git.sesse.net Git - vlc/blob - modules/video_filter/seamcarving.c

   1 /*****************************************************************************
   2  * seamcarving.c: "Seam Carving for Content-Aware Image Resizing"
   3  * Based on paper by Shai Avidan and Ariel Shamir.
   4  *****************************************************************************
   5  * Copyright (C) 2007 the VideoLAN team
   6  * $Id$
   7  *
   8  * Authors: Antoine Cellerier <dionoea -at- videolan -dot- org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <vlc/vlc.h>
  34 #include <vlc_sout.h>
  35 #include <vlc_vout.h>
  36
  37 #include "vlc_filter.h"
  38
  39 #include <assert.h>
  40
  41 /*****************************************************************************
  42  * Local prototypes
  43  *****************************************************************************/
  44 static int  Create    ( vlc_object_t * );
  45 static void Destroy   ( vlc_object_t * );
  46
  47 static picture_t *Filter( filter_t *, picture_t * );
  48 static int CropCallback( vlc_object_t *, char const *,
  49                          vlc_value_t, vlc_value_t,
  50                          void * );
  51
  52 static void FilterSeamCarving( filter_t *, picture_t *, picture_t * );
  53
  54 /*****************************************************************************
  55  * Module descriptor
  56  *****************************************************************************/
  57
  58 #define FILTER_PREFIX "seamcarving-"
  59
  60 vlc_module_begin();
  61     set_description( _("Seam Carving video filter") );
  62     set_shortname( _( "Seam Carving" ));
  63     set_capability( "video filter2", 0 );
  64     set_category( CAT_VIDEO );
  65     set_subcategory( SUBCAT_VIDEO_VFILTER );
  66
  67     set_callbacks( Create, Destroy );
  68 vlc_module_end();
  69
  70 static const char *ppsz_filter_options[] = {
  71     NULL
  72 };
  73
  74 struct filter_sys_t
  75 {
  76     int *p_energy;
  77     int *p_grad;
  78
  79     int i_crop;
  80 };
  81
  82 static int Create( vlc_object_t *p_this )
  83 {
  84     filter_t *p_filter = (filter_t *)p_this;
  85
  86     /* Allocate structure */
  87     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
  88     if( p_filter->p_sys == NULL )
  89     {
  90         msg_Err( p_filter, "out of memory" );
  91         return VLC_ENOMEM;
  92     }
  93
  94     p_filter->pf_video_filter = Filter;
  95     p_filter->p_sys->p_energy = NULL;
  96     p_filter->p_sys->p_grad = NULL;
  97     p_filter->p_sys->i_crop = 0;
  98
  99     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
 100                    p_filter->p_cfg );
 101
 102     var_Create( p_filter, "crop", VLC_VAR_INTEGER|VLC_VAR_ISCOMMAND );
 103     var_AddCallback( p_filter, "crop", CropCallback, p_filter->p_sys );
 104
 105     return VLC_SUCCESS;
 106 }
 107
 108 static void Destroy( vlc_object_t *p_this )
 109 {
 110     filter_t *p_filter = (filter_t *)p_this;
 111
 112     free( p_filter->p_sys->p_energy );
 113     free( p_filter->p_sys->p_grad );
 114
 115     free( p_filter->p_sys );
 116 }
 117
 118 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 119 {
 120     picture_t *p_outpic;
 121
 122     if( !p_pic ) return NULL;
 123
 124     p_outpic = p_filter->pf_vout_buffer_new( p_filter );
 125     if( !p_outpic )
 126     {
 127         msg_Warn( p_filter, "can't get output picture" );
 128         if( p_pic->pf_release )
 129             p_pic->pf_release( p_pic );
 130         return NULL;
 131     }
 132
 133     FilterSeamCarving( p_filter, p_pic, p_outpic );
 134
 135     p_outpic->date = p_pic->date;
 136     p_outpic->b_force = p_pic->b_force;
 137     p_outpic->i_nb_fields = p_pic->i_nb_fields;
 138     p_outpic->b_progressive = p_pic->b_progressive;
 139     p_outpic->b_top_field_first = p_pic->b_top_field_first;
 140
 141     if( p_pic->pf_release )
 142         p_pic->pf_release( p_pic );
 143
 144     return p_outpic;
 145 }
 146
 147 static inline int my_min3( int a, int b, int c );
 148 static inline int my_min( int a, int b );
 149 static int RemoveVerticalSeam( filter_t *p_filter, picture_t *p_inpic, picture_t *p_outpic, int i_src_visible );
 150
 151 //#define DRAW_GRADIENT
 152 //#define DRAW_ENERGY
 153 //#define DRAW_SEAM
 154
 155 static void FilterSeamCarving( filter_t *p_filter, picture_t *p_inpic,
 156                                                 picture_t *p_outpic )
 157 {
 158     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 159     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 160
 161     int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 162
 163     if( !p_filter->p_sys->p_energy )
 164         p_filter->p_sys->p_energy = (int*)malloc(i_src_pitch * i_num_lines * sizeof(int));
 165     if( !p_filter->p_sys->p_grad )
 166         p_filter->p_sys->p_grad = (int*)malloc(i_src_pitch * i_num_lines * sizeof(int));
 167
 168 //#if defined( DRAW_GRADIENT ) || defined( DRAW_ENERGY ) || defined( DRAW_SEAM )
 169     vlc_memcpy( p_outpic->p[Y_PLANE].p_pixels, p_inpic->p[Y_PLANE].p_pixels,
 170         p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 171 //#else
 172 //    vlc_memset( p_outpix, 0x80,
 173 //        p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 174 //#endif
 175     vlc_memset( p_outpic->p[U_PLANE].p_pixels, 0x80,
 176         p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 177     vlc_memset( p_outpic->p[V_PLANE].p_pixels, 0x80,
 178         p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 179
 180 #if defined( DRAW_GRADIENT ) || defined( DRAW_ENERGY ) || defined( DRAW_SEAM )
 181     i_src_visible = RemoveVerticalSeam( p_filter, p_outpic, p_outpic, i_src_visible );
 182 #else
 183     static int j = 1;
 184     static int k = 1;
 185     int i;
 186     if( p_filter->p_sys->i_crop != 0 )
 187         j = p_filter->p_sys->i_crop;
 188     for( i = 0; i < j; i++ )
 189     i_src_visible = RemoveVerticalSeam( p_filter, p_outpic, p_outpic, i_src_visible );
 190     int y;
 191     for( y = 0; y < p_outpic->p[Y_PLANE].i_lines; y++ )
 192         vlc_memset( p_outpic->p[Y_PLANE].p_pixels + y*p_outpic->p[Y_PLANE].i_pitch + i_src_visible, 0x00, p_outpic->p[Y_PLANE].i_pitch - i_src_visible );
 193     j += k;
 194     if( j == 100 ) k = -1;
 195     if( j == 1 ) k = 1;
 196 #endif
 197 }
 198
 199 static int ComputeGradient( filter_t *p_filter, picture_t *p_inpic, int i_src_visible )
 200 {
 201     int x, y;
 202     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 203     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 204
 205     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 206     int *p_grad = p_filter->p_sys->p_grad;
 207
 208     for( y = 1; y < i_num_lines - 1;
 209          y++, p_grad += i_src_pitch )
 210     {
 211         /* Compute line y's gradient */
 212 #define GRADx( x ) \
 213             ( \
 214               abs( \
 215                  ( p_inpix[(y-1)*i_src_pitch+x-1] \
 216                    - p_inpix[(y+1)*i_src_pitch+x-1] ) \
 217                + ( ( p_inpix[(y-1)*i_src_pitch+x] \
 218                     - p_inpix[(y+1)*i_src_pitch+x] ) <<1 ) \
 219                + ( p_inpix[(y-1)*i_src_pitch+x+1] \
 220                    - p_inpix[(y+1)*i_src_pitch+x+1] ) \
 221               ) \
 222             + \
 223               abs( \
 224                  ( p_inpix[(y-1)*i_src_pitch+x-1] \
 225                    - p_inpix[(y-1)*i_src_pitch+x+1] ) \
 226                + ( ( p_inpix[y*i_src_pitch+x-1] \
 227                     - p_inpix[y*i_src_pitch+x+1] ) <<1 ) \
 228                + ( p_inpix[(y+1)*i_src_pitch+x-1] \
 229                    - p_inpix[(y+1)*i_src_pitch+x+1] ) \
 230               ) \
 231             )
 232         for( x = 1; x < i_src_visible - 1; x++ )
 233         {
 234             p_grad[x] = GRADx( x );
 235 #ifdef DRAW_GRADIENT
 236             p_outpix[y*i_src_pitch+x] = p_grad[x]>>3;
 237 #endif
 238         }
 239     }
 240     return 0;
 241 }
 242
 243 static int RemoveVerticalSeam( filter_t *p_filter, picture_t *p_inpic, picture_t *p_outpic, int i_src_visible )
 244 {
 245     int x, y;
 246     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 247     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 248
 249     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
 250
 251     int *p_energy = p_filter->p_sys->p_energy;
 252     int *p_grad = p_filter->p_sys->p_grad;
 253
 254     ComputeGradient( p_filter, p_inpic, i_src_visible );
 255
 256     /** Compute the image's energy (using a sobel gradient as the base energy
 257      ** function) */
 258     /* Set the first energy line to 0 */
 259     memset( p_energy, 0, i_src_pitch*sizeof(int));
 260
 261     int *p_energy_prev = p_energy;
 262     for( y = 1; y < i_num_lines - 1;
 263          y++, p_energy_prev = p_energy, p_energy += i_src_pitch,
 264          p_grad += i_src_pitch )
 265     {
 266         /* Compute line y's minimum energy value for paths ending on
 267          * each x */
 268         x = 1;
 269         p_energy[x] = my_min( p_energy_prev[x  ]+p_grad[x  ],
 270                            p_energy_prev[x+1]+p_grad[x+1] );
 271         for( x = 2; x < i_src_visible - 2; x++ )
 272         {
 273             p_energy[x] = my_min3( p_energy_prev[x-1]+p_grad[x-1],
 274                                 p_energy_prev[x  ]+p_grad[x  ],
 275                                 p_energy_prev[x+1]+p_grad[x+1] );
 276         }
 277         p_energy[x] = my_min( p_energy_prev[x-1]+p_grad[x-1],
 278                            p_energy_prev[x  ]+p_grad[x  ] );
 279
 280 #ifdef DRAW_ENERGY
 281         int max = p_energy[1];
 282         for( x = 1; x < i_src_visible - 1; x++ )
 283             if( p_energy[x] > max ) max = p_energy[x];
 284         for( x = 1; x < i_src_visible - 1; x++ )
 285             p_outpix[y*i_src_pitch+x] = p_energy[x]*0xff/max;
 286 #endif
 287     }
 288
 289     /* Find the minimum energy point on the last line */
 290     y--;
 291     p_energy -= i_src_pitch;
 292     p_grad -= i_src_pitch;
 293
 294     int m = p_energy[1];
 295     int xmin = 1;
 296     for( x = 1; x < i_src_visible - 1; x++ )
 297     {
 298         if( p_energy[x] < m )
 299         {
 300             m = p_energy[x];
 301             xmin = x;
 302         }
 303     }
 304
 305 #ifdef DRAW_SEAM
 306     p_outpix[y*i_src_pitch+xmin] = 0xff;
 307     p_outpix[(y+1)*i_src_pitch+xmin] = 0xff;
 308 #else
 309     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 310     memmove( p_outpix+(y+1)*i_src_pitch+xmin, p_outpix+(y+1)*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 311 #endif
 312
 313     p_energy -= i_src_pitch;
 314     for( ; y>1; y--, p_energy -= i_src_pitch, p_grad -= i_src_pitch )
 315     {
 316         if( m != p_energy[xmin]+p_grad[xmin] )
 317         {
 318             if( xmin > 1 && m == p_energy[xmin-1]+p_grad[xmin-1] )
 319             {
 320                 xmin--;
 321             }
 322             else if( xmin < i_src_visible - 2 && m == p_energy[xmin+1]+p_grad[xmin+1] )
 323             {
 324                 xmin++;
 325             }
 326             else
 327             {
 328                 printf("Alarm! %d\n" ,y);
 329                 //assert( 0 );
 330             }
 331         }
 332         m = p_energy[xmin];
 333 #ifdef DRAW_SEAM
 334         p_outpix[y*i_src_pitch+xmin] = 0xff;
 335 #else
 336         memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 337 #endif
 338     }
 339 #ifdef DRAW_SEAM
 340     p_outpix[y*i_src_pitch+xmin] = 0xff;
 341 #else
 342     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 343 #endif
 344     y--;
 345 #ifdef DRAW_SEAM
 346     p_outpix[y*i_src_pitch+xmin] = 0xff;
 347 #else
 348     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 349 #endif
 350
 351 #if defined( DRAW_SEAM )
 352     return i_src_visible;
 353 #else
 354     return i_src_visible-1;
 355 #endif
 356 }
 357
 358 static inline int my_min3( int a, int b, int c )
 359 {
 360     if( a < b )
 361     {
 362         if( a < c ) return a;
 363         return c;
 364     }
 365     if( b < c ) return b;
 366     return c;
 367 }
 368 static inline int my_min( int a, int b )
 369 {
 370     return a < b ? a : b;
 371 }
 372
 373 static int CropCallback( vlc_object_t *p_this, char const *psz_var,
 374                                 vlc_value_t oldval, vlc_value_t newval,
 375                                 void *p_data )
 376 {
 377     VLC_UNUSED(p_this); VLC_UNUSED(psz_var); VLC_UNUSED(oldval);
 378     filter_sys_t *p_sys = (filter_sys_t *)p_data;
 379     p_sys->i_crop = newval.i_int;
 380     return VLC_SUCCESS;
 381 }