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
  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 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->mask_w = 20;
  89                 geometry->mask_h = 20;
  90         }
  91
  92         // Parse the geomtry string
  93         if ( property != NULL )
  94         {
  95                 char *ptr = property;
  96                 geometry->x = parse_value( &ptr, nw, ',', geometry->x );
  97                 geometry->y = parse_value( &ptr, nh, ':', geometry->y );
  98                 geometry->w = parse_value( &ptr, nw, 'x', geometry->w );
  99                 geometry->h = parse_value( &ptr, nh, ':', geometry->h );
 100                 geometry->mask_w = parse_value( &ptr, nw, 'x', geometry->mask_w );
 101                 geometry->mask_h = parse_value( &ptr, nh, ' ', geometry->mask_h );
 102         }
 103 }
 104
 105 /** A Timism but not as clean ;-).
 106 */
 107
 108 static float lerp( float value, float lower, float upper )
 109 {
 110         if ( value < lower )
 111                 return lower;
 112         else if ( value > upper )
 113                 return upper;
 114         return value;
 115 }
 116
 117 /** Calculate real geometry.
 118 */
 119
 120 static void geometry_calculate( struct geometry_s *output, struct geometry_s *in, struct geometry_s *out, float position, int ow, int oh )
 121 {
 122         // Calculate this frames geometry
 123         output->x = lerp( ( in->x + ( out->x - in->x ) * position ) / ( float )out->nw * ow, 0, ow );
 124         output->y = lerp( ( in->y + ( out->y - in->y ) * position ) / ( float )out->nh * oh, 0, oh );
 125         output->w = lerp( ( in->w + ( out->w - in->w ) * position ) / ( float )out->nw * ow, 0, ow - output->x );
 126         output->h = lerp( ( in->h + ( out->h - in->h ) * position ) / ( float )out->nh * oh, 0, oh - output->y );
 127         output->mask_w = in->mask_w + ( out->mask_w - in->mask_w ) * position;
 128         output->mask_h = in->mask_h + ( out->mask_h - in->mask_h ) * position;
 129 }
 130
 131 /** Calculate the position for this frame.
 132 */
 133
 134 static float position_calculate( mlt_filter this, mlt_frame frame )
 135 {
 136         // Get the in and out position
 137         mlt_position in = mlt_filter_get_in( this );
 138         mlt_position out = mlt_filter_get_out( this );
 139
 140         // Get the position of the frame
 141         mlt_position position = mlt_frame_get_position( frame );
 142
 143         // Now do the calcs
 144         return ( float )( position - in ) / ( float )( out - in + 1 );
 145 }
 146
 147 /** The averaging function...
 148 */
 149
 150 void obscure_average( uint8_t *start, int width, int height, int stride )
 151 {
 152         int y;
 153         int x;
 154         register int Y = ( *start + *( start + 2 ) ) / 2;
 155         register int U = *( start + 1 );
 156         register int V = *( start + 3 );
 157         register uint8_t *p;
 158
 159         for ( y = 0; y < height; y ++ )
 160         {
 161                 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                 p = start + y * stride;
 174
 175                 for ( x = 0; x < width / 2; x ++ )
 176                 {
 177                         *p ++ = Y;
 178                         *p ++ = U;
 179                         *p ++ = Y;
 180                         *p ++ = V;
 181                 }
 182         }
 183 }
 184
 185
 186 /** The obscurer rendering function...
 187 */
 188
 189 static void obscure_render( uint8_t *image, int width, int height, struct geometry_s result )
 190 {
 191         int area_x = result.x;
 192         int area_y = result.y;
 193         int area_w = result.w;
 194         int area_h = result.h;
 195
 196         int mw = result.mask_w;
 197         int mh = result.mask_h;
 198         int w;
 199         int h;
 200         int aw;
 201         int ah;
 202
 203         uint8_t *p = image + area_y * width * 2 + area_x * 2;
 204
 205         for ( w = 0; w < area_w; w += mw )
 206         {
 207                 for ( h = 0; h < area_h; h += mh )
 208                 {
 209                         aw = w + mw > area_w ? mw - ( w + mw - area_w ) : mw;
 210                         ah = h + mh > area_h ? mh - ( h + mh - area_h ) : mh;
 211                         if ( aw > 1 && ah > 1 )
 212                                 obscure_average( p + h * width * 2 + w * 2, aw, ah, width * 2 );
 213                 }
 214         }
 215 }
 216
 217 /** Do it :-).
 218 */
 219
 220 static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 221 {
 222         // Get the frame properties
 223         mlt_properties frame_properties = mlt_frame_properties( frame );
 224
 225         // Pop the top of stack now
 226         mlt_filter this = mlt_frame_pop_service( frame );
 227
 228         // Get the image from the frame
 229         int error = mlt_frame_get_image( frame, image, format, width, height, 1 );
 230
 231         // Get the image from the frame
 232         if ( error == 0 && *format == mlt_image_yuv422 )
 233         {
 234                 if ( this != NULL )
 235                 {
 236                         // Get the filter properties
 237                         mlt_properties properties = mlt_filter_properties( this );
 238
 239                         // Obtain the normalised width and height from the frame
 240                         int normalised_width = mlt_properties_get_int( frame_properties, "normalised_width" );
 241                         int normalised_height = mlt_properties_get_int( frame_properties, "normalised_height" );
 242
 243                         // Structures for geometry
 244                         struct geometry_s result;
 245                         struct geometry_s start;
 246                         struct geometry_s end;
 247
 248                         // Calculate the position
 249                         float position = position_calculate( this, frame );
 250
 251                         // Now parse the geometries
 252                         geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ), normalised_width, normalised_height );
 253                         geometry_parse( &end, &start, mlt_properties_get( properties, "end" ), normalised_width, normalised_height );
 254
 255                         // Do the calculation
 256                         geometry_calculate( &result, &start, &end, position, *width, *height );
 257
 258                         // Now actually render it
 259                         obscure_render( *image, *width, *height, result );
 260                 }
 261         }
 262
 263         return error;
 264 }
 265
 266 /** Filter processing.
 267 */
 268
 269 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 270 {
 271         // Push this on to the service stack
 272         mlt_frame_push_service( frame, this );
 273
 274         // Push the get image call
 275         mlt_frame_push_get_image( frame, filter_get_image );
 276
 277         return frame;
 278 }
 279
 280 /** Constructor for the filter.
 281 */
 282
 283 mlt_filter filter_obscure_init( void *arg )
 284 {
 285         mlt_filter this = mlt_filter_new( );
 286         if ( this != NULL )
 287         {
 288                 mlt_properties properties = mlt_filter_properties( this );
 289                 this->process = filter_process;
 290                 mlt_properties_set( properties, "start", arg != NULL ? arg : "0%,0%:100%x100%" );
 291                 mlt_properties_set( properties, "end", "" );
 292         }
 293         return this;
 294 }
 295