research.m1stereo.tv/gitweb/ - melted/blob - src/modules/core/filter_obscure.c

   1 /*
   2  * filter_obscure.c -- obscure 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_obscure.h"
  22
  23 #include <framework/mlt_frame.h>
  24 #include <framework/mlt_deque.h>
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28
  29 /** Geometry struct.
  30 */
  31
  32 struct geometry_s
  33 {
  34         float x;
  35         float y;
  36         float w;
  37         float h;
  38         int mask_w;
  39         int mask_h;
  40 };
  41
  42 /** Parse a geometry property string.
  43 */
  44
  45 static void geometry_parse( struct geometry_s *geometry, struct geometry_s *defaults, char *property )
  46 {
  47         // Assign from defaults if available
  48         if ( defaults != NULL )
  49         {
  50                 geometry->x = defaults->x;
  51                 geometry->y = defaults->y;
  52                 geometry->w = defaults->w;
  53                 geometry->h = defaults->h;
  54                 geometry->mask_w = defaults->mask_w;
  55                 geometry->mask_h = defaults->mask_h;
  56         }
  57         else
  58         {
  59                 geometry->mask_w = 20;
  60                 geometry->mask_h = 20;
  61         }
  62
  63         // Parse the geomtry string
  64         if ( property != NULL )
  65                 sscanf( property, "%f,%f:%fx%f:%dx%d", &geometry->x, &geometry->y, &geometry->w, &geometry->h, &geometry->mask_w, &geometry->mask_h );
  66 }
  67
  68 /** A Timism but not as clean ;-).
  69 */
  70
  71 static float lerp( float value, float lower, float upper )
  72 {
  73         if ( value < lower )
  74                 return lower;
  75         else if ( value > upper )
  76                 return upper;
  77         return value;
  78 }
  79
  80 /** Calculate real geometry.
  81 */
  82
  83 static void geometry_calculate( struct geometry_s *output, struct geometry_s *in, struct geometry_s *out, float position )
  84 {
  85         // Calculate this frames geometry
  86         output->x = lerp( in->x + ( out->x - in->x ) * position, 0, 100 );
  87         output->y = lerp( in->y + ( out->y - in->y ) * position, 0, 100 );
  88         output->w = lerp( in->w + ( out->w - in->w ) * position, 0, 100 - output->x );
  89         output->h = lerp( in->h + ( out->h - in->h ) * position, 0, 100 - output->y );
  90         output->mask_w = in->mask_w + ( out->mask_w - in->mask_w ) * position;
  91         output->mask_h = in->mask_h + ( out->mask_h - in->mask_h ) * position;
  92 }
  93
  94 /** Calculate the position for this frame.
  95 */
  96
  97 static float position_calculate( mlt_filter this, mlt_frame frame )
  98 {
  99         // Get the in and out position
 100         mlt_position in = mlt_filter_get_in( this );
 101         mlt_position out = mlt_filter_get_out( this );
 102
 103         // Get the position of the frame
 104         mlt_position position = mlt_frame_get_position( frame );
 105
 106         // Now do the calcs
 107         return ( float )( position - in ) / ( float )( out - in + 1 );
 108 }
 109
 110 /** The averaging function...
 111 */
 112
 113 void obscure_average( uint8_t *start, int width, int height, int stride )
 114 {
 115         int y;
 116         int x;
 117         int Y = ( *start + *( start + 2 ) ) / 2;
 118         int U = *( start + 1 );
 119         int V = *( start + 3 );
 120
 121         for ( y = 0; y < height; y ++ )
 122         {
 123                 uint8_t *p = start + y * stride;
 124                 for ( x = 0; x < width / 2; x ++ )
 125                 {
 126                         Y = ( Y + *p ++ ) / 2;
 127                         U = ( U + *p ++ ) / 2;
 128                         Y = ( Y + *p ++ ) / 2;
 129                         V = ( V + *p ++ ) / 2;
 130                 }
 131         }
 132
 133         for ( y = 0; y < height; y ++ )
 134         {
 135                 uint8_t *p = start + y * stride;
 136                 for ( x = 0; x < width / 2; x ++ )
 137                 {
 138                         *p ++ = Y;
 139                         *p ++ = U;
 140                         *p ++ = Y;
 141                         *p ++ = V;
 142                 }
 143         }
 144 }
 145
 146
 147 /** The obscurer rendering function...
 148 */
 149
 150 static void obscure_render( uint8_t *image, int width, int height, struct geometry_s result )
 151 {
 152         int area_x = ( result.x / 100 ) * width;
 153         int area_y = ( result.y / 100 ) * height;
 154         int area_w = ( result.w / 100 ) * width;
 155         int area_h = ( result.h / 100 ) * height;
 156
 157         int mw = result.mask_w;
 158         int mh = result.mask_h;
 159         int w;
 160         int h;
 161
 162         uint8_t *p = image + area_y * width * 2 + area_x * 2;
 163
 164         for ( w = 0; w < area_w; w += mw )
 165         {
 166                 for ( h = 0; h < area_h; h += mh )
 167                 {
 168                         int aw = w + mw > area_w ? mw - ( w + mw - area_w ) : mw;
 169                         int ah = h + mh > area_h ? mh - ( h + mh - area_h ) : mh;
 170                         if ( aw > 1 && ah > 1 );
 171                                 obscure_average( p + h * width * 2 + w * 2, aw, ah, width * 2 );
 172                 }
 173         }
 174 }
 175
 176 /** Do it :-).
 177 */
 178
 179 static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 180 {
 181         // Get the frame properties
 182         mlt_properties frame_properties = mlt_frame_properties( frame );
 183
 184         // Fetch the obscure stack for this frame
 185         mlt_deque deque = mlt_properties_get_data( frame_properties, "filter_obscure", NULL );
 186
 187         // Pop the top of stack now
 188         mlt_filter this = mlt_deque_pop_back( deque );
 189
 190         // Get the image from the frame
 191         if ( mlt_frame_get_image( frame, image, format, width, height, 1 ) == 0 )
 192         {
 193                 if ( this != NULL )
 194                 {
 195                         // Get the filter properties
 196                         mlt_properties properties = mlt_filter_properties( this );
 197
 198                         // Structures for geometry
 199                         struct geometry_s result;
 200                         struct geometry_s start;
 201                         struct geometry_s end;
 202
 203                         // Calculate the position
 204                         float position = position_calculate( this, frame );
 205
 206                         // Now parse the geometries
 207                         geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ) );
 208                         geometry_parse( &end, &start, mlt_properties_get( properties, "end" ) );
 209
 210                         // Do the calculation
 211                         geometry_calculate( &result, &start, &end, position );
 212
 213                         // Now actually render it
 214                         obscure_render( *image, *width, *height, result );
 215                 }
 216         }
 217
 218         return 0;
 219 }
 220
 221 /** Filter processing.
 222 */
 223
 224 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 225 {
 226         // Get the frame properties
 227         mlt_properties frame_properties = mlt_frame_properties( frame );
 228
 229         // Fetch the obscure stack for this frame
 230         mlt_deque deque = mlt_properties_get_data( frame_properties, "filter_obscure", NULL );
 231
 232         // Create stack if necessary
 233         if ( deque == NULL )
 234         {
 235                 // Create the deque
 236                 deque = mlt_deque_init( );
 237
 238                 // Assign to the frame
 239                 mlt_properties_set_data( frame_properties, "filter_obscure", deque, 0, ( mlt_destructor )mlt_deque_close, NULL );
 240         }
 241
 242         // Push this on to the obscure stack
 243         mlt_deque_push_back( deque, this );
 244
 245         // Push the get image call
 246         mlt_frame_push_get_image( frame, filter_get_image );
 247
 248         return frame;
 249 }
 250
 251 /** Constructor for the filter.
 252 */
 253
 254 mlt_filter filter_obscure_init( void *arg )
 255 {
 256         mlt_filter this = calloc( 1, sizeof( struct mlt_filter_s ) );
 257         mlt_properties properties = mlt_filter_properties( this );
 258         mlt_filter_init( this, NULL );
 259         this->process = filter_process;
 260         mlt_properties_set( properties, "start", arg != NULL ? arg : "0,0:100x100" );
 261         mlt_properties_set( properties, "end", "" );
 262         return this;
 263 }
 264