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, uint8_t *alpha )
 152 {
 153         int y;
 154         int x;
 155         int Y = ( *start + *( start + 2 ) ) / 2;
 156         int U = *( start + 1 );
 157         int V = *( start + 3 );
 158
 159         for ( y = 0; y < height; y ++ )
 160         {
 161                 uint8_t *p = start + y * stride;
 162                 for ( x = 0; x < width / 2; x ++ )
 163                 {
 164                         Y = ( Y + *p ++ ) / 2;
 165                         U = ( U + *p ++ ) / 2;
 166                         Y = ( Y + *p ++ ) / 2;
 167                         V = ( V + *p ++ ) / 2;
 168                 }
 169         }
 170
 171         for ( y = 0; y < height; y ++ )
 172         {
 173                 uint8_t *p = start + y * stride;
 174                 uint8_t *z = alpha;
 175
 176                 if ( z != NULL )
 177                         z += y * stride / 2;
 178
 179                 for ( x = 0; x < width / 2; x ++ )
 180                 {
 181                         if ( z == NULL || ( z != NULL && *z++ > 127 ) )
 182                         {
 183                                 *p ++ = Y;
 184                                 *p ++ = U;
 185                         }
 186                         else
 187                         {
 188                                 p += 2;
 189                         }
 190
 191                         if ( z == NULL || ( z != NULL && *z++ > 127 ) )
 192                         {
 193
 194                                 *p ++ = Y;
 195                                 *p ++ = V;
 196                         }
 197                         else
 198                         {
 199                                 p += 2;
 200                         }
 201                 }
 202         }
 203 }
 204
 205
 206 /** The obscurer rendering function...
 207 */
 208
 209 static void obscure_render( uint8_t *image, int width, int height, struct geometry_s result, uint8_t *alpha )
 210 {
 211         int area_x = result.x;
 212         int area_y = result.y;
 213         int area_w = result.w;
 214         int area_h = result.h;
 215
 216         int mw = result.mask_w;
 217         int mh = result.mask_h;
 218         int w;
 219         int h;
 220
 221         uint8_t *p = image + area_y * width * 2 + area_x * 2;
 222         uint8_t *z = alpha;
 223         if ( z != NULL )
 224                 z += area_y * width + area_x;
 225
 226         for ( w = 0; w < area_w; w += mw )
 227         {
 228                 for ( h = 0; h < area_h; h += mh )
 229                 {
 230                         int aw = w + mw > area_w ? mw - ( w + mw - area_w ) : mw;
 231                         int ah = h + mh > area_h ? mh - ( h + mh - area_h ) : mh;
 232                         if ( aw > 1 && ah > 1 )
 233                                 obscure_average( p + h * width * 2 + w * 2, aw, ah, width * 2,
 234                                         ( z == NULL ? z : z + h * width + w ) );
 235                 }
 236         }
 237 }
 238
 239 /** Do it :-).
 240 */
 241
 242 static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 243 {
 244         // Get the frame properties
 245         mlt_properties frame_properties = mlt_frame_properties( frame );
 246
 247         // Fetch the obscure stack for this frame
 248         mlt_deque deque = mlt_properties_get_data( frame_properties, "filter_obscure", NULL );
 249
 250         // Pop the top of stack now
 251         mlt_filter this = mlt_deque_pop_back( deque );
 252
 253         // Get the image from the frame
 254         if ( mlt_frame_get_image( frame, image, format, width, height, 1 ) == 0 )
 255         {
 256                 if ( this != NULL )
 257                 {
 258                         // Get the filter properties
 259                         mlt_properties properties = mlt_filter_properties( this );
 260
 261                         // Obtain the normalised width and height from the frame
 262                         int normalised_width = mlt_properties_get_int( frame_properties, "normalised_width" );
 263                         int normalised_height = mlt_properties_get_int( frame_properties, "normalised_height" );
 264
 265                         // Structures for geometry
 266                         struct geometry_s result;
 267                         struct geometry_s start;
 268                         struct geometry_s end;
 269
 270                         // Calculate the position
 271                         float position = position_calculate( this, frame );
 272
 273                         // Now parse the geometries
 274                         geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ), normalised_width, normalised_height );
 275                         geometry_parse( &end, &start, mlt_properties_get( properties, "end" ), normalised_width, normalised_height );
 276
 277                         // Do the calculation
 278                         geometry_calculate( &result, &start, &end, position, *width, *height );
 279
 280                         // Now actually render it
 281                         obscure_render( *image, *width, *height, result, mlt_frame_get_alpha_mask( frame ) );
 282                 }
 283         }
 284
 285         return 0;
 286 }
 287
 288 /** Filter processing.
 289 */
 290
 291 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 292 {
 293         // Get the frame properties
 294         mlt_properties frame_properties = mlt_frame_properties( frame );
 295
 296         // Fetch the obscure stack for this frame
 297         mlt_deque deque = mlt_properties_get_data( frame_properties, "filter_obscure", NULL );
 298
 299         // Create stack if necessary
 300         if ( deque == NULL )
 301         {
 302                 // Create the deque
 303                 deque = mlt_deque_init( );
 304
 305                 // Assign to the frame
 306                 mlt_properties_set_data( frame_properties, "filter_obscure", deque, 0, ( mlt_destructor )mlt_deque_close, NULL );
 307         }
 308
 309         // Push this on to the obscure stack
 310         mlt_deque_push_back( deque, this );
 311
 312         // Push the get image call
 313         mlt_frame_push_get_image( frame, filter_get_image );
 314
 315         return frame;
 316 }
 317
 318 /** Constructor for the filter.
 319 */
 320
 321 mlt_filter filter_obscure_init( void *arg )
 322 {
 323         mlt_filter this = calloc( 1, sizeof( struct mlt_filter_s ) );
 324         mlt_properties properties = mlt_filter_properties( this );
 325         mlt_filter_init( this, NULL );
 326         this->process = filter_process;
 327         mlt_properties_set( properties, "start", arg != NULL ? arg : "0%,0%:100%x100%" );
 328         mlt_properties_set( properties, "end", "" );
 329         return this;
 330 }
 331