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 library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, 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
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27
  28 /** Geometry struct.
  29 */
  30
  31 struct geometry_s
  32 {
  33         int nw;
  34         int nh;
  35         float x;
  36         float y;
  37         float w;
  38         float h;
  39         int mask_w;
  40         int mask_h;
  41 };
  42
  43 /** Parse a value from a geometry string.
  44 */
  45
  46 static inline float parse_value( char **ptr, int normalisation, char delim, float defaults )
  47 {
  48         float value = defaults;
  49
  50         if ( *ptr != NULL && **ptr != '\0' )
  51         {
  52                 char *end = NULL;
  53                 value = strtod( *ptr, &end );
  54                 if ( end != NULL )
  55                 {
  56                         if ( *end == '%' )
  57                                 value = ( value / 100.0 ) * normalisation;
  58                         while ( *end == delim || *end == '%' )
  59                                 end ++;
  60                 }
  61                 *ptr = end;
  62         }
  63
  64         return value;
  65 }
  66
  67 /** Parse a geometry property string.
  68 */
  69
  70 static void geometry_parse( struct geometry_s *geometry, struct geometry_s *defaults, char *property, int nw, int nh )
  71 {
  72         // Assign normalised width and height
  73         geometry->nw = nw;
  74         geometry->nh = nh;
  75
  76         // Assign from defaults if available
  77         if ( defaults != NULL )
  78         {
  79                 geometry->x = defaults->x;
  80                 geometry->y = defaults->y;
  81                 geometry->w = defaults->w;
  82                 geometry->h = defaults->h;
  83                 geometry->mask_w = defaults->mask_w;
  84                 geometry->mask_h = defaults->mask_h;
  85         }
  86         else
  87         {
  88                 geometry->x = 0;
  89                 geometry->y = 0;
  90                 geometry->w = nw;
  91                 geometry->h = nh;
  92                 geometry->mask_w = 20;
  93                 geometry->mask_h = 20;
  94         }
  95
  96         // Parse the geomtry string
  97         if ( property != NULL )
  98         {
  99                 char *ptr = property;
 100                 geometry->x = parse_value( &ptr, nw, ',', geometry->x );
 101                 geometry->y = parse_value( &ptr, nh, ':', geometry->y );
 102                 geometry->w = parse_value( &ptr, nw, 'x', geometry->w );
 103                 geometry->h = parse_value( &ptr, nh, ':', geometry->h );
 104                 geometry->mask_w = parse_value( &ptr, nw, 'x', geometry->mask_w );
 105                 geometry->mask_h = parse_value( &ptr, nh, ' ', geometry->mask_h );
 106         }
 107 }
 108
 109 /** A Timism but not as clean ;-).
 110 */
 111
 112 static float lerp( float value, float lower, float upper )
 113 {
 114         if ( value < lower )
 115                 return lower;
 116         else if ( value > upper )
 117                 return upper;
 118         return value;
 119 }
 120
 121 /** Calculate real geometry.
 122 */
 123
 124 static void geometry_calculate( struct geometry_s *output, struct geometry_s *in, struct geometry_s *out, float position, int ow, int oh )
 125 {
 126         // Calculate this frames geometry
 127         output->x = lerp( ( in->x + ( out->x - in->x ) * position ) / ( float )out->nw * ow, 0, ow );
 128         output->y = lerp( ( in->y + ( out->y - in->y ) * position ) / ( float )out->nh * oh, 0, oh );
 129         output->w = lerp( ( in->w + ( out->w - in->w ) * position ) / ( float )out->nw * ow, 0, ow - output->x );
 130         output->h = lerp( ( in->h + ( out->h - in->h ) * position ) / ( float )out->nh * oh, 0, oh - output->y );
 131         output->mask_w = in->mask_w + ( out->mask_w - in->mask_w ) * position;
 132         output->mask_h = in->mask_h + ( out->mask_h - in->mask_h ) * position;
 133 }
 134
 135 /** Calculate the position for this frame.
 136 */
 137
 138 static float position_calculate( mlt_filter this, mlt_frame frame )
 139 {
 140         // Get the in and out position
 141         mlt_position in = mlt_filter_get_in( this );
 142         mlt_position out = mlt_filter_get_out( this );
 143
 144         // Get the position of the frame
 145         mlt_position position = mlt_frame_get_position( frame );
 146
 147         // Now do the calcs
 148         return ( float )( position - in ) / ( float )( out - in + 1 );
 149 }
 150
 151 /** The averaging function...
 152 */
 153
 154 static inline void obscure_average( uint8_t *start, int width, int height, int stride )
 155 {
 156         register int y;
 157         register int x;
 158         register int Y = ( *start + *( start + 2 ) ) / 2;
 159         register int U = *( start + 1 );
 160         register int V = *( start + 3 );
 161         register uint8_t *p;
 162         register int components = width >> 1;
 163
 164         y = height;
 165         while( y -- )
 166         {
 167                 p = start;
 168                 x = components;
 169                 while( x -- )
 170                 {
 171                         Y = ( Y + *p ++ ) >> 1;
 172                         U = ( U + *p ++ ) >> 1;
 173                         Y = ( Y + *p ++ ) >> 1;
 174                         V = ( V + *p ++ ) >> 1;
 175                 }
 176                 start += stride;
 177         }
 178
 179         start -= height * stride;
 180         y = height;
 181         while( y -- )
 182         {
 183                 p = start;
 184                 x = components;
 185                 while( x -- )
 186                 {
 187                         *p ++ = Y;
 188                         *p ++ = U;
 189                         *p ++ = Y;
 190                         *p ++ = V;
 191                 }
 192                 start += stride;
 193         }
 194 }
 195
 196
 197 /** The obscurer rendering function...
 198 */
 199
 200 static void obscure_render( uint8_t *image, int width, int height, struct geometry_s result )
 201 {
 202         int area_x = result.x;
 203         int area_y = result.y;
 204         int area_w = result.w;
 205         int area_h = result.h;
 206
 207         int mw = result.mask_w;
 208         int mh = result.mask_h;
 209         int w;
 210         int h;
 211         int aw;
 212         int ah;
 213
 214         uint8_t *p = image + area_y * width * 2 + area_x * 2;
 215
 216         for ( w = 0; w < area_w; w += mw )
 217         {
 218                 for ( h = 0; h < area_h; h += mh )
 219                 {
 220                         aw = w + mw > area_w ? mw - ( w + mw - area_w ) : mw;
 221                         ah = h + mh > area_h ? mh - ( h + mh - area_h ) : mh;
 222                         if ( aw > 1 && ah > 1 )
 223                                 obscure_average( p + h * ( width << 1 ) + ( w << 1 ), aw, ah, width << 1 );
 224                 }
 225         }
 226 }
 227
 228 /** Do it :-).
 229 */
 230
 231 static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 232 {
 233         // Get the frame properties
 234         mlt_properties frame_properties = MLT_FRAME_PROPERTIES( frame );
 235
 236         // Pop the top of stack now
 237         mlt_filter this = mlt_frame_pop_service( frame );
 238
 239         // Get the image from the frame
 240         int error = mlt_frame_get_image( frame, image, format, width, height, 1 );
 241
 242         // Get the image from the frame
 243         if ( error == 0 && *format == mlt_image_yuv422 )
 244         {
 245                 if ( this != NULL )
 246                 {
 247                         // Get the filter properties
 248                         mlt_properties properties = MLT_FILTER_PROPERTIES( this );
 249
 250                         // Obtain the normalised width and height from the frame
 251                         int normalised_width = mlt_properties_get_int( frame_properties, "normalised_width" );
 252                         int normalised_height = mlt_properties_get_int( frame_properties, "normalised_height" );
 253
 254                         // Structures for geometry
 255                         struct geometry_s result;
 256                         struct geometry_s start;
 257                         struct geometry_s end;
 258
 259                         // Retrieve the position
 260                         float position = mlt_properties_get_double(frame_properties, "filter_position");
 261
 262                         // Now parse the geometries
 263                         geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ), normalised_width, normalised_height );
 264                         geometry_parse( &end, &start, mlt_properties_get( properties, "end" ), normalised_width, normalised_height );
 265
 266                         // Do the calculation
 267                         geometry_calculate( &result, &start, &end, position, *width, *height );
 268
 269                         // Now actually render it
 270                         obscure_render( *image, *width, *height, result );
 271                 }
 272         }
 273
 274         return error;
 275 }
 276
 277 /** Filter processing.
 278 */
 279
 280 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 281 {
 282         // Push this on to the service stack
 283         mlt_frame_push_service( frame, this );
 284
 285         // Calculate the position for the filter effect
 286         float position = position_calculate( this, frame );
 287         mlt_properties_set_double( MLT_FRAME_PROPERTIES( frame ), "filter_position", position );
 288
 289         // Push the get image call
 290         mlt_frame_push_get_image( frame, filter_get_image );
 291
 292         return frame;
 293 }
 294
 295 /** Constructor for the filter.
 296 */
 297
 298 mlt_filter filter_obscure_init( void *arg )
 299 {
 300         mlt_filter this = mlt_filter_new( );
 301         if ( this != NULL )
 302         {
 303                 mlt_properties properties = MLT_FILTER_PROPERTIES( this );
 304                 this->process = filter_process;
 305                 mlt_properties_set( properties, "start", arg != NULL ? arg : "0%,0%:100%x100%" );
 306                 mlt_properties_set( properties, "end", "" );
 307         }
 308         return this;
 309 }
 310