Multitrack rearrangement and tractor cleanup
[melted] / src / framework / mlt_playlist.c
index 2f75219..222d5bf 100644 (file)
 #include "config.h"
 
 #include "mlt_playlist.h"
+#include "mlt_tractor.h"
+#include "mlt_multitrack.h"
+#include "mlt_field.h"
 #include "mlt_frame.h"
+#include "mlt_transition.h"
 
 #include <stdio.h>
 #include <stdlib.h>
 /** Virtual playlist entry.
 */
 
-typedef struct
+typedef struct playlist_entry_s
 {
        mlt_producer producer;
        mlt_position frame_in;
        mlt_position frame_out;
        mlt_position frame_count;
+       int repeat;
+       mlt_position producer_length;
        mlt_event event;
+       int preservation_hack;
 }
 playlist_entry;
 
@@ -57,6 +64,8 @@ struct mlt_playlist_s
 */
 
 static int producer_get_frame( mlt_producer producer, mlt_frame_ptr frame, int index );
+static int mlt_playlist_unmix( mlt_playlist this, int clip );
+static int mlt_playlist_resize_mix( mlt_playlist this, int clip, int in, int out );
 
 /** Constructor.
 */
@@ -142,6 +151,7 @@ static int mlt_playlist_virtual_refresh( mlt_playlist this )
        {
                // Get the producer
                mlt_producer producer = this->list[ i ]->producer;
+               int current_length = mlt_producer_get_out( producer ) - mlt_producer_get_in( producer ) + 1;
 
                // If fps is 0
                if ( fps == 0 )
@@ -158,6 +168,32 @@ static int mlt_playlist_virtual_refresh( mlt_playlist this )
                        mlt_properties_set_double( mlt_producer_properties( producer ), "fps", fps );
                }
 
+               // Check if the length of the producer has changed
+               if ( this->list[ i ]->producer != &this->blank &&
+                        ( this->list[ i ]->frame_in != mlt_producer_get_in( producer ) ||
+                          this->list[ i ]->frame_out != mlt_producer_get_out( producer ) ) )
+               {
+                       // This clip should be removed...
+                       if ( current_length < 1 )
+                       {
+                               this->list[ i ]->frame_in = 0;
+                               this->list[ i ]->frame_out = -1;
+                               this->list[ i ]->frame_count = 0;
+                       }
+                       else 
+                       {
+                               this->list[ i ]->frame_in = mlt_producer_get_in( producer );
+                               this->list[ i ]->frame_out = mlt_producer_get_out( producer );
+                               this->list[ i ]->frame_count = current_length;
+                       }
+
+                       // Update the producer_length
+                       this->list[ i ]->producer_length = current_length;
+               }
+
+               // Calculate the frame_count
+               this->list[ i ]->frame_count = ( this->list[ i ]->frame_out - this->list[ i ]->frame_in + 1 ) * this->list[ i ]->repeat;
+
                // Update the frame_count for this clip
                frame_count += this->list[ i ]->frame_count;
        }
@@ -184,9 +220,42 @@ static void mlt_playlist_listener( mlt_producer producer, mlt_playlist this )
 /** Append to the virtual playlist.
 */
 
-static int mlt_playlist_virtual_append( mlt_playlist this, mlt_producer producer, mlt_position in, mlt_position out )
+static int mlt_playlist_virtual_append( mlt_playlist this, mlt_producer source, mlt_position in, mlt_position out )
 {
-       mlt_properties properties = mlt_producer_properties( producer );
+       char *resource = source != NULL ? mlt_properties_get( mlt_producer_properties( source ), "resource" ) : NULL;
+       mlt_producer producer = NULL;
+       mlt_properties properties = NULL;
+       mlt_properties parent = NULL;
+
+       // If we have a cut, then use the in/out points from the cut
+       if ( resource == NULL || !strcmp( resource, "blank" ) )
+       {
+               producer = &this->blank;
+               properties = mlt_producer_properties( producer );
+               mlt_properties_inc_ref( properties );
+       }
+       else if ( mlt_producer_is_cut( source ) )
+       {
+               producer = source;
+               if ( in == -1 )
+                       in = mlt_producer_get_in( producer );
+               if ( out == -1 || out > mlt_producer_get_out( producer ) )
+                       out = mlt_producer_get_out( producer );
+               properties = mlt_producer_properties( producer );
+               mlt_properties_inc_ref( properties );
+       }
+       else
+       {
+               producer = mlt_producer_cut( source, in, out );
+               if ( in == -1 || in < mlt_producer_get_in( producer ) )
+                       in = mlt_producer_get_in( producer );
+               if ( out == -1 || out > mlt_producer_get_out( producer ) )
+                       out = mlt_producer_get_out( producer );
+               properties = mlt_producer_properties( producer );
+       }
+
+       // Fetch the cuts parent properties
+       parent = mlt_producer_properties( mlt_producer_cut_parent( producer ) );
 
        // Check that we have room
        if ( this->count >= this->size )
@@ -197,21 +266,22 @@ static int mlt_playlist_virtual_append( mlt_playlist this, mlt_producer producer
                this->size += 10;
        }
 
+       // Create the entry
        this->list[ this->count ] = calloc( sizeof( playlist_entry ), 1 );
-       this->list[ this->count ]->producer = producer;
-       this->list[ this->count ]->frame_in = in;
-       this->list[ this->count ]->frame_out = out;
-       this->list[ this->count ]->frame_count = out - in + 1;
-       this->list[ this->count ]->event = mlt_events_listen( properties, this, "producer-changed", ( mlt_listener )mlt_playlist_listener );
-       mlt_event_inc_ref( this->list[ this->count ]->event );
-
-       mlt_properties_set( properties, "eof", "pause" );
-
-       mlt_producer_set_speed( producer, 0 );
-
-       this->count ++;
-
-       mlt_properties_inc_ref( properties );
+       if ( this->list[ this->count ] != NULL )
+       {
+               this->list[ this->count ]->producer = producer;
+               this->list[ this->count ]->frame_in = in;
+               this->list[ this->count ]->frame_out = out;
+               this->list[ this->count ]->frame_count = out - in + 1;
+               this->list[ this->count ]->repeat = 1;
+               this->list[ this->count ]->producer_length = mlt_producer_get_out( producer ) - mlt_producer_get_in( producer ) + 1;
+               this->list[ this->count ]->event = mlt_events_listen( parent, this, "producer-changed", ( mlt_listener )mlt_playlist_listener );
+               mlt_event_inc_ref( this->list[ this->count ]->event );
+               mlt_properties_set( properties, "eof", "pause" );
+               mlt_producer_set_speed( producer, 0 );
+               this->count ++;
+       }
 
        return mlt_playlist_virtual_refresh( this );
 }
@@ -248,6 +318,7 @@ static mlt_service mlt_playlist_virtual_seek( mlt_playlist this )
                total += this->list[ i ]->frame_count;
 
                // Check if the position indicates that we have found the clip
+               // Note that 0 length clips get skipped automatically
                if ( position < this->list[ i ]->frame_count )
                {
                        // Found it, now break
@@ -264,8 +335,8 @@ static mlt_service mlt_playlist_virtual_seek( mlt_playlist this )
        // Seek in real producer to relative position
        if ( producer != NULL )
        {
-               position += this->list[ i ]->frame_in;
-               mlt_producer_seek( producer, position );
+               int count = this->list[ i ]->frame_count / this->list[ i ]->repeat;
+               mlt_producer_seek( producer, position % count );
        }
        else if ( !strcmp( eof, "pause" ) && total > 0 )
        {
@@ -283,7 +354,7 @@ static mlt_service mlt_playlist_virtual_seek( mlt_playlist this )
                mlt_producer this_producer = mlt_playlist_producer( this );
                mlt_producer_seek( this_producer, 0 );
                producer = entry->producer;
-               mlt_producer_seek( producer, entry->frame_in );
+               mlt_producer_seek( producer, 0 );
        }
        else
        {
@@ -423,26 +494,19 @@ int mlt_playlist_get_clip_info( mlt_playlist this, mlt_playlist_clip_info *info,
        memset( info, 0, sizeof( mlt_playlist_clip_info ) );
        if ( !error )
        {
-               mlt_producer producer = this->list[ index ]->producer;
+               mlt_producer producer = mlt_producer_cut_parent( this->list[ index ]->producer );
                mlt_properties properties = mlt_producer_properties( producer );
                info->clip = index;
                info->producer = producer;
+               info->cut = this->list[ index ]->producer;
                info->start = mlt_playlist_clip( this, mlt_whence_relative_start, index );
                info->resource = mlt_properties_get( properties, "resource" );
                info->frame_in = this->list[ index ]->frame_in;
                info->frame_out = this->list[ index ]->frame_out;
                info->frame_count = this->list[ index ]->frame_count;
+               info->repeat = this->list[ index ]->repeat;
                info->length = mlt_producer_get_length( producer );
                info->fps = mlt_producer_get_fps( producer );
-               info->event = this->list[ index ]->event;
-       }
-
-       // Determine the consuming filter service
-       if ( info->producer != NULL )
-       {
-               info->service = mlt_producer_service( info->producer );
-               while ( mlt_service_consumer( info->service ) != NULL )
-                       info->service = mlt_service_consumer( info->service );
        }
 
        return error;
@@ -523,7 +587,8 @@ int mlt_playlist_insert( mlt_playlist this, mlt_producer producer, int where, ml
 
 int mlt_playlist_remove( mlt_playlist this, int where )
 {
-       if ( this->count > 0 )
+       int error = where < 0 || where >= this->count;
+       if ( error == 0 && mlt_playlist_unmix( this, where ) != 0 )
        {
                // We need to know the current clip and the position within the playlist
                int current = mlt_playlist_current_clip( this );
@@ -531,28 +596,47 @@ int mlt_playlist_remove( mlt_playlist this, int where )
 
                // We need all the details about the clip we're removing
                mlt_playlist_clip_info where_info;
+               playlist_entry *entry = this->list[ where ];
+               mlt_properties properties = mlt_producer_properties( entry->producer );
 
                // Loop variable
                int i = 0;
 
+               // Get the clip info 
+               mlt_playlist_get_clip_info( this, &where_info, where );
+
                // Make sure the clip to be removed is valid and correct if necessary
                if ( where < 0 ) 
                        where = 0;
                if ( where >= this->count )
                        where = this->count - 1;
 
-               // Get the clip info of the clip to be removed
-               mlt_playlist_get_clip_info( this, &where_info, where );
-
-               // Close the producer associated to the clip info
-               mlt_event_close( where_info.event );
-               mlt_producer_close( where_info.producer );
-
                // Reorganise the list
                for ( i = where + 1; i < this->count; i ++ )
                        this->list[ i - 1 ] = this->list[ i ];
                this->count --;
 
+               if ( entry->preservation_hack == 0 )
+               {
+                       // Decouple from mix_in/out if necessary
+                       if ( mlt_properties_get_data( properties, "mix_in", NULL ) != NULL )
+                       {
+                               mlt_properties mix = mlt_properties_get_data( properties, "mix_in", NULL );
+                               mlt_properties_set_data( mix, "mix_out", NULL, 0, NULL, NULL );
+                       }
+                       if ( mlt_properties_get_data( properties, "mix_out", NULL ) != NULL )
+                       {
+                               mlt_properties mix = mlt_properties_get_data( properties, "mix_out", NULL );
+                               mlt_properties_set_data( mix, "mix_in", NULL, 0, NULL, NULL );
+                       }
+       
+                       mlt_producer_clear( entry->producer );
+               }
+
+               // Close the producer associated to the clip info
+               mlt_event_close( entry->event );
+               mlt_producer_close( entry->producer );
+
                // Correct position
                if ( where == current )
                        mlt_producer_seek( mlt_playlist_producer( this ), where_info.start );
@@ -561,11 +645,14 @@ int mlt_playlist_remove( mlt_playlist this, int where )
                else if ( this->count == 0 )
                        mlt_producer_seek( mlt_playlist_producer( this ), 0 );
 
+               // Free the entry
+               free( entry );
+
                // Refresh the playlist
                mlt_playlist_virtual_refresh( this );
        }
 
-       return 0;
+       return error;
 }
 
 /** Move an entry in the playlist.
@@ -626,21 +713,36 @@ int mlt_playlist_move( mlt_playlist this, int src, int dest )
        return 0;
 }
 
-/** Resize the current clip.
+/** Repeat the specified clip n times.
+*/
+
+int mlt_playlist_repeat_clip( mlt_playlist this, int clip, int repeat )
+{
+       int error = repeat < 1 || clip < 0 || clip >= this->count;
+       if ( error == 0 )
+       {
+               playlist_entry *entry = this->list[ clip ];
+               entry->repeat = repeat;
+               mlt_playlist_virtual_refresh( this );
+       }
+       return error;
+}
+
+/** Resize the specified clip.
 */
 
 int mlt_playlist_resize_clip( mlt_playlist this, int clip, mlt_position in, mlt_position out )
 {
        int error = clip < 0 || clip >= this->count;
-       if ( error == 0 )
+       if ( error == 0 && mlt_playlist_resize_mix( this, clip, in, out ) != 0 )
        {
                playlist_entry *entry = this->list[ clip ];
                mlt_producer producer = entry->producer;
 
                if ( in <= -1 )
                        in = 0;
-               if ( out <= -1 || out >= mlt_producer_get_playtime( producer ) )
-                       out = mlt_producer_get_playtime( producer ) - 1;
+               if ( out <= -1 || out >= mlt_producer_get_length( producer ) )
+                       out = mlt_producer_get_length( producer ) - 1;
 
                if ( out < in )
                {
@@ -649,10 +751,7 @@ int mlt_playlist_resize_clip( mlt_playlist this, int clip, mlt_position in, mlt_
                        out = t;
                }
 
-               entry->frame_in = in;
-               entry->frame_out = out;
-               entry->frame_count = out - in + 1;
-               mlt_playlist_virtual_refresh( this );
+               mlt_producer_set_in_and_out( producer, in, out );
        }
        return error;
 }
@@ -666,14 +765,19 @@ int mlt_playlist_split( mlt_playlist this, int clip, mlt_position position )
        if ( error == 0 )
        {
                playlist_entry *entry = this->list[ clip ];
-               if ( position > 0 && position < entry->frame_count )
+               position = position < 0 ? entry->frame_count + position - 1 : position;
+               if ( position >= 0 && position <= entry->frame_count )
                {
+                       mlt_producer split = NULL;
                        int in = entry->frame_in;
                        int out = entry->frame_out;
                        mlt_events_block( mlt_playlist_properties( this ), this );
                        mlt_playlist_resize_clip( this, clip, in, in + position );
+                       split = mlt_producer_cut( entry->producer, in + position + 1, out );
+                       mlt_playlist_insert( this, split, clip + 1, 0, -1 );
+                       mlt_producer_close( split );
                        mlt_events_unblock( mlt_playlist_properties( this ), this );
-                       mlt_playlist_insert( this, entry->producer, clip + 1, in + position + 1, out );
+                       mlt_events_fire( mlt_playlist_properties( this ), "producer-changed", NULL );
                }
                else
                {
@@ -688,7 +792,7 @@ int mlt_playlist_split( mlt_playlist this, int clip, mlt_position position )
 
 int mlt_playlist_join( mlt_playlist this, int clip, int count, int merge )
 {
-       int error = clip < 0 || ( clip + 1 ) >= this->count;
+       int error = clip < 0 || ( clip ) >= this->count;
        if ( error == 0 )
        {
                int i = clip;
@@ -699,7 +803,11 @@ int mlt_playlist_join( mlt_playlist this, int clip, int count, int merge )
                for ( i = 0; i <= count; i ++ )
                {
                        playlist_entry *entry = this->list[ clip ];
-                       mlt_playlist_append_io( new_clip, entry->producer, entry->frame_in, entry->frame_out );
+                       mlt_playlist_append( new_clip, entry->producer );
+                       mlt_playlist_repeat_clip( new_clip, i, entry->repeat );
+                       if ( entry->frame_count == entry->repeat )
+                               mlt_properties_set_int( mlt_playlist_properties( new_clip ), "hide", 2 );
+                       entry->preservation_hack = 1;
                        mlt_playlist_remove( this, clip );
                }
                mlt_events_unblock( mlt_playlist_properties( this ), this );
@@ -709,6 +817,216 @@ int mlt_playlist_join( mlt_playlist this, int clip, int count, int merge )
        return error;
 }
 
+/** Mix consecutive clips for a specified length and apply transition if specified.
+*/
+
+int mlt_playlist_mix( mlt_playlist this, int clip, int length, mlt_transition transition )
+{
+       int error = ( clip < 0 || clip + 1 >= this->count );
+       if ( error == 0 )
+       {
+               playlist_entry *clip_a = this->list[ clip ];
+               playlist_entry *clip_b = this->list[ clip + 1 ];
+               mlt_producer track_a;
+               mlt_producer track_b;
+               mlt_tractor tractor = mlt_tractor_new( );
+               mlt_events_block( mlt_playlist_properties( this ), this );
+
+               // TODO: Check length is valid for both clips and resize if necessary.
+
+               // Create the a and b tracks/cuts
+               track_a = mlt_producer_cut( clip_a->producer, clip_a->frame_out - length + 1, clip_a->frame_out );
+               track_b = mlt_producer_cut( clip_b->producer, clip_b->frame_in, clip_b->frame_in + length - 1 );
+
+               // Set the tracks on the tractor
+               mlt_tractor_set_track( tractor, track_a, 0 );
+               mlt_tractor_set_track( tractor, track_b, 1 );
+
+               // Insert the mix object into the playlist
+               mlt_playlist_insert( this, mlt_tractor_producer( tractor ), clip + 1, -1, -1 );
+               mlt_properties_set_data( mlt_tractor_properties( tractor ), "mlt_mix", tractor, 0, NULL, NULL );
+
+               // Attach the transition
+               if ( transition != NULL )
+               {
+                       mlt_field field = mlt_tractor_field( tractor );
+                       mlt_field_plant_transition( field, transition, 0, 1 );
+                       mlt_transition_set_in_and_out( transition, 0, length - 1 );
+               }
+
+               // Check if we have anything left on the right hand clip
+               if ( clip_b->frame_out - clip_b->frame_in > length )
+               {
+                       mlt_playlist_resize_clip( this, clip + 2, clip_b->frame_in + length, clip_b->frame_out );
+                       mlt_properties_set_data( mlt_producer_properties( clip_b->producer ), "mix_in", tractor, 0, NULL, NULL );
+                       mlt_properties_set_data( mlt_tractor_properties( tractor ), "mix_out", clip_b->producer, 0, NULL, NULL );
+               }
+               else
+               {
+                       mlt_producer_clear( clip_b->producer );
+                       mlt_playlist_remove( this, clip + 2 );
+               }
+
+               // Check if we have anything left on the left hand clip
+               if ( clip_a->frame_out - clip_a->frame_in > length )
+               {
+                       mlt_playlist_resize_clip( this, clip, clip_a->frame_in, clip_a->frame_out - length );
+                       mlt_properties_set_data( mlt_producer_properties( clip_a->producer ), "mix_out", tractor, 0, NULL, NULL );
+                       mlt_properties_set_data( mlt_tractor_properties( tractor ), "mix_in", clip_a->producer, 0, NULL, NULL );
+               }
+               else
+               {
+                       mlt_producer_clear( clip_a->producer );
+                       mlt_playlist_remove( this, clip );
+               }
+
+               mlt_events_unblock( mlt_playlist_properties( this ), this );
+               mlt_events_fire( mlt_playlist_properties( this ), "producer-changed", NULL );
+               mlt_producer_close( track_a );
+               mlt_producer_close( track_b );
+               mlt_tractor_close( tractor );
+       }
+       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.
+*/
+
+static int mlt_playlist_unmix( mlt_playlist this, int clip )
+{
+       int error = ( clip < 0 || clip >= this->count ); 
+
+       // Ensure that the clip request is actually a mix
+       if ( error == 0 )
+       {
+               mlt_producer producer = mlt_producer_cut_parent( this->list[ clip ]->producer );
+               mlt_properties properties = mlt_producer_properties( producer );
+               error = mlt_properties_get_data( properties, "mlt_mix", NULL ) == NULL;
+       }
+
+       if ( error == 0 )
+       {
+               playlist_entry *mix = this->list[ clip ];
+               mlt_tractor tractor = ( mlt_tractor )mlt_producer_cut_parent( mix->producer );
+               mlt_properties properties = mlt_tractor_properties( tractor );
+               mlt_producer clip_a = mlt_properties_get_data( properties, "mix_in", NULL );
+               mlt_producer clip_b = mlt_properties_get_data( properties, "mix_out", NULL );
+               int length = mlt_producer_get_playtime( mlt_tractor_producer( tractor ) );
+               mlt_events_block( mlt_playlist_properties( this ), this );
+
+               if ( clip_a != NULL )
+               {
+                       mlt_producer_set_in_and_out( clip_a, mlt_producer_get_in( clip_a ), mlt_producer_get_out( clip_a ) + length );
+               }
+               else
+               {
+                       mlt_producer cut = mlt_tractor_get_track( tractor, 0 );
+                       mlt_playlist_insert( this, cut, clip, -1, -1 );
+                       clip ++;
+               }
+
+               if ( clip_b != NULL )
+               {
+                       mlt_producer_set_in_and_out( clip_b, mlt_producer_get_in( clip_b ) - length, mlt_producer_get_out( clip_b ) );
+               }
+               else
+               {
+                       mlt_producer cut = mlt_tractor_get_track( tractor, 1 );
+                       mlt_playlist_insert( this, cut, clip + 1, -1, -1 );
+               }
+
+               mlt_properties_set_data( properties, "mlt_mix", NULL, 0, NULL, NULL );
+               mlt_playlist_remove( this, clip );
+               mlt_events_unblock( mlt_playlist_properties( this ), this );
+               mlt_events_fire( mlt_playlist_properties( this ), "producer-changed", NULL );
+       }
+       return error;
+}
+
+static int mlt_playlist_resize_mix( mlt_playlist this, int clip, int in, int out )
+{
+       int error = ( clip < 0 || clip >= this->count ); 
+
+       // Ensure that the clip request is actually a mix
+       if ( error == 0 )
+       {
+               mlt_producer producer = mlt_producer_cut_parent( this->list[ clip ]->producer );
+               mlt_properties properties = mlt_producer_properties( producer );
+               error = mlt_properties_get_data( properties, "mlt_mix", NULL ) == NULL;
+       }
+
+       if ( error == 0 )
+       {
+               playlist_entry *mix = this->list[ clip ];
+               mlt_tractor tractor = ( mlt_tractor )mlt_producer_cut_parent( mix->producer );
+               mlt_properties properties = mlt_tractor_properties( tractor );
+               mlt_producer clip_a = mlt_properties_get_data( properties, "mix_in", NULL );
+               mlt_producer clip_b = mlt_properties_get_data( properties, "mix_out", NULL );
+               mlt_producer track_a = mlt_tractor_get_track( tractor, 0 );
+               mlt_producer track_b = mlt_tractor_get_track( tractor, 1 );
+               int length = out - in + 1;
+               int length_diff = length - mlt_producer_get_playtime( mlt_tractor_producer( tractor ) );
+               mlt_events_block( mlt_playlist_properties( this ), this );
+
+               if ( clip_a != NULL )
+                       mlt_producer_set_in_and_out( clip_a, mlt_producer_get_in( clip_a ), mlt_producer_get_out( clip_a ) - length_diff );
+
+               if ( clip_b != NULL )
+                       mlt_producer_set_in_and_out( clip_b, mlt_producer_get_in( clip_b ) + length_diff, mlt_producer_get_out( clip_b ) );
+
+               mlt_producer_set_in_and_out( track_a, mlt_producer_get_in( track_a ) - length_diff, mlt_producer_get_out( track_a ) );
+               mlt_producer_set_in_and_out( track_b, mlt_producer_get_in( track_b ), mlt_producer_get_out( track_b ) + length_diff );
+               mlt_producer_set_in_and_out( mlt_multitrack_producer( mlt_tractor_multitrack( tractor ) ), in, out );
+               mlt_producer_set_in_and_out( mlt_tractor_producer( tractor ), in, out );
+               mlt_properties_set_position( mlt_producer_properties( mix->producer ), "length", out - in + 1 );
+               mlt_producer_set_in_and_out( mix->producer, in, out );
+
+               mlt_events_unblock( mlt_playlist_properties( this ), this );
+               mlt_playlist_virtual_refresh( this );
+       }
+       return error;
+}
+
 /** Get the current frame.
 */