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         int error = 0;
  43
  44         // Get the properties from the frame
  45         mlt_properties properties = mlt_frame_properties( this );
  46
  47         // Assign requested width/height from our subordinate
  48         int owidth = *width;
  49         int oheight = *height;
  50
  51         // Hmmm...
  52         char *rescale = mlt_properties_get( properties, "rescale.interp" );
  53         if ( rescale != NULL && !strcmp( rescale, "none" ) )
  54                 return mlt_frame_get_image( this, image, format, width, height, writable );
  55
  56         if ( mlt_properties_get( properties, "distort" ) == NULL )
  57         {
  58                 // Normalise the input and out display aspect
  59                 int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
  60                 int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
  61                 double input_ar = mlt_frame_get_aspect_ratio( this );
  62                 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" );
  63
  64                 // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
  65                 int scaled_width = normalised_width;
  66                 int scaled_height = output_ar / input_ar * normalised_height;
  67
  68                 // Now ensure that our images fit in the normalised frame
  69                 if ( scaled_height > normalised_height )
  70                 {
  71                         scaled_width = input_ar / output_ar * normalised_width;
  72                         scaled_height = normalised_height;
  73                 }
  74
  75                 // Now calculate the actual image size that we want
  76                 owidth = scaled_width * owidth / normalised_width;
  77                 oheight = scaled_height * oheight / normalised_height;
  78
  79                 // Tell frame we have conformed the aspect to the consumer
  80                 mlt_frame_set_aspect_ratio( this, output_ar );
  81         }
  82
  83         // Now pass on the calculations down the line
  84         mlt_properties_set_int( properties, "resize_width", *width );
  85         mlt_properties_set_int( properties, "resize_height", *height );
  86
  87         // Now get the image
  88         error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
  89
  90         // We only know how to process yuv422 at the moment
  91         if ( error == 0 && *format == mlt_image_yuv422 )
  92         {
  93                 // Correct field order if needed
  94                 if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
  95                 {
  96                         // Get the input image, width and height
  97                         int size;
  98                         uint8_t *image = mlt_properties_get_data( properties, "image", &size );
  99
 100                         // Keep the original image around to be destroyed on frame close
 101                         mlt_properties_rename( properties, "image", "original_image" );
 102
 103                         // Offset the image pointer by one line
 104                         image += owidth * 2;
 105                         size -= owidth * 2;
 106
 107                         // Set the new image pointer with no destructor
 108                         mlt_properties_set_data( properties, "image", image, size, NULL, NULL );
 109
 110                         // Set the normalised field order
 111                         mlt_properties_set_int( properties, "top_field_first", 0 );
 112                 }
 113
 114                 if ( !strcmp( mlt_properties_get( properties, "resize.scale" ), "affine" ) )
 115                 {
 116                         *image = mlt_frame_rescale_yuv422( this, *width, *height );
 117                 }
 118                 else if ( strcmp( mlt_properties_get( properties, "resize.scale" ), "none" ) != 0 )
 119                 {
 120                         *image = mlt_frame_resize_yuv422( this, *width, *height );
 121                 }
 122                 else
 123                 {
 124                         *width = owidth;
 125                         *height = oheight;
 126                 }
 127         }
 128
 129         return 0;
 130 }
 131
 132 /** Filter processing.
 133 */
 134
 135 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 136 {
 137         mlt_frame_push_get_image( frame, filter_get_image );
 138         mlt_properties_set( mlt_frame_properties( frame ), "resize.scale", mlt_properties_get( mlt_filter_properties( this ), "scale" ) );
 139         return frame;
 140 }
 141
 142 /** Constructor for the filter.
 143 */
 144
 145 mlt_filter filter_resize_init( char *arg )
 146 {
 147         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
 148         if ( mlt_filter_init( this, this ) == 0 )
 149         {
 150                 this->process = filter_process;
 151                 if ( arg != NULL )
 152                         mlt_properties_set( mlt_filter_properties( this ), "scale", arg );
 153                 else
 154                         mlt_properties_set( mlt_filter_properties( this ), "scale", "off" );
 155         }
 156         return this;
 157 }
 158