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