git.sesse.net Git - mlt/blob - src/modules/core/filter_crop.c

   1 /*
   2  * filter_crop.c -- cropping filter
   3  * Copyright (C) 2009 Ushodaya Enterprises Limited
   4  * Author: Dan Dennedy <dan@dennedy.org>
   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 #include <framework/mlt_log.h>
  24 #include <framework/mlt_profile.h>
  25
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29 #include <math.h>
  30
  31 static void crop( uint8_t *src, uint8_t *dest, int bpp, int width, int height, int left, int right, int top, int bottom )
  32 {
  33         int src_stride = ( width  ) * bpp;
  34         int dest_stride = ( width - left - right ) * bpp;
  35         int y      = height - top - bottom + 1;
  36         src += top * src_stride + left * bpp;
  37
  38         while ( --y )
  39         {
  40                 memcpy( dest, src, dest_stride );
  41                 dest += dest_stride;
  42                 src += src_stride;
  43         }
  44 }
  45
  46 /** Do it :-).
  47 */
  48
  49 static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
  50 {
  51         int error = 0;
  52
  53         // Get the properties from the frame
  54         mlt_properties properties = MLT_FRAME_PROPERTIES( frame );
  55
  56         // Correct Width/height if necessary
  57         if ( *width == 0 || *height == 0 )
  58         {
  59                 *width  = mlt_properties_get_int( properties, "normalised_width" );
  60                 *height = mlt_properties_get_int( properties, "normalised_height" );
  61         }
  62
  63         int left    = mlt_properties_get_int( properties, "crop.left" );
  64         int right   = mlt_properties_get_int( properties, "crop.right" );
  65         int top     = mlt_properties_get_int( properties, "crop.top" );
  66         int bottom  = mlt_properties_get_int( properties, "crop.bottom" );
  67
  68         // Request the image at its original resolution
  69         if ( left || right || top || bottom )
  70         {
  71                 mlt_properties_set_int( properties, "rescale_width", mlt_properties_get_int( properties, "crop.original_width" ) );
  72                 mlt_properties_set_int( properties, "rescale_height", mlt_properties_get_int( properties, "crop.original_height" ) );
  73         }
  74
  75         // Now get the image
  76         error = mlt_frame_get_image( frame, image, format, width, height, writable );
  77
  78         int owidth  = *width - left - right;
  79         int oheight = *height - top - bottom;
  80         owidth = owidth < 0 ? 0 : owidth;
  81         oheight = oheight < 0 ? 0 : oheight;
  82
  83         if ( ( owidth != *width || oheight != *height ) &&
  84                 error == 0 && *image != NULL && owidth > 0 && oheight > 0 )
  85         {
  86                 int bpp;
  87
  88                 // Subsampled YUV is messy and less precise.
  89                 if ( *format == mlt_image_yuv422 && frame->convert_image )
  90                 {
  91                         mlt_image_format requested_format = mlt_image_rgb24;
  92                         frame->convert_image( frame, image, format, requested_format );
  93                 }
  94
  95                 mlt_log_debug( NULL, "[filter crop] %s %dx%d -> %dx%d\n", mlt_image_format_name(*format),
  96                                  *width, *height, owidth, oheight);
  97
  98                 // Provides a manual override for misreported field order
  99                 if ( mlt_properties_get( properties, "meta.top_field_first" ) )
 100                 {
 101                         mlt_properties_set_int( properties, "top_field_first", mlt_properties_get_int( properties, "meta.top_field_first" ) );
 102                         mlt_properties_set_int( properties, "meta.top_field_first", 0 );
 103                 }
 104
 105                 if ( top % 2 )
 106                         mlt_properties_set_int( properties, "top_field_first", !mlt_properties_get_int( properties, "top_field_first" ) );
 107
 108                 // Create the output image
 109                 int size = mlt_image_format_size( *format, owidth, oheight, &bpp );
 110                 uint8_t *output = mlt_pool_alloc( size );
 111                 if ( output )
 112                 {
 113                         // Call the generic resize
 114                         crop( *image, output, bpp, *width, *height, left, right, top, bottom );
 115
 116                         // Now update the frame
 117                         mlt_frame_set_image( frame, output, size, mlt_pool_release );
 118                         *image = output;
 119                 }
 120
 121                 // We should resize the alpha too
 122                 uint8_t *alpha = mlt_frame_get_alpha_mask( frame );
 123                 int alpha_size = 0;
 124                 mlt_properties_get_data( properties, "alpha", &alpha_size );
 125                 if ( alpha && alpha_size >= ( *width * *height ) )
 126                 {
 127                         uint8_t *newalpha = mlt_pool_alloc( owidth * oheight );
 128                         if ( newalpha )
 129                         {
 130                                 crop( alpha, newalpha, 1, *width, *height, left, right, top, bottom );
 131                                 mlt_frame_set_alpha( frame, newalpha, owidth * oheight, mlt_pool_release );
 132                         }
 133                 }
 134                 *width = owidth;
 135                 *height = oheight;
 136         }
 137
 138         return error;
 139 }
 140
 141 /** Filter processing.
 142 */
 143
 144 static mlt_frame filter_process( mlt_filter filter, mlt_frame frame )
 145 {
 146         if ( mlt_properties_get_int( MLT_FILTER_PROPERTIES( filter ), "active" ) )
 147         {
 148                 // Push the get_image method on to the stack
 149                 mlt_frame_push_get_image( frame, filter_get_image );
 150         }
 151         else
 152         {
 153                 mlt_properties filter_props = MLT_FILTER_PROPERTIES( filter );
 154                 mlt_properties frame_props = MLT_FRAME_PROPERTIES( frame );
 155                 int left   = mlt_properties_get_int( filter_props, "left" );
 156                 int right  = mlt_properties_get_int( filter_props, "right" );
 157                 int top    = mlt_properties_get_int( filter_props, "top" );
 158                 int bottom = mlt_properties_get_int( filter_props, "bottom" );
 159                 int width  = mlt_properties_get_int( frame_props, "real_width" );
 160                 int height = mlt_properties_get_int( frame_props, "real_height" );
 161                 int use_profile = mlt_properties_get_int( filter_props, "use_profile" );
 162                 mlt_profile profile = mlt_service_profile( MLT_FILTER_SERVICE( filter ) );
 163
 164                 if ( use_profile )
 165                 {
 166                         top = top * height / profile->height;
 167                         bottom = bottom * height / profile->height;
 168                         left = left * width / profile->width;
 169                         right = right * width / profile->width;
 170                 }
 171                 if ( mlt_properties_get_int( filter_props, "center" ) )
 172                 {
 173                         double aspect_ratio = mlt_frame_get_aspect_ratio( frame );
 174                         if ( aspect_ratio == 0.0 )
 175                                 aspect_ratio = mlt_properties_get_double( frame_props, "consumer_aspect_ratio" );
 176                         double input_ar = aspect_ratio * width / height;
 177                         double output_ar = mlt_profile_dar( mlt_service_profile( MLT_FILTER_SERVICE(filter) ) );
 178                         int bias = mlt_properties_get_int( filter_props, "center_bias" );
 179
 180                         if ( input_ar > output_ar )
 181                         {
 182                                 left = right = ( width - rint( output_ar * height / aspect_ratio ) ) / 2;
 183                                 if ( abs(bias) > left )
 184                                         bias = bias < 0 ? -left : left;
 185                                 else if ( use_profile )
 186                                         bias = bias * width / profile->width;
 187                                 left -= bias;
 188                                 right += bias;
 189                         }
 190                         else
 191                         {
 192                                 top = bottom = ( height - rint( aspect_ratio * width / output_ar ) ) / 2;
 193                                 if ( abs(bias) > top )
 194                                         bias = bias < 0 ? -top : top;
 195                                 else if ( use_profile )
 196                                         bias = bias * height / profile->height;
 197                                 top -= bias;
 198                                 bottom += bias;
 199                         }
 200                 }
 201
 202                 // Coerce the output to an even width because subsampled YUV with odd widths is too
 203                 // risky for downstream processing to handle correctly.
 204                 left += ( width - left - right ) & 1;
 205                 if ( width - left - right < 8 )
 206                         left = right = 0;
 207                 if ( height - top - bottom < 8 )
 208                         top = bottom = 0;
 209                 mlt_properties_set_int( frame_props, "crop.left", left );
 210                 mlt_properties_set_int( frame_props, "crop.right", right );
 211                 mlt_properties_set_int( frame_props, "crop.top", top );
 212                 mlt_properties_set_int( frame_props, "crop.bottom", bottom );
 213                 mlt_properties_set_int( frame_props, "crop.original_width", width );
 214                 mlt_properties_set_int( frame_props, "crop.original_height", height );
 215                 mlt_properties_set_int( frame_props, "real_width", width - left - right );
 216                 mlt_properties_set_int( frame_props, "real_height", height - top - bottom );
 217         }
 218         return frame;
 219 }
 220
 221 /** Constructor for the filter.
 222 */
 223
 224 mlt_filter filter_crop_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
 225 {
 226         mlt_filter filter = calloc( sizeof( struct mlt_filter_s ), 1 );
 227         if ( mlt_filter_init( filter, filter ) == 0 )
 228         {
 229                 filter->process = filter_process;
 230                 if ( arg )
 231                         mlt_properties_set_int( MLT_FILTER_PROPERTIES( filter ), "active", atoi( arg ) );
 232         }
 233         return filter;
 234 }