clip and mix manipulation on playlist

[melted] / src / framework / mlt_playlist.c

diff --git a/src/framework/mlt_playlist.c b/src/framework/mlt_playlist.c
index 6788f1e..7f71d49 100644 (file)
--- a/src/framework/mlt_playlist.c
+++ b/src/framework/mlt_playlist.c
@@ -890,6 +890,45 @@ int mlt_playlist_mix( mlt_playlist this, int clip, int length, mlt_transition tr
        return error;
 }
 
+/** Add a transition to an existing mix.
+*/
+
+int mlt_playlist_mix_add( mlt_playlist this, int clip, mlt_transition transition )
+{
+       mlt_producer producer = mlt_producer_cut_parent( mlt_playlist_get_clip( this, clip ) );
+       mlt_properties properties = producer != NULL ? mlt_producer_properties( producer ) : NULL;
+       mlt_tractor tractor = properties != NULL ? mlt_properties_get_data( properties, "mlt_mix", NULL ) : NULL;
+       int error = transition == NULL || tractor == NULL;
+       if ( error == 0 )
+       {
+               mlt_field field = mlt_tractor_field( tractor );
+               mlt_field_plant_transition( field, transition, 0, 1 );
+               mlt_transition_set_in_and_out( transition, 0, this->list[ clip ]->frame_count - 1 );
+       }
+       return error;
+}
+
+/** Return the clip at the position.
+*/
+
+mlt_producer mlt_playlist_get_clip( mlt_playlist this, int clip )
+{
+       if ( clip > 0 && clip < this->count )
+               return this->list[ clip ]->producer;
+       return NULL;
+}
+
+/** Determine if the clip is a mix.
+*/
+
+int mlt_playlist_clip_is_mix( mlt_playlist this, int clip )
+{
+       mlt_producer producer = mlt_producer_cut_parent( mlt_playlist_get_clip( this, clip ) );
+       mlt_properties properties = producer != NULL ? mlt_producer_properties( producer ) : NULL;
+       mlt_tractor tractor = properties != NULL ? mlt_properties_get_data( properties, "mlt_mix", NULL ) : NULL;
+       return tractor != NULL;
+}
+
 /** Remove a mixed clip - ensure that the cuts included in the mix find their way
        back correctly on to the playlist.
 */