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         // Retrieve the aspect ratio
  43         double aspect_ratio = mlt_deque_pop_back_double( MLT_FRAME_IMAGE_STACK( this ) );
  44
  45         // Assign requested width/height from our subordinate
  46         int owidth = *width;
  47         int oheight = *height;
  48
  49         // Check for the special case - no aspect ratio means no problem :-)
  50         if ( aspect_ratio == 0.0 )
  51                 aspect_ratio = mlt_properties_get_double( properties, "consumer_aspect_ratio" );
  52
  53         // Reset the aspect ratio
  54         mlt_properties_set_double( properties, "aspect_ratio", aspect_ratio );
  55
  56         // Hmmm...
  57         char *rescale = mlt_properties_get( properties, "rescale.interp" );
  58         if ( rescale != NULL && !strcmp( rescale, "none" ) )
  59                 return mlt_frame_get_image( this, image, format, width, height, writable );
  60
  61         if ( mlt_properties_get_int( properties, "distort" ) == 0 )
  62         {
  63                 // Normalise the input and out display aspect
  64                 int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
  65                 int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
  66                 int real_width = mlt_properties_get_int( properties, "real_width" );
  67                 int real_height = mlt_properties_get_int( properties, "real_height" );
  68                 if ( real_width == 0 )
  69                         real_width = mlt_properties_get_int( properties, "width" );
  70                 if ( real_height == 0 )
  71                         real_height = mlt_properties_get_int( properties, "height" );
  72                 double input_ar = aspect_ratio * real_width / real_height;
  73                 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" ) * owidth / oheight;
  74
  75                 //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 );
  76
  77                 // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
  78                 int scaled_width = input_ar / output_ar * normalised_width + 0.5;
  79                 int scaled_height = normalised_height;
  80
  81                 // Now ensure that our images fit in the output frame
  82                 if ( scaled_width > normalised_width )
  83                 {
  84                         scaled_width = normalised_width;
  85                         scaled_height = output_ar / input_ar * normalised_height + 0.5;
  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                 // Tell frame we have conformed the aspect to the consumer
  93                 mlt_frame_set_aspect_ratio( this, mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
  94         }
  95
  96         mlt_properties_set_int( properties, "distort", 0 );
  97
  98         // Now pass on the calculations down the line
  99         mlt_properties_set_int( properties, "resize_width", *width );
 100         mlt_properties_set_int( properties, "resize_height", *height );
 101
 102         // Now get the image
 103         error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
 104
 105         // We only know how to process yuv422 at the moment
 106         if ( error == 0 && *format == mlt_image_yuv422 && *image != NULL )
 107         {
 108                 // Get the requested scale operation
 109                 char *op = mlt_properties_get( MLT_FILTER_PROPERTIES( filter ), "scale" );
 110
 111                 // Correct field order if needed
 112                 if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
 113                 {
 114                         // Get the input image, width and height
 115                         int size;
 116                         uint8_t *image = mlt_properties_get_data( properties, "image", &size );
 117
 118                         // Keep the original image around to be destroyed on frame close
 119                         mlt_properties_rename( properties, "image", "original_image" );
 120
 121                         // Duplicate the last line in the field to avoid artifact
 122                         memcpy( image + oheight * owidth * 2, image + oheight * owidth * 2 - owidth * 4, owidth * 2 );
 123
 124                         // Offset the image pointer by one line
 125                         image += owidth * 2;
 126                         size -= owidth * 2;
 127
 128                         // Set the new image pointer with no destructor
 129                         mlt_properties_set_data( properties, "image", image, size, NULL, NULL );
 130
 131                         // Set the normalised field order
 132                         mlt_properties_set_int( properties, "top_field_first", 0 );
 133                 }
 134
 135                 if ( !strcmp( op, "affine" ) )
 136                 {
 137                         *image = mlt_frame_rescale_yuv422( this, *width, *height );
 138                 }
 139                 else if ( strcmp( op, "none" ) != 0 )
 140                 {
 141                         *image = mlt_frame_resize_yuv422( this, *width, *height );
 142                 }
 143                 else
 144                 {
 145                         *width = owidth;
 146                         *height = oheight;
 147                 }
 148         }
 149
 150         return error;
 151 }
 152
 153 /** Filter processing.
 154 */
 155
 156 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 157 {
 158         // Store the aspect ratio reported by the source
 159         mlt_deque_push_back_double( MLT_FRAME_IMAGE_STACK( frame ), mlt_frame_get_aspect_ratio( frame ) );
 160
 161         // Push this on to the service stack
 162         mlt_frame_push_service( frame, this );
 163
 164         // Push the get_image method on to the stack
 165         mlt_frame_push_get_image( frame, filter_get_image );
 166
 167         return frame;
 168 }
 169
 170 /** Constructor for the filter.
 171 */
 172
 173 mlt_filter filter_resize_init( char *arg )
 174 {
 175         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
 176         if ( mlt_filter_init( this, this ) == 0 )
 177         {
 178                 this->process = filter_process;
 179                 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "scale", arg == NULL ? "off" : arg );
 180         }
 181         return this;
 182 }