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) 2000-2006 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 #include <string.h>
  29
  30 #include <math.h>                                            /* sin(), cos() */
  31
  32 #include <vlc/vlc.h>
  33 #include <vlc_sout.h>
  34 #include <vlc_vout.h>
  35
  36 #include "vlc_filter.h"
  37
  38 enum { GRADIENT, EDGE, HOUGH };
  39
  40 /*****************************************************************************
  41  * Local prototypes
  42  *****************************************************************************/
  43 static int  Create    ( vlc_object_t * );
  44 static void Destroy   ( vlc_object_t * );
  45
  46 static picture_t *Filter( filter_t *, picture_t * );
  47 static int GradientCallback( vlc_object_t *, char const *,
  48                              vlc_value_t, vlc_value_t,
  49                              void * );
  50
  51 static void FilterGradient( filter_t *, picture_t *, picture_t * );
  52 static void FilterEdge    ( filter_t *, picture_t *, picture_t * );
  53 static void FilterHough   ( filter_t *, picture_t *, picture_t * );
  54
  55 /*****************************************************************************
  56  * Module descriptor
  57  *****************************************************************************/
  58 #define MODE_TEXT N_("Distort mode")
  59 #define MODE_LONGTEXT N_("Distort mode, one of \"gradient\", \"edge\" and \"hough\".")
  60
  61 #define GRADIENT_TEXT N_("Gradient image type")
  62 #define GRADIENT_LONGTEXT N_("Gradient image type (0 or 1). 0 will " \
  63         "turn the image to white while 1 will keep colors." )
  64
  65 #define CARTOON_TEXT N_("Apply cartoon effect")
  66 #define CARTOON_LONGTEXT N_("Apply cartoon effect. It is only used by " \
  67     "\"gradient\" and \"edge\".")
  68
  69 static const char *mode_list[] = { "gradient", "edge", "hough" };
  70 static const char *mode_list_text[] = { N_("Gradient"), N_("Edge"), N_("Hough") };
  71
  72 #define FILTER_PREFIX "gradient-"
  73
  74 vlc_module_begin();
  75     set_description( _("Gradient video filter") );
  76     set_shortname( _( "Gradient" ));
  77     set_capability( "video filter2", 0 );
  78     set_category( CAT_VIDEO );
  79     set_subcategory( SUBCAT_VIDEO_VFILTER );
  80
  81     add_string( FILTER_PREFIX "mode", "gradient", NULL,
  82                 MODE_TEXT, MODE_LONGTEXT, VLC_FALSE );
  83         change_string_list( mode_list, mode_list_text, 0 );
  84
  85     add_integer_with_range( FILTER_PREFIX "type", 0, 0, 1, NULL,
  86                 GRADIENT_TEXT, GRADIENT_LONGTEXT, VLC_FALSE );
  87     add_bool( FILTER_PREFIX "cartoon", 1, NULL,
  88                 CARTOON_TEXT, CARTOON_LONGTEXT, VLC_FALSE );
  89
  90     add_shortcut( "gradient" );
  91     set_callbacks( Create, Destroy );
  92 vlc_module_end();
  93
  94 static const char *ppsz_filter_options[] = {
  95     "mode", "type", "cartoon", NULL
  96 };
  97
  98 /*****************************************************************************
  99  * vout_sys_t: Distort video output method descriptor
 100  *****************************************************************************
 101  * This structure is part of the video output thread descriptor.
 102  * It describes the Distort specific properties of an output thread.
 103  *****************************************************************************/
 104 struct filter_sys_t
 105 {
 106     int i_mode;
 107
 108     /* For the gradient mode */
 109     int i_gradient_type;
 110     vlc_bool_t b_cartoon;
 111
 112     uint32_t *p_buf32;
 113     uint32_t *p_buf32_bis;
 114     uint8_t *p_buf8;
 115
 116     /* For hough mode */
 117     int *p_pre_hough;
 118 };
 119
 120 /*****************************************************************************
 121  * Create: allocates Distort video thread output method
 122  *****************************************************************************
 123  * This function allocates and initializes a Distort vout method.
 124  *****************************************************************************/
 125 static int Create( vlc_object_t *p_this )
 126 {
 127     filter_t *p_filter = (filter_t *)p_this;
 128     char *psz_method;
 129
 130     /* Allocate structure */
 131     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 132     if( p_filter->p_sys == NULL )
 133     {
 134         msg_Err( p_filter, "out of memory" );
 135         return VLC_ENOMEM;
 136     }
 137
 138     p_filter->pf_video_filter = Filter;
 139
 140     p_filter->p_sys->p_pre_hough = NULL;
 141
 142     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
 143                    p_filter->p_cfg );
 144
 145     if( !(psz_method =
 146         var_CreateGetNonEmptyStringCommand( p_filter, FILTER_PREFIX "mode" )) )
 147     {
 148         msg_Err( p_filter, "configuration variable "
 149                  FILTER_PREFIX "mode empty" );
 150         p_filter->p_sys->i_mode = GRADIENT;
 151     }
 152     else
 153     {
 154         if( !strcmp( psz_method, "gradient" ) )
 155         {
 156             p_filter->p_sys->i_mode = GRADIENT;
 157         }
 158         else if( !strcmp( psz_method, "edge" ) )
 159         {
 160             p_filter->p_sys->i_mode = EDGE;
 161         }
 162         else if( !strcmp( psz_method, "hough" ) )
 163         {
 164             p_filter->p_sys->i_mode = HOUGH;
 165         }
 166         else
 167         {
 168             msg_Err( p_filter, "no valid gradient mode provided (%s)", psz_method );
 169             p_filter->p_sys->i_mode = GRADIENT;
 170         }
 171     }
 172     free( psz_method );
 173
 174     p_filter->p_sys->i_gradient_type =
 175         var_CreateGetIntegerCommand( p_filter, FILTER_PREFIX "type" );
 176     p_filter->p_sys->b_cartoon =
 177         var_CreateGetBoolCommand( p_filter, FILTER_PREFIX "cartoon" );
 178
 179     var_AddCallback( p_filter, FILTER_PREFIX "mode",
 180                      GradientCallback, p_filter->p_sys );
 181     var_AddCallback( p_filter, FILTER_PREFIX "type",
 182                      GradientCallback, p_filter->p_sys );
 183     var_AddCallback( p_filter, FILTER_PREFIX "cartoon",
 184                      GradientCallback, p_filter->p_sys );
 185
 186     p_filter->p_sys->p_buf32 = NULL;
 187     p_filter->p_sys->p_buf32_bis = NULL;
 188     p_filter->p_sys->p_buf8 = NULL;
 189
 190     return VLC_SUCCESS;
 191 }
 192
 193 /*****************************************************************************
 194  * Destroy: destroy Distort video thread output method
 195  *****************************************************************************
 196  * Terminate an output method created by DistortCreateOutputMethod
 197  *****************************************************************************/
 198 static void Destroy( vlc_object_t *p_this )
 199 {
 200     filter_t *p_filter = (filter_t *)p_this;
 201
 202     free( p_filter->p_sys->p_buf32 );
 203     free( p_filter->p_sys->p_buf32_bis );
 204     free( p_filter->p_sys->p_buf8 );
 205     free( p_filter->p_sys->p_pre_hough );
 206
 207     free( p_filter->p_sys );
 208 }
 209
 210 /*****************************************************************************
 211  * Render: displays previously rendered output
 212  *****************************************************************************
 213  * This function send the currently rendered image to Distort image, waits
 214  * until it is displayed and switch the two rendering buffers, preparing next
 215  * frame.
 216  *****************************************************************************/
 217 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 218 {
 219     picture_t *p_outpic;
 220
 221     if( !p_pic ) return NULL;
 222
 223     p_outpic = p_filter->pf_vout_buffer_new( p_filter );
 224     if( !p_outpic )
 225     {
 226         msg_Warn( p_filter, "can't get output picture" );
 227         if( p_pic->pf_release )
 228             p_pic->pf_release( p_pic );
 229         return NULL;
 230     }
 231
 232     switch( p_filter->p_sys->i_mode )
 233     {
 234         case EDGE:
 235             FilterEdge( p_filter, p_pic, p_outpic );
 236             break;
 237
 238         case GRADIENT:
 239             FilterGradient( p_filter, p_pic, p_outpic );
 240             break;
 241
 242         case HOUGH:
 243             FilterHough( p_filter, p_pic, p_outpic );
 244             break;
 245
 246         default:
 247             break;
 248     }
 249
 250     p_outpic->date = p_pic->date;
 251     p_outpic->b_force = p_pic->b_force;
 252     p_outpic->i_nb_fields = p_pic->i_nb_fields;
 253     p_outpic->b_progressive = p_pic->b_progressive;
 254     p_outpic->b_top_field_first = p_pic->b_top_field_first;
 255
 256     if( p_pic->pf_release )
 257         p_pic->pf_release( p_pic );
 258
 259     return p_outpic;
 260 }
 261
 262 /*****************************************************************************
 263  * Gaussian Convolution
 264  *****************************************************************************
 265  *    Gaussian convolution ( sigma == 1.4 )
 266  *
 267  *    |  2  4  5  4  2  |   |  2  4  4  4  2 |
 268  *    |  4  9 12  9  4  |   |  4  8 12  8  4 |
 269  *    |  5 12 15 12  5  | ~ |  4 12 16 12  4 |
 270  *    |  4  9 12  9  4  |   |  4  8 12  8  4 |
 271  *    |  2  4  5  4  2  |   |  2  4  4  4  2 |
 272  *****************************************************************************/
 273 static void GaussianConvolution( picture_t *p_inpic, uint32_t *p_smooth )
 274 {
 275     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 276     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 277     const int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 278     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 279
 280     int x,y;
 281     for( y = 2; y < i_num_lines - 2; y++ )
 282     {
 283         for( x = 2; x < i_src_visible - 2; x++ )
 284         {
 285             p_smooth[y*i_src_visible+x] = (uint32_t)(
 286               /* 2 rows up */
 287                 ( p_inpix[(y-2)*i_src_pitch+x-2] )
 288               + ((p_inpix[(y-2)*i_src_pitch+x-1]
 289               +   p_inpix[(y-2)*i_src_pitch+x]
 290               +   p_inpix[(y-2)*i_src_pitch+x+1])<<1 )
 291               + ( p_inpix[(y-2)*i_src_pitch+x+2] )
 292               /* 1 row up */
 293               + ((p_inpix[(y-1)*i_src_pitch+x-2]
 294               + ( p_inpix[(y-1)*i_src_pitch+x-1]<<1 )
 295               + ( p_inpix[(y-1)*i_src_pitch+x]*3 )
 296               + ( p_inpix[(y-1)*i_src_pitch+x+1]<<1 )
 297               +   p_inpix[(y-1)*i_src_pitch+x+2]
 298               /* */
 299               +   p_inpix[y*i_src_pitch+x-2]
 300               + ( p_inpix[y*i_src_pitch+x-1]*3 )
 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               /* 1 row down */
 305               +   p_inpix[(y+1)*i_src_pitch+x-2]
 306               + ( p_inpix[(y+1)*i_src_pitch+x-1]<<1 )
 307               + ( p_inpix[(y+1)*i_src_pitch+x]*3 )
 308               + ( p_inpix[(y+1)*i_src_pitch+x+1]<<1 )
 309               +   p_inpix[(y+1)*i_src_pitch+x+2] )<<1 )
 310               /* 2 rows down */
 311               + ( p_inpix[(y+2)*i_src_pitch+x-2] )
 312               + ((p_inpix[(y+2)*i_src_pitch+x-1]
 313               +   p_inpix[(y+2)*i_src_pitch+x]
 314               +   p_inpix[(y+2)*i_src_pitch+x+1])<<1 )
 315               + ( p_inpix[(y+2)*i_src_pitch+x+2] )
 316               ) >> 6 /* 115 */;
 317         }
 318     }
 319 }
 320
 321 /*****************************************************************************
 322  * FilterGradient: Sobel
 323  *****************************************************************************/
 324 static void FilterGradient( filter_t *p_filter, picture_t *p_inpic,
 325                                                 picture_t *p_outpic )
 326 {
 327     int x, y;
 328     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 329     const int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 330     const int i_dst_pitch = p_outpic->p[Y_PLANE].i_pitch;
 331     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 332
 333     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 334     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
 335
 336     uint32_t *p_smooth;
 337     if( !p_filter->p_sys->p_buf32 )
 338         p_filter->p_sys->p_buf32 =
 339         (uint32_t *)malloc( i_num_lines * i_src_visible * sizeof(uint32_t));
 340     p_smooth = p_filter->p_sys->p_buf32;
 341
 342     if( !p_smooth ) return;
 343
 344     if( p_filter->p_sys->b_cartoon )
 345     {
 346         p_filter->p_libvlc->pf_memcpy( p_outpic->p[U_PLANE].p_pixels,
 347             p_inpic->p[U_PLANE].p_pixels,
 348             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 349         p_filter->p_libvlc->pf_memcpy( p_outpic->p[V_PLANE].p_pixels,
 350             p_inpic->p[V_PLANE].p_pixels,
 351             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 352     }
 353     else
 354     {
 355         p_filter->p_libvlc->pf_memset( p_outpic->p[U_PLANE].p_pixels, 0x80,
 356             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 357         p_filter->p_libvlc->pf_memset( p_outpic->p[V_PLANE].p_pixels, 0x80,
 358             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 359     }
 360
 361     GaussianConvolution( p_inpic, p_smooth );
 362
 363     /* Sobel gradient
 364
 365      | -1 0 1 |     |  1  2  1 |
 366      | -2 0 2 | and |  0  0  0 |
 367      | -1 0 1 |     | -1 -2 -1 | */
 368
 369 #define FOR                                                     \
 370     for( y = 1; y < i_num_lines - 1; y++ )                      \
 371     {                                                           \
 372         for( x = 1; x < i_src_visible - 1; x++ )                \
 373         {                                                       \
 374             const uint32_t a =                                  \
 375             (                                                   \
 376               abs(                                              \
 377                  ( p_smooth[(y-1)*i_src_visible+x-1]            \
 378                    - p_smooth[(y+1)*i_src_visible+x-1] )        \
 379                + ( ( p_smooth[(y-1)*i_src_visible+x]            \
 380                     - p_smooth[(y+1)*i_src_visible+x] ) <<1 )   \
 381                + ( p_smooth[(y-1)*i_src_visible+x+1]            \
 382                    - p_smooth[(y+1)*i_src_visible+x+1] )        \
 383               )                                                 \
 384             +                                                   \
 385               abs(                                              \
 386                  ( p_smooth[(y-1)*i_src_visible+x-1]            \
 387                    - p_smooth[(y-1)*i_src_visible+x+1] )        \
 388                + ( ( p_smooth[y*i_src_visible+x-1]              \
 389                     - p_smooth[y*i_src_visible+x+1] ) <<1 )     \
 390                + ( p_smooth[(y+1)*i_src_visible+x-1]            \
 391                    - p_smooth[(y+1)*i_src_visible+x+1] )        \
 392               )                                                 \
 393             );
 394     if( p_filter->p_sys->i_gradient_type )
 395     {
 396         if( p_filter->p_sys->b_cartoon )
 397         {
 398             FOR
 399             if( a > 60 )
 400             {
 401                 p_outpix[y*i_dst_pitch+x] = 0x00;
 402             }
 403             else
 404             {
 405                 if( p_smooth[y*i_src_visible+x] > 0xa0 )
 406                     p_outpix[y*i_dst_pitch+x] =
 407                         0xff - ((0xff - p_inpix[y*i_src_pitch+x] )>>2);
 408                 else if( p_smooth[y*i_src_visible+x] > 0x70 )
 409                     p_outpix[y*i_dst_pitch+x] =
 410                         0xa0 - ((0xa0 - p_inpix[y*i_src_pitch+x] )>>2);
 411                 else if( p_smooth[y*i_src_visible+x] > 0x28 )
 412                     p_outpix[y*i_dst_pitch+x] =
 413                         0x70 - ((0x70 - p_inpix[y*i_src_pitch+x] )>>2);
 414                 else
 415                     p_outpix[y*i_dst_pitch+x] =
 416                         0x28 - ((0x28 - p_inpix[y*i_src_pitch+x] )>>2);
 417             }
 418             }}
 419         }
 420         else
 421         {
 422             FOR
 423             p_outpix[y*i_dst_pitch+x] = clip_uint8_vlc( a );
 424             }}
 425         }
 426     }
 427     else
 428     {
 429         FOR
 430         if( a>>8 )
 431             p_outpix[y*i_dst_pitch+x] = 0;
 432         else
 433             p_outpix[y*i_dst_pitch+x] = 0xff-(uint8_t)a;
 434         }}
 435     }
 436 #undef FOR
 437 }
 438
 439 /*****************************************************************************
 440  * FilterEdge: Canny edge detection algorithm
 441  *****************************************************************************
 442  * http://fourier.eng.hmc.edu/e161/lectures/canny/node1.html
 443  * (well ... my implementation isn't really the canny algorithm ... but some
 444  * ideas are the same)
 445  *****************************************************************************/
 446 /* angle : | */
 447 #define THETA_Y 0
 448 /* angle : - */
 449 #define THETA_X 1
 450 /* angle : / */
 451 #define THETA_P 2
 452 /* angle : \ */
 453 #define THETA_M 3
 454 static void FilterEdge( filter_t *p_filter, picture_t *p_inpic,
 455                                             picture_t *p_outpic )
 456 {
 457     int x, y;
 458
 459     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 460     const int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 461     const int i_dst_pitch = p_outpic->p[Y_PLANE].i_pitch;
 462     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 463
 464     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 465     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
 466
 467     uint32_t *p_smooth;
 468     uint32_t *p_grad;
 469     uint8_t *p_theta;
 470
 471     if( !p_filter->p_sys->p_buf32 )
 472         p_filter->p_sys->p_buf32 =
 473         (uint32_t *)malloc( i_num_lines * i_src_visible * sizeof(uint32_t));
 474     p_smooth = p_filter->p_sys->p_buf32;
 475
 476     if( !p_filter->p_sys->p_buf32_bis )
 477         p_filter->p_sys->p_buf32_bis =
 478         (uint32_t *)malloc( i_num_lines * i_src_visible * sizeof(uint32_t));
 479     p_grad = p_filter->p_sys->p_buf32_bis;
 480
 481     if( !p_filter->p_sys->p_buf8 )
 482         p_filter->p_sys->p_buf8 =
 483         (uint8_t *)malloc( i_num_lines * i_src_visible * sizeof(uint8_t));
 484     p_theta = p_filter->p_sys->p_buf8;
 485
 486     if( !p_smooth || !p_grad || !p_theta ) return;
 487
 488     if( p_filter->p_sys->b_cartoon )
 489     {
 490         p_filter->p_libvlc->pf_memcpy( p_outpic->p[U_PLANE].p_pixels,
 491             p_inpic->p[U_PLANE].p_pixels,
 492             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 493         p_filter->p_libvlc->pf_memcpy( p_outpic->p[V_PLANE].p_pixels,
 494             p_inpic->p[V_PLANE].p_pixels,
 495             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 496     }
 497     else
 498     {
 499         p_filter->p_libvlc->pf_memset( p_outpic->p[Y_PLANE].p_pixels, 0xff,
 500               p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 501         p_filter->p_libvlc->pf_memset( p_outpic->p[U_PLANE].p_pixels, 0x80,
 502             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 503         p_filter->p_libvlc->pf_memset( p_outpic->p[V_PLANE].p_pixels, 0x80,
 504             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 505     }
 506
 507     GaussianConvolution( p_inpic, p_smooth );
 508
 509     /* Sobel gradient
 510
 511      | -1 0 1 |     |  1  2  1 |
 512      | -2 0 2 | and |  0  0  0 |
 513      | -1 0 1 |     | -1 -2 -1 | */
 514
 515     for( y = 1; y < i_num_lines - 1; y++ )
 516     {
 517         for( x = 1; x < i_src_visible - 1; x++ )
 518         {
 519
 520             const int gradx =
 521                  ( p_smooth[(y-1)*i_src_visible+x-1]
 522                    - p_smooth[(y+1)*i_src_visible+x-1] )
 523                + ( ( p_smooth[(y-1)*i_src_visible+x]
 524                     - p_smooth[(y+1)*i_src_visible+x] ) <<1 )
 525                + ( p_smooth[(y-1)*i_src_visible+x+1]
 526                    - p_smooth[(y+1)*i_src_visible+x+1] );
 527             const int grady =
 528                  ( p_smooth[(y-1)*i_src_visible+x-1]
 529                    - p_smooth[(y-1)*i_src_visible+x+1] )
 530                + ( ( p_smooth[y*i_src_visible+x-1]
 531                     - p_smooth[y*i_src_visible+x+1] ) <<1 )
 532                + ( p_smooth[(y+1)*i_src_visible+x-1]
 533                    - p_smooth[(y+1)*i_src_visible+x+1] );
 534
 535             p_grad[y*i_src_visible+x] = (uint32_t)(abs( gradx ) + abs( grady ));
 536
 537             /* tan( 22.5 ) = 0,414213562 .. * 128 = 53
 538              * tan( 26,565051177 ) = 0.5
 539              * tan( 45 + 22.5 ) = 2,414213562 .. * 128 = 309
 540              * tan( 63,434948823 ) 2 */
 541             if( (grady<<1) > gradx )
 542                 p_theta[y*i_src_visible+x] = THETA_P;
 543             else if( (grady<<1) < -gradx )
 544                 p_theta[y*i_src_visible+x] = THETA_M;
 545             else if( !gradx || abs(grady) > abs(gradx)<<1 )
 546                 p_theta[y*i_src_visible+x] = THETA_Y;
 547             else
 548                 p_theta[y*i_src_visible+x] = THETA_X;
 549         }
 550     }
 551
 552     /* edge computing */
 553     for( y = 1; y < i_num_lines - 1; y++ )
 554     {
 555         for( x = 1; x < i_src_visible - 1; x++ )
 556         {
 557             if( p_grad[y*i_src_visible+x] > 40 )
 558             {
 559                 switch( p_theta[y*i_src_visible+x] )
 560                 {
 561                     case THETA_Y:
 562                         if(    p_grad[y*i_src_visible+x] > p_grad[(y-1)*i_src_visible+x]
 563                             && p_grad[y*i_src_visible+x] > p_grad[(y+1)*i_src_visible+x] )
 564                         {
 565                             p_outpix[y*i_dst_pitch+x] = 0;
 566                             break;
 567                         } else goto colorize;
 568                     case THETA_P:
 569                         if(    p_grad[y*i_src_visible+x] > p_grad[(y-1)*i_src_visible+x-1]
 570                             && p_grad[y*i_src_visible+x] > p_grad[(y+1)*i_src_visible+x+1] )
 571                         {
 572                             p_outpix[y*i_dst_pitch+x] = 0;
 573                             break;
 574                         } else goto colorize;
 575                     case THETA_M:
 576                         if(    p_grad[y*i_src_visible+x] > p_grad[(y-1)*i_src_visible+x+1]
 577                             && p_grad[y*i_src_visible+x] > p_grad[(y+1)*i_src_visible+x-1] )
 578                         {
 579                             p_outpix[y*i_dst_pitch+x] = 0;
 580                             break;
 581                         } else goto colorize;
 582                     case THETA_X:
 583                         if(    p_grad[y*i_src_visible+x] > p_grad[y*i_src_visible+x-1]
 584                             && p_grad[y*i_src_visible+x] > p_grad[y*i_src_visible+x+1] )
 585                         {
 586                             p_outpix[y*i_dst_pitch+x] = 0;
 587                             break;
 588                         } else goto colorize;
 589                 }
 590             }
 591             else
 592             {
 593                 colorize:
 594                 if( p_filter->p_sys->b_cartoon )
 595                 {
 596                     if( p_smooth[y*i_src_visible+x] > 0xa0 )
 597                         p_outpix[y*i_dst_pitch+x] = (uint8_t)
 598                             0xff - ((0xff - p_inpix[y*i_src_pitch+x] )>>2);
 599                     else if( p_smooth[y*i_src_visible+x] > 0x70 )
 600                         p_outpix[y*i_dst_pitch+x] =(uint8_t)
 601                             0xa0 - ((0xa0 - p_inpix[y*i_src_pitch+x] )>>2);
 602                     else if( p_smooth[y*i_src_visible+x] > 0x28 )
 603                         p_outpix[y*i_dst_pitch+x] =(uint8_t)
 604                             0x70 - ((0x70 - p_inpix[y*i_src_pitch+x] )>>2);
 605                     else
 606                         p_outpix[y*i_dst_pitch+x] =(uint8_t)
 607                             0x28 - ((0x28 - p_inpix[y*i_src_pitch+x] )>>2);
 608                 }
 609             }
 610         }
 611     }
 612 }
 613
 614 /*****************************************************************************
 615  * FilterHough
 616  *****************************************************************************/
 617 #define p_pre_hough p_filter->p_sys->p_pre_hough
 618 static void FilterHough( filter_t *p_filter, picture_t *p_inpic,
 619                                              picture_t *p_outpic )
 620 {
 621     int x, y, i;
 622     int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 623     int i_dst_pitch = p_outpic->p[Y_PLANE].i_pitch;
 624     int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 625
 626     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
 627
 628     int i_diag = sqrt( i_num_lines * i_num_lines +
 629                         i_src_visible * i_src_visible);
 630     int i_max, i_phi_max, i_rho, i_rho_max;
 631     int i_nb_steps = 90;
 632     double d_step = M_PI / i_nb_steps;
 633     double d_sin;
 634     double d_cos;
 635     uint32_t *p_smooth;
 636     int *p_hough = malloc( i_diag * i_nb_steps * sizeof(int) );
 637     if( ! p_hough ) return;
 638     p_smooth = (uint32_t *)malloc( i_num_lines*i_src_visible*sizeof(uint32_t));
 639     if( !p_smooth ) return;
 640
 641     if( ! p_pre_hough )
 642     {
 643         msg_Dbg(p_filter, "Starting precalculation");
 644         p_pre_hough = malloc( i_num_lines*i_src_visible*i_nb_steps*sizeof(int));
 645         if( ! p_pre_hough ) return;
 646         for( i = 0 ; i < i_nb_steps ; i++)
 647         {
 648             d_sin = sin(d_step * i);
 649             d_cos = cos(d_step * i);
 650             for( y = 0 ; y < i_num_lines ; y++ )
 651                 for( x = 0 ; x < i_src_visible ; x++ )
 652                 {
 653                     p_pre_hough[(i*i_num_lines+y)*i_src_visible + x] =
 654                         ceil(x*d_sin + y*d_cos);
 655                 }
 656         }
 657         msg_Dbg(p_filter, "Precalculation done");
 658     }
 659
 660     p_filter->p_libvlc->pf_memset( p_hough, 0,
 661                                    i_diag * i_nb_steps * sizeof(int) );
 662
 663     p_filter->p_libvlc->pf_memcpy(
 664         p_outpic->p[Y_PLANE].p_pixels, p_inpic->p[Y_PLANE].p_pixels,
 665         p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 666     p_filter->p_libvlc->pf_memcpy(
 667         p_outpic->p[U_PLANE].p_pixels, p_inpic->p[U_PLANE].p_pixels,
 668         p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 669     p_filter->p_libvlc->pf_memcpy(
 670         p_outpic->p[V_PLANE].p_pixels, p_inpic->p[V_PLANE].p_pixels,
 671         p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 672
 673     GaussianConvolution( p_inpic, p_smooth );
 674
 675     /* Sobel gradient
 676
 677      | -1 0 1 |     |  1  2  1 |
 678      | -2 0 2 | and |  0  0  0 |
 679      | -1 0 1 |     | -1 -2 -1 | */
 680
 681     i_max = 0;
 682     i_rho_max = 0;
 683     i_phi_max = 0;
 684     for( y = 4; y < i_num_lines - 4; y++ )
 685     {
 686         for( x = 4; x < i_src_visible - 4; x++ )
 687         {
 688             uint32_t a =
 689             (
 690               abs(
 691                 ( ( p_smooth[(y-1)*i_src_visible+x]
 692                     - p_smooth[(y+1)*i_src_visible+x] ) <<1 )
 693                + ( p_smooth[(y-1)*i_src_visible+x-1]
 694                    - p_smooth[(y+1)*i_src_visible+x-1] )
 695                + ( p_smooth[(y-1)*i_src_visible+x+1]
 696                    - p_smooth[(y+1)*i_src_visible+x+1] )
 697               )
 698             +
 699               abs(
 700                 ( ( p_smooth[y*i_src_visible+x-1]
 701                     - p_smooth[y*i_src_visible+x+1] ) <<1 )
 702                + ( p_smooth[(y-1)*i_src_visible+x-1]
 703                    - p_smooth[(y-1)*i_src_visible+x+1] )
 704                + ( p_smooth[(y+1)*i_src_visible+x-1]
 705                    - p_smooth[(y+1)*i_src_visible+x+1] )
 706               )
 707             );
 708             if( a>>8 )
 709             {
 710                 for( i = 0 ; i < i_nb_steps ; i ++ )
 711                 {
 712                     i_rho = p_pre_hough[(i*i_num_lines+y)*i_src_visible + x];
 713                     if( p_hough[i_rho + i_diag/2 + i * i_diag]++ > i_max )
 714                     {
 715                         i_max = p_hough[i_rho + i_diag/2 + i * i_diag];
 716                         i_rho_max = i_rho;
 717                         i_phi_max = i;
 718                     }
 719                 }
 720             }
 721         }
 722     }
 723
 724     d_sin = sin(i_phi_max*d_step);
 725     d_cos = cos(i_phi_max*d_step);
 726     if( d_cos != 0 )
 727     {
 728         for( x = 0 ; x < i_src_visible ; x++ )
 729         {
 730             y = (i_rho_max - x * d_sin) / d_cos;
 731             if( y >= 0 && y < i_num_lines )
 732                 p_outpix[y*i_dst_pitch+x] = 255;
 733         }
 734     }
 735
 736     if( p_hough ) free( p_hough );
 737     if( p_smooth ) free( p_smooth );
 738 }
 739 #undef p_pre_hough
 740
 741
 742 static int GradientCallback( vlc_object_t *p_this, char const *psz_var,
 743                              vlc_value_t oldval, vlc_value_t newval,
 744                              void *p_data )
 745 {
 746     filter_sys_t *p_sys = (filter_sys_t *)p_data;
 747     if( !strcmp( psz_var, FILTER_PREFIX "mode" ) )
 748     {
 749         if( !strcmp( newval.psz_string, "gradient" ) )
 750         {
 751             p_sys->i_mode = GRADIENT;
 752         }
 753         else if( !strcmp( newval.psz_string, "edge" ) )
 754         {
 755             p_sys->i_mode = EDGE;
 756         }
 757         else if( !strcmp( newval.psz_string, "hough" ) )
 758         {
 759             p_sys->i_mode = HOUGH;
 760         }
 761         else
 762         {
 763             msg_Err( p_this, "no valid gradient mode provided (%s)", newval.psz_string );
 764             p_sys->i_mode = GRADIENT;
 765         }
 766     }
 767     else if( !strcmp( psz_var, FILTER_PREFIX "type" ) )
 768     {
 769         p_sys->i_gradient_type = newval.i_int;
 770     }
 771     else if( !strcmp( psz_var, FILTER_PREFIX "cartoon" ) )
 772     {
 773         p_sys->b_cartoon = newval.b_bool;
 774     }
 775     return VLC_SUCCESS;
 776 }