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 library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, 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 /** Swapbytes inline.
  31 */
  32
  33 static inline void swap_bytes( uint8_t *upper, uint8_t *lower )
  34 {
  35         uint8_t t = *lower;
  36         *lower = *upper;
  37         *upper = t;
  38 }
  39
  40 /** Do it :-).
  41 */
  42
  43 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
  44 {
  45         int error = 0;
  46
  47         // Get the properties from the frame
  48         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
  49
  50         // Pop the top of stack now
  51         mlt_filter filter = mlt_frame_pop_service( this );
  52
  53         // Retrieve the aspect ratio
  54         double aspect_ratio = mlt_deque_pop_back_double( MLT_FRAME_IMAGE_STACK( this ) );
  55
  56         // Assign requested width/height from our subordinate
  57         int owidth = *width;
  58         int oheight = *height;
  59
  60         // Check for the special case - no aspect ratio means no problem :-)
  61         if ( aspect_ratio == 0.0 )
  62                 aspect_ratio = mlt_properties_get_double( properties, "consumer_aspect_ratio" );
  63
  64         // Reset the aspect ratio
  65         mlt_properties_set_double( properties, "aspect_ratio", aspect_ratio );
  66
  67         // Hmmm...
  68         char *rescale = mlt_properties_get( properties, "rescale.interp" );
  69         if ( rescale != NULL && !strcmp( rescale, "none" ) )
  70                 return mlt_frame_get_image( this, image, format, width, height, writable );
  71
  72         if ( mlt_properties_get_int( properties, "distort" ) == 0 )
  73         {
  74                 // Normalise the input and out display aspect
  75                 int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
  76                 int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
  77                 int real_width = mlt_properties_get_int( properties, "real_width" );
  78                 int real_height = mlt_properties_get_int( properties, "real_height" );
  79                 if ( real_width == 0 )
  80                         real_width = mlt_properties_get_int( properties, "width" );
  81                 if ( real_height == 0 )
  82                         real_height = mlt_properties_get_int( properties, "height" );
  83                 double input_ar = aspect_ratio * real_width / real_height;
  84                 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" ) * owidth / oheight;
  85
  86                 //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 );
  87
  88                 // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
  89                 int scaled_width = rint( 0.5 + ( input_ar * normalised_width ) / output_ar );
  90                 int scaled_height = normalised_height;
  91
  92                 // Now ensure that our images fit in the output frame
  93                 if ( scaled_width > normalised_width )
  94                 {
  95                         scaled_width = normalised_width;
  96                         scaled_height = rint( 0.5 + ( output_ar * normalised_height ) / input_ar );
  97                 }
  98
  99                 // Now calculate the actual image size that we want
 100                 owidth = rint( 0.5 + scaled_width * owidth / normalised_width );
 101                 oheight = rint( 0.5 + scaled_height * oheight / normalised_height );
 102
 103                 // Tell frame we have conformed the aspect to the consumer
 104                 mlt_frame_set_aspect_ratio( this, mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
 105         }
 106
 107         mlt_properties_set_int( properties, "distort", 0 );
 108
 109         // Now pass on the calculations down the line
 110         mlt_properties_set_int( properties, "resize_width", *width );
 111         mlt_properties_set_int( properties, "resize_height", *height );
 112
 113         // Now get the image
 114         error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
 115
 116         // We only know how to process yuv422 at the moment
 117         if ( error == 0 && *format == mlt_image_yuv422 && *image != NULL )
 118         {
 119                 // Get the requested scale operation
 120                 char *op = mlt_properties_get( MLT_FILTER_PROPERTIES( filter ), "scale" );
 121
 122                 // Provides a manual override for misreported field order
 123                 if ( mlt_properties_get( properties, "meta.top_field_first" ) )
 124                         mlt_properties_set( properties, "top_field_first", mlt_properties_get_int( properties, "meta.top_field_first" ) );
 125
 126                 // Correct field order if needed
 127                 if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
 128                 {
 129                         // Get the input image, width and height
 130                         int size;
 131                         uint8_t *image = mlt_properties_get_data( properties, "image", &size );
 132                         uint8_t *ptr = image + owidth * 2;
 133                         int h = oheight / 2;
 134                         int w = owidth;
 135
 136                         // Swap the lines around
 137                         while( h -- )
 138                         {
 139                                 w = owidth;
 140                                 while( w -- )
 141                                 {
 142                                         swap_bytes( image ++, ptr ++ );
 143                                         swap_bytes( image ++, ptr ++ );
 144                                 }
 145                                 image += owidth * 2;
 146                                 ptr += owidth * 2;
 147                         }
 148
 149                         // Set the normalised field order
 150                         mlt_properties_set_int( properties, "top_field_first", 0 );
 151                         mlt_properties_set_int( properties, "meta.top_field_first", 0 );
 152                 }
 153
 154                 if ( !strcmp( op, "affine" ) )
 155                 {
 156                         *image = mlt_frame_rescale_yuv422( this, *width, *height );
 157                 }
 158                 else if ( strcmp( op, "none" ) != 0 )
 159                 {
 160                         *image = mlt_frame_resize_yuv422( this, *width, *height );
 161                 }
 162                 else
 163                 {
 164                         *width = owidth;
 165                         *height = oheight;
 166                 }
 167         }
 168
 169         return error;
 170 }
 171
 172 /** Filter processing.
 173 */
 174
 175 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 176 {
 177         // Store the aspect ratio reported by the source
 178         mlt_deque_push_back_double( MLT_FRAME_IMAGE_STACK( frame ), mlt_frame_get_aspect_ratio( frame ) );
 179
 180         // Push this on to the service stack
 181         mlt_frame_push_service( frame, this );
 182
 183         // Push the get_image method on to the stack
 184         mlt_frame_push_get_image( frame, filter_get_image );
 185
 186         return frame;
 187 }
 188
 189 /** Constructor for the filter.
 190 */
 191
 192 mlt_filter filter_resize_init( char *arg )
 193 {
 194         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
 195         if ( mlt_filter_init( this, this ) == 0 )
 196         {
 197                 this->process = filter_process;
 198                 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "scale", arg == NULL ? "off" : arg );
 199         }
 200         return this;
 201 }