+/*
+ * filter_shape.c -- Arbitrary alpha channel shaping
+ * Copyright (C) 2005 Visual Media Fx Inc.
+ * Author: Charles Yates <charles.yates@pandora.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include "filter_shape.h"
+#include <string.h>
+#include <framework/mlt_factory.h>
+#include <framework/mlt_frame.h>
+#include <framework/mlt_producer.h>
+#include <framework/mlt_geometry.h>
+
+inline double smoothstep( const double e1, const double e2, const double a )
+{
+ if ( a < e1 ) return 0.0;
+ if ( a > e2 ) return 1.0;
+ double v = ( a - e1 ) / ( e2 - e1 );
+ return ( v * v * ( 3 - 2 * v ) );
+}
+
+/** Get the images and apply the luminance of the mask to the alpha of the frame.
+*/
+
+static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
+{
+ // Fetch the data from the stack (mix, mask, filter)
+ double mix = mlt_deque_pop_back_double( MLT_FRAME_IMAGE_STACK( this ) );
+ mlt_frame mask = mlt_frame_pop_service( this );
+ mlt_filter filter = mlt_frame_pop_service( this );
+
+ // Obtain the constants
+ double softness = mlt_properties_get_double( MLT_FILTER_PROPERTIES( filter ), "softness" );
+ int use_luminance = mlt_properties_get_int( MLT_FILTER_PROPERTIES( filter ), "use_luminance" );
+ int invert = mlt_properties_get_int( MLT_FILTER_PROPERTIES( filter ), "invert" ) * 255;
+
+ // Render the frame
+ if ( mlt_frame_get_image( this, image, format, width, height, writable ) == 0 )
+ {
+ // Get the alpha mask of the source
+ uint8_t *alpha = mlt_frame_get_alpha_mask( this );
+
+ // Obtain a scaled/distorted mask to match
+ uint8_t *mask_img = NULL;
+ mlt_image_format mask_fmt = mlt_image_yuv422;
+ mlt_properties_set_int( MLT_FRAME_PROPERTIES( mask ), "distort", 1 );
+ mlt_properties_pass_list( MLT_FRAME_PROPERTIES( mask ), MLT_FRAME_PROPERTIES( this ), "deinterlace,deinterlace_method,rescale.interp" );
+
+ if ( mlt_frame_get_image( mask, &mask_img, &mask_fmt, width, height, 0 ) == 0 )
+ {
+ int size = *width * *height;
+ uint8_t *p = alpha;
+ double a = 0;
+ double b = 0;
+ if ( !use_luminance )
+ {
+ uint8_t *q = mlt_frame_get_alpha_mask( mask );
+ while( size -- )
+ {
+ a = ( double )*q ++ / 255.0;
+ b = 1.0 - smoothstep( a, a + softness, mix );
+ *p = ( uint8_t )( *p * b ) ^ invert;
+ p ++;
+ }
+ }
+ else if ( mix != 1.0 )
+ {
+ uint8_t *q = mask_img;
+ while( size -- )
+ {
+ a = ( ( double )*q - 16 ) / 235.0;
+ b = smoothstep( a, a + softness, mix );
+ *p = ( uint8_t )( *p * b ) ^ invert;
+ p ++;
+ q += 2;
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+/** Filter processing.
+*/
+
+static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
+{
+ // Obtain the shape instance
+ char *resource = mlt_properties_get( MLT_FILTER_PROPERTIES( this ), "resource" );
+ mlt_producer producer = mlt_properties_get_data( MLT_FILTER_PROPERTIES( this ), "instance", NULL );
+
+ // Get the key framed values
+ mlt_geometry alpha = mlt_properties_get_data( MLT_FILTER_PROPERTIES( this ), "_alpha", NULL );
+ char *alpha_data = mlt_properties_get( MLT_FILTER_PROPERTIES( this ), "mix" );
+ double alpha_mix = 0.0;
+
+ // Calculate the position and length
+ int position = mlt_frame_get_position( frame ) - mlt_filter_get_in( this );
+ int in = mlt_filter_get_in( this );
+ int out = mlt_filter_get_out( this );
+ int length;
+
+ // Special case for attached filters - in/out come through on the frame
+ if ( out == 0 )
+ {
+ in = mlt_properties_get_int( MLT_FRAME_PROPERTIES( frame ), "in" );
+ out = mlt_properties_get_int( MLT_FRAME_PROPERTIES( frame ), "out" );
+ }
+
+ // Duration of the shape
+ length = out - in + 1;
+
+ // If we haven't created the instance or it's changed
+ if ( producer == NULL || strcmp( resource, mlt_properties_get( MLT_PRODUCER_PROPERTIES( producer ), "resource" ) ) )
+ {
+ producer = mlt_factory_producer( NULL, resource );
+ if ( producer != NULL )
+ mlt_properties_set( MLT_PRODUCER_PROPERTIES( producer ), "eof", "loop" );
+ mlt_properties_set_data( MLT_FILTER_PROPERTIES( this ), "instance", producer, 0, ( mlt_destructor )mlt_producer_close, NULL );
+ }
+
+ // Construct the geometry item if needed, otherwise refresh it
+ if ( alpha == NULL )
+ {
+ alpha = mlt_geometry_init( );
+ mlt_properties_set_data( MLT_FILTER_PROPERTIES( this ), "_alpha", alpha, 0, ( mlt_destructor )mlt_geometry_close, NULL );
+ mlt_geometry_parse( alpha, alpha_data, length, 100, 100 );
+ }
+ else
+ {
+ mlt_geometry_refresh( alpha, alpha_data, length, 100, 100 );
+ }
+
+ // We may still not have a producer in which case, we do nothing
+ if ( producer != NULL )
+ {
+ mlt_frame mask = NULL;
+ struct mlt_geometry_item_s item;
+ mlt_geometry_fetch( alpha, &item, position );
+ alpha_mix = item.x;
+ mlt_properties_pass( MLT_PRODUCER_PROPERTIES( producer ), MLT_FILTER_PROPERTIES( this ), "producer." );
+ mlt_producer_seek( producer, position );
+ if ( mlt_service_get_frame( MLT_PRODUCER_SERVICE( producer ), &mask, 0 ) == 0 )
+ {
+ char *name = mlt_properties_get( MLT_FILTER_PROPERTIES( this ), "_unique_id" );
+ mlt_properties_set_data( MLT_FRAME_PROPERTIES( frame ), name, mask, 0, ( mlt_destructor )mlt_frame_close, NULL );
+ mlt_frame_push_service( frame, this );
+ mlt_frame_push_service( frame, mask );
+ mlt_deque_push_back_double( MLT_FRAME_IMAGE_STACK( frame ), alpha_mix / 100.0 );
+ mlt_frame_push_get_image( frame, filter_get_image );
+ if ( mlt_properties_get_int( MLT_FILTER_PROPERTIES( this ), "audio_match" ) )
+ mlt_properties_set_double( MLT_FRAME_PROPERTIES( frame ), "meta.volume", alpha_mix / 100.0 );
+ }
+ }
+
+ return frame;
+}
+
+/** Constructor for the filter.
+*/
+
+mlt_filter filter_shape_init( char *arg )
+{
+ mlt_filter this = mlt_filter_new( );
+ if ( this != NULL )
+ {
+ mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "resource", arg );
+ mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "mix", "100" );
+ mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "audio_match", 1 );
+ mlt_properties_set_int( MLT_FILTER_PROPERTIES( this ), "invert", 0 );
+ mlt_properties_set_double( MLT_FILTER_PROPERTIES( this ), "softness", 0.1 );
+ this->process = filter_process;
+ }
+ return this;
+}
+