modules/video_filter/erase.c

   1 /*****************************************************************************
   2  * erase.c : logo erase video filter
   3  *****************************************************************************
   4  * Copyright (C) 2007 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Antoine Cellerier <dionoea -at- videolan -dot- org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_sout.h>
  35 #include <vlc_image.h>
  36 #include <vlc_filter.h>
  37 #include <vlc_picture.h>
  38 #include <vlc_url.h>
  39 #include "filter_picture.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 void FilterErase( filter_t *, picture_t *, picture_t * );
  49 static int EraseCallback( vlc_object_t *, char const *,
  50                           vlc_value_t, vlc_value_t, void * );
  51
  52 /*****************************************************************************
  53  * Module descriptor
  54  *****************************************************************************/
  55 #define MASK_TEXT N_("Image mask")
  56 #define MASK_LONGTEXT N_("Image mask. Pixels with an alpha value greater than 50% will be erased.")
  57
  58 #define POSX_TEXT N_("X coordinate")
  59 #define POSX_LONGTEXT N_("X coordinate of the mask.")
  60 #define POSY_TEXT N_("Y coordinate")
  61 #define POSY_LONGTEXT N_("Y coordinate of the mask.")
  62
  63 #define ERASE_HELP N_("Remove zones of the video using a picture as mask")
  64
  65 #define CFG_PREFIX "erase-"
  66
  67 vlc_module_begin ()
  68     set_description( N_("Erase video filter") )
  69     set_shortname( N_( "Erase" ))
  70     set_capability( "video filter", 0 )
  71     set_help(ERASE_HELP)
  72     set_category( CAT_VIDEO )
  73     set_subcategory( SUBCAT_VIDEO_VFILTER )
  74
  75     add_loadfile( CFG_PREFIX "mask", NULL,
  76                   MASK_TEXT, MASK_LONGTEXT, false )
  77     add_integer( CFG_PREFIX "x", 0, POSX_TEXT, POSX_LONGTEXT, false )
  78     add_integer( CFG_PREFIX "y", 0, POSY_TEXT, POSY_LONGTEXT, false )
  79
  80     add_shortcut( "erase" )
  81     set_callbacks( Create, Destroy )
  82 vlc_module_end ()
  83
  84 static const char *const ppsz_filter_options[] = {
  85     "mask", "x", "y", NULL
  86 };
  87
  88 /*****************************************************************************
  89  * filter_sys_t
  90  *****************************************************************************/
  91 struct filter_sys_t
  92 {
  93     int i_x;
  94     int i_y;
  95     picture_t *p_mask;
  96     vlc_mutex_t lock;
  97 };
  98
  99 static void LoadMask( filter_t *p_filter, const char *psz_filename )
 100 {
 101     image_handler_t *p_image;
 102     video_format_t fmt_in, fmt_out;
 103     picture_t *p_old_mask = p_filter->p_sys->p_mask;
 104     video_format_Init( &fmt_in, 0 );
 105     video_format_Init( &fmt_out, VLC_CODEC_YUVA );
 106     p_image = image_HandlerCreate( p_filter );
 107     char *psz_url = vlc_path2uri( psz_filename, NULL );
 108     p_filter->p_sys->p_mask =
 109         image_ReadUrl( p_image, psz_url, &fmt_in, &fmt_out );
 110     free( psz_url );
 111     video_format_Clean( &fmt_in );
 112     video_format_Clean( &fmt_out );
 113     if( p_filter->p_sys->p_mask )
 114     {
 115         if( p_old_mask )
 116             picture_Release( p_old_mask );
 117     }
 118     else if( p_old_mask )
 119     {
 120         p_filter->p_sys->p_mask = p_old_mask;
 121         msg_Err( p_filter, "Error while loading new mask. Keeping old mask." );
 122     }
 123     else
 124         msg_Err( p_filter, "Error while loading new mask. No mask available." );
 125
 126     image_HandlerDelete( p_image );
 127 }
 128
 129 /*****************************************************************************
 130  * Create
 131  *****************************************************************************/
 132 static int Create( vlc_object_t *p_this )
 133 {
 134     filter_t *p_filter = (filter_t *)p_this;
 135     filter_sys_t *p_sys;
 136     char *psz_filename;
 137
 138     switch( p_filter->fmt_in.video.i_chroma )
 139     {
 140         case VLC_CODEC_I420:
 141         case VLC_CODEC_J420:
 142         case VLC_CODEC_YV12:
 143
 144         case VLC_CODEC_I422:
 145         case VLC_CODEC_J422:
 146             break;
 147
 148         default:
 149             msg_Err( p_filter, "Unsupported input chroma (%4.4s)",
 150                      (char*)&(p_filter->fmt_in.video.i_chroma) );
 151             return VLC_EGENERIC;
 152     }
 153
 154     /* Allocate structure */
 155     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 156     if( p_filter->p_sys == NULL )
 157         return VLC_ENOMEM;
 158     p_sys = p_filter->p_sys;
 159
 160     p_filter->pf_video_filter = Filter;
 161
 162     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
 163                        p_filter->p_cfg );
 164
 165     psz_filename =
 166         var_CreateGetNonEmptyStringCommand( p_filter, CFG_PREFIX "mask" );
 167
 168     if( !psz_filename )
 169     {
 170         msg_Err( p_filter, "Missing 'mask' option value." );
 171         free( p_sys );
 172         return VLC_EGENERIC;
 173     }
 174
 175     p_sys->p_mask = NULL;
 176     LoadMask( p_filter, psz_filename );
 177     free( psz_filename );
 178
 179     p_sys->i_x = var_CreateGetIntegerCommand( p_filter, CFG_PREFIX "x" );
 180     p_sys->i_y = var_CreateGetIntegerCommand( p_filter, CFG_PREFIX "y" );
 181
 182     vlc_mutex_init( &p_sys->lock );
 183     var_AddCallback( p_filter, CFG_PREFIX "x", EraseCallback, p_sys );
 184     var_AddCallback( p_filter, CFG_PREFIX "y", EraseCallback, p_sys );
 185     var_AddCallback( p_filter, CFG_PREFIX "mask", EraseCallback, p_sys );
 186
 187     return VLC_SUCCESS;
 188 }
 189
 190 /*****************************************************************************
 191  * Destroy
 192  *****************************************************************************/
 193 static void Destroy( vlc_object_t *p_this )
 194 {
 195     filter_t *p_filter = (filter_t *)p_this;
 196     filter_sys_t *p_sys = p_filter->p_sys;
 197     if( p_sys->p_mask )
 198         picture_Release( p_sys->p_mask );
 199
 200     var_DelCallback( p_filter, CFG_PREFIX "x", EraseCallback, p_sys );
 201     var_DelCallback( p_filter, CFG_PREFIX "y", EraseCallback, p_sys );
 202     var_DelCallback( p_filter, CFG_PREFIX "mask", EraseCallback, p_sys );
 203     vlc_mutex_destroy( &p_sys->lock );
 204
 205     free( p_filter->p_sys );
 206 }
 207
 208 /*****************************************************************************
 209  * Filter
 210  *****************************************************************************/
 211 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 212 {
 213     picture_t *p_outpic;
 214     filter_sys_t *p_sys = p_filter->p_sys;
 215
 216     if( !p_pic ) return NULL;
 217
 218     p_outpic = filter_NewPicture( p_filter );
 219     if( !p_outpic )
 220     {
 221         picture_Release( p_pic );
 222         return NULL;
 223     }
 224
 225     /* If the mask is empty: just copy the image */
 226     vlc_mutex_lock( &p_sys->lock );
 227     if( p_sys->p_mask )
 228         FilterErase( p_filter, p_pic, p_outpic );
 229     else
 230         picture_CopyPixels( p_outpic, p_pic );
 231     vlc_mutex_unlock( &p_sys->lock );
 232
 233     return CopyInfoAndRelease( p_outpic, p_pic );
 234 }
 235
 236 /*****************************************************************************
 237  * FilterErase
 238  *****************************************************************************/
 239 static void FilterErase( filter_t *p_filter, picture_t *p_inpic,
 240                                              picture_t *p_outpic )
 241 {
 242     filter_sys_t *p_sys = p_filter->p_sys;
 243
 244     const int i_mask_pitch = p_sys->p_mask->A_PITCH;
 245     const int i_mask_visible_pitch = p_sys->p_mask->p[A_PLANE].i_visible_pitch;
 246     const int i_mask_visible_lines = p_sys->p_mask->p[A_PLANE].i_visible_lines;
 247
 248     for( int i_plane = 0; i_plane < p_inpic->i_planes; i_plane++ )
 249     {
 250         const int i_pitch = p_outpic->p[i_plane].i_pitch;
 251         const int i_2pitch = i_pitch<<1;
 252         const int i_visible_pitch = p_inpic->p[i_plane].i_visible_pitch;
 253         const int i_visible_lines = p_inpic->p[i_plane].i_visible_lines;
 254
 255         uint8_t *p_mask = p_sys->p_mask->A_PIXELS;
 256         int i_x = p_sys->i_x, i_y = p_sys->i_y;
 257
 258         int i_height = i_mask_visible_lines;
 259         int i_width  = i_mask_visible_pitch;
 260
 261         const bool b_line_factor = ( i_plane /* U_PLANE or V_PLANE */ &&
 262             !( p_inpic->format.i_chroma == VLC_CODEC_I422
 263             || p_inpic->format.i_chroma == VLC_CODEC_J422 ) );
 264
 265         if( i_plane ) /* U_PLANE or V_PLANE */
 266         {
 267             i_width  >>= 1;
 268             i_x      >>= 1;
 269         }
 270         if( b_line_factor )
 271         {
 272             i_height >>= 1;
 273             i_y      >>= 1;
 274         }
 275         i_height = __MIN( i_visible_lines - i_y, i_height );
 276         i_width  = __MIN( i_visible_pitch - i_x, i_width  );
 277
 278         /* Copy original pixel buffer */
 279         plane_CopyPixels( &p_outpic->p[i_plane], &p_inpic->p[i_plane] );
 280
 281         /* Horizontal linear interpolation of masked areas */
 282         uint8_t *p_outpix = p_outpic->p[i_plane].p_pixels + i_y*i_pitch + i_x;
 283         for( int y = 0; y < i_height;
 284              y++, p_mask += i_mask_pitch, p_outpix += i_pitch )
 285         {
 286             uint8_t prev, next = 0;
 287             int prev_x = -1, next_x = -2;
 288             int quot = 0;
 289
 290             /* Find a suitable value for the previous color to use when
 291              * interpoling a masked pixel's value */
 292             if( i_x )
 293             {
 294                 /* There are pixels before current position on the same line.
 295                  * Use those */
 296                 prev = *(p_outpix-1);
 297             }
 298             else if( y || i_y )
 299             {
 300                 /* This is the first pixel on a line but there other lines
 301                  * above us. Use the pixel right above */
 302                 prev = *(p_outpix-i_pitch);
 303             }
 304             else
 305             {
 306                 /* We're in the upper left corner. This sucks. We can't use
 307                  * any previous value, so we'll use a dummy one. In most
 308                  * cases this dummy value will be fixed later on in the
 309                  * algorithm */
 310                 prev = 0xff;
 311             }
 312
 313             for( int x = 0; x < i_width; x++ )
 314             {
 315                 if( p_mask[i_plane?x<<1:x] > 127 )
 316                 {
 317                     /* This is a masked pixel */
 318                     if( next_x <= prev_x )
 319                     {
 320                         int x0;
 321                         /* Look for the next non masked pixel on the same
 322                          * line (inside the mask's bounding box) */
 323                         for( x0 = x; x0 < i_width; x0++ )
 324                         {
 325                             if( p_mask[i_plane?x0<<1:x0] <= 127 )
 326                             {
 327                                 /* We found an unmasked pixel. Victory! */
 328                                 next_x = x0;
 329                                 next = p_outpix[x0];
 330                                 break;
 331                             }
 332                         }
 333                         if( next_x <= prev_x )
 334                         {
 335                             /* We didn't find an unmasked pixel yet. Try
 336                              * harder */
 337                             if( x0 == x ) x0++;
 338                             if( x0 < i_visible_pitch )
 339                             {
 340                                 /* If we didn't find a non masked pixel on the
 341                                  * same line inside the mask's bounding box,
 342                                  * use the next pixel on the line (except if
 343                                  * it doesn't exist) */
 344                                 next_x = x0;
 345                                 next = p_outpix[x0];
 346                             }
 347                             else
 348                             {
 349                                 /* The last pixel on the line is masked,
 350                                  * so we'll use the "prev" value. A better
 351                                  * approach would be to use unmasked pixels
 352                                  * at the end of adjacent lines */
 353                                 next_x = x0;
 354                                 next = prev;
 355                             }
 356                         }
 357                         if( !( i_x || y || i_y ) )
 358                             /* We were unable to find a suitable value for
 359                              * the previous color (which means that we are
 360                              * on the first line in the upper left corner)
 361                              */
 362                             prev = next;
 363
 364                         /* Divide only once instead of next_x-prev_x-1 times */
 365                         quot = ((next-prev)<<16)/(next_x-prev_x);
 366                     }
 367                     /* Interpolate new value, and round correctly */
 368                     p_outpix[x] = prev + (((x-prev_x)*quot+(1<<16))>>16);
 369                 }
 370                 else
 371                 {
 372                     /* This pixel isn't masked. It's thus suitable as a
 373                      * previous color for the next interpolation */
 374                     prev = p_outpix[x];
 375                     prev_x = x;
 376                 }
 377             }
 378         }
 379
 380         /* Vertical bluring */
 381         p_mask = p_sys->p_mask->A_PIXELS;
 382         i_height = b_line_factor ? i_mask_visible_lines>>1
 383                                  : i_mask_visible_lines;
 384         /* Make sure that we stop at least 2 lines before the picture's end
 385          * (since our bluring algorithm uses the 2 next lines) */
 386         i_height = __MIN( i_visible_lines - i_y - 2, i_height );
 387         /* Make sure that we start at least 2 lines from the top (since our
 388          * bluring algorithm uses the 2 previous lines) */
 389         int y = __MAX(i_y,2);
 390         p_outpix = p_outpic->p[i_plane].p_pixels + (i_y+y)*i_pitch + i_x;
 391         for( ; y < i_height; y++, p_mask += i_mask_pitch, p_outpix += i_pitch )
 392         {
 393             for( int x = 0; x < i_width; x++ )
 394             {
 395                 if( p_mask[i_plane?x<<1:x] > 127 )
 396                 {
 397                     /* Ugly bluring function */
 398                     p_outpix[x] =
 399                         ( (p_outpix[x-i_2pitch]<<1)       /* 2 */
 400                         + (p_outpix[x-i_pitch ]<<2)       /* 4 */
 401                         + (p_outpix[x         ]<<2)       /* 4 */
 402                         + (p_outpix[x+i_pitch ]<<2)       /* 4 */
 403                         + (p_outpix[x+i_2pitch]<<1) )>>4; /* 2 */
 404                 }
 405             }
 406         }
 407     }
 408 }
 409
 410 static int EraseCallback( vlc_object_t *p_this, char const *psz_var,
 411                           vlc_value_t oldval, vlc_value_t newval, void *p_data )
 412 {
 413     VLC_UNUSED(oldval);
 414     filter_sys_t *p_sys = (filter_sys_t *)p_data;
 415
 416     if( !strcmp( psz_var, CFG_PREFIX "x" ) )
 417     {
 418         vlc_mutex_lock( &p_sys->lock );
 419         p_sys->i_x = newval.i_int;
 420         vlc_mutex_unlock( &p_sys->lock );
 421     }
 422     else if( !strcmp( psz_var, CFG_PREFIX "y" ) )
 423     {
 424         vlc_mutex_lock( &p_sys->lock );
 425         p_sys->i_y = newval.i_int;
 426         vlc_mutex_unlock( &p_sys->lock );
 427     }
 428     else if( !strcmp( psz_var, CFG_PREFIX "mask" ) )
 429     {
 430         vlc_mutex_lock( &p_sys->lock );
 431         LoadMask( (filter_t*)p_this, newval.psz_string );
 432         vlc_mutex_unlock( &p_sys->lock );
 433     }
 434     else
 435     {
 436         msg_Warn( p_this, "Unknown callback command." );
 437     }
 438     return VLC_SUCCESS;
 439 }