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