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

   1 /*
   2  * filter_resize.c -- resizing filter
   3  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
   4  * Author: Charles Yates <charles.yates@pandora.be>
   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 "filter_resize.h"
  22
  23 #include <framework/mlt_frame.h>
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdlib.h>
  28
  29 static int get_value( mlt_properties properties, char *preferred, char *fallback )
  30 {
  31         int value = mlt_properties_get_int( properties, preferred );
  32         if ( value == 0 )
  33                 value = mlt_properties_get_int( properties, fallback );
  34         return value;
  35 }
  36
  37 /** Do it :-).
  38 */
  39
  40 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
  41 {
  42         // Get the properties from the frame
  43         mlt_properties properties = mlt_frame_properties( this );
  44
  45         // Assign requested width/height from our subordinate
  46         int owidth = *width;
  47         int oheight = *height;
  48
  49         // Hmmm...
  50         char *rescale = mlt_properties_get( properties, "rescale.interp" );
  51         if ( rescale != NULL && !strcmp( rescale, "none" ) )
  52                 return mlt_frame_get_image( this, image, format, width, height, writable );
  53
  54         if ( mlt_properties_get( properties, "distort" ) == NULL )
  55         {
  56                 // Now do additional calcs based on real_width/height etc
  57                 int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
  58                 int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
  59                 int real_width = get_value( properties, "real_width", "width" );
  60                 int real_height = get_value( properties, "real_height", "height" );
  61                 double input_ar = mlt_frame_get_aspect_ratio( this );
  62                 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" );
  63                 int scaled_width = ( input_ar > output_ar ? input_ar / output_ar : output_ar / input_ar ) * real_width;
  64                 int scaled_height = ( input_ar > output_ar ? input_ar / output_ar : output_ar / input_ar ) * real_height;
  65
  66                 // Now ensure that our images fit in the normalised frame
  67                 if ( scaled_width > normalised_width )
  68                 {
  69                         scaled_height = scaled_height * normalised_width / scaled_width;
  70                         scaled_width = normalised_width;
  71                 }
  72                 if ( scaled_height > normalised_height )
  73                 {
  74                         scaled_width = scaled_width * normalised_height / scaled_height;
  75                         scaled_height = normalised_height;
  76                 }
  77
  78                 if ( input_ar == output_ar && scaled_height == normalised_height )
  79                 {
  80                         scaled_width = normalised_width;
  81                 }
  82                 else if ( ( real_height * 2 ) == normalised_height )
  83                 {
  84                         scaled_width = normalised_width;
  85                         scaled_height = normalised_height;
  86                 }
  87
  88                 // Now calculate the actual image size that we want
  89                 owidth = scaled_width * owidth / normalised_width;
  90                 oheight = scaled_height * oheight / normalised_height;
  91         }
  92
  93         // Now pass on the calculations down the line
  94         mlt_properties_set_int( properties, "resize_width", *width );
  95         mlt_properties_set_int( properties, "resize_height", *height );
  96
  97         // Now get the image
  98         mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
  99
 100         // Correct field order if needed
 101         if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
 102         {
 103                 // Get the input image, width and height
 104                 int size;
 105                 uint8_t *image = mlt_properties_get_data( properties, "image", &size );
 106
 107                 // Keep the original image around to be destroyed on frame close
 108                 mlt_properties_rename( properties, "image", "original_image" );
 109
 110                 // Offset the image pointer by one line
 111                 image += owidth * 2;
 112                 size -= owidth * 2;
 113
 114                 // Set the new image pointer with no destructor
 115                 mlt_properties_set_data( properties, "image", image, size, NULL, NULL );
 116
 117                 // Set the normalised field order
 118                 mlt_properties_set_int( properties, "top_field_first", 0 );
 119         }
 120
 121         if ( !strcmp( mlt_properties_get( properties, "resize.scale" ), "affine" ) )
 122                 *image = mlt_frame_rescale_yuv422( this, *width, *height );
 123         else if ( strcmp( mlt_properties_get( properties, "resize.scale" ), "none" ) != 0 )
 124                 *image = mlt_frame_resize_yuv422( this, *width, *height );
 125         else
 126         {
 127                 *width = owidth;
 128                 *height = oheight;
 129         }
 130         return 0;
 131 }
 132
 133 /** Filter processing.
 134 */
 135
 136 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 137 {
 138         mlt_frame_push_get_image( frame, filter_get_image );
 139         mlt_properties_set( mlt_frame_properties( frame ), "resize.scale", mlt_properties_get( mlt_filter_properties( this ), "scale" ) );
 140         return frame;
 141 }
 142
 143 /** Constructor for the filter.
 144 */
 145
 146 mlt_filter filter_resize_init( char *arg )
 147 {
 148         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
 149         if ( mlt_filter_init( this, this ) == 0 )
 150         {
 151                 this->process = filter_process;
 152                 if ( arg != NULL )
 153                         mlt_properties_set( mlt_filter_properties( this ), "scale", arg );
 154                 else
 155                         mlt_properties_set( mlt_filter_properties( this ), "scale", "off" );
 156         }
 157         return this;
 158 }
 159