research.m1stereo.tv/gitweb/ - melted/blob - src/modules/plus/filter_charcoal.c

   1 /*
   2  * filter_charcoal.c -- charcoal filter
   3  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
   4  * Author: Charles Yates <charles.yates@pandora.be>
   5  *
   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.
  10  *
  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.
  15  *
  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.
  19  */
  20
  21 #include "filter_charcoal.h"
  22
  23 #include <framework/mlt_frame.h>
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <math.h>
  28
  29 static inline int get_Y( uint8_t *pixels, int width, int height, int x, int y )
  30 {
  31         if ( x < 0 || x >= width || y < 0 || y >= height )
  32         {
  33                 return 235;
  34         }
  35         else
  36         {
  37                 uint8_t *pixel = pixels + y * ( width << 1 ) + ( x << 1 );
  38                 return *pixel;
  39         }
  40 }
  41
  42 static inline int sqrti( int n )
  43 {
  44         int p = 0;
  45         int q = 1;
  46         int r = n;
  47         int h = 0;
  48
  49         while( q <= n )
  50                 q = q << 2;
  51
  52         while( q != 1 )
  53         {
  54                 q = q >> 2;
  55                 h = p + q;
  56                 p = p >> 1;
  57                 if ( r >= h )
  58                 {
  59                         p = p + q;
  60                         r = r - h;
  61                 }
  62         }
  63
  64         return p;
  65 }
  66
  67 /** Do it :-).
  68 */
  69
  70 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
  71 {
  72         // Get the filter
  73         mlt_filter filter = mlt_frame_pop_service( this );
  74
  75         // Get the image
  76         int error = mlt_frame_get_image( this, image, format, width, height, 1 );
  77
  78         // Only process if we have no error and a valid colour space
  79         if ( error == 0 && *format == mlt_image_yuv422 )
  80         {
  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" );
  87
  88                 // We'll process pixel by pixel
  89                 int x = 0;
  90                 int y = 0;
  91
  92                 // We need to create a new frame as this effect modifies the input
  93                 uint8_t *temp = mlt_pool_alloc( *width * *height * 2 );
  94                 uint8_t *p = temp;
  95                 uint8_t *q = *image;
  96
  97                 // Calculations are carried out on a 3x3 matrix
  98                 int matrix[ 3 ][ 3 ];
  99
 100                 // Used to carry out the matrix calculations
 101                 int sum1;
 102                 int sum2;
 103                 float sum;
 104
 105                 // Loop for each row
 106                 for ( y = 0; y < *height; y ++ )
 107                 {
 108                         // Loop for each pixel
 109                         for ( x = 0; x < *width; x ++ )
 110                         {
 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 );
 120
 121                                 // Do calculations
 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 );
 125
 126                                 // Assign value
 127                                 *p ++ = !invert ? ( sum >= 16 && sum <= 235 ? 251 - sum : sum < 16 ? 235 : 16 ) :
 128                                                                   ( sum >= 16 && sum <= 235 ? sum : sum < 16 ? 16 : 235 );
 129                                 q ++;
 130                                 *p ++ = 128 + mix * ( *q ++ - 128 );
 131                         }
 132                 }
 133
 134                 // Return the created image
 135                 *image = temp;
 136
 137                 // Store new and destroy old
 138                 mlt_properties_set_data( mlt_frame_properties( this ), "image", *image, *width * *height * 2, mlt_pool_release, NULL );
 139         }
 140
 141         return error;
 142 }
 143
 144 /** Filter processing.
 145 */
 146
 147 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 148 {
 149         // Push the frame filter
 150         mlt_frame_push_service( frame, this );
 151         mlt_frame_push_get_image( frame, filter_get_image );
 152
 153         return frame;
 154 }
 155
 156 /** Constructor for the filter.
 157 */
 158
 159 mlt_filter filter_charcoal_init( char *arg )
 160 {
 161         mlt_filter this = mlt_filter_new( );
 162         if ( this != NULL )
 163         {
 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" );
 169         }
 170         return this;
 171 }
 172