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         float x;
  33         float y;
  34         float w;
  35         float h;
  36         float mix;
  37 };
  38
  39 /** Parse a geometry property string.
  40 */
  41
  42 static void geometry_parse( struct geometry_s *geometry, struct geometry_s *defaults, char *property )
  43 {
  44         // Assign from defaults if available
  45         if ( defaults != NULL )
  46         {
  47                 geometry->x = defaults->x;
  48                 geometry->y = defaults->y;
  49                 geometry->w = defaults->w;
  50                 geometry->h = defaults->h;
  51                 geometry->mix = defaults->mix;
  52         }
  53         else
  54         {
  55                 geometry->mix = 100;
  56         }
  57
  58         // Parse the geomtry string
  59         if ( property != NULL )
  60                 sscanf( property, "%f,%f:%fx%f:%f", &geometry->x, &geometry->y, &geometry->w, &geometry->h, &geometry->mix );
  61 }
  62
  63 /** Calculate real geometry.
  64 */
  65
  66 static void geometry_calculate( struct geometry_s *output, struct geometry_s *in, struct geometry_s *out, float position )
  67 {
  68         // Calculate this frames geometry
  69         output->x = in->x + ( out->x - in->x ) * position;
  70         output->y = in->y + ( out->y - in->y ) * position;
  71         output->w = in->w + ( out->w - in->w ) * position;
  72         output->h = in->h + ( out->h - in->h ) * position;
  73         output->mix = in->mix + ( out->mix - in->mix ) * position;
  74 }
  75
  76 /** Calculate the position for this frame.
  77 */
  78
  79 static float position_calculate( mlt_transition this, mlt_frame frame )
  80 {
  81         // Get the in and out position
  82         mlt_position in = mlt_transition_get_in( this );
  83         mlt_position out = mlt_transition_get_out( this );
  84
  85         // Get the position of the frame
  86         mlt_position position = mlt_frame_get_position( frame );
  87
  88         // Now do the calcs
  89         return ( float )( position - in ) / ( float )( out - in + 1 );
  90 }
  91
  92 /** Composite function.
  93 */
  94
  95 static int composite_yuv( uint8_t *p_dest, mlt_image_format format_dest, int width_dest, int height_dest, mlt_frame that, struct geometry_s geometry )
  96 {
  97         int ret = 0;
  98         uint8_t *p_src;
  99         int i, j;
 100         int stride_src;
 101         int stride_dest;
 102         int x_src = 0, y_src = 0;
 103
 104         mlt_image_format format_src = format_dest;
 105         int x = ( int )( ( float )width_dest * geometry.x / 100 );
 106         int y = ( int )( ( float )height_dest * geometry.y / 100 );
 107         float weight = geometry.mix / 100;
 108
 109         // Compute the dimensioning rectangle
 110         int width_src = ( int )( ( float )width_dest * geometry.w / 100 );
 111         int height_src = ( int )( ( float )height_dest * geometry.h / 100 );
 112
 113         mlt_properties b_props = mlt_frame_properties( that );
 114         mlt_transition this = mlt_properties_get_data( b_props, "transition_composite", NULL );
 115         mlt_properties properties = mlt_transition_properties( this );
 116
 117         if ( mlt_properties_get( properties, "distort" ) == NULL &&
 118                  mlt_properties_get( mlt_frame_properties( that ), "real_width" ) != NULL )
 119         {
 120                 int width_b = mlt_properties_get_double( b_props, "real_width" );
 121                 int height_b = mlt_properties_get_double( b_props, "real_height" );
 122
 123                 // Maximise the dimensioning rectangle to the aspect of the b_frame
 124                 if ( mlt_properties_get_double( b_props, "aspect_ratio" ) * height_src > width_src )
 125                         height_src = ( double )width_src / mlt_properties_get_double( b_props, "aspect_ratio" ) + 0.5;
 126                 else
 127                         width_src = mlt_properties_get_double( b_props, "aspect_ratio" ) * height_src + 0.5;
 128
 129                 // See if we need to normalise pixel aspect ratio
 130                 // We can use consumer_aspect_ratio because the a_frame will take on this aspect
 131                 double aspect = mlt_properties_get_double( b_props, "consumer_aspect_ratio" );
 132                 if ( aspect != 0 )
 133                 {
 134                         // Derive the consumer pixel aspect
 135                         double oaspect = aspect / ( double )width_dest * height_dest;
 136
 137                         // Get the b frame pixel aspect - usually 1
 138                         double iaspect = mlt_properties_get_double( b_props, "aspect_ratio" ) / width_b * height_b;
 139
 140                         // Normalise pixel aspect
 141                         if ( iaspect != 0 && iaspect != oaspect )
 142                         {
 143                                 width_b = iaspect / oaspect * ( double )width_b + 0.5;
 144                                 width_src = iaspect / oaspect * ( double )width_src + 0.5;
 145                         }
 146
 147                         // Tell rescale not to normalise display aspect
 148                         mlt_frame_set_aspect_ratio( that, aspect );
 149                 }
 150
 151                 // Adjust overall scale for consumer
 152                 double consumer_scale = mlt_properties_get_double( b_props, "consumer_scale" );
 153                 if ( consumer_scale > 0 )
 154                 {
 155                         width_b = consumer_scale * width_b + 0.5;
 156                         height_b = consumer_scale * height_b + 0.5;
 157                 }
 158
 159 //              fprintf( stderr, "bounding rect %dx%d for overlay %dx%d\n",     width_src, height_src, width_b, height_b );
 160                 // Constrain the overlay to the dimensioning rectangle
 161                 if ( width_b < width_src && height_b < height_src )
 162                 {
 163                         width_src = width_b;
 164                         height_src = height_b;
 165                 }
 166         }
 167         else if ( mlt_properties_get( b_props, "real_width" ) != NULL )
 168         {
 169                 // Tell rescale not to normalise display aspect
 170                 mlt_properties_set_double( b_props, "consumer_aspect_ratio", 0 );
 171         }
 172
 173         x -= x % 2;
 174
 175         // optimization points - no work to do
 176         if ( width_src <= 0 || height_src <= 0 )
 177                 return ret;
 178
 179         if ( ( x < 0 && -x >= width_src ) || ( y < 0 && -y >= height_src ) )
 180                 return ret;
 181
 182         format_src = mlt_image_yuv422;
 183         format_dest = mlt_image_yuv422;
 184
 185         mlt_frame_get_image( that, &p_src, &format_src, &width_src, &height_src, 1 /* writable */ );
 186
 187         stride_src = width_src * 2;
 188         stride_dest = width_dest * 2;
 189
 190         // crop overlay off the left edge of frame
 191         if ( x < 0 )
 192         {
 193                 x_src = -x;
 194                 width_src -= x_src;
 195                 x = 0;
 196         }
 197
 198         // crop overlay beyond right edge of frame
 199         else if ( x + width_src > width_dest )
 200                 width_src = width_dest - x;
 201
 202         // crop overlay off the top edge of the frame
 203         if ( y < 0 )
 204         {
 205                 y_src = -y;
 206                 height_src -= y_src;
 207         }
 208         // crop overlay below bottom edge of frame
 209         else if ( y + height_src > height_dest )
 210                 height_src = height_dest - y;
 211
 212         // offset pointer into overlay buffer based on cropping
 213         p_src += x_src * 2 + y_src * stride_src;
 214
 215         // offset pointer into frame buffer based upon positive, even coordinates only!
 216         p_dest += ( x < 0 ? 0 : x ) * 2 + ( y < 0 ? 0 : y ) * stride_dest;
 217
 218         // Get the alpha channel of the overlay
 219         uint8_t *p_alpha = mlt_frame_get_alpha_mask( that );
 220
 221         // offset pointer into alpha channel based upon cropping
 222         if ( p_alpha )
 223                 p_alpha += x_src + y_src * stride_src / 2;
 224
 225         uint8_t *p = p_src;
 226         uint8_t *q = p_dest;
 227         uint8_t *o = p_dest;
 228         uint8_t *z = p_alpha;
 229
 230         uint8_t Y;
 231         uint8_t UV;
 232         uint8_t a;
 233         float value;
 234
 235         // now do the compositing only to cropped extents
 236         for ( i = 0; i < height_src; i++ )
 237         {
 238                 p = p_src;
 239                 q = p_dest;
 240                 o = p_dest;
 241                 z = p_alpha;
 242
 243                 for ( j = 0; j < width_src; j ++ )
 244                 {
 245                         Y = *p ++;
 246                         UV = *p ++;
 247                         a = ( z == NULL ) ? 255 : *z ++;
 248                         value = ( weight * ( float ) a / 255.0 );
 249                         *o ++ = (uint8_t)( Y * value + *q++ * ( 1 - value ) );
 250                         *o ++ = (uint8_t)( UV * value + *q++ * ( 1 - value ) );
 251                 }
 252
 253                 p_src += stride_src;
 254                 p_dest += stride_dest;
 255                 if ( p_alpha )
 256                         p_alpha += stride_src / 2;
 257         }
 258
 259         return ret;
 260 }
 261
 262
 263 /** Get the image.
 264 */
 265
 266 static int transition_get_image( mlt_frame a_frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 267 {
 268         // Get the b frame from the stack
 269         mlt_frame b_frame = mlt_frame_pop_frame( a_frame );
 270
 271         // Get the image from the a frame
 272         mlt_frame_get_image( a_frame, image, format, width, height, 1 );
 273
 274         if ( b_frame != NULL )
 275         {
 276                 // Get the properties of the b frame
 277                 mlt_properties b_props = mlt_frame_properties( b_frame );
 278
 279                 // Get the transition from the b frame
 280                 mlt_transition this = mlt_properties_get_data( b_props, "transition_composite", NULL );
 281
 282                 // Get the properties from the transition
 283                 mlt_properties properties = mlt_transition_properties( this );
 284
 285                 // Structures for geometry
 286                 struct geometry_s result;
 287                 struct geometry_s start;
 288                 struct geometry_s end;
 289
 290                 // Calculate the position
 291                 float position = position_calculate( this, a_frame );
 292
 293                 // Now parse the geometries
 294                 geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ) );
 295                 geometry_parse( &end, &start, mlt_properties_get( properties, "end" ) );
 296
 297                 // Do the calculation
 298                 geometry_calculate( &result, &start, &end, position );
 299
 300                 // Since we are the consumer of the b_frame, we must pass along these
 301                 // consumer properties from the a_frame
 302                 mlt_properties_set_double( b_props, "consumer_aspect_ratio",
 303                         mlt_properties_get_double( mlt_frame_properties( a_frame ), "consumer_aspect_ratio" ) );
 304                 mlt_properties_set_double( b_props, "consumer_scale",
 305                         mlt_properties_get_double( mlt_frame_properties( a_frame ), "consumer_scale" ) );
 306
 307                 // Composite the b_frame on the a_frame
 308                 composite_yuv( *image, *format, *width, *height, b_frame, result );
 309         }
 310
 311         return 0;
 312 }
 313
 314 /** Composition transition processing.
 315 */
 316
 317 static mlt_frame composite_process( mlt_transition this, mlt_frame a_frame, mlt_frame b_frame )
 318 {
 319         // Propogate the transition properties to the b frame
 320         mlt_properties b_props = mlt_frame_properties( b_frame );
 321         mlt_properties_set_data( b_props, "transition_composite", this, 0, NULL, NULL );
 322         mlt_frame_push_get_image( a_frame, transition_get_image );
 323         mlt_frame_push_frame( a_frame, b_frame );
 324         return a_frame;
 325 }
 326
 327 /** Constructor for the filter.
 328 */
 329
 330 mlt_transition transition_composite_init( char *arg )
 331 {
 332         mlt_transition this = calloc( sizeof( struct mlt_transition_s ), 1 );
 333         if ( this != NULL && mlt_transition_init( this, NULL ) == 0 )
 334         {
 335                 this->process = composite_process;
 336                 mlt_properties_set( mlt_transition_properties( this ), "start", arg != NULL ? arg : "85,5:10x10" );
 337                 mlt_properties_set( mlt_transition_properties( this ), "end", "" );
 338         }
 339         return this;
 340 }
 341