if the movie is not currently bound to a
     window, an MV_PORT_GFX port, or an MV_PORT_VIDEO playback port.


SEE ALSO
     mvBindOpenGLWindow(3dm), mvBindMovieToPorts(3dm), mvGetErrno(3dm),
     mvGetEventFD(3dm), mvIntro(3dm), mvNextEvent(3dm) mvSetPlaySpeed(3dm).