modules/video_filter/erase.c

   1 /*****************************************************************************
   2  * erase.c : logo erase video filter
   3  *****************************************************************************
   4  * Copyright (C) 2007 the VideoLAN team
   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
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 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 General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, 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
  37 #include <vlc_filter.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 filter2", 0 )
  71     set_help(ERASE_HELP)
  72     set_category( CAT_VIDEO )
  73     set_subcategory( SUBCAT_VIDEO_VFILTER )
  74
  75     add_file( CFG_PREFIX "mask", NULL, NULL,
  76               MASK_TEXT, MASK_LONGTEXT, false )
  77     add_integer( CFG_PREFIX "x", 0, NULL, POSX_TEXT, POSX_LONGTEXT, false )
  78     add_integer( CFG_PREFIX "y", 0, NULL, 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     memset( &fmt_in, 0, sizeof( video_format_t ) );
 105     memset( &fmt_out, 0, sizeof( video_format_t ) );
 106     fmt_out.i_chroma = VLC_CODEC_YUVA;
 107     p_image = image_HandlerCreate( p_filter );
 108     char *psz_url = make_URI( psz_filename, NULL );
 109     p_filter->p_sys->p_mask =
 110         image_ReadUrl( p_image, psz_url, &fmt_in, &fmt_out );
 111     free( psz_url );
 112     if( p_filter->p_sys->p_mask )
 113     {
 114         if( p_old_mask )
 115             picture_Release( p_old_mask );
 116     }
 117     else if( p_old_mask )
 118     {
 119         p_filter->p_sys->p_mask = p_old_mask;
 120         msg_Err( p_filter, "Error while loading new mask. Keeping old mask." );
 121     }
 122     else
 123         msg_Err( p_filter, "Error while loading new mask. No mask available." );
 124
 125     image_HandlerDelete( p_image );
 126 }
 127
 128 /*****************************************************************************
 129  * Create
 130  *****************************************************************************/
 131 static int Create( vlc_object_t *p_this )
 132 {
 133     filter_t *p_filter = (filter_t *)p_this;
 134     filter_sys_t *p_sys;
 135     char *psz_filename;
 136
 137     switch( p_filter->fmt_in.video.i_chroma )
 138     {
 139         case VLC_CODEC_I420:
 140         case VLC_CODEC_J420:
 141         case VLC_CODEC_YV12:
 142
 143         case VLC_CODEC_I422:
 144         case VLC_CODEC_J422:
 145             break;
 146
 147         default:
 148             msg_Err( p_filter, "Unsupported input chroma (%4.4s)",
 149                      (char*)&(p_filter->fmt_in.video.i_chroma) );
 150             return VLC_EGENERIC;
 151     }
 152
 153     /* Allocate structure */
 154     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 155     if( p_filter->p_sys == NULL )
 156         return VLC_ENOMEM;
 157     p_sys = p_filter->p_sys;
 158
 159     p_filter->pf_video_filter = Filter;
 160
 161     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
 162                        p_filter->p_cfg );
 163
 164     psz_filename =
 165         var_CreateGetNonEmptyStringCommand( p_filter, CFG_PREFIX "mask" );
 166
 167     if( !psz_filename )
 168     {
 169         msg_Err( p_filter, "Missing 'mask' option value." );
 170         free( p_sys );
 171         return VLC_EGENERIC;
 172     }
 173
 174     p_sys->p_mask = NULL;
 175     LoadMask( p_filter, psz_filename );
 176     free( psz_filename );
 177
 178     p_sys->i_x = var_CreateGetIntegerCommand( p_filter, CFG_PREFIX "x" );
 179     p_sys->i_y = var_CreateGetIntegerCommand( p_filter, CFG_PREFIX "y" );
 180
 181     vlc_mutex_init( &p_sys->lock );
 182     var_AddCallback( p_filter, CFG_PREFIX "x", EraseCallback, p_sys );
 183     var_AddCallback( p_filter, CFG_PREFIX "y", EraseCallback, p_sys );
 184     var_AddCallback( p_filter, CFG_PREFIX "mask", EraseCallback, p_sys );
 185
 186     return VLC_SUCCESS;
 187 }
 188
 189 /*****************************************************************************
 190  * Destroy
 191  *****************************************************************************/
 192 static void Destroy( vlc_object_t *p_this )
 193 {
 194     filter_t *p_filter = (filter_t *)p_this;
 195     filter_sys_t *p_sys = p_filter->p_sys;
 196     if( p_sys->p_mask )
 197         picture_Release( p_sys->p_mask );
 198
 199     var_DelCallback( p_filter, CFG_PREFIX "x", EraseCallback, p_sys );
 200     var_DelCallback( p_filter, CFG_PREFIX "y", EraseCallback, p_sys );
 201     var_DelCallback( p_filter, CFG_PREFIX "mask", EraseCallback, p_sys );
 202     vlc_mutex_destroy( &p_sys->lock );
 203
 204     free( p_filter->p_sys );
 205 }
 206
 207 /*****************************************************************************
 208  * Filter
 209  *****************************************************************************/
 210 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 211 {
 212     picture_t *p_outpic;
 213     filter_sys_t *p_sys = p_filter->p_sys;
 214
 215     if( !p_pic ) return NULL;
 216
 217     p_outpic = filter_NewPicture( p_filter );
 218     if( !p_outpic )
 219     {
 220         picture_Release( p_pic );
 221         return NULL;
 222     }
 223
 224     /* If the mask is empty: just copy the image */
 225     vlc_mutex_lock( &p_sys->lock );
 226     if( p_sys->p_mask )
 227         FilterErase( p_filter, p_pic, p_outpic );
 228     else
 229         picture_CopyPixels( p_outpic, p_pic );
 230     vlc_mutex_unlock( &p_sys->lock );
 231
 232     return CopyInfoAndRelease( p_outpic, p_pic );
 233 }
 234
 235 /*****************************************************************************
 236  * FilterErase
 237  *****************************************************************************/
 238 static void FilterErase( filter_t *p_filter, picture_t *p_inpic,
 239                                              picture_t *p_outpic )
 240 {
 241     filter_sys_t *p_sys = p_filter->p_sys;
 242
 243     const int i_mask_pitch = p_sys->p_mask->A_PITCH;
 244     const int i_mask_visible_pitch = p_sys->p_mask->p[A_PLANE].i_visible_pitch;
 245     const int i_mask_visible_lines = p_sys->p_mask->p[A_PLANE].i_visible_lines;
 246
 247     for( int i_plane = 0; i_plane < p_inpic->i_planes; i_plane++ )
 248     {
 249         const int i_pitch = p_inpic->p[i_plane].i_pitch;
 250         const int i_2pitch = i_pitch<<1;
 251         const int i_visible_pitch = p_inpic->p[i_plane].i_visible_pitch;
 252         const int i_lines = p_inpic->p[i_plane].i_lines;
 253         const int i_visible_lines = p_inpic->p[i_plane].i_visible_lines;
 254
 255         uint8_t *p_inpix = p_inpic->p[i_plane].p_pixels;
 256         uint8_t *p_outpix = p_outpic->p[i_plane].p_pixels;
 257         uint8_t *p_mask = p_sys->p_mask->A_PIXELS;
 258         int i_x = p_sys->i_x, i_y = p_sys->i_y;
 259
 260         int x, y;
 261         int i_height = i_mask_visible_lines;
 262         int i_width  = i_mask_visible_pitch;
 263
 264         const bool b_line_factor = ( i_plane /* U_PLANE or V_PLANE */ &&
 265             !( p_inpic->format.i_chroma == VLC_CODEC_I422
 266             || p_inpic->format.i_chroma == VLC_CODEC_J422 ) );
 267
 268         if( i_plane ) /* U_PLANE or V_PLANE */
 269         {
 270             i_width  >>= 1;
 271             i_x      >>= 1;
 272         }
 273         if( b_line_factor )
 274         {
 275             i_height >>= 1;
 276             i_y      >>= 1;
 277         }
 278         i_height = __MIN( i_visible_lines - i_y, i_height );
 279         i_width  = __MIN( i_visible_pitch - i_x, i_width  );
 280
 281         /* Copy original pixel buffer */
 282         vlc_memcpy( p_outpix, p_inpix, i_pitch * i_lines );
 283
 284         /* Horizontal linear interpolation of masked areas */
 285         p_outpix = p_outpic->p[i_plane].p_pixels + i_y*i_pitch + i_x;
 286         for( y = 0; y < i_height;
 287              y++, p_mask += i_mask_pitch, p_outpix += i_pitch )
 288         {
 289             uint8_t prev, next = 0;
 290             int prev_x = -1, next_x = -2;
 291             int quot = 0;
 292
 293             /* Find a suitable value for the previous color to use when
 294              * interpoling a masked pixel's value */
 295             if( i_x )
 296             {
 297                 /* There are pixels before current position on the same line.
 298                  * Use those */
 299                 prev = *(p_outpix-1);
 300             }
 301             else if( y || i_y )
 302             {
 303                 /* This is the first pixel on a line but there other lines
 304                  * above us. Use the pixel right above */
 305                 prev = *(p_outpix-i_pitch);
 306             }
 307             else
 308             {
 309                 /* We're in the upper left corner. This sucks. We can't use
 310                  * any previous value, so we'll use a dummy one. In most
 311                  * cases this dummy value will be fixed later on in the
 312                  * algorithm */
 313                 prev = 0xff;
 314             }
 315
 316             for( x = 0; x < i_width; x++ )
 317             {
 318                 if( p_mask[i_plane?x<<1:x] > 127 )
 319                 {
 320                     /* This is a masked pixel */
 321                     if( next_x <= prev_x )
 322                     {
 323                         int x0;
 324                         /* Look for the next non masked pixel on the same
 325                          * line (inside the mask's bounding box) */
 326                         for( x0 = x; x0 < i_width; x0++ )
 327                         {
 328                             if( p_mask[i_plane?x0<<1:x0] <= 127 )
 329                             {
 330                                 /* We found an unmasked pixel. Victory! */
 331                                 next_x = x0;
 332                                 next = p_outpix[x0];
 333                                 break;
 334                             }
 335                         }
 336                         if( next_x <= prev_x )
 337                         {
 338                             /* We didn't find an unmasked pixel yet. Try
 339                              * harder */
 340                             if( x0 == x ) x0++;
 341                             if( x0 < i_visible_pitch )
 342                             {
 343                                 /* If we didn't find a non masked pixel on the
 344                                  * same line inside the mask's bounding box,
 345                                  * use the next pixel on the line (except if
 346                                  * it doesn't exist) */
 347                                 next_x = x0;
 348                                 next = p_outpix[x0];
 349                             }
 350                             else
 351                             {
 352                                 /* The last pixel on the line is masked,
 353                                  * so we'll use the "prev" value. A better
 354                                  * approach would be to use unmasked pixels
 355                                  * at the end of adjacent lines */
 356                                 next_x = x0;
 357                                 next = prev;
 358                             }
 359                         }
 360                         if( !( i_x || y || i_y ) )
 361                             /* We were unable to find a suitable value for
 362                              * the previous color (which means that we are
 363                              * on the first line in the upper left corner)
 364                              */
 365                             prev = next;
 366
 367                         /* Divide only once instead of next_x-prev_x-1 times */
 368                         quot = ((next-prev)<<16)/(next_x-prev_x);
 369                     }
 370                     /* Interpolate new value, and round correctly */
 371                     p_outpix[x] = prev + (((x-prev_x)*quot+(1<<16))>>16);
 372                 }
 373                 else
 374                 {
 375                     /* This pixel isn't masked. It's thus suitable as a
 376                      * previous color for the next interpolation */
 377                     prev = p_outpix[x];
 378                     prev_x = x;
 379                 }
 380             }
 381         }
 382
 383         /* Vertical bluring */
 384         p_mask = p_sys->p_mask->A_PIXELS;
 385         i_height = b_line_factor ? i_mask_visible_lines>>1
 386                                  : i_mask_visible_lines;
 387         /* Make sure that we stop at least 2 lines before the picture's end
 388          * (since our bluring algorithm uses the 2 next lines) */
 389         i_height = __MIN( i_visible_lines - i_y - 2, i_height );
 390         /* Make sure that we start at least 2 lines from the top (since our
 391          * bluring algorithm uses the 2 previous lines) */
 392         y = __MAX(i_y,2);
 393         p_outpix = p_outpic->p[i_plane].p_pixels + (i_y+y)*i_pitch + i_x;
 394         for( ; y < i_height; y++, p_mask += i_mask_pitch, p_outpix += i_pitch )
 395         {
 396             for( x = 0; x < i_width; x++ )
 397             {
 398                 if( p_mask[i_plane?x<<1:x] > 127 )
 399                 {
 400                     /* Ugly bluring function */
 401                     p_outpix[x] =
 402                         ( (p_outpix[x-i_2pitch]<<1)       /* 2 */
 403                         + (p_outpix[x-i_pitch ]<<2)       /* 4 */
 404                         + (p_outpix[x         ]<<2)       /* 4 */
 405                         + (p_outpix[x+i_pitch ]<<2)       /* 4 */
 406                         + (p_outpix[x+i_2pitch]<<1) )>>4; /* 2 */
 407                 }
 408             }
 409         }
 410     }
 411 }
 412
 413 static int EraseCallback( vlc_object_t *p_this, char const *psz_var,
 414                           vlc_value_t oldval, vlc_value_t newval, void *p_data )
 415 {
 416     VLC_UNUSED(oldval);
 417     filter_sys_t *p_sys = (filter_sys_t *)p_data;
 418
 419     if( !strcmp( psz_var, CFG_PREFIX "x" ) )
 420     {
 421         vlc_mutex_lock( &p_sys->lock );
 422         p_sys->i_x = newval.i_int;
 423         vlc_mutex_unlock( &p_sys->lock );
 424     }
 425     else if( !strcmp( psz_var, CFG_PREFIX "y" ) )
 426     {
 427         vlc_mutex_lock( &p_sys->lock );
 428         p_sys->i_y = newval.i_int;
 429         vlc_mutex_unlock( &p_sys->lock );
 430     }
 431     else if( !strcmp( psz_var, CFG_PREFIX "mask" ) )
 432     {
 433         vlc_mutex_lock( &p_sys->lock );
 434         LoadMask( (filter_t*)p_this, newval.psz_string );
 435         vlc_mutex_unlock( &p_sys->lock );
 436     }
 437     else
 438     {
 439         msg_Warn( p_this, "Unknown callback command." );
 440     }
 441     return VLC_SUCCESS;
 442 }