research.m1stereo.tv/gitweb/ - melted/blob - src/modules/core/transition_composite.c

   1 /*
   2  * transition_composite.c -- compose one image over another using alpha channel
   3  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
   4  * Author: Dan Dennedy <dan@dennedy.org>
   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 "transition_composite.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         float mix;
  39 };
  40
  41 /** Parse a value from a geometry string.
  42 */
  43
  44 static float parse_value( char **ptr, int normalisation, char delim, float defaults )
  45 {
  46         float value = defaults;
  47
  48         if ( *ptr != NULL && **ptr != '\0' )
  49         {
  50                 char *end = NULL;
  51                 value = strtod( *ptr, &end );
  52                 if ( end != NULL )
  53                 {
  54                         if ( *end == '%' )
  55                                 value = ( value / 100.0 ) * normalisation;
  56                         while ( *end == delim || *end == '%' )
  57                                 end ++;
  58                 }
  59                 *ptr = end;
  60         }
  61
  62         return value;
  63 }
  64
  65 /** Parse a geometry property string with the syntax X,Y:WxH:MIX. Any value can be
  66         expressed as a percentage by appending a % after the value, otherwise values are
  67         assumed to be relative to the normalised dimensions of the consumer.
  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->mix = defaults->mix;
  84         }
  85         else
  86         {
  87                 geometry->mix = 100;
  88         }
  89
  90         // Parse the geomtry string
  91         if ( property != NULL )
  92         {
  93                 char *ptr = property;
  94                 geometry->x = parse_value( &ptr, nw, ',', geometry->x );
  95                 geometry->y = parse_value( &ptr, nh, ':', geometry->y );
  96                 geometry->w = parse_value( &ptr, nw, 'x', geometry->w );
  97                 geometry->h = parse_value( &ptr, nh, ':', geometry->h );
  98                 geometry->mix = parse_value( &ptr, 100, ' ', geometry->mix );
  99         }
 100 }
 101
 102 /** Calculate real geometry.
 103 */
 104
 105 static void geometry_calculate( struct geometry_s *output, struct geometry_s *in, struct geometry_s *out, float position )
 106 {
 107         // Calculate this frames geometry
 108         output->nw = in->nw;
 109         output->nh = in->nh;
 110         output->x = in->x + ( out->x - in->x ) * position;
 111         output->y = in->y + ( out->y - in->y ) * position;
 112         output->w = in->w + ( out->w - in->w ) * position;
 113         output->h = in->h + ( out->h - in->h ) * position;
 114         output->mix = in->mix + ( out->mix - in->mix ) * position;
 115 }
 116
 117 /** Calculate the position for this frame.
 118 */
 119
 120 static float position_calculate( mlt_transition this, mlt_frame frame )
 121 {
 122         // Get the in and out position
 123         mlt_position in = mlt_transition_get_in( this );
 124         mlt_position out = mlt_transition_get_out( this );
 125
 126         // Get the position of the frame
 127         mlt_position position = mlt_frame_get_position( frame );
 128
 129         // Now do the calcs
 130         return ( float )( position - in ) / ( float )( out - in + 1 );
 131 }
 132
 133 static int get_value( mlt_properties properties, char *preferred, char *fallback )
 134 {
 135         int value = mlt_properties_get_int( properties, preferred );
 136         if ( value == 0 )
 137                 value = mlt_properties_get_int( properties, fallback );
 138         return value;
 139 }
 140
 141 /** Composite function.
 142 */
 143
 144 static int composite_yuv( uint8_t *p_dest, int width_dest, int height_dest, uint8_t *p_src, int width_src, int height_src, uint8_t *p_alpha, struct geometry_s geometry )
 145 {
 146         int ret = 0;
 147         int i, j;
 148         int x_src = 0, y_src = 0;
 149         float weight = geometry.mix / 100;
 150         int x = ( geometry.x * width_dest ) / geometry.nw;
 151         int y = ( geometry.y * height_dest ) / geometry.nh;
 152         int stride_src = width_src * 2;
 153         int stride_dest = width_dest * 2;
 154
 155         x -= x % 2;
 156
 157         // optimization points - no work to do
 158         if ( width_src <= 0 || height_src <= 0 )
 159                 return ret;
 160
 161         if ( ( x < 0 && -x >= width_src ) || ( y < 0 && -y >= height_src ) )
 162                 return ret;
 163
 164         // crop overlay off the left edge of frame
 165         if ( x < 0 )
 166         {
 167                 x_src = -x;
 168                 width_src -= x_src;
 169                 x = 0;
 170         }
 171
 172         // crop overlay beyond right edge of frame
 173         else if ( x + width_src > width_dest )
 174                 width_src = width_dest - x;
 175
 176         // crop overlay off the top edge of the frame
 177         if ( y < 0 )
 178         {
 179                 y_src = -y;
 180                 height_src -= y_src;
 181         }
 182         // crop overlay below bottom edge of frame
 183         else if ( y + height_src > height_dest )
 184                 height_src = height_dest - y;
 185
 186         // offset pointer into overlay buffer based on cropping
 187         p_src += x_src * 2 + y_src * stride_src;
 188
 189         // offset pointer into frame buffer based upon positive, even coordinates only!
 190         p_dest += ( x < 0 ? 0 : x ) * 2 + ( y < 0 ? 0 : y ) * stride_dest;
 191
 192         // offset pointer into alpha channel based upon cropping
 193         if ( p_alpha )
 194                 p_alpha += x_src + y_src * stride_src / 2;
 195
 196         uint8_t *p = p_src;
 197         uint8_t *q = p_dest;
 198         uint8_t *o = p_dest;
 199         uint8_t *z = p_alpha;
 200
 201         uint8_t Y;
 202         uint8_t UV;
 203         uint8_t a;
 204         float value;
 205
 206         // now do the compositing only to cropped extents
 207         for ( i = 0; i < height_src; i++ )
 208         {
 209                 p = p_src;
 210                 q = p_dest;
 211                 o = p_dest;
 212                 z = p_alpha;
 213
 214                 for ( j = 0; j < width_src; j ++ )
 215                 {
 216                         Y = *p ++;
 217                         UV = *p ++;
 218                         a = ( z == NULL ) ? 255 : *z ++;
 219                         value = ( weight * ( float ) a / 255.0 );
 220                         *o ++ = (uint8_t)( Y * value + *q++ * ( 1 - value ) );
 221                         *o ++ = (uint8_t)( UV * value + *q++ * ( 1 - value ) );
 222                 }
 223
 224                 p_src += stride_src;
 225                 p_dest += stride_dest;
 226                 if ( p_alpha )
 227                         p_alpha += stride_src / 2;
 228         }
 229
 230         return ret;
 231 }
 232
 233
 234 /** Get the properly sized image from b_frame.
 235 */
 236
 237 static int get_b_frame_image( mlt_frame b_frame, uint8_t **image, int *width, int *height, struct geometry_s *geometry )
 238 {
 239         int ret = 0;
 240         mlt_image_format format = mlt_image_yuv422;
 241
 242         // Compute the dimensioning rectangle
 243         mlt_properties b_props = mlt_frame_properties( b_frame );
 244         mlt_transition this = mlt_properties_get_data( b_props, "transition_composite", NULL );
 245         mlt_properties properties = mlt_transition_properties( this );
 246
 247         if ( mlt_properties_get( properties, "distort" ) == NULL )
 248         {
 249                 // Now do additional calcs based on real_width/height etc
 250                 //int normalised_width = mlt_properties_get_int( b_props, "normalised_width" );
 251                 //int normalised_height = mlt_properties_get_int( b_props, "normalised_height" );
 252                 int normalised_width = geometry->w;
 253                 int normalised_height = geometry->h;
 254                 int real_width = get_value( b_props, "real_width", "width" );
 255                 int real_height = get_value( b_props, "real_height", "height" );
 256                 double input_ar = mlt_frame_get_aspect_ratio( b_frame );
 257                 double output_ar = mlt_properties_get_double( b_props, "consumer_aspect_ratio" );
 258                 int scaled_width = ( input_ar > output_ar ? input_ar / output_ar : output_ar / input_ar ) * real_width;
 259                 int scaled_height = ( input_ar > output_ar ? input_ar / output_ar : output_ar / input_ar ) * real_height;
 260
 261                 // Now ensure that our images fit in the normalised frame
 262                 if ( scaled_width > normalised_width )
 263                 {
 264                         scaled_height = scaled_height * normalised_width / scaled_width;
 265                         scaled_width = normalised_width;
 266                 }
 267                 if ( scaled_height > normalised_height )
 268                 {
 269                         scaled_width = scaled_width * normalised_height / scaled_height;
 270                         scaled_height = normalised_height;
 271                 }
 272
 273                 // Special case
 274                 if ( scaled_height == normalised_height )
 275                         scaled_width = normalised_width;
 276
 277                 // Now we need to align to the geometry
 278                 if ( scaled_width <= geometry->w && scaled_height <= geometry->h )
 279                 {
 280                         // TODO: Should take into account requested alignment here...
 281                         // Assume centred alignment for now
 282
 283                         geometry->x = geometry->x + ( geometry->w - scaled_width ) / 2;
 284                         geometry->y = geometry->y + ( geometry->h - scaled_height ) / 2;
 285                         geometry->w = scaled_width;
 286                         geometry->h = scaled_height;
 287                         mlt_properties_set( b_props, "distort", "true" );
 288                 }
 289                 else
 290                 {
 291                         mlt_properties_set( b_props, "distort", "true" );
 292                 }
 293         }
 294         else
 295         {
 296                 // We want to ensure that we bypass resize now...
 297                 mlt_properties_set( b_props, "distort", "true" );
 298         }
 299
 300         int x = ( geometry->x * *width ) / geometry->nw;
 301         int y = ( geometry->y * *height ) / geometry->nh;
 302         *width = ( geometry->w * *width ) / geometry->nw;
 303         *height = ( geometry->h * *height ) / geometry->nh;
 304
 305         x -= x % 2;
 306
 307         // optimization points - no work to do
 308         if ( *width <= 0 || *height <= 0 )
 309                 return 1;
 310
 311         if ( ( x < 0 && -x >= *width ) || ( y < 0 && -y >= *height ) )
 312                 return 1;
 313
 314         ret = mlt_frame_get_image( b_frame, image, &format, width, height, 1 /* writable */ );
 315
 316         return ret;
 317 }
 318
 319
 320 /** Get the image.
 321 */
 322
 323 static int transition_get_image( mlt_frame a_frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 324 {
 325         // Get the b frame from the stack
 326         mlt_frame b_frame = mlt_frame_pop_frame( a_frame );
 327
 328         // This compositer is yuv422 only
 329         *format = mlt_image_yuv422;
 330
 331         // Get the image from the a frame
 332         mlt_frame_get_image( a_frame, image, format, width, height, 1 );
 333
 334         if ( b_frame != NULL )
 335         {
 336                 // Get the properties of the a frame
 337                 mlt_properties a_props = mlt_frame_properties( a_frame );
 338
 339                 // Get the properties of the b frame
 340                 mlt_properties b_props = mlt_frame_properties( b_frame );
 341
 342                 // Get the transition from the b frame
 343                 mlt_transition this = mlt_properties_get_data( b_props, "transition_composite", NULL );
 344
 345                 // Get the properties from the transition
 346                 mlt_properties properties = mlt_transition_properties( this );
 347
 348                 // Structures for geometry
 349                 struct geometry_s result;
 350                 struct geometry_s start;
 351                 struct geometry_s end;
 352
 353                 // Calculate the position
 354                 float position = position_calculate( this, a_frame );
 355
 356                 // Obtain the normalised width and height from the a_frame
 357                 int normalised_width = mlt_properties_get_int( a_props, "normalised_width" );
 358                 int normalised_height = mlt_properties_get_int( a_props, "normalised_height" );
 359
 360                 // Now parse the geometries
 361                 geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ), normalised_width, normalised_height );
 362                 geometry_parse( &end, &start, mlt_properties_get( properties, "end" ), normalised_width, normalised_height );
 363
 364                 // Do the calculation
 365                 geometry_calculate( &result, &start, &end, position );
 366
 367                 // Since we are the consumer of the b_frame, we must pass along these
 368                 // consumer properties from the a_frame
 369                 mlt_properties_set_double( b_props, "consumer_aspect_ratio", mlt_properties_get_double( a_props, "consumer_aspect_ratio" ) );
 370                 mlt_properties_set_double( b_props, "consumer_scale", mlt_properties_get_double( a_props, "consumer_scale" ) );
 371
 372                 // Get the image from the b frame
 373                 uint8_t *image_b;
 374                 int width_b = *width;
 375                 int height_b = *height;
 376                 if ( get_b_frame_image( b_frame, &image_b, &width_b, &height_b, &result ) == 0 )
 377                 {
 378                         uint8_t *alpha = mlt_frame_get_alpha_mask( b_frame );
 379
 380                         // Composite the b_frame on the a_frame
 381                         composite_yuv( *image, *width, *height, image_b, width_b, height_b, alpha, result );
 382                 }
 383         }
 384
 385         return 0;
 386 }
 387
 388 /** Composition transition processing.
 389 */
 390
 391 static mlt_frame composite_process( mlt_transition this, mlt_frame a_frame, mlt_frame b_frame )
 392 {
 393         // Propogate the transition properties to the b frame
 394         mlt_properties b_props = mlt_frame_properties( b_frame );
 395         mlt_properties_set_data( b_props, "transition_composite", this, 0, NULL, NULL );
 396         mlt_frame_push_get_image( a_frame, transition_get_image );
 397         mlt_frame_push_frame( a_frame, b_frame );
 398         return a_frame;
 399 }
 400
 401 /** Constructor for the filter.
 402 */
 403
 404 mlt_transition transition_composite_init( char *arg )
 405 {
 406         mlt_transition this = calloc( sizeof( struct mlt_transition_s ), 1 );
 407         if ( this != NULL && mlt_transition_init( this, NULL ) == 0 )
 408         {
 409                 this->process = composite_process;
 410                 mlt_properties_set( mlt_transition_properties( this ), "start", arg != NULL ? arg : "85%,5%:10%x10%" );
 411                 mlt_properties_set( mlt_transition_properties( this ), "end", "" );
 412         }
 413         return this;
 414 }
 415