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         int width_src = ( int )( ( float )width_dest * geometry.w / 100 );
 109         int height_src = ( int )( ( float )height_dest * geometry.h / 100 );
 110
 111         mlt_properties b_props = mlt_frame_properties( that );
 112         mlt_transition this = mlt_properties_get_data( b_props, "transition_composite", NULL );
 113         mlt_properties properties = mlt_transition_properties( this );
 114
 115         if ( mlt_properties_get( properties, "distort" ) == NULL &&
 116                  mlt_properties_get( mlt_frame_properties( that ), "real_width" ) != NULL )
 117         {
 118                 int width_b = mlt_properties_get_int( mlt_frame_properties( that ), "real_width" );
 119                 int height_b = mlt_properties_get_int( mlt_frame_properties( that ), "real_height" );
 120
 121                 if ( width_b < width_src )
 122                         width_src = width_b;
 123                 if ( height_b < height_src )
 124                         height_src = height_b;
 125                 mlt_properties_set( mlt_frame_properties( that ), "rescale.interp", "none" );
 126         }
 127         else if ( mlt_properties_get( mlt_frame_properties( that ), "real_width" ) != NULL )
 128         {
 129                 mlt_properties_set( mlt_frame_properties( that ), "rescale.interp", "none" );
 130         }
 131
 132         x -= x % 2;
 133
 134         if ( width_src <= 0 || height_src <= 0 )
 135                 return ret;
 136
 137         // optimization point - no work to do
 138         if ( ( x < 0 && -x >= width_src ) || ( y < 0 && -y >= height_src ) )
 139                 return ret;
 140
 141         format_src = mlt_image_yuv422;
 142         format_dest = mlt_image_yuv422;
 143
 144         mlt_frame_get_image( that, &p_src, &format_src, &width_src, &height_src, 1 /* writable */ );
 145
 146         stride_src = width_src * 2;
 147         stride_dest = width_dest * 2;
 148
 149         // crop overlay off the left edge of frame
 150         if ( x < 0 )
 151         {
 152                 x_src = -x;
 153                 width_src -= x_src;
 154                 x = 0;
 155         }
 156
 157         // crop overlay beyond right edge of frame
 158         else if ( x + width_src > width_dest )
 159                 width_src = width_dest - x;
 160
 161         // crop overlay off the top edge of the frame
 162         if ( y < 0 )
 163         {
 164                 y_src = -y;
 165                 height_src -= y_src;
 166         }
 167         // crop overlay below bottom edge of frame
 168         else if ( y + height_src > height_dest )
 169                 height_src = height_dest - y;
 170
 171         // offset pointer into overlay buffer based on cropping
 172         p_src += x_src * 2 + y_src * stride_src;
 173
 174         // offset pointer into frame buffer based upon positive, even coordinates only!
 175         p_dest += ( x < 0 ? 0 : x ) * 2 + ( y < 0 ? 0 : y ) * stride_dest;
 176
 177         // Get the alpha channel of the overlay
 178         uint8_t *p_alpha = mlt_frame_get_alpha_mask( that );
 179
 180         // offset pointer into alpha channel based upon cropping
 181         if ( p_alpha )
 182                 p_alpha += x_src + y_src * stride_src / 2;
 183
 184         uint8_t *p = p_src;
 185         uint8_t *q = p_dest;
 186         uint8_t *o = p_dest;
 187         uint8_t *z = p_alpha;
 188
 189         uint8_t Y;
 190         uint8_t UV;
 191         uint8_t a;
 192         float value;
 193
 194         // now do the compositing only to cropped extents
 195         for ( i = 0; i < height_src; i++ )
 196         {
 197                 p = p_src;
 198                 q = p_dest;
 199                 o = p_dest;
 200                 z = p_alpha;
 201
 202                 for ( j = 0; j < width_src; j ++ )
 203                 {
 204                         Y = *p ++;
 205                         UV = *p ++;
 206                         a = ( z == NULL ) ? 255 : *z ++;
 207                         value = ( weight * ( float ) a / 255.0 );
 208                         *o ++ = (uint8_t)( Y * value + *q++ * ( 1 - value ) );
 209                         *o ++ = (uint8_t)( UV * value + *q++ * ( 1 - value ) );
 210                 }
 211
 212                 p_src += stride_src;
 213                 p_dest += stride_dest;
 214                 if ( p_alpha )
 215                         p_alpha += stride_src / 2;
 216         }
 217
 218         return ret;
 219 }
 220
 221
 222 /** Get the image.
 223 */
 224
 225 static int transition_get_image( mlt_frame a_frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 226 {
 227         // Get the b frame from the stack
 228         mlt_frame b_frame = mlt_frame_pop_frame( a_frame );
 229
 230         // Get the image from the a frame
 231         mlt_frame_get_image( a_frame, image, format, width, height, 1 );
 232
 233         if ( b_frame != NULL )
 234         {
 235                 // Get the properties of the b frame
 236                 mlt_properties b_props = mlt_frame_properties( b_frame );
 237
 238                 // Get the transition from the b frame
 239                 mlt_transition this = mlt_properties_get_data( b_props, "transition_composite", NULL );
 240
 241                 // Get the properties from the transition
 242                 mlt_properties properties = mlt_transition_properties( this );
 243
 244                 // Structures for geometry
 245                 struct geometry_s result;
 246                 struct geometry_s start;
 247                 struct geometry_s end;
 248
 249                 // Calculate the position
 250                 float position = position_calculate( this, a_frame );
 251
 252                 // Now parse the geometries
 253                 geometry_parse( &start, NULL, mlt_properties_get( properties, "start" ) );
 254                 geometry_parse( &end, &start, mlt_properties_get( properties, "end" ) );
 255
 256                 // Do the calculation
 257                 geometry_calculate( &result, &start, &end, position );
 258
 259                 // Composite the b_frame on the a_frame
 260                 composite_yuv( *image, *format, *width, *height, b_frame, result );
 261         }
 262
 263         return 0;
 264 }
 265
 266 /** Composition transition processing.
 267 */
 268
 269 static mlt_frame composite_process( mlt_transition this, mlt_frame a_frame, mlt_frame b_frame )
 270 {
 271         // Propogate the transition properties to the b frame
 272         mlt_properties b_props = mlt_frame_properties( b_frame );
 273         mlt_properties_set_data( b_props, "transition_composite", this, 0, NULL, NULL );
 274         mlt_frame_push_get_image( a_frame, transition_get_image );
 275         mlt_frame_push_frame( a_frame, b_frame );
 276         return a_frame;
 277 }
 278
 279 /** Constructor for the filter.
 280 */
 281
 282 mlt_transition transition_composite_init( char *arg )
 283 {
 284         mlt_transition this = calloc( sizeof( struct mlt_transition_s ), 1 );
 285         if ( this != NULL && mlt_transition_init( this, NULL ) == 0 )
 286         {
 287                 this->process = composite_process;
 288                 mlt_properties_set( mlt_transition_properties( this ), "start", arg != NULL ? arg : "85,5:10x10" );
 289                 mlt_properties_set( mlt_transition_properties( this ), "end", "" );
 290         }
 291         return this;
 292 }
 293