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 #include <math.h>
  29
  30 /** Do it :-).
  31 */
  32
  33 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
  34 {
  35         int error = 0;
  36
  37         // Get the properties from the frame
  38         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
  39
  40         // Pop the top of stack now
  41         mlt_filter filter = mlt_frame_pop_service( this );
  42
  43         // Retrieve the aspect ratio
  44         double aspect_ratio = mlt_deque_pop_back_double( MLT_FRAME_IMAGE_STACK( this ) );
  45
  46         // Assign requested width/height from our subordinate
  47         int owidth = *width;
  48         int oheight = *height;
  49
  50         // Check for the special case - no aspect ratio means no problem :-)
  51         if ( aspect_ratio == 0.0 )
  52                 aspect_ratio = mlt_properties_get_double( properties, "consumer_aspect_ratio" );
  53
  54         // Reset the aspect ratio
  55         mlt_properties_set_double( properties, "aspect_ratio", aspect_ratio );
  56
  57         // Hmmm...
  58         char *rescale = mlt_properties_get( properties, "rescale.interp" );
  59         if ( rescale != NULL && !strcmp( rescale, "none" ) )
  60                 return mlt_frame_get_image( this, image, format, width, height, writable );
  61
  62         if ( mlt_properties_get_int( properties, "distort" ) == 0 )
  63         {
  64                 // Normalise the input and out display aspect
  65                 int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
  66                 int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
  67                 int real_width = mlt_properties_get_int( properties, "real_width" );
  68                 int real_height = mlt_properties_get_int( properties, "real_height" );
  69                 if ( real_width == 0 )
  70                         real_width = mlt_properties_get_int( properties, "width" );
  71                 if ( real_height == 0 )
  72                         real_height = mlt_properties_get_int( properties, "height" );
  73                 double input_ar = aspect_ratio * real_width / real_height;
  74                 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" ) * owidth / oheight;
  75
  76                 //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 );
  77
  78                 // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
  79                 int scaled_width = rint( 0.5 + ( input_ar * normalised_width ) / output_ar );
  80                 int scaled_height = normalised_height;
  81
  82                 // Now ensure that our images fit in the output frame
  83                 if ( scaled_width > normalised_width )
  84                 {
  85                         scaled_width = normalised_width;
  86                         scaled_height = rint( 0.5 + ( output_ar * normalised_height ) / input_ar );
  87                 }
  88
  89                 // Now calculate the actual image size that we want
  90                 owidth = rint( 0.5 + scaled_width * owidth / normalised_width );
  91                 oheight = rint( 0.5 + scaled_height * oheight / normalised_height );
  92
  93                 // Tell frame we have conformed the aspect to the consumer
  94                 mlt_frame_set_aspect_ratio( this, mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
  95         }
  96
  97         mlt_properties_set_int( properties, "distort", 0 );
  98
  99         // Now pass on the calculations down the line
 100         mlt_properties_set_int( properties, "resize_width", *width );
 101         mlt_properties_set_int( properties, "resize_height", *height );
 102
 103         // Now get the image
 104         error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
 105
 106         // We only know how to process yuv422 at the moment
 107         if ( error == 0 && *format == mlt_image_yuv422 && *image != NULL )
 108         {
 109                 // Get the requested scale operation
 110                 char *op = mlt_properties_get( MLT_FILTER_PROPERTIES( filter ), "scale" );
 111
 112                 // Correct field order if needed
 113                 if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
 114                 {
 115                         // Get the input image, width and height
 116                         int size;
 117                         uint8_t *image = mlt_properties_get_data( properties, "image", &size );
 118
 119                         // Keep the original image around to be destroyed on frame close
 120                         mlt_properties_rename( properties, "image", "original_image" );
 121
 122                         // Duplicate the last line in the field to avoid artifact
 123                         memcpy( image + oheight * owidth * 2, image + oheight * owidth * 2 - owidth * 4, owidth * 2 );
 124
 125                         // Offset the image pointer by one line
 126                         image += owidth * 2;
 127                         size -= owidth * 2;
 128
 129                         // Set the new image pointer with no destructor
 130                         mlt_properties_set_data( properties, "image", image, size, NULL, NULL );
 131
 132                         // Set the normalised field order
 133                         mlt_properties_set_int( properties, "top_field_first", 0 );
 134                 }
 135
 136                 if ( !strcmp( op, "affine" ) )
 137                 {
 138                         *image = mlt_frame_rescale_yuv422( this, *width, *height );
 139                 }
 140                 else if ( strcmp( op, "none" ) != 0 )
 141                 {
 142                         *image = mlt_frame_resize_yuv422( this, *width, *height );
 143                 }
 144                 else
 145                 {
 146                         *width = owidth;
 147                         *height = oheight;
 148                 }
 149         }
 150
 151         return error;
 152 }
 153
 154 /** Filter processing.
 155 */
 156
 157 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 158 {
 159         // Store the aspect ratio reported by the source
 160         mlt_deque_push_back_double( MLT_FRAME_IMAGE_STACK( frame ), mlt_frame_get_aspect_ratio( frame ) );
 161
 162         // Push this on to the service stack
 163         mlt_frame_push_service( frame, this );
 164
 165         // Push the get_image method on to the stack
 166         mlt_frame_push_get_image( frame, filter_get_image );
 167
 168         return frame;
 169 }
 170
 171 /** Constructor for the filter.
 172 */
 173
 174 mlt_filter filter_resize_init( char *arg )
 175 {
 176         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
 177         if ( mlt_filter_init( this, this ) == 0 )
 178         {
 179                 this->process = filter_process;
 180                 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "scale", arg == NULL ? "off" : arg );
 181         }
 182         return this;
 183 }