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 <framework/mlt_filter.h>
  22 #include <framework/mlt_frame.h>
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26
  27 /** Geometry struct.
  28 */
  29
  30 struct geometry_s
  31 {
  32         int nw;
  33         int nh;
  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 value from a geometry string.
  43 */
  44
  45 static inline float parse_value( char **ptr, int normalisation, char delim, float defaults )
  46 {
  47         float value = defaults;
  48
  49         if ( *ptr != NULL && **ptr != '\0' )
  50         {
  51                 char *end = NULL;
  52                 value = strtod( *ptr, &end );
  53                 if ( end != NULL )
  54                 {
  55                         if ( *end == '%' )
  56                                 value = ( value / 100.0 ) * normalisation;
  57                         while ( *end == delim || *end == '%' )
  58                                 end ++;
  59                 }
  60                 *ptr = end;
  61         }
  62
  63         return value;
  64 }
  65
  66 /** Parse a geometry property string.
  67 */
  68
  69 static void geometry_parse( struct geometry_s *geometry, struct geometry_s *defaults, char *property, int nw, int nh )
  70 {
  71         // Assign normalised width and height
  72         geometry->nw = nw;
  73         geometry->nh = nh;
  74
  75         // Assign from defaults if available
  76         if ( defaults != NULL )
  77         {
  78                 geometry->x = defaults->x;
  79                 geometry->y = defaults->y;
  80                 geometry->w = defaults->w;
  81                 geometry->h = defaults->h;
  82                 geometry->mask_w = defaults->mask_w;
  83                 geometry->mask_h = defaults->mask_h;
  84         }
  85         else
  86         {
  87                 geometry->x = 0;
  88                 geometry->y = 0;
  89                 geometry->w = nw;
  90                 geometry->h = nh;
  91                 geometry->mask_w = 20;
  92                 geometry->mask_h = 20;
  93         }
  94
  95         // Parse the geomtry string
  96         if ( property != NULL )
  97         {
  98                 char *ptr = property;
  99                 geometry->x = parse_value( &ptr, nw, ',', geometry->x );
 100                 geometry->y = parse_value( &ptr, nh, ':', geometry->y );
 101                 geometry->w = parse_value( &ptr, nw, 'x', geometry->w );
 102                 geometry->h = parse_value( &ptr, nh, ':', geometry->h );
 103                 geometry->mask_w = parse_value( &ptr, nw, 'x', geometry->mask_w );
 104                 geometry->mask_h = parse_value( &ptr, nh, ' ', geometry->mask_h );
 105         }
 106 }
 107
 108 /** A Timism but not as clean ;-).
 109 */
 110
 111 static float lerp( float value, float lower, float upper )
 112 {
 113         if ( value < lower )
 114                 return lower;
 115         else if ( value > upper )
 116                 return upper;
 117         return value;
 118 }
 119
 120 /** Calculate real geometry.
 121 */
 122
 123 static void geometry_calculate( struct geometry_s *output, struct geometry_s *in, struct geometry_s *out, float position, int ow, int oh )
 124 {
 125         // Calculate this frames geometry
 126         output->x = lerp( ( in->x + ( out->x - in->x ) * position ) / ( float )out->nw * ow, 0, ow );
 127         output->y = lerp( ( in->y + ( out->y - in->y ) * position ) / ( float )out->nh * oh, 0, oh );
 128         output->w = lerp( ( in->w + ( out->w - in->w ) * position ) / ( float )out->nw * ow, 0, ow - output->x );
 129         output->h = lerp( ( in->h + ( out->h - in->h ) * position ) / ( float )out->nh * oh, 0, oh - output->y );
 130         output->mask_w = in->mask_w + ( out->mask_w - in->mask_w ) * position;
 131         output->mask_h = in->mask_h + ( out->mask_h - in->mask_h ) * position;
 132 }
 133
 134 /** Calculate the position for this frame.
 135 */
 136
 137 static float position_calculate( mlt_filter this, mlt_frame frame )
 138 {
 139         // Get the in and out position
 140         mlt_position in = mlt_filter_get_in( this );
 141         mlt_position out = mlt_filter_get_out( this );
 142
 143         // Get the position of the frame
 144         mlt_position position = mlt_frame_get_position( frame );
 145
 146         // Now do the calcs
 147         return ( float )( position - in ) / ( float )( out - in + 1 );
 148 }
 149
 150 /** The averaging function...
 151 */
 152
 153 static inline void obscure_average( uint8_t *start, int width, int height, int stride )
 154 {
 155         register int y;
 156         register int x;
 157         register int Y = ( *start + *( start + 2 ) ) / 2;
 158         register int U = *( start + 1 );
 159         register int V = *( start + 3 );
 160         register uint8_t *p;
 161         register int components = width >> 1;
 162
 163         y = height;
 164         while( y -- )
 165         {
 166                 p = start;
 167                 x = components;
 168                 while( x -- )
 169                 {
 170                         Y = ( Y + *p ++ ) >> 1;
 171                         U = ( U + *p ++ ) >> 1;
 172                         Y = ( Y + *p ++ ) >> 1;
 173                         V = ( V + *p ++ ) >> 1;
 174                 }
 175                 start += stride;
 176         }
 177
 178         start -= height * stride;
 179         y = height;
 180         while( y -- )
 181         {
 182                 p = start;
 183                 x = components;
 184                 while( x -- )
 185                 {
 186                         *p ++ = Y;
 187                         *p ++ = U;
 188                         *p ++ = Y;
 189                         *p ++ = V;
 190                 }
 191                 start += stride;
 192         }
 193 }
 194
 195
 196 /** The obscurer rendering function...
 197 */
 198
 199 static void obscure_render( uint8_t *image, int width, int height, struct geometry_s result )
 200 {
 201         int area_x = result.x;
 202         int area_y = result.y;
 203         int area_w = result.w;
 204         int area_h = result.h;
 205
 206         int mw = result.mask_w;
 207         int mh = result.mask_h;
 208         int w;
 209         int h;
 210         int aw;
 211         int ah;
 212
 213         uint8_t *p = image + area_y * width * 2 + area_x * 2;
 214
 215         for ( w = 0; w < area_w; w += mw )
 216         {
 217                 for ( h = 0; h < area_h; h += mh )
 218                 {
 219                         aw = w + mw > area_w ? mw - ( w + mw - area_w ) : mw;
 220                         ah = h + mh > area_h ? mh - ( h + mh - area_h ) : mh;
 221                         if ( aw > 1 && ah > 1 )
 222                                 obscure_average( p + h * ( width << 1 ) + ( w << 1 ), aw, ah, width << 1 );
 223                 }
 224         }
 225 }
 226
 227 /** Do it :-).
 228 */
 229
 230 static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 231 {
 232         // Get the frame properties
 233         mlt_properties frame_properties = MLT_FRAME_PROPERTIES( frame );
 234
 235         // Pop the top of stack now
 236         mlt_filter this = mlt_frame_pop_service( frame );
 237
 238         // Get the image from the frame
 239         int error = mlt_frame_get_image( frame, image, format, width, height, 1 );
 240
 241         // Get the image from the frame
 242         if ( error == 0 && *format == mlt_image_yuv422 )
 243         {
 244                 if ( this != NULL )
 245                 {
 246                         // Get the filter properties
 247                         mlt_properties properties = MLT_FILTER_PROPERTIES( this );
 248
 249                         // Obtain the normalised width and height from the frame
 250                         int normalised_width = mlt_properties_get_int( frame_properties, "normalised_width" );
 251                         int normalised_height = mlt_properties_get_int( frame_properties, "normalised_height" );
 252
 253                         // Structures for geometry
 254                         struct geometry_s result;
 255                         struct geometry_s start;
 256                         struct geometry_s end;
 257
 258                         // Retrieve the position
 259                         float position = mlt_properties_get_double(frame_properties, "filter_position");
 260
 261                         // Now parse the geometries
 262                         geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ), normalised_width, normalised_height );
 263                         geometry_parse( &end, &start, mlt_properties_get( properties, "end" ), normalised_width, normalised_height );
 264
 265                         // Do the calculation
 266                         geometry_calculate( &result, &start, &end, position, *width, *height );
 267
 268                         // Now actually render it
 269                         obscure_render( *image, *width, *height, result );
 270                 }
 271         }
 272
 273         return error;
 274 }
 275
 276 /** Filter processing.
 277 */
 278
 279 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 280 {
 281         // Push this on to the service stack
 282         mlt_frame_push_service( frame, this );
 283
 284         // Calculate the position for the filter effect
 285         float position = position_calculate( this, frame );
 286         mlt_properties_set_double( MLT_FRAME_PROPERTIES( frame ), "filter_position", position );
 287
 288         // Push the get image call
 289         mlt_frame_push_get_image( frame, filter_get_image );
 290
 291         return frame;
 292 }
 293
 294 /** Constructor for the filter.
 295 */
 296
 297 mlt_filter filter_obscure_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
 298 {
 299         mlt_filter this = mlt_filter_new( );
 300         if ( this != NULL )
 301         {
 302                 mlt_properties properties = MLT_FILTER_PROPERTIES( this );
 303                 this->process = filter_process;
 304                 mlt_properties_set( properties, "start", arg != NULL ? arg : "0%,0%:100%x100%" );
 305                 mlt_properties_set( properties, "end", "" );
 306         }
 307         return this;
 308 }
 309