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         int nw;
  35         int nh;
  36         float x;
  37         float y;
  38         float w;
  39         float h;
  40         int mask_w;
  41         int mask_h;
  42 };
  43
  44 /** Parse a value from a geometry string.
  45 */
  46
  47 static float parse_value( char **ptr, int normalisation, char delim, float defaults )
  48 {
  49         float value = defaults;
  50
  51         if ( *ptr != NULL && **ptr != '\0' )
  52         {
  53                 char *end = NULL;
  54                 value = strtod( *ptr, &end );
  55                 if ( end != NULL )
  56                 {
  57                         if ( *end == '%' )
  58                                 value = ( value / 100.0 ) * normalisation;
  59                         while ( *end == delim || *end == '%' )
  60                                 end ++;
  61                 }
  62                 *ptr = end;
  63         }
  64
  65         return value;
  66 }
  67
  68 /** Parse a geometry property string.
  69 */
  70
  71 static void geometry_parse( struct geometry_s *geometry, struct geometry_s *defaults, char *property, int nw, int nh )
  72 {
  73         // Assign normalised width and height
  74         geometry->nw = nw;
  75         geometry->nh = nh;
  76
  77         // Assign from defaults if available
  78         if ( defaults != NULL )
  79         {
  80                 geometry->x = defaults->x;
  81                 geometry->y = defaults->y;
  82                 geometry->w = defaults->w;
  83                 geometry->h = defaults->h;
  84                 geometry->mask_w = defaults->mask_w;
  85                 geometry->mask_h = defaults->mask_h;
  86         }
  87         else
  88         {
  89                 geometry->mask_w = 20;
  90                 geometry->mask_h = 20;
  91         }
  92
  93         // Parse the geomtry string
  94         if ( property != NULL )
  95         {
  96                 char *ptr = property;
  97                 geometry->x = parse_value( &ptr, nw, ',', geometry->x );
  98                 geometry->y = parse_value( &ptr, nh, ':', geometry->y );
  99                 geometry->w = parse_value( &ptr, nw, 'x', geometry->w );
 100                 geometry->h = parse_value( &ptr, nh, ':', geometry->h );
 101                 geometry->mask_w = parse_value( &ptr, nw, 'x', geometry->mask_w );
 102                 geometry->mask_h = parse_value( &ptr, nh, ' ', geometry->mask_h );
 103         }
 104 }
 105
 106 /** A Timism but not as clean ;-).
 107 */
 108
 109 static float lerp( float value, float lower, float upper )
 110 {
 111         if ( value < lower )
 112                 return lower;
 113         else if ( value > upper )
 114                 return upper;
 115         return value;
 116 }
 117
 118 /** Calculate real geometry.
 119 */
 120
 121 static void geometry_calculate( struct geometry_s *output, struct geometry_s *in, struct geometry_s *out, float position, int ow, int oh )
 122 {
 123         // Calculate this frames geometry
 124         output->x = lerp( ( in->x + ( out->x - in->x ) * position ) / ( float )out->nw * ow, 0, ow );
 125         output->y = lerp( ( in->y + ( out->y - in->y ) * position ) / ( float )out->nh * oh, 0, oh );
 126         output->w = lerp( ( in->w + ( out->w - in->w ) * position ) / ( float )out->nw * ow, 0, ow - output->x );
 127         output->h = lerp( ( in->h + ( out->h - in->h ) * position ) / ( float )out->nh * oh, 0, oh - output->y );
 128         output->mask_w = in->mask_w + ( out->mask_w - in->mask_w ) * position;
 129         output->mask_h = in->mask_h + ( out->mask_h - in->mask_h ) * position;
 130 }
 131
 132 /** Calculate the position for this frame.
 133 */
 134
 135 static float position_calculate( mlt_filter this, mlt_frame frame )
 136 {
 137         // Get the in and out position
 138         mlt_position in = mlt_filter_get_in( this );
 139         mlt_position out = mlt_filter_get_out( this );
 140
 141         // Get the position of the frame
 142         mlt_position position = mlt_frame_get_position( frame );
 143
 144         // Now do the calcs
 145         return ( float )( position - in ) / ( float )( out - in + 1 );
 146 }
 147
 148 /** The averaging function...
 149 */
 150
 151 void obscure_average( uint8_t *start, int width, int height, int stride )
 152 {
 153         int y;
 154         int x;
 155         register int Y = ( *start + *( start + 2 ) ) / 2;
 156         register int U = *( start + 1 );
 157         register int V = *( start + 3 );
 158         register uint8_t *p;
 159
 160         for ( y = 0; y < height; y ++ )
 161         {
 162                 p = start + y * stride;
 163                 for ( x = 0; x < width / 2; x ++ )
 164                 {
 165                         Y = ( Y + *p ++ ) / 2;
 166                         U = ( U + *p ++ ) / 2;
 167                         Y = ( Y + *p ++ ) / 2;
 168                         V = ( V + *p ++ ) / 2;
 169                 }
 170         }
 171
 172         for ( y = 0; y < height; y ++ )
 173         {
 174                 p = start + y * stride;
 175
 176                 for ( x = 0; x < width / 2; x ++ )
 177                 {
 178                         *p ++ = Y;
 179                         *p ++ = U;
 180                         *p ++ = Y;
 181                         *p ++ = V;
 182                 }
 183         }
 184 }
 185
 186
 187 /** The obscurer rendering function...
 188 */
 189
 190 static void obscure_render( uint8_t *image, int width, int height, struct geometry_s result )
 191 {
 192         int area_x = result.x;
 193         int area_y = result.y;
 194         int area_w = result.w;
 195         int area_h = result.h;
 196
 197         int mw = result.mask_w;
 198         int mh = result.mask_h;
 199         int w;
 200         int h;
 201         int aw;
 202         int ah;
 203
 204         uint8_t *p = image + area_y * width * 2 + area_x * 2;
 205
 206         for ( w = 0; w < area_w; w += mw )
 207         {
 208                 for ( h = 0; h < area_h; h += mh )
 209                 {
 210                         aw = w + mw > area_w ? mw - ( w + mw - area_w ) : mw;
 211                         ah = h + mh > area_h ? mh - ( h + mh - area_h ) : mh;
 212                         if ( aw > 1 && ah > 1 )
 213                                 obscure_average( p + h * width * 2 + w * 2, aw, ah, width * 2 );
 214                 }
 215         }
 216 }
 217
 218 /** Do it :-).
 219 */
 220
 221 static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 222 {
 223         // Get the frame properties
 224         mlt_properties frame_properties = mlt_frame_properties( frame );
 225
 226         // Fetch the obscure stack for this frame
 227         mlt_deque deque = mlt_properties_get_data( frame_properties, "filter_obscure", NULL );
 228
 229         // Pop the top of stack now
 230         mlt_filter this = mlt_deque_pop_back( deque );
 231
 232         // Get the image from the frame
 233         if ( mlt_frame_get_image( frame, image, format, width, height, 1 ) == 0 )
 234         {
 235                 if ( this != NULL )
 236                 {
 237                         // Get the filter properties
 238                         mlt_properties properties = mlt_filter_properties( this );
 239
 240                         // Obtain the normalised width and height from the frame
 241                         int normalised_width = mlt_properties_get_int( frame_properties, "normalised_width" );
 242                         int normalised_height = mlt_properties_get_int( frame_properties, "normalised_height" );
 243
 244                         // Structures for geometry
 245                         struct geometry_s result;
 246                         struct geometry_s start;
 247                         struct geometry_s end;
 248
 249                         // Calculate the position
 250                         float position = position_calculate( this, frame );
 251
 252                         // Now parse the geometries
 253                         geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ), normalised_width, normalised_height );
 254                         geometry_parse( &end, &start, mlt_properties_get( properties, "end" ), normalised_width, normalised_height );
 255
 256                         // Do the calculation
 257                         geometry_calculate( &result, &start, &end, position, *width, *height );
 258
 259                         // Now actually render it
 260                         obscure_render( *image, *width, *height, result );
 261                 }
 262         }
 263
 264         return 0;
 265 }
 266
 267 /** Filter processing.
 268 */
 269
 270 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 271 {
 272         // Get the frame properties
 273         mlt_properties frame_properties = mlt_frame_properties( frame );
 274
 275         // Fetch the obscure stack for this frame
 276         mlt_deque deque = mlt_properties_get_data( frame_properties, "filter_obscure", NULL );
 277
 278         // Create stack if necessary
 279         if ( deque == NULL )
 280         {
 281                 // Create the deque
 282                 deque = mlt_deque_init( );
 283
 284                 // Assign to the frame
 285                 mlt_properties_set_data( frame_properties, "filter_obscure", deque, 0, ( mlt_destructor )mlt_deque_close, NULL );
 286         }
 287
 288         // Push this on to the obscure stack
 289         mlt_deque_push_back( deque, this );
 290
 291         // Push the get image call
 292         mlt_frame_push_get_image( frame, filter_get_image );
 293
 294         return frame;
 295 }
 296
 297 /** Constructor for the filter.
 298 */
 299
 300 mlt_filter filter_obscure_init( void *arg )
 301 {
 302         mlt_filter this = mlt_filter_new( );
 303         if ( this != NULL )
 304         {
 305                 mlt_properties properties = mlt_filter_properties( this );
 306                 this->process = filter_process;
 307                 mlt_properties_set( properties, "start", arg != NULL ? arg : "0%,0%:100%x100%" );
 308                 mlt_properties_set( properties, "end", "" );
 309         }
 310         return this;
 311 }
 312