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 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 <framework/mlt_filter.h>
  22 #include <framework/mlt_frame.h>
  23
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <stdlib.h>
  27 #include <math.h>
  28
  29 /** Swapbytes inline.
  30 */
  31
  32 static inline void swap_bytes( uint8_t *upper, uint8_t *lower )
  33 {
  34         uint8_t t = *lower;
  35         *lower = *upper;
  36         *upper = t;
  37 }
  38
  39 /** Do it :-).
  40 */
  41
  42 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
  43 {
  44         int error = 0;
  45
  46         // Get the properties from the frame
  47         mlt_properties properties = MLT_FRAME_PROPERTIES( this );
  48
  49         // Pop the top of stack now
  50         mlt_filter filter = mlt_frame_pop_service( this );
  51
  52         // Retrieve the aspect ratio
  53         double aspect_ratio = mlt_deque_pop_back_double( MLT_FRAME_IMAGE_STACK( this ) );
  54
  55         // Assign requested width/height from our subordinate
  56         int owidth = *width;
  57         int oheight = *height;
  58
  59         // Check for the special case - no aspect ratio means no problem :-)
  60         if ( aspect_ratio == 0.0 )
  61                 aspect_ratio = mlt_properties_get_double( properties, "consumer_aspect_ratio" );
  62
  63         // Reset the aspect ratio
  64         mlt_properties_set_double( properties, "aspect_ratio", aspect_ratio );
  65
  66         // Hmmm...
  67         char *rescale = mlt_properties_get( properties, "rescale.interp" );
  68         if ( rescale != NULL && !strcmp( rescale, "none" ) )
  69                 return mlt_frame_get_image( this, image, format, width, height, writable );
  70
  71         if ( mlt_properties_get_int( properties, "distort" ) == 0 )
  72         {
  73                 // Normalise the input and out display aspect
  74                 int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
  75                 int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
  76                 int real_width = mlt_properties_get_int( properties, "real_width" );
  77                 int real_height = mlt_properties_get_int( properties, "real_height" );
  78                 if ( real_width == 0 )
  79                         real_width = mlt_properties_get_int( properties, "width" );
  80                 if ( real_height == 0 )
  81                         real_height = mlt_properties_get_int( properties, "height" );
  82                 double input_ar = aspect_ratio * real_width / real_height;
  83                 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" ) * owidth / oheight;
  84
  85                 //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 );
  86
  87                 // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
  88                 int scaled_width = rint( 0.5 + ( input_ar * normalised_width ) / output_ar );
  89                 int scaled_height = normalised_height;
  90
  91                 // Now ensure that our images fit in the output frame
  92                 if ( scaled_width > normalised_width )
  93                 {
  94                         scaled_width = normalised_width;
  95                         scaled_height = rint( 0.5 + ( output_ar * normalised_height ) / input_ar );
  96                 }
  97
  98                 // Now calculate the actual image size that we want
  99                 owidth = rint( 0.5 + scaled_width * owidth / normalised_width );
 100                 oheight = rint( 0.5 + scaled_height * oheight / normalised_height );
 101
 102                 // Tell frame we have conformed the aspect to the consumer
 103                 mlt_frame_set_aspect_ratio( this, mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
 104         }
 105
 106         mlt_properties_set_int( properties, "distort", 0 );
 107
 108         // Now pass on the calculations down the line
 109         mlt_properties_set_int( properties, "resize_width", *width );
 110         mlt_properties_set_int( properties, "resize_height", *height );
 111
 112         // Now get the image
 113         error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
 114
 115         // We only know how to process yuv422 at the moment
 116         if ( error == 0 && *format == mlt_image_yuv422 && *image != NULL )
 117         {
 118                 // Get the requested scale operation
 119                 char *op = mlt_properties_get( MLT_FILTER_PROPERTIES( filter ), "scale" );
 120
 121                 // Provides a manual override for misreported field order
 122                 if ( mlt_properties_get( properties, "meta.top_field_first" ) )
 123                         mlt_properties_set_int( properties, "top_field_first", mlt_properties_get_int( properties, "meta.top_field_first" ) );
 124
 125                 // Correct field order if needed
 126                 if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
 127                 {
 128                         // Get the input image, width and height
 129                         int size;
 130                         uint8_t *image = mlt_properties_get_data( properties, "image", &size );
 131                         uint8_t *ptr = image + owidth * 2;
 132                         int h = oheight / 2;
 133                         int w = owidth;
 134
 135                         // Swap the lines around
 136                         while( h -- )
 137                         {
 138                                 w = owidth;
 139                                 while( w -- )
 140                                 {
 141                                         swap_bytes( image ++, ptr ++ );
 142                                         swap_bytes( image ++, ptr ++ );
 143                                 }
 144                                 image += owidth * 2;
 145                                 ptr += owidth * 2;
 146                         }
 147
 148                         // Set the normalised field order
 149                         mlt_properties_set_int( properties, "top_field_first", 0 );
 150                         mlt_properties_set_int( properties, "meta.top_field_first", 0 );
 151                 }
 152
 153                 if ( !strcmp( op, "affine" ) )
 154                 {
 155                         *image = mlt_frame_rescale_yuv422( this, *width, *height );
 156                 }
 157                 else if ( strcmp( op, "none" ) != 0 )
 158                 {
 159                         *image = mlt_frame_resize_yuv422( this, *width, *height );
 160                 }
 161                 else
 162                 {
 163                         *width = owidth;
 164                         *height = oheight;
 165                 }
 166         }
 167
 168         return error;
 169 }
 170
 171 /** Filter processing.
 172 */
 173
 174 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 175 {
 176         // Store the aspect ratio reported by the source
 177         mlt_deque_push_back_double( MLT_FRAME_IMAGE_STACK( frame ), mlt_frame_get_aspect_ratio( frame ) );
 178
 179         // Push this on to the service stack
 180         mlt_frame_push_service( frame, this );
 181
 182         // Push the get_image method on to the stack
 183         mlt_frame_push_get_image( frame, filter_get_image );
 184
 185         return frame;
 186 }
 187
 188 /** Constructor for the filter.
 189 */
 190
 191 mlt_filter filter_resize_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
 192 {
 193         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
 194         if ( mlt_filter_init( this, this ) == 0 )
 195         {
 196                 this->process = filter_process;
 197                 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "scale", arg == NULL ? "off" : arg );
 198         }
 199         return this;
 200 }