research.m1stereo.tv/gitweb/ - melted/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 /** Do it :-).
  30 */
  31
  32 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
  33 {
  34         int error = 0;
  35
  36         // Get the properties from the frame
  37         mlt_properties properties = mlt_frame_properties( this );
  38
  39         // Assign requested width/height from our subordinate
  40         int owidth = *width;
  41         int oheight = *height;
  42
  43         // Hmmm...
  44         char *rescale = mlt_properties_get( properties, "rescale.interp" );
  45         if ( rescale != NULL && !strcmp( rescale, "none" ) )
  46                 return mlt_frame_get_image( this, image, format, width, height, writable );
  47
  48         if ( mlt_properties_get( properties, "distort" ) == NULL )
  49         {
  50                 // Normalise the input and out display aspect
  51                 int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
  52                 int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
  53                 double input_ar = mlt_frame_get_aspect_ratio( this );
  54                 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" );
  55
  56                 // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
  57                 int scaled_width = normalised_width;
  58                 int scaled_height = output_ar / input_ar * normalised_height;
  59
  60                 // Now ensure that our images fit in the normalised frame
  61                 if ( scaled_height > normalised_height )
  62                 {
  63                         scaled_width = input_ar / output_ar * normalised_width;
  64                         scaled_height = normalised_height;
  65                 }
  66
  67                 // Now calculate the actual image size that we want
  68                 owidth = scaled_width * owidth / normalised_width;
  69                 oheight = scaled_height * oheight / normalised_height;
  70
  71                 // Tell frame we have conformed the aspect to the consumer
  72                 mlt_frame_set_aspect_ratio( this, output_ar );
  73         }
  74
  75         // Now pass on the calculations down the line
  76         mlt_properties_set_int( properties, "resize_width", *width );
  77         mlt_properties_set_int( properties, "resize_height", *height );
  78
  79         // Now get the image
  80         error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
  81
  82         // We only know how to process yuv422 at the moment
  83         if ( error == 0 && *format == mlt_image_yuv422 )
  84         {
  85                 // Correct field order if needed
  86                 if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
  87                 {
  88                         // Get the input image, width and height
  89                         int size;
  90                         uint8_t *image = mlt_properties_get_data( properties, "image", &size );
  91
  92                         // Keep the original image around to be destroyed on frame close
  93                         mlt_properties_rename( properties, "image", "original_image" );
  94
  95                         // Offset the image pointer by one line
  96                         image += owidth * 2;
  97                         size -= owidth * 2;
  98
  99                         // Set the new image pointer with no destructor
 100                         mlt_properties_set_data( properties, "image", image, size, NULL, NULL );
 101
 102                         // Set the normalised field order
 103                         mlt_properties_set_int( properties, "top_field_first", 0 );
 104                 }
 105
 106                 if ( !strcmp( mlt_properties_get( properties, "resize.scale" ), "affine" ) )
 107                 {
 108                         *image = mlt_frame_rescale_yuv422( this, *width, *height );
 109                 }
 110                 else if ( strcmp( mlt_properties_get( properties, "resize.scale" ), "none" ) != 0 )
 111                 {
 112                         *image = mlt_frame_resize_yuv422( this, *width, *height );
 113                 }
 114                 else
 115                 {
 116                         *width = owidth;
 117                         *height = oheight;
 118                 }
 119         }
 120
 121         return 0;
 122 }
 123
 124 /** Filter processing.
 125 */
 126
 127 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 128 {
 129         mlt_frame_push_get_image( frame, filter_get_image );
 130         mlt_properties_set( mlt_frame_properties( frame ), "resize.scale", mlt_properties_get( mlt_filter_properties( this ), "scale" ) );
 131         return frame;
 132 }
 133
 134 /** Constructor for the filter.
 135 */
 136
 137 mlt_filter filter_resize_init( char *arg )
 138 {
 139         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
 140         if ( mlt_filter_init( this, this ) == 0 )
 141         {
 142                 this->process = filter_process;
 143                 mlt_properties_set( mlt_filter_properties( this ), "scale", arg == NULL ? "off" : arg );
 144         }
 145         return this;
 146 }
 147