NB: Not all transitions will accept a and b frames being the same...
*/
-static int filter_get_audio( mlt_frame this, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
+static int filter_get_audio( mlt_frame this, void **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
{
// Obtain the transition instance
mlt_transition transition = mlt_frame_pop_audio( this );