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         mlt_profile profile = mlt_frame_pop_service( frame );
  53
  54         // Get the properties from the frame
  55         mlt_properties properties = MLT_FRAME_PROPERTIES( frame );
  56
  57         // Correct Width/height if necessary
  58         if ( *width == 0 || *height == 0 )
  59         {
  60                 *width  = profile->width;
  61                 *height = profile->height;
  62         }
  63
  64         int left    = mlt_properties_get_int( properties, "crop.left" );
  65         int right   = mlt_properties_get_int( properties, "crop.right" );
  66         int top     = mlt_properties_get_int( properties, "crop.top" );
  67         int bottom  = mlt_properties_get_int( properties, "crop.bottom" );
  68
  69         // Request the image at its original resolution
  70         if ( left || right || top || bottom )
  71         {
  72                 mlt_properties_set_int( properties, "rescale_width", mlt_properties_get_int( properties, "crop.original_width" ) );
  73                 mlt_properties_set_int( properties, "rescale_height", mlt_properties_get_int( properties, "crop.original_height" ) );
  74         }
  75
  76         // Now get the image
  77         error = mlt_frame_get_image( frame, image, format, width, height, writable );
  78
  79         int owidth  = *width - left - right;
  80         int oheight = *height - top - bottom;
  81         owidth = owidth < 0 ? 0 : owidth;
  82         oheight = oheight < 0 ? 0 : oheight;
  83
  84         if ( ( owidth != *width || oheight != *height ) &&
  85                 error == 0 && *image != NULL && owidth > 0 && oheight > 0 )
  86         {
  87                 int bpp;
  88
  89                 // Subsampled YUV is messy and less precise.
  90                 if ( *format == mlt_image_yuv422 && frame->convert_image )
  91                 {
  92                         mlt_image_format requested_format = mlt_image_rgb24;
  93                         frame->convert_image( frame, image, format, requested_format );
  94                 }
  95
  96                 mlt_log_debug( NULL, "[filter crop] %s %dx%d -> %dx%d\n", mlt_image_format_name(*format),
  97                                  *width, *height, owidth, oheight);
  98
  99                 // Provides a manual override for misreported field order
 100                 if ( mlt_properties_get( properties, "meta.top_field_first" ) )
 101                 {
 102                         mlt_properties_set_int( properties, "top_field_first", mlt_properties_get_int( properties, "meta.top_field_first" ) );
 103                         mlt_properties_set_int( properties, "meta.top_field_first", 0 );
 104                 }
 105
 106                 if ( top % 2 )
 107                         mlt_properties_set_int( properties, "top_field_first", !mlt_properties_get_int( properties, "top_field_first" ) );
 108
 109                 // Create the output image
 110                 int size = mlt_image_format_size( *format, owidth, oheight, &bpp );
 111                 uint8_t *output = mlt_pool_alloc( size );
 112                 if ( output )
 113                 {
 114                         // Call the generic resize
 115                         crop( *image, output, bpp, *width, *height, left, right, top, bottom );
 116
 117                         // Now update the frame
 118                         mlt_frame_set_image( frame, output, size, mlt_pool_release );
 119                         *image = output;
 120                 }
 121
 122                 // We should resize the alpha too
 123                 uint8_t *alpha = mlt_frame_get_alpha_mask( frame );
 124                 int alpha_size = 0;
 125                 mlt_properties_get_data( properties, "alpha", &alpha_size );
 126                 if ( alpha && alpha_size >= ( *width * *height ) )
 127                 {
 128                         uint8_t *newalpha = mlt_pool_alloc( owidth * oheight );
 129                         if ( newalpha )
 130                         {
 131                                 crop( alpha, newalpha, 1, *width, *height, left, right, top, bottom );
 132                                 mlt_frame_set_alpha( frame, newalpha, owidth * oheight, mlt_pool_release );
 133                         }
 134                 }
 135                 *width = owidth;
 136                 *height = oheight;
 137         }
 138
 139         return error;
 140 }
 141
 142 /** Filter processing.
 143 */
 144
 145 static mlt_frame filter_process( mlt_filter filter, mlt_frame frame )
 146 {
 147         if ( mlt_properties_get_int( MLT_FILTER_PROPERTIES( filter ), "active" ) )
 148         {
 149                 // Push the get_image method on to the stack
 150                 mlt_frame_push_service( frame, mlt_service_profile( MLT_FILTER_SERVICE( filter ) ) );
 151                 mlt_frame_push_get_image( frame, filter_get_image );
 152         }
 153         else
 154         {
 155                 mlt_properties filter_props = MLT_FILTER_PROPERTIES( filter );
 156                 mlt_properties frame_props = MLT_FRAME_PROPERTIES( frame );
 157                 int left   = mlt_properties_get_int( filter_props, "left" );
 158                 int right  = mlt_properties_get_int( filter_props, "right" );
 159                 int top    = mlt_properties_get_int( filter_props, "top" );
 160                 int bottom = mlt_properties_get_int( filter_props, "bottom" );
 161                 int width  = mlt_properties_get_int( frame_props, "meta.media.width" );
 162                 int height = mlt_properties_get_int( frame_props, "meta.media.height" );
 163                 int use_profile = mlt_properties_get_int( filter_props, "use_profile" );
 164                 mlt_profile profile = mlt_service_profile( MLT_FILTER_SERVICE( filter ) );
 165
 166                 if ( use_profile )
 167                 {
 168                         top = top * height / profile->height;
 169                         bottom = bottom * height / profile->height;
 170                         left = left * width / profile->width;
 171                         right = right * width / profile->width;
 172                 }
 173                 if ( mlt_properties_get_int( filter_props, "center" ) )
 174                 {
 175                         double aspect_ratio = mlt_frame_get_aspect_ratio( frame );
 176                         if ( aspect_ratio == 0.0 )
 177                                 aspect_ratio = mlt_profile_sar( profile );
 178                         double input_ar = aspect_ratio * width / height;
 179                         double output_ar = mlt_profile_dar( mlt_service_profile( MLT_FILTER_SERVICE(filter) ) );
 180                         int bias = mlt_properties_get_int( filter_props, "center_bias" );
 181
 182                         if ( input_ar > output_ar )
 183                         {
 184                                 left = right = ( width - rint( output_ar * height / aspect_ratio ) ) / 2;
 185                                 if ( abs(bias) > left )
 186                                         bias = bias < 0 ? -left : left;
 187                                 else if ( use_profile )
 188                                         bias = bias * width / profile->width;
 189                                 left -= bias;
 190                                 right += bias;
 191                         }
 192                         else
 193                         {
 194                                 top = bottom = ( height - rint( aspect_ratio * width / output_ar ) ) / 2;
 195                                 if ( abs(bias) > top )
 196                                         bias = bias < 0 ? -top : top;
 197                                 else if ( use_profile )
 198                                         bias = bias * height / profile->height;
 199                                 top -= bias;
 200                                 bottom += bias;
 201                         }
 202                 }
 203
 204                 // Coerce the output to an even width because subsampled YUV with odd widths is too
 205                 // risky for downstream processing to handle correctly.
 206                 left += ( width - left - right ) & 1;
 207                 if ( width - left - right < 8 )
 208                         left = right = 0;
 209                 if ( height - top - bottom < 8 )
 210                         top = bottom = 0;
 211                 mlt_properties_set_int( frame_props, "crop.left", left );
 212                 mlt_properties_set_int( frame_props, "crop.right", right );
 213                 mlt_properties_set_int( frame_props, "crop.top", top );
 214                 mlt_properties_set_int( frame_props, "crop.bottom", bottom );
 215                 mlt_properties_set_int( frame_props, "crop.original_width", width );
 216                 mlt_properties_set_int( frame_props, "crop.original_height", height );
 217                 mlt_properties_set_int( frame_props, "meta.media.width", width - left - right );
 218                 mlt_properties_set_int( frame_props, "meta.media.height", height - top - bottom );
 219         }
 220         return frame;
 221 }
 222
 223 /** Constructor for the filter.
 224 */
 225
 226 mlt_filter filter_crop_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
 227 {
 228         mlt_filter filter = calloc( 1, sizeof( struct mlt_filter_s ) );
 229         if ( mlt_filter_init( filter, filter ) == 0 )
 230         {
 231                 filter->process = filter_process;
 232                 if ( arg )
 233                         mlt_properties_set_int( MLT_FILTER_PROPERTIES( filter ), "active", atoi( arg ) );
 234         }
 235         return filter;
 236 }