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 <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         // Correct Width/height if necessary
  56         if ( *width == 0 || *height == 0 )
  57         {
  58                 *width = mlt_properties_get_int( properties, "normalised_width" );
  59                 *height = mlt_properties_get_int( properties, "normalised_height" );
  60         }
  61
  62         // Assign requested width/height from our subordinate
  63         int owidth = *width;
  64         int oheight = *height;
  65
  66         // Check for the special case - no aspect ratio means no problem :-)
  67         if ( aspect_ratio == 0.0 )
  68                 aspect_ratio = mlt_properties_get_double( properties, "consumer_aspect_ratio" );
  69
  70         // Reset the aspect ratio
  71         mlt_properties_set_double( properties, "aspect_ratio", aspect_ratio );
  72
  73         // Hmmm...
  74         char *rescale = mlt_properties_get( properties, "rescale.interp" );
  75         if ( rescale != NULL && !strcmp( rescale, "none" ) )
  76                 return mlt_frame_get_image( this, image, format, width, height, writable );
  77
  78         if ( mlt_properties_get_int( properties, "distort" ) == 0 )
  79         {
  80                 // Normalise the input and out display aspect
  81                 int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
  82                 int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
  83                 int real_width = mlt_properties_get_int( properties, "real_width" );
  84                 int real_height = mlt_properties_get_int( properties, "real_height" );
  85                 if ( real_width == 0 )
  86                         real_width = mlt_properties_get_int( properties, "width" );
  87                 if ( real_height == 0 )
  88                         real_height = mlt_properties_get_int( properties, "height" );
  89                 double input_ar = aspect_ratio * real_width / real_height;
  90                 double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" ) * owidth / oheight;
  91
  92 //              fprintf( stderr, "real %dx%d normalised %dx%d output %dx%d sar %f in-dar %f out-dar %f\n",
  93 //              real_width, real_height, normalised_width, normalised_height, owidth, oheight, aspect_ratio, input_ar, output_ar);
  94
  95                 // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
  96                 int scaled_width = rint( ( input_ar * normalised_width ) / output_ar );
  97                 int scaled_height = normalised_height;
  98
  99                 // Now ensure that our images fit in the output frame
 100                 if ( scaled_width > normalised_width )
 101                 {
 102                         scaled_width = normalised_width;
 103                         scaled_height = rint( ( output_ar * normalised_height ) / input_ar );
 104                 }
 105
 106                 // Now calculate the actual image size that we want
 107                 owidth = rint( scaled_width * owidth / normalised_width );
 108                 oheight = rint( scaled_height * oheight / normalised_height );
 109
 110                 // Tell frame we have conformed the aspect to the consumer
 111                 mlt_frame_set_aspect_ratio( this, mlt_properties_get_double( properties, "consumer_aspect_ratio" ) );
 112         }
 113
 114         mlt_properties_set_int( properties, "distort", 0 );
 115
 116         // Now pass on the calculations down the line
 117         mlt_properties_set_int( properties, "resize_width", *width );
 118         mlt_properties_set_int( properties, "resize_height", *height );
 119
 120         // Now get the image
 121         error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
 122
 123         // We only know how to process yuv422 at the moment
 124         if ( error == 0 && *format == mlt_image_yuv422 && *image != NULL )
 125         {
 126                 // Get the requested scale operation
 127                 char *op = mlt_properties_get( MLT_FILTER_PROPERTIES( filter ), "scale" );
 128
 129                 // Provides a manual override for misreported field order
 130                 if ( mlt_properties_get( properties, "meta.top_field_first" ) )
 131                         mlt_properties_set_int( properties, "top_field_first", mlt_properties_get_int( properties, "meta.top_field_first" ) );
 132
 133                 // Correct field order if needed
 134                 if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
 135                 {
 136                         // Get the input image, width and height
 137                         int size;
 138                         uint8_t *image = mlt_properties_get_data( properties, "image", &size );
 139                         uint8_t *ptr = image + owidth * 2;
 140                         memmove( ptr, image, size - owidth * 2 );
 141
 142                         // Set the normalised field order
 143                         mlt_properties_set_int( properties, "top_field_first", 0 );
 144                         mlt_properties_set_int( properties, "meta.top_field_first", 0 );
 145                 }
 146
 147                 if ( !strcmp( op, "affine" ) )
 148                 {
 149                         *image = mlt_frame_rescale_yuv422( this, *width, *height );
 150                 }
 151                 else if ( strcmp( op, "none" ) != 0 )
 152                 {
 153                         *image = mlt_frame_resize_yuv422( this, *width, *height );
 154                 }
 155                 else
 156                 {
 157                         *width = owidth;
 158                         *height = oheight;
 159                 }
 160         }
 161
 162         return error;
 163 }
 164
 165 /** Filter processing.
 166 */
 167
 168 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 169 {
 170         // Store the aspect ratio reported by the source
 171         mlt_deque_push_back_double( MLT_FRAME_IMAGE_STACK( frame ), mlt_frame_get_aspect_ratio( frame ) );
 172
 173         // Push this on to the service stack
 174         mlt_frame_push_service( frame, this );
 175
 176         // Push the get_image method on to the stack
 177         mlt_frame_push_get_image( frame, filter_get_image );
 178
 179         return frame;
 180 }
 181
 182 /** Constructor for the filter.
 183 */
 184
 185 mlt_filter filter_resize_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
 186 {
 187         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
 188         if ( mlt_filter_init( this, this ) == 0 )
 189         {
 190                 this->process = filter_process;
 191                 mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "scale", arg == NULL ? "off" : arg );
 192         }
 193         return this;
 194 }