git.sesse.net Git - mlt/blob - src/modules/core/filter_rescale.c

   1 /*
   2  * filter_rescale.c -- scale the producer video frame size to match the consumer
   3  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
   4  * Author: Dan Dennedy <dan@dennedy.org>
   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 <string.h>
  26 #include <stdlib.h>
  27 #include <math.h>
  28
  29 typedef int ( *image_scaler )( mlt_frame this, uint8_t **image, mlt_image_format iformat, mlt_image_format oformat, int iwidth, int iheight, int owidth, int oheight );
  30
  31 static void scale_alpha( mlt_frame this, int iwidth, int iheight, int owidth, int oheight );
  32
  33 static int filter_scale( mlt_frame this, uint8_t **image, mlt_image_format iformat, mlt_image_format oformat, int iwidth, int iheight, int owidth, int oheight )
  34 {
  35         // Get the properties
  36         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
  37
  38         // Get the rescaling interpolsation
  39         char *interps = mlt_properties_get( properties, "rescale.interp" );
  40
  41         // Carry out the rescaling
  42         if ( iformat == mlt_image_yuv422 && oformat == mlt_image_yuv422 )
  43         {
  44                 // Scale the frame
  45                 mlt_frame_rescale_yuv422( this, owidth, oheight );
  46
  47                 // Return the output
  48                 *image = mlt_properties_get_data( properties, "image", NULL );
  49
  50                 // Scale the alpha channel only if exists and not correct size
  51                 int alpha_size = 0;
  52                 mlt_properties_get_data( properties, "alpha", &alpha_size );
  53                 if ( alpha_size > 0 && alpha_size != ( owidth * oheight ) )
  54                         scale_alpha( this, iwidth, iheight, owidth, oheight );
  55         }
  56         else if ( iformat == mlt_image_rgb24 || iformat == mlt_image_rgb24a )
  57         {
  58                 int bpp = (iformat == mlt_image_rgb24a ? 4 : 3 );
  59
  60                 // Create the yuv image
  61                 uint8_t *output = mlt_pool_alloc( iwidth * ( iheight + 1 ) * 2 );
  62
  63                 if ( strcmp( interps, "none" ) && ( iwidth != owidth || iheight != oheight ) )
  64                 {
  65                         // Extract YUV422 and alpha
  66                         if ( bpp == 4 )
  67                         {
  68                                 // Allocate the alpha mask
  69                                 uint8_t *alpha = mlt_pool_alloc( iwidth * ( iheight + 1 ) );
  70
  71                                 // Convert the image and extract alpha
  72                                 mlt_convert_rgb24a_to_yuv422( *image, iwidth, iheight, iwidth * 4, output, alpha );
  73
  74                                 mlt_properties_set_data( properties, "alpha", alpha, iwidth * ( iheight + 1 ), ( mlt_destructor )mlt_pool_release, NULL );
  75
  76                                 scale_alpha( this, iwidth, iheight, owidth, oheight );
  77                         }
  78                         else
  79                         {
  80                                 // No alpha to extract
  81                                 mlt_convert_rgb24_to_yuv422( *image, iwidth, iheight, iwidth * 3, output );
  82                         }
  83
  84                         mlt_properties_set_data( properties, "image", output, iwidth * ( iheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
  85
  86                         // Scale the frame
  87                         output = mlt_frame_rescale_yuv422( this, owidth, oheight );
  88
  89                 }
  90                 else
  91                 {
  92                         // Extract YUV422 and alpha
  93                         if ( bpp == 4 )
  94                         {
  95                                 // Allocate the alpha mask
  96                                 uint8_t *alpha = mlt_pool_alloc( owidth * ( oheight + 1 ) );
  97
  98                                 // Convert the image and extract alpha
  99                                 mlt_convert_rgb24a_to_yuv422( *image, owidth, oheight, owidth * 4, output, alpha );
 100
 101                                 mlt_properties_set_data( properties, "alpha", alpha, owidth * ( oheight + 1 ), ( mlt_destructor )mlt_pool_release, NULL );
 102
 103                                 scale_alpha( this, iwidth, iheight, owidth, oheight );
 104                         }
 105                         else
 106                         {
 107                                 // No alpha to extract
 108                                 mlt_convert_rgb24_to_yuv422( *image, owidth, oheight, owidth * 3, output );
 109                         }
 110                 }
 111
 112                 // Now update the frame
 113                 mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
 114                 mlt_properties_set_int( properties, "width", owidth );
 115                 mlt_properties_set_int( properties, "height", oheight );
 116
 117                 *image = output;
 118         }
 119
 120         return 0;
 121 }
 122
 123 static void scale_alpha( mlt_frame this, int iwidth, int iheight, int owidth, int oheight )
 124 {
 125         // Scale the alpha
 126         uint8_t *output = NULL;
 127         uint8_t *input = mlt_frame_get_alpha_mask( this );
 128
 129         if ( input != NULL )
 130         {
 131                 uint8_t *out_line;
 132                 int x, y;
 133                 int ox = ( iwidth << 10 ) / owidth;
 134                 int oy = ( iheight << 10 ) / oheight;
 135
 136                 output = mlt_pool_alloc( owidth * oheight );
 137                 out_line = output;
 138
 139                 // Loop for the entirety of our output height.
 140                 for ( y = 0; y < oheight; y ++ )
 141                         for ( x = 0; x < owidth; x ++ )
 142                                 *out_line ++ = *( input + ( ( 512 + ( y * oy * iwidth ) + x * ox ) >> 10 ) );
 143
 144                 // Set it back on the frame
 145                 mlt_properties_set_data( MLT_FRAME_PROPERTIES( this ), "alpha", output, owidth * oheight, mlt_pool_release, NULL );
 146         }
 147 }
 148
 149 /** Do it :-).
 150 */
 151
 152 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 153 {
 154         // Get the frame properties
 155         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
 156
 157         // Get the filter from the stack
 158         mlt_filter filter = mlt_frame_pop_service( this );
 159
 160         // Get the filter properties
 161         mlt_properties filter_properties = MLT_FILTER_PROPERTIES( filter );
 162
 163         // Get the image scaler method
 164         image_scaler scaler_method = mlt_properties_get_data( filter_properties, "method", NULL );
 165
 166         // Correct Width/height if necessary
 167         if ( *width == 0 || *height == 0 )
 168         {
 169                 *width = mlt_properties_get_int( properties, "normalised_width" );
 170                 *height = mlt_properties_get_int( properties, "normalised_height" );
 171         }
 172
 173         // There can be problems with small images - avoid them (by hacking - gah)
 174         if ( *width >= 6 && *height >= 6 )
 175         {
 176                 int iwidth = *width;
 177                 int iheight = *height;
 178                 int owidth = *width;
 179                 int oheight = *height;
 180                 char *interps = mlt_properties_get( properties, "rescale.interp" );
 181                 int wanted_format = *format;
 182
 183                 // Default from the scaler if not specifed on the frame
 184                 if ( interps == NULL )
 185                 {
 186                         interps = mlt_properties_get( MLT_FILTER_PROPERTIES( filter ), "interpolation" );
 187                         mlt_properties_set( properties, "rescale.interp", interps );
 188                 }
 189
 190                 // If real_width/height exist, we want that as minimum information
 191                 if ( mlt_properties_get_int( properties, "real_width" ) )
 192                 {
 193                         iwidth = mlt_properties_get_int( properties, "real_width" );
 194                         iheight = mlt_properties_get_int( properties, "real_height" );
 195                 }
 196
 197                 // Let the producer know what we are actually requested to obtain
 198                 if ( *format == mlt_image_yuv422 && strcmp( interps, "none" ) )
 199                 {
 200                         mlt_properties_set_int( properties, "rescale_width", *width );
 201                         mlt_properties_set_int( properties, "rescale_height", *height );
 202                 }
 203                 else
 204                 {
 205                         // When no scaling is requested, revert the requested dimensions if possible
 206                         mlt_properties_set_int( properties, "rescale_width", iwidth );
 207                         mlt_properties_set_int( properties, "rescale_height", iheight );
 208                 }
 209
 210                 // Get the image as requested
 211                 mlt_frame_get_image( this, image, format, &iwidth, &iheight, writable );
 212
 213                 // Get rescale interpretation again, in case the producer wishes to override scaling
 214                 interps = mlt_properties_get( properties, "rescale.interp" );
 215
 216                 if ( *image != NULL && ( *format != mlt_image_yuv422 || ( iwidth != owidth || iheight != oheight ) ) )
 217                 {
 218                         // If the colour space is correct and scaling is off, do nothing
 219                         if ( *format == mlt_image_yuv422 && !strcmp( interps, "none" ) )
 220                         {
 221                                 *width = iwidth;
 222                                 *height = iheight;
 223                         }
 224                         else if ( *format == mlt_image_yuv422 )
 225                         {
 226                                 // Call the local scaler
 227                                 scaler_method( this, image, *format, mlt_image_yuv422, iwidth, iheight, owidth, oheight );
 228                                 *width = owidth;
 229                                 *height = oheight;
 230                         }
 231                         else if ( *format == mlt_image_rgb24 && wanted_format == mlt_image_rgb24 )
 232                         {
 233                                 // Call the local scaler
 234                                 scaler_method( this, image, *format, mlt_image_rgb24, iwidth, iheight, owidth, oheight );
 235
 236                                 // Return the output
 237                                 *width = owidth;
 238                                 *height = oheight;
 239                         }
 240                         else if ( *format == mlt_image_rgb24 || *format == mlt_image_rgb24a )
 241                         {
 242                                 // Call the local scaler
 243                                 scaler_method( this, image, *format, mlt_image_yuv422, iwidth, iheight, owidth, oheight );
 244
 245                                 // Return the output
 246                                 *format = mlt_image_yuv422;
 247                                 *width = owidth;
 248                                 *height = oheight;
 249                         }
 250                         else
 251                         {
 252                                 *width = iwidth;
 253                                 *height = iheight;
 254                         }
 255                 }
 256                 else
 257                 {
 258                         *width = iwidth;
 259                         *height = iheight;
 260                 }
 261         }
 262         else
 263         {
 264                 // Store the requested width/height
 265                 int iwidth = *width;
 266                 int iheight = *height;
 267
 268                 // Get the image as requested
 269                 mlt_frame_get_image( this, image, format, &iwidth, &iheight, writable );
 270
 271                 // Too small - for now just assign as though we got what we wanted
 272                 *width = iwidth;
 273                 *height = iheight;
 274         }
 275
 276
 277         return 0;
 278 }
 279
 280 /** Filter processing.
 281 */
 282
 283 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 284 {
 285         // Push the filter
 286         mlt_frame_push_service( frame, this );
 287
 288         // Push the get image method
 289         mlt_frame_push_service( frame, filter_get_image );
 290
 291         return frame;
 292 }
 293
 294 /** Constructor for the filter.
 295 */
 296
 297 mlt_filter filter_rescale_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
 298 {
 299         // Create a new scaler
 300         mlt_filter this = mlt_filter_new( );
 301
 302         // If successful, then initialise it
 303         if ( this != NULL )
 304         {
 305                 // Get the properties
 306                 mlt_properties properties = MLT_FILTER_PROPERTIES( this );
 307
 308                 // Set the process method
 309                 this->process = filter_process;
 310
 311                 // Set the inerpolation
 312                 mlt_properties_set( properties, "interpolation", arg == NULL ? "bilinear" : arg );
 313
 314                 // Set the method
 315                 mlt_properties_set_data( properties, "method", filter_scale, 0, NULL, NULL );
 316         }
 317
 318         return this;
 319 }
 320