transition region

[melted] / src / modules / core / transition_region.c

/*
 * transition_region.c -- region transition
 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
 * 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 "transition_region.h"
#include "transition_composite.h"

#include <framework/mlt.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static int create_instance( mlt_transition this, char *name, char *value, int count )
{
        // Return from this function
        int error = 0;

        // Duplicate the value
        char *type = strdup( value );

        // Pointer to filter argument
        char *arg = type == NULL ? NULL : strchr( type, ':' );

        // New filter being created
        mlt_filter filter = NULL;

        // Cleanup type and arg
        if ( arg != NULL )
                *arg ++ = '\0';

        // Create the filter
        filter = mlt_factory_filter( type, arg );

        // If we have a filter, then initialise and store it
        if ( filter != NULL )
        {
                // Properties of this
                mlt_properties properties = mlt_transition_properties( this );

                // String to hold the property name
                char id[ 256 ];

                // String to hold the passdown key
                char key[ 256 ];

                // Construct id
                sprintf( id, "_filter_%d", count );

                // Counstruct key
                sprintf( key, "%s.", name );

                // Just in case, let's assume that the filter here has a composite
                mlt_properties_set( mlt_filter_properties( filter ), "composite.start", "0%,0%:100%x100%" );
                mlt_properties_set( mlt_filter_properties( filter ), "composite.fill", "true" );

                // Pass all the key properties on the filter down
                mlt_properties_pass( mlt_filter_properties( filter ), properties, key );

                // Ensure that filter is assigned
                mlt_properties_set_data( properties, id, filter, 0, ( mlt_destructor )mlt_filter_close, NULL );
        }
        else
        {
                // Indicate that an error has occurred
                error = 1;
        }

        // Cleanup
        free( type );

        // Return error condition
        return error;
}

static uint8_t *filter_get_alpha_mask( mlt_frame this )
{
        // Obtain properties of frame
        mlt_properties properties = mlt_frame_properties( this );

        // Get the shape frame
        mlt_frame shape_frame = mlt_properties_get_data( properties, "shape_frame", NULL );

        // Get the width and height of the image
        int region_width = mlt_properties_get_int( mlt_frame_properties( this ), "width" );
        int region_height = mlt_properties_get_int( mlt_frame_properties( this ), "height" );
        uint8_t *image = NULL;
        mlt_image_format format = mlt_image_yuv422;
                                        
        // Get the shape image to trigger alpha creation
        mlt_properties_set( mlt_frame_properties( shape_frame ), "distort", "true" );
        mlt_frame_get_image( shape_frame, &image, &format, &region_width, &region_height, 0 );

        return mlt_frame_get_alpha_mask( shape_frame );
}

/** Do it :-).
*/

static int transition_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
{
        // Error we will return
        int error = 0;

        // Get the watermark transition object
        mlt_transition this = mlt_frame_pop_service( frame );

        // We will get the 'b frame' from the frame stack
        mlt_frame b_frame = mlt_frame_pop_frame( frame );

        // Get the properties of the transition
        mlt_properties properties = mlt_transition_properties( this );

        // Get the composite from the transition
        mlt_transition composite = mlt_properties_get_data( properties, "composite", NULL );

        // Look for the first filter
        mlt_filter filter = mlt_properties_get_data( properties, "_filter_0", NULL );

        // Get the unique id of the filter (used to reacquire the producer position)
        char *name = mlt_properties_get( properties, "_unique_id" );

        // Get the original producer position
        mlt_position position = mlt_properties_get_position( mlt_frame_properties( frame ), name );

        // Create a composite if we don't have one
        if ( composite == NULL )
        {
                // Create composite via the factory
                composite = mlt_factory_transition( "composite", NULL );

                // If we have one
                if ( composite != NULL )
                {
                        // Get the properties
                        mlt_properties composite_properties = mlt_transition_properties( composite );

                        // We want to ensure that we don't get a wobble...
                        mlt_properties_set( composite_properties, "distort", "true" );
                        mlt_properties_set( composite_properties, "progressive", "1" );

                        // Pass all the composite. properties on the transition down
                        mlt_properties_pass( composite_properties, properties, "composite." );

                        // Register the composite for reuse/destruction
                        mlt_properties_set_data( properties, "composite", composite, 0, ( mlt_destructor )mlt_transition_close, NULL );
                }
        }

        // Create filters
        if ( filter == NULL )
        {
                // Loop Variable
                int i = 0;

                // Number of filters created
                int count = 0;

                // Loop for all properties
                for ( i = 0; i < mlt_properties_count( properties ); i ++ )
                {
                        // Get the name of this property
                        char *name = mlt_properties_get_name( properties, i );

                        // If the name does not contain a . and matches filter
                        if ( strchr( name, '.' ) == NULL && !strncmp( name, "filter", 6 ) )
                        {
                                // Get the filter constructor
                                char *value = mlt_properties_get_value( properties, i );

                                // Create an instance
                                if ( create_instance( this, name, value, count ) == 0 )
                                        count ++;
                        }
                }
        }

        // Get the image
        error = mlt_frame_get_image( frame, image, format, width, height, 1 );

        // Only continue if we have both filter and composite
        if ( composite != NULL )
        {
                // Get the resource of this filter (could be a shape [rectangle/circle] or an alpha provider of choice
                char *resource =  mlt_properties_get( properties, "resource" );

                // String to hold the filter to query on
                char id[ 256 ];

                // Index to hold the count
                int i = 0;

                // We will get the 'b frame' from the composite only if it's NULL
                if ( b_frame == NULL )
                {
                        // Copy the region
                        b_frame = composite_copy_region( composite, frame, position );

                        // Ensure a destructor
                        mlt_properties_set_data( mlt_frame_properties( frame ), name, b_frame, 0, ( mlt_destructor )mlt_frame_close, NULL );
                }

                // Make sure the filter is in the correct position
                while ( filter != NULL )
                {
                        // Stack this filter
                        mlt_filter_process( filter, b_frame );

                        // Generate the key for the next
                        sprintf( id, "_filter_%d", ++ i );

                        // Get the next filter
                        filter = mlt_properties_get_data( properties, id, NULL );
                }

                // Hmm - this is probably going to go wrong....
                mlt_frame_set_position( frame, position );

                // Get the b frame and process with composite if successful
                mlt_transition_process( composite, frame, b_frame );

                // If we have a shape producer copy the alpha mask from the shape frame to the b_frame
                if ( strcmp( resource, "rectangle" ) != 0 )
                {
                        // Get the producer from the transition
                        mlt_producer producer = mlt_properties_get_data( properties, "producer", NULL );

                        // If We have no producer then create one
                        if ( producer == NULL )
                        {
                                // Get the factory producer service
                                char *factory = mlt_properties_get( properties, "factory" );

                                // Special case circle resource
                                if ( strcmp( resource, "circle" ) == 0 )
                                {
                                        // Special case to ensure that fezzik produces a pixbuf with a NULL constructor
                                        resource = "pixbuf";

                                        // Specify the svg circle
                                        mlt_properties_set( properties, "producer.resource", "<svg width='100' height='100'><circle cx='50' cy='50' r='50' fill='black'/></svg>" );
                                }

                                // Create the producer 
                                producer = mlt_factory_producer( factory, resource );

                                // If we have one
                                if ( producer != NULL )
                                {
                                        // Get the producer properties
                                        mlt_properties producer_properties = mlt_producer_properties( producer );

                                        // Ensure that we loop
                                        mlt_properties_set( producer_properties, "eof", "loop" );

                                        // Now pass all producer. properties on the transition down
                                        mlt_properties_pass( producer_properties, properties, "producer." );

                                        // Register the producer for reuse/destruction
                                        mlt_properties_set_data( properties, "producer", producer, 0, ( mlt_destructor )mlt_producer_close, NULL );
                                }
                        }

                        // Now use the shape producer
                        if ( producer != NULL )
                        {
                                // We will get the alpha frame from the producer
                                mlt_frame shape_frame = NULL;

                                // Make sure the producer is in the correct position
                                mlt_producer_seek( producer, position );

                                // Get the shape frame
                                if ( mlt_service_get_frame( mlt_producer_service( producer ), &shape_frame, 0 ) == 0 )
                                {
                                        // Ensure that the shape frame will be closed
                                        mlt_properties_set_data( mlt_frame_properties( b_frame ), "shape_frame", shape_frame, 0, ( mlt_destructor )mlt_frame_close, NULL );

                                        // Specify the callback for evaluation
                                        b_frame->get_alpha_mask = filter_get_alpha_mask;
                                }
                        }
                }

                // Get the image
                error = mlt_frame_get_image( frame, image, format, width, height, 0 );
        }

        return error;
}

/** Filter processing.
*/

static mlt_frame transition_process( mlt_transition this, mlt_frame a_frame, mlt_frame b_frame )
{
        // Get the properties of the frame
        mlt_properties properties = mlt_frame_properties( a_frame );

        // Get a unique name to store the frame position
        char *name = mlt_properties_get( mlt_transition_properties( this ), "_unique_id" );

        // Assign the current position to the name
        mlt_properties_set_position( properties, name, mlt_frame_get_position( a_frame ) );

        // Push the transition on to the frame
        mlt_frame_push_service( a_frame, this );

        // Push the transition method
        mlt_frame_push_get_image( a_frame, transition_get_image );

        // Push the b_frame on to the stack
        mlt_frame_push_frame( a_frame, b_frame );

        // Return the frame
        return a_frame;
}

/** Constructor for the transition.
*/

mlt_transition transition_region_init( void *arg )
{
        // Create a new transition
        mlt_transition this = mlt_transition_new( );

        // Further initialisation
        if ( this != NULL )
        {
                // Get the properties from the transition
                mlt_properties properties = mlt_transition_properties( this );

                // Assign the transition process method
                this->process = transition_process;

                // Default factory
                mlt_properties_set( properties, "factory", "fezzik" );
                
                // Resource defines the shape of the region
                mlt_properties_set( properties, "resource", arg == NULL ? "rectangle" : arg );
        }

        // Return the transition
        return this;
}