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 /** 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         // Pop the top of stack now
  40         mlt_filter filter = mlt_frame_pop_service( this );
  41
  42         // Assign requested width/height from our subordinate
  43         int owidth = *width;
  44         int oheight = *height;
  45
  46         // Check for the special case - no aspect ratio means no problem :-)
  47         if ( mlt_frame_get_aspect_ratio( this ) == 0 )
  48                 mlt_properties_set_double( properties, "aspect_ratio", mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
  49
  50         // Hmmm...
  51         char *rescale = mlt_properties_get( properties, "rescale.interp" );
  52         if ( rescale != NULL && !strcmp( rescale, "none" ) )
  53                 return mlt_frame_get_image( this, image, format, width, height, writable );
  54
  55         if ( mlt_properties_get_int( properties, "distort" ) == 0 )
  56         {
  57                 // Normalise the input and out display aspect
  58                 int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
  59                 int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
  60                 int real_width = mlt_properties_get_int( properties, "real_width" );
  61                 int real_height = mlt_properties_get_int( properties, "real_height" );
  62                 if ( real_width == 0 )
  63                         real_width = mlt_properties_get_int( properties, "width" );
  64                 if ( real_height == 0 )
  65                         real_height = mlt_properties_get_int( properties, "height" );
  66                 double input_ar = mlt_frame_get_aspect_ratio( this ) * real_width / real_height;
  67                 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" ) * owidth / oheight;
  68
  69
  70                 //fprintf( stderr, "normalised %dx%d output %dx%d %f %f\n", normalised_width, normalised_height, owidth, oheight, ( float )output_ar, ( float )mlt_properties_get_double( properties, "consumer_aspect_ratio" ) * owidth / oheight );
  71
  72                 // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
  73                 int scaled_width = input_ar / output_ar * normalised_width + 0.5;
  74                 int scaled_height = normalised_height;
  75
  76                 // Now ensure that our images fit in the output frame
  77                 if ( scaled_width > normalised_width )
  78                 {
  79                         scaled_width = normalised_width;
  80                         scaled_height = output_ar / input_ar * normalised_height + 0.5;
  81                 }
  82
  83                 // Now calculate the actual image size that we want
  84                 owidth = scaled_width * owidth / normalised_width;
  85                 oheight = scaled_height * oheight / normalised_height;
  86
  87                 // Tell frame we have conformed the aspect to the consumer
  88                 mlt_frame_set_aspect_ratio( this, mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
  89         }
  90
  91         // Now pass on the calculations down the line
  92         mlt_properties_set_int( properties, "resize_width", *width );
  93         mlt_properties_set_int( properties, "resize_height", *height );
  94
  95         // Now get the image
  96         error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
  97
  98         // We only know how to process yuv422 at the moment
  99         if ( error == 0 && *format == mlt_image_yuv422 && *image != NULL )
 100         {
 101                 // Get the requested scale operation
 102                 char *op = mlt_properties_get( MLT_FILTER_PROPERTIES( filter ), "scale" );
 103
 104                 // Correct field order if needed
 105                 if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
 106                 {
 107                         // Get the input image, width and height
 108                         int size;
 109                         uint8_t *image = mlt_properties_get_data( properties, "image", &size );
 110
 111                         // Keep the original image around to be destroyed on frame close
 112                         mlt_properties_rename( properties, "image", "original_image" );
 113
 114                         // Duplicate the last line in the field to avoid artifact
 115                         memcpy( image + oheight * owidth * 2, image + oheight * owidth * 2 - owidth * 4, owidth * 2 );
 116
 117                         // Offset the image pointer by one line
 118                         image += owidth * 2;
 119                         size -= owidth * 2;
 120
 121                         // Set the new image pointer with no destructor
 122                         mlt_properties_set_data( properties, "image", image, size, NULL, NULL );
 123
 124                         // Set the normalised field order
 125                         mlt_properties_set_int( properties, "top_field_first", 0 );
 126                 }
 127
 128                 if ( !strcmp( op, "affine" ) )
 129                 {
 130                         *image = mlt_frame_rescale_yuv422( this, *width, *height );
 131                 }
 132                 else if ( strcmp( op, "none" ) != 0 )
 133                 {
 134                         *image = mlt_frame_resize_yuv422( this, *width, *height );
 135                 }
 136                 else
 137                 {
 138                         *width = owidth;
 139                         *height = oheight;
 140                 }
 141         }
 142
 143         return error;
 144 }
 145
 146 /** Filter processing.
 147 */
 148
 149 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 150 {
 151         // Push this on to the service stack
 152         mlt_frame_push_service( frame, this );
 153
 154         // Push the get_image method on to the stack
 155         mlt_frame_push_get_image( frame, filter_get_image );
 156
 157         return frame;
 158 }
 159
 160 /** Constructor for the filter.
 161 */
 162
 163 mlt_filter filter_resize_init( char *arg )
 164 {
 165         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
 166         if ( mlt_filter_init( this, this ) == 0 )
 167         {
 168                 this->process = filter_process;
 169                 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "scale", arg == NULL ? "off" : arg );
 170         }
 171         return this;
 172 }