2 * filter_charcoal.c -- charcoal filter
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Charles Yates <charles.yates@pandora.be>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 #include "filter_charcoal.h"
23 #include <framework/mlt_frame.h>
29 static inline int get_Y( uint8_t *pixels, int width, int height, int x, int y )
31 if ( x < 0 || x >= width || y < 0 || y >= height )
37 uint8_t *pixel = pixels + y * ( width << 1 ) + ( x << 1 );
42 static inline int sqrti( int n )
70 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
73 mlt_filter filter = mlt_frame_pop_service( this );
76 int error = mlt_frame_get_image( this, image, format, width, height, 1 );
78 // Only process if we have no error and a valid colour space
79 if ( error == 0 && *format == mlt_image_yuv422 )
81 // Get the charcoal scatter value
82 int x_scatter = mlt_properties_get_double( mlt_filter_properties( filter ), "x_scatter" );
83 int y_scatter = mlt_properties_get_double( mlt_filter_properties( filter ), "y_scatter" );
84 float scale = mlt_properties_get_double( mlt_filter_properties( filter ), "scale" );
85 float mix = mlt_properties_get_double( mlt_filter_properties( filter ), "mix" );
86 int invert = mlt_properties_get_int( mlt_filter_properties( filter ), "invert" );
88 // We'll process pixel by pixel
92 // We need to create a new frame as this effect modifies the input
93 uint8_t *temp = mlt_pool_alloc( *width * *height * 2 );
97 // Calculations are carried out on a 3x3 matrix
100 // Used to carry out the matrix calculations
106 for ( y = 0; y < *height; y ++ )
108 // Loop for each pixel
109 for ( x = 0; x < *width; x ++ )
111 // Populate the matrix
112 matrix[ 0 ][ 0 ] = get_Y( *image, *width, *height, x - x_scatter, y - y_scatter );
113 matrix[ 0 ][ 1 ] = get_Y( *image, *width, *height, x , y - y_scatter );
114 matrix[ 0 ][ 2 ] = get_Y( *image, *width, *height, x + x_scatter, y - y_scatter );
115 matrix[ 1 ][ 0 ] = get_Y( *image, *width, *height, x - x_scatter, y );
116 matrix[ 1 ][ 2 ] = get_Y( *image, *width, *height, x + x_scatter, y );
117 matrix[ 2 ][ 0 ] = get_Y( *image, *width, *height, x - x_scatter, y + y_scatter );
118 matrix[ 2 ][ 1 ] = get_Y( *image, *width, *height, x , y + y_scatter );
119 matrix[ 2 ][ 2 ] = get_Y( *image, *width, *height, x + x_scatter, y + y_scatter );
122 sum1 = (matrix[2][0] - matrix[0][0]) + ( (matrix[2][1] - matrix[0][1]) << 1 ) + (matrix[2][2] - matrix[2][0]);
123 sum2 = (matrix[0][2] - matrix[0][0]) + ( (matrix[1][2] - matrix[1][0]) << 1 ) + (matrix[2][2] - matrix[2][0]);
124 sum = scale * sqrti( sum1 * sum1 + sum2 * sum2 );
127 *p ++ = !invert ? ( sum >= 16 && sum <= 235 ? 251 - sum : sum < 16 ? 235 : 16 ) :
128 ( sum >= 16 && sum <= 235 ? sum : sum < 16 ? 16 : 235 );
130 *p ++ = 128 + mix * ( *q ++ - 128 );
134 // Return the created image
137 // Store new and destroy old
138 mlt_properties_set_data( mlt_frame_properties( this ), "image", *image, *width * *height * 2, mlt_pool_release, NULL );
144 /** Filter processing.
147 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
149 // Push the frame filter
150 mlt_frame_push_service( frame, this );
151 mlt_frame_push_get_image( frame, filter_get_image );
156 /** Constructor for the filter.
159 mlt_filter filter_charcoal_init( char *arg )
161 mlt_filter this = mlt_filter_new( );
164 this->process = filter_process;
165 mlt_properties_set( mlt_filter_properties( this ), "x_scatter", "1" );
166 mlt_properties_set( mlt_filter_properties( this ), "y_scatter", "1" );
167 mlt_properties_set( mlt_filter_properties( this ), "scale", "1.5" );
168 mlt_properties_set( mlt_filter_properties( this ), "mix", "0" );