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 "filter_rescale.h"
  22
  23 #include <framework/mlt_frame.h>
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdlib.h>
  28 #include <math.h>
  29
  30 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 );
  31
  32 static void scale_alpha( mlt_frame this, int iwidth, int iheight, int owidth, int oheight );
  33
  34 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 )
  35 {
  36         // Get the properties
  37         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
  38
  39         // Get the rescaling interpolsation
  40         char *interps = mlt_properties_get( properties, "rescale.interp" );
  41
  42         // Carry out the rescaling
  43         if ( iformat == mlt_image_yuv422 && oformat == mlt_image_yuv422 )
  44         {
  45                 // Scale the frame
  46                 mlt_frame_rescale_yuv422( this, owidth, oheight );
  47
  48                 // Return the output
  49                 *image = mlt_properties_get_data( properties, "image", NULL );
  50
  51                 // Scale the alpha channel only if exists and not correct size
  52                 int alpha_size = 0;
  53                 mlt_properties_get_data( properties, "alpha", &alpha_size );
  54                 if ( alpha_size > 0 && alpha_size != ( owidth * oheight ) )
  55                         scale_alpha( this, iwidth, iheight, owidth, oheight );
  56         }
  57         else if ( iformat == mlt_image_rgb24 || iformat == mlt_image_rgb24a )
  58         {
  59                 int bpp = (iformat == mlt_image_rgb24a ? 4 : 3 );
  60
  61                 // Create the yuv image
  62                 uint8_t *output = mlt_pool_alloc( iwidth * ( iheight + 1 ) * 2 );
  63
  64                 if ( strcmp( interps, "none" ) && ( iwidth != owidth || iheight != oheight ) )
  65                 {
  66                         // Extract YUV422 and alpha
  67                         if ( bpp == 4 )
  68                         {
  69                                 // Allocate the alpha mask
  70                                 uint8_t *alpha = mlt_pool_alloc( iwidth * ( iheight + 1 ) );
  71
  72                                 // Convert the image and extract alpha
  73                                 mlt_convert_rgb24a_to_yuv422( *image, iwidth, iheight, iwidth * 4, output, alpha );
  74
  75                                 mlt_properties_set_data( properties, "alpha", alpha, iwidth * ( iheight + 1 ), ( mlt_destructor )mlt_pool_release, NULL );
  76
  77                                 scale_alpha( this, iwidth, iheight, owidth, oheight );
  78                         }
  79                         else
  80                         {
  81                                 // No alpha to extract
  82                                 mlt_convert_rgb24_to_yuv422( *image, iwidth, iheight, iwidth * 3, output );
  83                         }
  84
  85                         mlt_properties_set_data( properties, "image", output, iwidth * ( iheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
  86
  87                         // Scale the frame
  88                         output = mlt_frame_rescale_yuv422( this, owidth, oheight );
  89
  90                 }
  91                 else
  92                 {
  93                         // Extract YUV422 and alpha
  94                         if ( bpp == 4 )
  95                         {
  96                                 // Allocate the alpha mask
  97                                 uint8_t *alpha = mlt_pool_alloc( owidth * ( oheight + 1 ) );
  98
  99                                 // Convert the image and extract alpha
 100                                 mlt_convert_rgb24a_to_yuv422( *image, owidth, oheight, owidth * 4, output, alpha );
 101
 102                                 mlt_properties_set_data( properties, "alpha", alpha, owidth * ( oheight + 1 ), ( mlt_destructor )mlt_pool_release, NULL );
 103
 104                                 scale_alpha( this, iwidth, iheight, owidth, oheight );
 105                         }
 106                         else
 107                         {
 108                                 // No alpha to extract
 109                                 mlt_convert_rgb24_to_yuv422( *image, owidth, oheight, owidth * 3, output );
 110                         }
 111                 }
 112
 113                 // Now update the frame
 114                 mlt_properties_set_data( properties, "image", output, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
 115                 mlt_properties_set_int( properties, "width", owidth );
 116                 mlt_properties_set_int( properties, "height", oheight );
 117
 118                 *image = output;
 119         }
 120
 121         return 0;
 122 }
 123
 124 static void scale_alpha( mlt_frame this, int iwidth, int iheight, int owidth, int oheight )
 125 {
 126         // Scale the alpha
 127         uint8_t *output = NULL;
 128         uint8_t *input = mlt_frame_get_alpha_mask( this );
 129
 130         if ( input != NULL )
 131         {
 132                 uint8_t *out_line;
 133                 int x, y;
 134                 int ox = ( iwidth << 10 ) / owidth;
 135                 int oy = ( iheight << 10 ) / oheight;
 136
 137                 output = mlt_pool_alloc( owidth * oheight );
 138                 out_line = output;
 139
 140                 // Loop for the entirety of our output height.
 141                 for ( y = 0; y < oheight; y ++ )
 142                         for ( x = 0; x < owidth; x ++ )
 143                                 *out_line ++ = *( input + ( ( 512 + ( y * oy * iwidth ) + x * ox ) >> 10 ) );
 144
 145                 // Set it back on the frame
 146                 mlt_properties_set_data( MLT_FRAME_PROPERTIES( this ), "alpha", output, owidth * oheight, mlt_pool_release, NULL );
 147         }
 148 }
 149
 150 /** Do it :-).
 151 */
 152
 153 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 154 {
 155         // Get the frame properties
 156         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
 157
 158         // Get the filter from the stack
 159         mlt_filter filter = mlt_frame_pop_service( this );
 160
 161         // Get the filter properties
 162         mlt_properties filter_properties = MLT_FILTER_PROPERTIES( filter );
 163
 164         // Get the image scaler method
 165         image_scaler scaler_method = mlt_properties_get_data( filter_properties, "method", NULL );
 166
 167         // Correct Width/height if necessary
 168         if ( *width == 0 || *height == 0 )
 169         {
 170                 *width = mlt_properties_get_int( properties, "normalised_width" );
 171                 *height = mlt_properties_get_int( properties, "normalised_height" );
 172         }
 173
 174         // There can be problems with small images - avoid them (by hacking - gah)
 175         if ( *width >= 6 && *height >= 6 )
 176         {
 177                 int iwidth = *width;
 178                 int iheight = *height;
 179                 int owidth = *width;
 180                 int oheight = *height;
 181                 char *interps = mlt_properties_get( properties, "rescale.interp" );
 182                 int wanted_format = *format;
 183
 184                 // Default from the scaler if not specifed on the frame
 185                 if ( interps == NULL )
 186                 {
 187                         interps = mlt_properties_get( MLT_FILTER_PROPERTIES( filter ), "interpolation" );
 188                         mlt_properties_set( properties, "rescale.interp", interps );
 189                 }
 190
 191                 // If real_width/height exist, we want that as minimum information
 192                 if ( mlt_properties_get_int( properties, "real_width" ) )
 193                 {
 194                         iwidth = mlt_properties_get_int( properties, "real_width" );
 195                         iheight = mlt_properties_get_int( properties, "real_height" );
 196                 }
 197
 198                 // Let the producer know what we are actually requested to obtain
 199                 if ( *format == mlt_image_yuv422 && strcmp( interps, "none" ) )
 200                 {
 201                         mlt_properties_set_int( properties, "rescale_width", *width );
 202                         mlt_properties_set_int( properties, "rescale_height", *height );
 203                 }
 204                 else
 205                 {
 206                         // When no scaling is requested, revert the requested dimensions if possible
 207                         mlt_properties_set_int( properties, "rescale_width", iwidth );
 208                         mlt_properties_set_int( properties, "rescale_height", iheight );
 209                 }
 210
 211                 // Get the image as requested
 212                 mlt_frame_get_image( this, image, format, &iwidth, &iheight, writable );
 213
 214                 // Get rescale interpretation again, in case the producer wishes to override scaling
 215                 interps = mlt_properties_get( properties, "rescale.interp" );
 216
 217                 if ( *image != NULL && ( *format != mlt_image_yuv422 || ( iwidth != owidth || iheight != oheight ) ) )
 218                 {
 219                         // If the colour space is correct and scaling is off, do nothing
 220                         if ( *format == mlt_image_yuv422 && !strcmp( interps, "none" ) )
 221                         {
 222                                 *width = iwidth;
 223                                 *height = iheight;
 224                         }
 225                         else if ( *format == mlt_image_yuv422 )
 226                         {
 227                                 // Call the local scaler
 228                                 scaler_method( this, image, *format, mlt_image_yuv422, iwidth, iheight, owidth, oheight );
 229                                 *width = owidth;
 230                                 *height = oheight;
 231                         }
 232                         else if ( *format == mlt_image_rgb24 && wanted_format == mlt_image_rgb24 )
 233                         {
 234                                 // Call the local scaler
 235                                 scaler_method( this, image, *format, mlt_image_rgb24, iwidth, iheight, owidth, oheight );
 236
 237                                 // Return the output
 238                                 *width = owidth;
 239                                 *height = oheight;
 240                         }
 241                         else if ( *format == mlt_image_rgb24 || *format == mlt_image_rgb24a )
 242                         {
 243                                 // Call the local scaler
 244                                 scaler_method( this, image, *format, mlt_image_yuv422, iwidth, iheight, owidth, oheight );
 245
 246                                 // Return the output
 247                                 *format = mlt_image_yuv422;
 248                                 *width = owidth;
 249                                 *height = oheight;
 250                         }
 251                         else
 252                         {
 253                                 *width = iwidth;
 254                                 *height = iheight;
 255                         }
 256                 }
 257                 else
 258                 {
 259                         *width = iwidth;
 260                         *height = iheight;
 261                 }
 262         }
 263         else
 264         {
 265                 // Store the requested width/height
 266                 int iwidth = *width;
 267                 int iheight = *height;
 268
 269                 // Get the image as requested
 270                 mlt_frame_get_image( this, image, format, &iwidth, &iheight, writable );
 271
 272                 // Too small - for now just assign as though we got what we wanted
 273                 *width = iwidth;
 274                 *height = iheight;
 275         }
 276
 277
 278         return 0;
 279 }
 280
 281 /** Filter processing.
 282 */
 283
 284 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 285 {
 286         // Push the filter
 287         mlt_frame_push_service( frame, this );
 288
 289         // Push the get image method
 290         mlt_frame_push_service( frame, filter_get_image );
 291
 292         return frame;
 293 }
 294
 295 /** Constructor for the filter.
 296 */
 297
 298 mlt_filter filter_rescale_init( char *arg )
 299 {
 300         // Create a new scaler
 301         mlt_filter this = mlt_filter_new( );
 302
 303         // If successful, then initialise it
 304         if ( this != NULL )
 305         {
 306                 // Get the properties
 307                 mlt_properties properties = MLT_FILTER_PROPERTIES( this );
 308
 309                 // Set the process method
 310                 this->process = filter_process;
 311
 312                 // Set the inerpolation
 313                 mlt_properties_set( properties, "interpolation", arg == NULL ? "bilinear" : arg );
 314
 315                 // Set the method
 316                 mlt_properties_set_data( properties, "method", filter_scale, 0, NULL, NULL );
 317         }
 318
 319         return this;
 320 }
 321