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

   1 /*****************************************************************************
   2  * gradient.c : Gradient and edge detection video effects plugin for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2000-2008 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.org>
   8  *          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 #include <math.h>                                            /* sin(), cos() */
  30
  31 #ifdef HAVE_CONFIG_H
  32 # include "config.h"
  33 #endif
  34
  35 #include <vlc/vlc.h>
  36 #include <vlc_plugin.h>
  37 #include <vlc_sout.h>
  38 #include <vlc_vout.h>
  39
  40 #include "vlc_filter.h"
  41 #include "filter_picture.h"
  42
  43 enum { GRADIENT, EDGE, HOUGH };
  44
  45 /*****************************************************************************
  46  * Local prototypes
  47  *****************************************************************************/
  48 static int  Create    ( vlc_object_t * );
  49 static void Destroy   ( vlc_object_t * );
  50
  51 static picture_t *Filter( filter_t *, picture_t * );
  52 static int GradientCallback( vlc_object_t *, char const *,
  53                              vlc_value_t, vlc_value_t,
  54                              void * );
  55
  56 static void FilterGradient( filter_t *, picture_t *, picture_t * );
  57 static void FilterEdge    ( filter_t *, picture_t *, picture_t * );
  58 static void FilterHough   ( filter_t *, picture_t *, picture_t * );
  59
  60 /*****************************************************************************
  61  * Module descriptor
  62  *****************************************************************************/
  63 #define MODE_TEXT N_("Distort mode")
  64 #define MODE_LONGTEXT N_("Distort mode, one of \"gradient\", \"edge\" and \"hough\".")
  65
  66 #define GRADIENT_TEXT N_("Gradient image type")
  67 #define GRADIENT_LONGTEXT N_("Gradient image type (0 or 1). 0 will " \
  68         "turn the image to white while 1 will keep colors." )
  69
  70 #define CARTOON_TEXT N_("Apply cartoon effect")
  71 #define CARTOON_LONGTEXT N_("Apply cartoon effect. It is only used by " \
  72     "\"gradient\" and \"edge\".")
  73
  74 static const char *const mode_list[] = { "gradient", "edge", "hough" };
  75 static const char *const mode_list_text[] = { N_("Gradient"), N_("Edge"), N_("Hough") };
  76
  77 #define FILTER_PREFIX "gradient-"
  78
  79 vlc_module_begin();
  80     set_description( N_("Gradient video filter") );
  81     set_shortname( N_( "Gradient" ));
  82     set_capability( "video filter2", 0 );
  83     set_category( CAT_VIDEO );
  84     set_subcategory( SUBCAT_VIDEO_VFILTER );
  85
  86     add_string( FILTER_PREFIX "mode", "gradient", NULL,
  87                 MODE_TEXT, MODE_LONGTEXT, false );
  88         change_string_list( mode_list, mode_list_text, 0 );
  89
  90     add_integer_with_range( FILTER_PREFIX "type", 0, 0, 1, NULL,
  91                 GRADIENT_TEXT, GRADIENT_LONGTEXT, false );
  92     add_bool( FILTER_PREFIX "cartoon", 1, NULL,
  93                 CARTOON_TEXT, CARTOON_LONGTEXT, false );
  94
  95     add_shortcut( "gradient" );
  96     set_callbacks( Create, Destroy );
  97 vlc_module_end();
  98
  99 static const char *const ppsz_filter_options[] = {
 100     "mode", "type", "cartoon", NULL
 101 };
 102
 103 /*****************************************************************************
 104  * vout_sys_t: Distort video output method descriptor
 105  *****************************************************************************
 106  * This structure is part of the video output thread descriptor.
 107  * It describes the Distort specific properties of an output thread.
 108  *****************************************************************************/
 109 struct filter_sys_t
 110 {
 111     int i_mode;
 112
 113     /* For the gradient mode */
 114     int i_gradient_type;
 115     bool b_cartoon;
 116
 117     uint32_t *p_buf32;
 118     uint32_t *p_buf32_bis;
 119     uint8_t *p_buf8;
 120
 121     /* For hough mode */
 122     int *p_pre_hough;
 123 };
 124
 125 /*****************************************************************************
 126  * Create: allocates Distort video thread output method
 127  *****************************************************************************
 128  * This function allocates and initializes a Distort vout method.
 129  *****************************************************************************/
 130 static int Create( vlc_object_t *p_this )
 131 {
 132     filter_t *p_filter = (filter_t *)p_this;
 133     char *psz_method;
 134
 135     switch( p_filter->fmt_in.video.i_chroma )
 136     {
 137         CASE_PLANAR_YUV
 138             break;
 139
 140         default:
 141              msg_Err( p_filter, "Unsupported input chroma (%4s)",
 142                       (char*)&(p_filter->fmt_in.video.i_chroma) );
 143             return VLC_EGENERIC;
 144     }
 145
 146     /* Allocate structure */
 147     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 148     if( p_filter->p_sys == NULL )
 149     {
 150         msg_Err( p_filter, "out of memory" );
 151         return VLC_ENOMEM;
 152     }
 153
 154     p_filter->pf_video_filter = Filter;
 155
 156     p_filter->p_sys->p_pre_hough = NULL;
 157
 158     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
 159                    p_filter->p_cfg );
 160
 161     if( !(psz_method =
 162         var_CreateGetNonEmptyStringCommand( p_filter, FILTER_PREFIX "mode" )) )
 163     {
 164         msg_Err( p_filter, "configuration variable "
 165                  FILTER_PREFIX "mode empty" );
 166         p_filter->p_sys->i_mode = GRADIENT;
 167     }
 168     else
 169     {
 170         if( !strcmp( psz_method, "gradient" ) )
 171         {
 172             p_filter->p_sys->i_mode = GRADIENT;
 173         }
 174         else if( !strcmp( psz_method, "edge" ) )
 175         {
 176             p_filter->p_sys->i_mode = EDGE;
 177         }
 178         else if( !strcmp( psz_method, "hough" ) )
 179         {
 180             p_filter->p_sys->i_mode = HOUGH;
 181         }
 182         else
 183         {
 184             msg_Err( p_filter, "no valid gradient mode provided (%s)", psz_method );
 185             p_filter->p_sys->i_mode = GRADIENT;
 186         }
 187     }
 188     free( psz_method );
 189
 190     p_filter->p_sys->i_gradient_type =
 191         var_CreateGetIntegerCommand( p_filter, FILTER_PREFIX "type" );
 192     p_filter->p_sys->b_cartoon =
 193         var_CreateGetBoolCommand( p_filter, FILTER_PREFIX "cartoon" );
 194
 195     var_AddCallback( p_filter, FILTER_PREFIX "mode",
 196                      GradientCallback, p_filter->p_sys );
 197     var_AddCallback( p_filter, FILTER_PREFIX "type",
 198                      GradientCallback, p_filter->p_sys );
 199     var_AddCallback( p_filter, FILTER_PREFIX "cartoon",
 200                      GradientCallback, p_filter->p_sys );
 201
 202     p_filter->p_sys->p_buf32 = NULL;
 203     p_filter->p_sys->p_buf32_bis = NULL;
 204     p_filter->p_sys->p_buf8 = NULL;
 205
 206     return VLC_SUCCESS;
 207 }
 208
 209 /*****************************************************************************
 210  * Destroy: destroy Distort video thread output method
 211  *****************************************************************************
 212  * Terminate an output method created by DistortCreateOutputMethod
 213  *****************************************************************************/
 214 static void Destroy( vlc_object_t *p_this )
 215 {
 216     filter_t *p_filter = (filter_t *)p_this;
 217
 218     free( p_filter->p_sys->p_buf32 );
 219     free( p_filter->p_sys->p_buf32_bis );
 220     free( p_filter->p_sys->p_buf8 );
 221     free( p_filter->p_sys->p_pre_hough );
 222
 223     free( p_filter->p_sys );
 224 }
 225
 226 /*****************************************************************************
 227  * Render: displays previously rendered output
 228  *****************************************************************************
 229  * This function send the currently rendered image to Distort image, waits
 230  * until it is displayed and switch the two rendering buffers, preparing next
 231  * frame.
 232  *****************************************************************************/
 233 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 234 {
 235     picture_t *p_outpic;
 236
 237     if( !p_pic ) return NULL;
 238
 239     p_outpic = p_filter->pf_vout_buffer_new( p_filter );
 240     if( !p_outpic )
 241     {
 242         msg_Warn( p_filter, "can't get output picture" );
 243         if( p_pic->pf_release )
 244             p_pic->pf_release( p_pic );
 245         return NULL;
 246     }
 247
 248     switch( p_filter->p_sys->i_mode )
 249     {
 250         case EDGE:
 251             FilterEdge( p_filter, p_pic, p_outpic );
 252             break;
 253
 254         case GRADIENT:
 255             FilterGradient( p_filter, p_pic, p_outpic );
 256             break;
 257
 258         case HOUGH:
 259             FilterHough( p_filter, p_pic, p_outpic );
 260             break;
 261
 262         default:
 263             break;
 264     }
 265
 266     p_outpic->date = p_pic->date;
 267     p_outpic->b_force = p_pic->b_force;
 268     p_outpic->i_nb_fields = p_pic->i_nb_fields;
 269     p_outpic->b_progressive = p_pic->b_progressive;
 270     p_outpic->b_top_field_first = p_pic->b_top_field_first;
 271
 272     if( p_pic->pf_release )
 273         p_pic->pf_release( p_pic );
 274
 275     return p_outpic;
 276 }
 277
 278 /*****************************************************************************
 279  * Gaussian Convolution
 280  *****************************************************************************
 281  *    Gaussian convolution ( sigma == 1.4 )
 282  *
 283  *    |  2  4  5  4  2  |   |  2  4  4  4  2 |
 284  *    |  4  9 12  9  4  |   |  4  8 12  8  4 |
 285  *    |  5 12 15 12  5  | ~ |  4 12 16 12  4 |
 286  *    |  4  9 12  9  4  |   |  4  8 12  8  4 |
 287  *    |  2  4  5  4  2  |   |  2  4  4  4  2 |
 288  *****************************************************************************/
 289 static void GaussianConvolution( picture_t *p_inpic, uint32_t *p_smooth )
 290 {
 291     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 292     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 293     const int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 294     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 295
 296     int x,y;
 297     for( y = 2; y < i_num_lines - 2; y++ )
 298     {
 299         for( x = 2; x < i_src_visible - 2; x++ )
 300         {
 301             p_smooth[y*i_src_visible+x] = (uint32_t)(
 302               /* 2 rows up */
 303                 ( p_inpix[(y-2)*i_src_pitch+x-2] )
 304               + ((p_inpix[(y-2)*i_src_pitch+x-1]
 305               +   p_inpix[(y-2)*i_src_pitch+x]
 306               +   p_inpix[(y-2)*i_src_pitch+x+1])<<1 )
 307               + ( p_inpix[(y-2)*i_src_pitch+x+2] )
 308               /* 1 row up */
 309               + ((p_inpix[(y-1)*i_src_pitch+x-2]
 310               + ( p_inpix[(y-1)*i_src_pitch+x-1]<<1 )
 311               + ( p_inpix[(y-1)*i_src_pitch+x]*3 )
 312               + ( p_inpix[(y-1)*i_src_pitch+x+1]<<1 )
 313               +   p_inpix[(y-1)*i_src_pitch+x+2]
 314               /* */
 315               +   p_inpix[y*i_src_pitch+x-2]
 316               + ( p_inpix[y*i_src_pitch+x-1]*3 )
 317               + ( p_inpix[y*i_src_pitch+x]<<2 )
 318               + ( p_inpix[y*i_src_pitch+x+1]*3 )
 319               +   p_inpix[y*i_src_pitch+x+2]
 320               /* 1 row down */
 321               +   p_inpix[(y+1)*i_src_pitch+x-2]
 322               + ( p_inpix[(y+1)*i_src_pitch+x-1]<<1 )
 323               + ( p_inpix[(y+1)*i_src_pitch+x]*3 )
 324               + ( p_inpix[(y+1)*i_src_pitch+x+1]<<1 )
 325               +   p_inpix[(y+1)*i_src_pitch+x+2] )<<1 )
 326               /* 2 rows down */
 327               + ( p_inpix[(y+2)*i_src_pitch+x-2] )
 328               + ((p_inpix[(y+2)*i_src_pitch+x-1]
 329               +   p_inpix[(y+2)*i_src_pitch+x]
 330               +   p_inpix[(y+2)*i_src_pitch+x+1])<<1 )
 331               + ( p_inpix[(y+2)*i_src_pitch+x+2] )
 332               ) >> 6 /* 115 */;
 333         }
 334     }
 335 }
 336
 337 /*****************************************************************************
 338  * FilterGradient: Sobel
 339  *****************************************************************************/
 340 static void FilterGradient( filter_t *p_filter, picture_t *p_inpic,
 341                                                 picture_t *p_outpic )
 342 {
 343     int x, y;
 344     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 345     const int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 346     const int i_dst_pitch = p_outpic->p[Y_PLANE].i_pitch;
 347     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 348
 349     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 350     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
 351
 352     uint32_t *p_smooth;
 353     if( !p_filter->p_sys->p_buf32 )
 354         p_filter->p_sys->p_buf32 =
 355         (uint32_t *)malloc( i_num_lines * i_src_visible * sizeof(uint32_t));
 356     p_smooth = p_filter->p_sys->p_buf32;
 357
 358     if( !p_smooth ) return;
 359
 360     if( p_filter->p_sys->b_cartoon )
 361     {
 362         vlc_memcpy( p_outpic->p[U_PLANE].p_pixels,
 363             p_inpic->p[U_PLANE].p_pixels,
 364             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 365         vlc_memcpy( p_outpic->p[V_PLANE].p_pixels,
 366             p_inpic->p[V_PLANE].p_pixels,
 367             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 368     }
 369     else
 370     {
 371         vlc_memset( p_outpic->p[U_PLANE].p_pixels, 0x80,
 372             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 373         vlc_memset( p_outpic->p[V_PLANE].p_pixels, 0x80,
 374             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 375     }
 376
 377     GaussianConvolution( p_inpic, p_smooth );
 378
 379     /* Sobel gradient
 380
 381      | -1 0 1 |     |  1  2  1 |
 382      | -2 0 2 | and |  0  0  0 |
 383      | -1 0 1 |     | -1 -2 -1 | */
 384
 385 #define FOR                                                     \
 386     for( y = 1; y < i_num_lines - 1; y++ )                      \
 387     {                                                           \
 388         for( x = 1; x < i_src_visible - 1; x++ )                \
 389         {                                                       \
 390             const uint32_t a =                                  \
 391             (                                                   \
 392               abs(                                              \
 393                  ( p_smooth[(y-1)*i_src_visible+x-1]            \
 394                    - p_smooth[(y+1)*i_src_visible+x-1] )        \
 395                + ( ( p_smooth[(y-1)*i_src_visible+x]            \
 396                     - p_smooth[(y+1)*i_src_visible+x] ) <<1 )   \
 397                + ( p_smooth[(y-1)*i_src_visible+x+1]            \
 398                    - p_smooth[(y+1)*i_src_visible+x+1] )        \
 399               )                                                 \
 400             +                                                   \
 401               abs(                                              \
 402                  ( p_smooth[(y-1)*i_src_visible+x-1]            \
 403                    - p_smooth[(y-1)*i_src_visible+x+1] )        \
 404                + ( ( p_smooth[y*i_src_visible+x-1]              \
 405                     - p_smooth[y*i_src_visible+x+1] ) <<1 )     \
 406                + ( p_smooth[(y+1)*i_src_visible+x-1]            \
 407                    - p_smooth[(y+1)*i_src_visible+x+1] )        \
 408               )                                                 \
 409             );
 410     if( p_filter->p_sys->i_gradient_type )
 411     {
 412         if( p_filter->p_sys->b_cartoon )
 413         {
 414             FOR
 415             if( a > 60 )
 416             {
 417                 p_outpix[y*i_dst_pitch+x] = 0x00;
 418             }
 419             else
 420             {
 421                 if( p_smooth[y*i_src_visible+x] > 0xa0 )
 422                     p_outpix[y*i_dst_pitch+x] =
 423                         0xff - ((0xff - p_inpix[y*i_src_pitch+x] )>>2);
 424                 else if( p_smooth[y*i_src_visible+x] > 0x70 )
 425                     p_outpix[y*i_dst_pitch+x] =
 426                         0xa0 - ((0xa0 - p_inpix[y*i_src_pitch+x] )>>2);
 427                 else if( p_smooth[y*i_src_visible+x] > 0x28 )
 428                     p_outpix[y*i_dst_pitch+x] =
 429                         0x70 - ((0x70 - p_inpix[y*i_src_pitch+x] )>>2);
 430                 else
 431                     p_outpix[y*i_dst_pitch+x] =
 432                         0x28 - ((0x28 - p_inpix[y*i_src_pitch+x] )>>2);
 433             }
 434             }}
 435         }
 436         else
 437         {
 438             FOR
 439             p_outpix[y*i_dst_pitch+x] = clip_uint8_vlc( a );
 440             }}
 441         }
 442     }
 443     else
 444     {
 445         FOR
 446         if( a>>8 )
 447             p_outpix[y*i_dst_pitch+x] = 0;
 448         else
 449             p_outpix[y*i_dst_pitch+x] = 0xff-(uint8_t)a;
 450         }}
 451     }
 452 #undef FOR
 453 }
 454
 455 /*****************************************************************************
 456  * FilterEdge: Canny edge detection algorithm
 457  *****************************************************************************
 458  * http://fourier.eng.hmc.edu/e161/lectures/canny/node1.html
 459  * (well ... my implementation isn't really the canny algorithm ... but some
 460  * ideas are the same)
 461  *****************************************************************************/
 462 /* angle : | */
 463 #define THETA_Y 0
 464 /* angle : - */
 465 #define THETA_X 1
 466 /* angle : / */
 467 #define THETA_P 2
 468 /* angle : \ */
 469 #define THETA_M 3
 470 static void FilterEdge( filter_t *p_filter, picture_t *p_inpic,
 471                                             picture_t *p_outpic )
 472 {
 473     int x, y;
 474
 475     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 476     const int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 477     const int i_dst_pitch = p_outpic->p[Y_PLANE].i_pitch;
 478     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 479
 480     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 481     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
 482
 483     uint32_t *p_smooth;
 484     uint32_t *p_grad;
 485     uint8_t *p_theta;
 486
 487     if( !p_filter->p_sys->p_buf32 )
 488         p_filter->p_sys->p_buf32 =
 489         (uint32_t *)malloc( i_num_lines * i_src_visible * sizeof(uint32_t));
 490     p_smooth = p_filter->p_sys->p_buf32;
 491
 492     if( !p_filter->p_sys->p_buf32_bis )
 493         p_filter->p_sys->p_buf32_bis =
 494         (uint32_t *)malloc( i_num_lines * i_src_visible * sizeof(uint32_t));
 495     p_grad = p_filter->p_sys->p_buf32_bis;
 496
 497     if( !p_filter->p_sys->p_buf8 )
 498         p_filter->p_sys->p_buf8 =
 499         (uint8_t *)malloc( i_num_lines * i_src_visible * sizeof(uint8_t));
 500     p_theta = p_filter->p_sys->p_buf8;
 501
 502     if( !p_smooth || !p_grad || !p_theta ) return;
 503
 504     if( p_filter->p_sys->b_cartoon )
 505     {
 506         vlc_memcpy( p_outpic->p[U_PLANE].p_pixels,
 507             p_inpic->p[U_PLANE].p_pixels,
 508             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 509         vlc_memcpy( p_outpic->p[V_PLANE].p_pixels,
 510             p_inpic->p[V_PLANE].p_pixels,
 511             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 512     }
 513     else
 514     {
 515         vlc_memset( p_outpic->p[Y_PLANE].p_pixels, 0xff,
 516               p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 517         vlc_memset( p_outpic->p[U_PLANE].p_pixels, 0x80,
 518             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 519         vlc_memset( p_outpic->p[V_PLANE].p_pixels, 0x80,
 520             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 521     }
 522
 523     GaussianConvolution( p_inpic, p_smooth );
 524
 525     /* Sobel gradient
 526
 527      | -1 0 1 |     |  1  2  1 |
 528      | -2 0 2 | and |  0  0  0 |
 529      | -1 0 1 |     | -1 -2 -1 | */
 530
 531     for( y = 1; y < i_num_lines - 1; y++ )
 532     {
 533         for( x = 1; x < i_src_visible - 1; x++ )
 534         {
 535
 536             const int gradx =
 537                  ( p_smooth[(y-1)*i_src_visible+x-1]
 538                    - p_smooth[(y+1)*i_src_visible+x-1] )
 539                + ( ( p_smooth[(y-1)*i_src_visible+x]
 540                     - p_smooth[(y+1)*i_src_visible+x] ) <<1 )
 541                + ( p_smooth[(y-1)*i_src_visible+x+1]
 542                    - p_smooth[(y+1)*i_src_visible+x+1] );
 543             const int grady =
 544                  ( p_smooth[(y-1)*i_src_visible+x-1]
 545                    - p_smooth[(y-1)*i_src_visible+x+1] )
 546                + ( ( p_smooth[y*i_src_visible+x-1]
 547                     - p_smooth[y*i_src_visible+x+1] ) <<1 )
 548                + ( p_smooth[(y+1)*i_src_visible+x-1]
 549                    - p_smooth[(y+1)*i_src_visible+x+1] );
 550
 551             p_grad[y*i_src_visible+x] = (uint32_t)(abs( gradx ) + abs( grady ));
 552
 553             /* tan( 22.5 ) = 0,414213562 .. * 128 = 53
 554              * tan( 26,565051177 ) = 0.5
 555              * tan( 45 + 22.5 ) = 2,414213562 .. * 128 = 309
 556              * tan( 63,434948823 ) 2 */
 557             if( (grady<<1) > gradx )
 558                 p_theta[y*i_src_visible+x] = THETA_P;
 559             else if( (grady<<1) < -gradx )
 560                 p_theta[y*i_src_visible+x] = THETA_M;
 561             else if( !gradx || abs(grady) > abs(gradx)<<1 )
 562                 p_theta[y*i_src_visible+x] = THETA_Y;
 563             else
 564                 p_theta[y*i_src_visible+x] = THETA_X;
 565         }
 566     }
 567
 568     /* edge computing */
 569     for( y = 1; y < i_num_lines - 1; y++ )
 570     {
 571         for( x = 1; x < i_src_visible - 1; x++ )
 572         {
 573             if( p_grad[y*i_src_visible+x] > 40 )
 574             {
 575                 switch( p_theta[y*i_src_visible+x] )
 576                 {
 577                     case THETA_Y:
 578                         if(    p_grad[y*i_src_visible+x] > p_grad[(y-1)*i_src_visible+x]
 579                             && p_grad[y*i_src_visible+x] > p_grad[(y+1)*i_src_visible+x] )
 580                         {
 581                             p_outpix[y*i_dst_pitch+x] = 0;
 582                             break;
 583                         } else goto colorize;
 584                     case THETA_P:
 585                         if(    p_grad[y*i_src_visible+x] > p_grad[(y-1)*i_src_visible+x-1]
 586                             && p_grad[y*i_src_visible+x] > p_grad[(y+1)*i_src_visible+x+1] )
 587                         {
 588                             p_outpix[y*i_dst_pitch+x] = 0;
 589                             break;
 590                         } else goto colorize;
 591                     case THETA_M:
 592                         if(    p_grad[y*i_src_visible+x] > p_grad[(y-1)*i_src_visible+x+1]
 593                             && p_grad[y*i_src_visible+x] > p_grad[(y+1)*i_src_visible+x-1] )
 594                         {
 595                             p_outpix[y*i_dst_pitch+x] = 0;
 596                             break;
 597                         } else goto colorize;
 598                     case THETA_X:
 599                         if(    p_grad[y*i_src_visible+x] > p_grad[y*i_src_visible+x-1]
 600                             && p_grad[y*i_src_visible+x] > p_grad[y*i_src_visible+x+1] )
 601                         {
 602                             p_outpix[y*i_dst_pitch+x] = 0;
 603                             break;
 604                         } else goto colorize;
 605                 }
 606             }
 607             else
 608             {
 609                 colorize:
 610                 if( p_filter->p_sys->b_cartoon )
 611                 {
 612                     if( p_smooth[y*i_src_visible+x] > 0xa0 )
 613                         p_outpix[y*i_dst_pitch+x] = (uint8_t)
 614                             0xff - ((0xff - p_inpix[y*i_src_pitch+x] )>>2);
 615                     else if( p_smooth[y*i_src_visible+x] > 0x70 )
 616                         p_outpix[y*i_dst_pitch+x] =(uint8_t)
 617                             0xa0 - ((0xa0 - p_inpix[y*i_src_pitch+x] )>>2);
 618                     else if( p_smooth[y*i_src_visible+x] > 0x28 )
 619                         p_outpix[y*i_dst_pitch+x] =(uint8_t)
 620                             0x70 - ((0x70 - p_inpix[y*i_src_pitch+x] )>>2);
 621                     else
 622                         p_outpix[y*i_dst_pitch+x] =(uint8_t)
 623                             0x28 - ((0x28 - p_inpix[y*i_src_pitch+x] )>>2);
 624                 }
 625             }
 626         }
 627     }
 628 }
 629
 630 /*****************************************************************************
 631  * FilterHough
 632  *****************************************************************************/
 633 #define p_pre_hough p_filter->p_sys->p_pre_hough
 634 static void FilterHough( filter_t *p_filter, picture_t *p_inpic,
 635                                              picture_t *p_outpic )
 636 {
 637     int x, y, i;
 638     int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 639     int i_dst_pitch = p_outpic->p[Y_PLANE].i_pitch;
 640     int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 641
 642     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
 643
 644     int i_diag = sqrt( i_num_lines * i_num_lines +
 645                         i_src_visible * i_src_visible);
 646     int i_max, i_phi_max, i_rho, i_rho_max;
 647     int i_nb_steps = 90;
 648     double d_step = M_PI / i_nb_steps;
 649     double d_sin;
 650     double d_cos;
 651     uint32_t *p_smooth;
 652     int *p_hough = malloc( i_diag * i_nb_steps * sizeof(int) );
 653     if( ! p_hough ) return;
 654     p_smooth = (uint32_t *)malloc( i_num_lines*i_src_visible*sizeof(uint32_t));
 655     if( !p_smooth ) return;
 656
 657     if( ! p_pre_hough )
 658     {
 659         msg_Dbg(p_filter, "Starting precalculation");
 660         p_pre_hough = malloc( i_num_lines*i_src_visible*i_nb_steps*sizeof(int));
 661         if( ! p_pre_hough ) return;
 662         for( i = 0 ; i < i_nb_steps ; i++)
 663         {
 664             d_sin = sin(d_step * i);
 665             d_cos = cos(d_step * i);
 666             for( y = 0 ; y < i_num_lines ; y++ )
 667                 for( x = 0 ; x < i_src_visible ; x++ )
 668                 {
 669                     p_pre_hough[(i*i_num_lines+y)*i_src_visible + x] =
 670                         ceil(x*d_sin + y*d_cos);
 671                 }
 672         }
 673         msg_Dbg(p_filter, "Precalculation done");
 674     }
 675
 676     vlc_memset( p_hough, 0, i_diag * i_nb_steps * sizeof(int) );
 677
 678     vlc_memcpy(
 679         p_outpic->p[Y_PLANE].p_pixels, p_inpic->p[Y_PLANE].p_pixels,
 680         p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 681     vlc_memcpy(
 682         p_outpic->p[U_PLANE].p_pixels, p_inpic->p[U_PLANE].p_pixels,
 683         p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 684     vlc_memcpy(
 685         p_outpic->p[V_PLANE].p_pixels, p_inpic->p[V_PLANE].p_pixels,
 686         p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 687
 688     GaussianConvolution( p_inpic, p_smooth );
 689
 690     /* Sobel gradient
 691
 692      | -1 0 1 |     |  1  2  1 |
 693      | -2 0 2 | and |  0  0  0 |
 694      | -1 0 1 |     | -1 -2 -1 | */
 695
 696     i_max = 0;
 697     i_rho_max = 0;
 698     i_phi_max = 0;
 699     for( y = 4; y < i_num_lines - 4; y++ )
 700     {
 701         for( x = 4; x < i_src_visible - 4; x++ )
 702         {
 703             uint32_t a =
 704             (
 705               abs(
 706                 ( ( p_smooth[(y-1)*i_src_visible+x]
 707                     - p_smooth[(y+1)*i_src_visible+x] ) <<1 )
 708                + ( p_smooth[(y-1)*i_src_visible+x-1]
 709                    - p_smooth[(y+1)*i_src_visible+x-1] )
 710                + ( p_smooth[(y-1)*i_src_visible+x+1]
 711                    - p_smooth[(y+1)*i_src_visible+x+1] )
 712               )
 713             +
 714               abs(
 715                 ( ( p_smooth[y*i_src_visible+x-1]
 716                     - p_smooth[y*i_src_visible+x+1] ) <<1 )
 717                + ( p_smooth[(y-1)*i_src_visible+x-1]
 718                    - p_smooth[(y-1)*i_src_visible+x+1] )
 719                + ( p_smooth[(y+1)*i_src_visible+x-1]
 720                    - p_smooth[(y+1)*i_src_visible+x+1] )
 721               )
 722             );
 723             if( a>>8 )
 724             {
 725                 for( i = 0 ; i < i_nb_steps ; i ++ )
 726                 {
 727                     i_rho = p_pre_hough[(i*i_num_lines+y)*i_src_visible + x];
 728                     if( p_hough[i_rho + i_diag/2 + i * i_diag]++ > i_max )
 729                     {
 730                         i_max = p_hough[i_rho + i_diag/2 + i * i_diag];
 731                         i_rho_max = i_rho;
 732                         i_phi_max = i;
 733                     }
 734                 }
 735             }
 736         }
 737     }
 738
 739     d_sin = sin(i_phi_max*d_step);
 740     d_cos = cos(i_phi_max*d_step);
 741     if( d_cos != 0 )
 742     {
 743         for( x = 0 ; x < i_src_visible ; x++ )
 744         {
 745             y = (i_rho_max - x * d_sin) / d_cos;
 746             if( y >= 0 && y < i_num_lines )
 747                 p_outpix[y*i_dst_pitch+x] = 255;
 748         }
 749     }
 750
 751     free( p_hough );
 752     free( p_smooth );
 753 }
 754 #undef p_pre_hough
 755
 756
 757 static int GradientCallback( vlc_object_t *p_this, char const *psz_var,
 758                              vlc_value_t oldval, vlc_value_t newval,
 759                              void *p_data )
 760 {
 761     VLC_UNUSED(oldval);
 762     filter_sys_t *p_sys = (filter_sys_t *)p_data;
 763     if( !strcmp( psz_var, FILTER_PREFIX "mode" ) )
 764     {
 765         if( !strcmp( newval.psz_string, "gradient" ) )
 766         {
 767             p_sys->i_mode = GRADIENT;
 768         }
 769         else if( !strcmp( newval.psz_string, "edge" ) )
 770         {
 771             p_sys->i_mode = EDGE;
 772         }
 773         else if( !strcmp( newval.psz_string, "hough" ) )
 774         {
 775             p_sys->i_mode = HOUGH;
 776         }
 777         else
 778         {
 779             msg_Err( p_this, "no valid gradient mode provided (%s)", newval.psz_string );
 780             p_sys->i_mode = GRADIENT;
 781         }
 782     }
 783     else if( !strcmp( psz_var, FILTER_PREFIX "type" ) )
 784     {
 785         p_sys->i_gradient_type = newval.i_int;
 786     }
 787     else if( !strcmp( psz_var, FILTER_PREFIX "cartoon" ) )
 788     {
 789         p_sys->b_cartoon = newval.b_bool;
 790     }
 791     return VLC_SUCCESS;
 792 }