eb6f7c9523989e05c91ab6de498c9414e214a8ec
[vlc.git] / 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 <stdlib.h>                                      /* malloc(), free() */
29 #include <string.h>
30
31 #include <math.h>                                            /* sin(), cos() */
32
33 #include <vlc/vlc.h>
34 #include <vlc/sout.h>
35 #include <vlc/decoder.h>
36
37 #include "vlc_filter.h"
38
39 enum { GRADIENT, EDGE, HOUGH };
40
41 /*****************************************************************************
42  * Local prototypes
43  *****************************************************************************/
44 static int  Create    ( vlc_object_t * );
45 static void Destroy   ( vlc_object_t * );
46
47 static picture_t *Filter( filter_t *, picture_t * );
48
49 static void FilterGradient( filter_t *, picture_t *, picture_t * );
50 static void FilterEdge    ( filter_t *, picture_t *, picture_t * );
51 static void FilterHough   ( filter_t *, picture_t *, picture_t * );
52
53 /*****************************************************************************
54  * Module descriptor
55  *****************************************************************************/
56 #define MODE_TEXT N_("Distort mode")
57 #define MODE_LONGTEXT N_("Distort mode, one of \"gradient\", \"edge\" and \"hough\".")
58
59 #define GRADIENT_TEXT N_("Gradient image type")
60 #define GRADIENT_LONGTEXT N_("Gradient image type (0 or 1). 0 will " \
61         "turn the image to white while 1 will keep colors." )
62
63 #define CARTOON_TEXT N_("Apply cartoon effect")
64 #define CARTOON_LONGTEXT N_("Apply cartoon effect. It is only used by " \
65     "\"gradient\" and \"edge\".")
66
67 static char *mode_list[] = { "gradient", "edge", "hough" };
68 static char *mode_list_text[] = { N_("Gradient"), N_("Edge"), N_("Hough") };
69
70 #define FILTER_PREFIX "gradient-"
71
72 vlc_module_begin();
73     set_description( _("Gradient video filter") );
74     set_shortname( N_( "Gradient" ));
75     set_capability( "video filter2", 0 );
76     set_category( CAT_VIDEO );
77     set_subcategory( SUBCAT_VIDEO_VFILTER );
78
79     add_string( FILTER_PREFIX "mode", "gradient", NULL,
80                 MODE_TEXT, MODE_LONGTEXT, VLC_FALSE );
81         change_string_list( mode_list, mode_list_text, 0 );
82
83     add_integer_with_range( FILTER_PREFIX "type", 0, 0, 1, NULL,
84                 GRADIENT_TEXT, GRADIENT_LONGTEXT, VLC_FALSE );
85     add_bool( FILTER_PREFIX "cartoon", 1, NULL,
86                 CARTOON_TEXT, CARTOON_LONGTEXT, VLC_FALSE );
87
88     add_shortcut( "gradient" );
89     set_callbacks( Create, Destroy );
90 vlc_module_end();
91
92 static const char *ppsz_filter_options[] = {
93     "mode", "type", "cartoon", NULL
94 };
95
96 /*****************************************************************************
97  * vout_sys_t: Distort video output method descriptor
98  *****************************************************************************
99  * This structure is part of the video output thread descriptor.
100  * It describes the Distort specific properties of an output thread.
101  *****************************************************************************/
102 struct filter_sys_t
103 {
104     int i_mode;
105
106     /* For the gradient mode */
107     int i_gradient_type;
108     vlc_bool_t b_cartoon;
109
110     uint32_t *p_buf32;
111     uint32_t *p_buf32_bis;
112     uint8_t *p_buf8;
113
114     /* For hough mode */
115     int *p_pre_hough;
116 };
117
118 /*****************************************************************************
119  * Create: allocates Distort video thread output method
120  *****************************************************************************
121  * This function allocates and initializes a Distort vout method.
122  *****************************************************************************/
123 static int Create( vlc_object_t *p_this )
124 {
125     filter_t *p_filter = (filter_t *)p_this;
126     char *psz_method;
127
128     /* Allocate structure */
129     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
130     if( p_filter->p_sys == NULL )
131     {
132         msg_Err( p_filter, "out of memory" );
133         return VLC_ENOMEM;
134     }
135
136     p_filter->pf_video_filter = Filter;
137
138     p_filter->p_sys->p_pre_hough = NULL;
139
140     sout_CfgParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
141                    p_filter->p_cfg );
142
143     var_Create( p_filter, FILTER_PREFIX "mode",
144                 VLC_VAR_STRING | VLC_VAR_DOINHERIT );
145     var_Create( p_filter, FILTER_PREFIX "type",
146                 VLC_VAR_STRING | VLC_VAR_DOINHERIT );
147     var_Create( p_filter, FILTER_PREFIX "cartoon",
148                 VLC_VAR_BOOL | VLC_VAR_DOINHERIT );
149
150     if( !(psz_method = var_GetString( p_filter, FILTER_PREFIX "mode" )) )
151     {
152         msg_Err( p_filter, "configuration variable "
153                  FILTER_PREFIX "mode empty" );
154         p_filter->p_sys->i_mode = GRADIENT;
155     }
156     else
157     {
158         if( !strcmp( psz_method, "gradient" ) )
159         {
160             p_filter->p_sys->i_mode = GRADIENT;
161         }
162         else if( !strcmp( psz_method, "edge" ) )
163         {
164             p_filter->p_sys->i_mode = EDGE;
165         }
166         else if( !strcmp( psz_method, "hough" ) )
167         {
168             p_filter->p_sys->i_mode = HOUGH;
169         }
170         else
171         {
172             msg_Err( p_filter, "no valid gradient mode provided" );
173             p_filter->p_sys->i_mode = GRADIENT;
174         }
175     }
176     free( psz_method );
177
178     p_filter->p_sys->i_gradient_type =
179         var_GetInteger( p_filter, FILTER_PREFIX "type" );
180     p_filter->p_sys->b_cartoon =
181         var_GetInteger( p_filter, FILTER_PREFIX "cartoon" );
182
183     p_filter->p_sys->p_buf32 = NULL;
184     p_filter->p_sys->p_buf32_bis = NULL;
185     p_filter->p_sys->p_buf8 = NULL;
186
187     return VLC_SUCCESS;
188 }
189
190 /*****************************************************************************
191  * Destroy: destroy Distort video thread output method
192  *****************************************************************************
193  * Terminate an output method created by DistortCreateOutputMethod
194  *****************************************************************************/
195 static void Destroy( vlc_object_t *p_this )
196 {
197     filter_t *p_filter = (filter_t *)p_this;
198
199     free( p_filter->p_sys->p_buf32 );
200     free( p_filter->p_sys->p_buf32_bis );
201     free( p_filter->p_sys->p_buf8 );
202     free( p_filter->p_sys->p_pre_hough );
203
204     free( p_filter->p_sys );
205 }
206
207 /*****************************************************************************
208  * Render: displays previously rendered output
209  *****************************************************************************
210  * This function send the currently rendered image to Distort image, waits
211  * until it is displayed and switch the two rendering buffers, preparing next
212  * frame.
213  *****************************************************************************/
214 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
215 {
216     picture_t *p_outpic;
217
218     if( !p_pic ) return NULL;
219
220     p_outpic = p_filter->pf_vout_buffer_new( p_filter );
221     if( !p_outpic )
222     {
223         msg_Warn( p_filter, "can't get output picture" );
224         if( p_pic->pf_release )
225             p_pic->pf_release( p_pic );
226         return NULL;
227     }
228
229     switch( p_filter->p_sys->i_mode )
230     {
231         case EDGE:
232             FilterEdge( p_filter, p_pic, p_outpic );
233             break;
234
235         case GRADIENT:
236             FilterGradient( p_filter, p_pic, p_outpic );
237             break;
238
239         case HOUGH:
240             FilterHough( p_filter, p_pic, p_outpic );
241             break;
242
243         default:
244             break;
245     }
246
247     p_outpic->date = p_pic->date;
248     p_outpic->b_force = p_pic->b_force;
249     p_outpic->i_nb_fields = p_pic->i_nb_fields;
250     p_outpic->b_progressive = p_pic->b_progressive;
251     p_outpic->b_top_field_first = p_pic->b_top_field_first;
252
253     if( p_pic->pf_release )
254         p_pic->pf_release( p_pic );
255
256     return p_outpic;
257 }
258
259
260 /*****************************************************************************
261  * Gaussian Convolution
262  *****************************************************************************
263  *    Gaussian convolution ( sigma == 1.4 )
264  *
265  *    |  2  4  5  4  2  |   |  2  4  4  4  2 |
266  *    |  4  9 12  9  4  |   |  4  8 12  8  4 |
267  *    |  5 12 15 12  5  | ~ |  4 12 16 12  4 |
268  *    |  4  9 12  9  4  |   |  4  8 12  8  4 |
269  *    |  2  4  5  4  2  |   |  2  4  4  4  2 |
270  *****************************************************************************/
271 static void GaussianConvolution( picture_t *p_inpic, uint32_t *p_smooth )
272 {
273     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
274     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
275     const int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
276     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
277
278     int x,y;
279     for( y = 2; y < i_num_lines - 2; y++ )
280     {
281         for( x = 2; x < i_src_visible - 2; x++ )
282         {
283             p_smooth[y*i_src_visible+x] = (uint32_t)(
284               /* 2 rows up */
285                 ( p_inpix[(y-2)*i_src_pitch+x-2] )
286               + ((p_inpix[(y-2)*i_src_pitch+x-1]
287               +   p_inpix[(y-2)*i_src_pitch+x]
288               +   p_inpix[(y-2)*i_src_pitch+x+1])<<1 )
289               + ( p_inpix[(y-2)*i_src_pitch+x+2] )
290               /* 1 row up */
291               + ((p_inpix[(y-1)*i_src_pitch+x-2]
292               + ( p_inpix[(y-1)*i_src_pitch+x-1]<<1 )
293               + ( p_inpix[(y-1)*i_src_pitch+x]*3 )
294               + ( p_inpix[(y-1)*i_src_pitch+x+1]<<1 )
295               +   p_inpix[(y-1)*i_src_pitch+x+2]
296               /* */
297               +   p_inpix[y*i_src_pitch+x-2]
298               + ( p_inpix[y*i_src_pitch+x-1]*3 )
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               /* 1 row down */
303               +   p_inpix[(y+1)*i_src_pitch+x-2]
304               + ( p_inpix[(y+1)*i_src_pitch+x-1]<<1 )
305               + ( p_inpix[(y+1)*i_src_pitch+x]*3 )
306               + ( p_inpix[(y+1)*i_src_pitch+x+1]<<1 )
307               +   p_inpix[(y+1)*i_src_pitch+x+2] )<<1 )
308               /* 2 rows down */
309               + ( p_inpix[(y+2)*i_src_pitch+x-2] )
310               + ((p_inpix[(y+2)*i_src_pitch+x-1]
311               +   p_inpix[(y+2)*i_src_pitch+x]
312               +   p_inpix[(y+2)*i_src_pitch+x+1])<<1 )
313               + ( p_inpix[(y+2)*i_src_pitch+x+2] )
314               ) >> 6 /* 115 */;
315         }
316     }
317 }
318
319 /*****************************************************************************
320  * FilterGradient: Sobel
321  *****************************************************************************/
322 static void FilterGradient( filter_t *p_filter, picture_t *p_inpic,
323                                                 picture_t *p_outpic )
324 {
325     int x, y;
326     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
327     const int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
328     const int i_dst_pitch = p_outpic->p[Y_PLANE].i_pitch;
329     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
330
331     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
332     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
333
334     uint32_t *p_smooth;
335     if( !p_filter->p_sys->p_buf32 )
336         p_filter->p_sys->p_buf32 =
337         (uint32_t *)malloc( i_num_lines * i_src_visible * sizeof(uint32_t));
338     p_smooth = p_filter->p_sys->p_buf32;
339
340     if( !p_smooth ) return;
341
342     if( p_filter->p_sys->b_cartoon )
343     {
344         p_filter->p_libvlc->pf_memcpy( p_outpic->p[U_PLANE].p_pixels,
345             p_inpic->p[U_PLANE].p_pixels,
346             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
347         p_filter->p_libvlc->pf_memcpy( p_outpic->p[V_PLANE].p_pixels,
348             p_inpic->p[V_PLANE].p_pixels,
349             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
350     }
351     else
352     {
353         p_filter->p_libvlc->pf_memset( p_outpic->p[U_PLANE].p_pixels, 0x80,
354             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
355         p_filter->p_libvlc->pf_memset( p_outpic->p[V_PLANE].p_pixels, 0x80,
356             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
357     }
358
359     GaussianConvolution( p_inpic, p_smooth );
360
361     /* Sobel gradient
362
363      | -1 0 1 |     |  1  2  1 |
364      | -2 0 2 | and |  0  0  0 |
365      | -1 0 1 |     | -1 -2 -1 | */
366
367 #define FOR                                                     \
368     for( y = 1; y < i_num_lines - 1; y++ )                      \
369     {                                                           \
370         for( x = 1; x < i_src_visible - 1; x++ )                \
371         {                                                       \
372             const uint32_t a =                                  \
373             (                                                   \
374               abs(                                              \
375                  ( p_smooth[(y-1)*i_src_visible+x-1]            \
376                    - p_smooth[(y+1)*i_src_visible+x-1] )        \
377                + ( ( p_smooth[(y-1)*i_src_visible+x]            \
378                     - p_smooth[(y+1)*i_src_visible+x] ) <<1 )   \
379                + ( p_smooth[(y-1)*i_src_visible+x+1]            \
380                    - p_smooth[(y+1)*i_src_visible+x+1] )        \
381               )                                                 \
382             +                                                   \
383               abs(                                              \
384                  ( p_smooth[(y-1)*i_src_visible+x-1]            \
385                    - p_smooth[(y-1)*i_src_visible+x+1] )        \
386                + ( ( p_smooth[y*i_src_visible+x-1]              \
387                     - p_smooth[y*i_src_visible+x+1] ) <<1 )     \
388                + ( p_smooth[(y+1)*i_src_visible+x-1]            \
389                    - p_smooth[(y+1)*i_src_visible+x+1] )        \
390               )                                                 \
391             );
392     if( p_filter->p_sys->i_gradient_type )
393     {
394         if( p_filter->p_sys->b_cartoon )
395         {
396             FOR
397             if( a > 60 )
398             {
399                 p_outpix[y*i_dst_pitch+x] = 0x00;
400             }
401             else
402             {
403                 if( p_smooth[y*i_src_visible+x] > 0xa0 )
404                     p_outpix[y*i_dst_pitch+x] =
405                         0xff - ((0xff - p_inpix[y*i_src_pitch+x] )>>2);
406                 else if( p_smooth[y*i_src_visible+x] > 0x70 )
407                     p_outpix[y*i_dst_pitch+x] =
408                         0xa0 - ((0xa0 - p_inpix[y*i_src_pitch+x] )>>2);
409                 else if( p_smooth[y*i_src_visible+x] > 0x28 )
410                     p_outpix[y*i_dst_pitch+x] =
411                         0x70 - ((0x70 - p_inpix[y*i_src_pitch+x] )>>2);
412                 else
413                     p_outpix[y*i_dst_pitch+x] =
414                         0x28 - ((0x28 - p_inpix[y*i_src_pitch+x] )>>2);
415             }
416             }}
417         }
418         else
419         {
420             FOR
421             if( a>>8 )
422                 p_outpix[y*i_dst_pitch+x] = 255;
423             else
424                 p_outpix[y*i_dst_pitch+x] = (uint8_t)a;
425             }}
426         }
427     }
428     else
429     {
430         FOR
431         if( a>>8 )
432             p_outpix[y*i_dst_pitch+x] = 0;
433         else
434             p_outpix[y*i_dst_pitch+x] = 0xff-(uint8_t)a;
435         }}
436     }
437 #undef FOR
438 }
439
440 /*****************************************************************************
441  * FilterEdge: Canny edge detection algorithm
442  *****************************************************************************
443  * http://fourier.eng.hmc.edu/e161/lectures/canny/node1.html
444  * (well ... my implementation isn't really the canny algorithm ... but some
445  * ideas are the same)
446  *****************************************************************************/
447 /* angle : | */
448 #define THETA_Y 0
449 /* angle : - */
450 #define THETA_X 1
451 /* angle : / */
452 #define THETA_P 2
453 /* angle : \ */
454 #define THETA_M 3
455 static void FilterEdge( filter_t *p_filter, picture_t *p_inpic,
456                                             picture_t *p_outpic )
457 {
458     int x, y;
459
460     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
461     const int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
462     const int i_dst_pitch = p_outpic->p[Y_PLANE].i_pitch;
463     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
464
465     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
466     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
467
468     uint32_t *p_smooth;
469     uint32_t *p_grad;
470     uint8_t *p_theta;
471
472     if( !p_filter->p_sys->p_buf32 )
473         p_filter->p_sys->p_buf32 =
474         (uint32_t *)malloc( i_num_lines * i_src_visible * sizeof(uint32_t));
475     p_smooth = p_filter->p_sys->p_buf32;
476
477     if( !p_filter->p_sys->p_buf32_bis )
478         p_filter->p_sys->p_buf32_bis =
479         (uint32_t *)malloc( i_num_lines * i_src_visible * sizeof(uint32_t));
480     p_grad = p_filter->p_sys->p_buf32_bis;
481
482     if( !p_filter->p_sys->p_buf8 )
483         p_filter->p_sys->p_buf8 =
484         (uint8_t *)malloc( i_num_lines * i_src_visible * sizeof(uint8_t));
485     p_theta = p_filter->p_sys->p_buf8;
486
487     if( !p_smooth || !p_grad || !p_theta ) return;
488
489     if( p_filter->p_sys->b_cartoon )
490     {
491         p_filter->p_libvlc->pf_memcpy( p_outpic->p[U_PLANE].p_pixels,
492             p_inpic->p[U_PLANE].p_pixels,
493             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
494         p_filter->p_libvlc->pf_memcpy( p_outpic->p[V_PLANE].p_pixels,
495             p_inpic->p[V_PLANE].p_pixels,
496             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
497     }
498     else
499     {
500         p_filter->p_libvlc->pf_memset( p_outpic->p[Y_PLANE].p_pixels, 0xff,
501               p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
502         p_filter->p_libvlc->pf_memset( p_outpic->p[U_PLANE].p_pixels, 0x80,
503             p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
504         memset( p_outpic->p[V_PLANE].p_pixels, 0x80,
505             p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
506     }
507
508     GaussianConvolution( p_inpic, p_smooth );
509
510     /* Sobel gradient
511
512      | -1 0 1 |     |  1  2  1 |
513      | -2 0 2 | and |  0  0  0 |
514      | -1 0 1 |     | -1 -2 -1 | */
515
516     for( y = 1; y < i_num_lines - 1; y++ )
517     {
518         for( x = 1; x < i_src_visible - 1; x++ )
519         {
520
521             const int gradx =
522                  ( p_smooth[(y-1)*i_src_visible+x-1]
523                    - p_smooth[(y+1)*i_src_visible+x-1] )
524                + ( ( p_smooth[(y-1)*i_src_visible+x]
525                     - p_smooth[(y+1)*i_src_visible+x] ) <<1 )
526                + ( p_smooth[(y-1)*i_src_visible+x+1]
527                    - p_smooth[(y+1)*i_src_visible+x+1] );
528             const int grady =
529                  ( p_smooth[(y-1)*i_src_visible+x-1]
530                    - p_smooth[(y-1)*i_src_visible+x+1] )
531                + ( ( p_smooth[y*i_src_visible+x-1]
532                     - p_smooth[y*i_src_visible+x+1] ) <<1 )
533                + ( p_smooth[(y+1)*i_src_visible+x-1]
534                    - p_smooth[(y+1)*i_src_visible+x+1] );
535
536             p_grad[y*i_src_visible+x] = (uint32_t)(abs( gradx ) + abs( grady ));
537
538             /* tan( 22.5 ) = 0,414213562 .. * 128 = 53
539              * tan( 26,565051177 ) = 0.5
540              * tan( 45 + 22.5 ) = 2,414213562 .. * 128 = 309
541              * tan( 63,434948823 ) 2 */
542             if( (grady<<1) > gradx )
543                 p_theta[y*i_src_visible+x] = THETA_P;
544             else if( (grady<<1) < -gradx )
545                 p_theta[y*i_src_visible+x] = THETA_M;
546             else if( !gradx || abs(grady) > abs(gradx)<<1 )
547                 p_theta[y*i_src_visible+x] = THETA_Y;
548             else
549                 p_theta[y*i_src_visible+x] = THETA_X;
550         }
551     }
552
553     /* edge computing */
554     for( y = 1; y < i_num_lines - 1; y++ )
555     {
556         for( x = 1; x < i_src_visible - 1; x++ )
557         {
558             if( p_grad[y*i_src_visible+x] > 40 )
559             {
560                 switch( p_theta[y*i_src_visible+x] )
561                 {
562                     case THETA_Y:
563                         if(    p_grad[y*i_src_visible+x] > p_grad[(y-1)*i_src_visible+x]
564                             && p_grad[y*i_src_visible+x] > p_grad[(y+1)*i_src_visible+x] )
565                         {
566                             p_outpix[y*i_dst_pitch+x] = 0;
567                             break;
568                         } else goto colorize;
569                     case THETA_P:
570                         if(    p_grad[y*i_src_visible+x] > p_grad[(y-1)*i_src_visible+x-1]
571                             && p_grad[y*i_src_visible+x] > p_grad[(y+1)*i_src_visible+x+1] )
572                         {
573                             p_outpix[y*i_dst_pitch+x] = 0;
574                             break;
575                         } else goto colorize;
576                     case THETA_M:
577                         if(    p_grad[y*i_src_visible+x] > p_grad[(y-1)*i_src_visible+x+1]
578                             && p_grad[y*i_src_visible+x] > p_grad[(y+1)*i_src_visible+x-1] )
579                         {
580                             p_outpix[y*i_dst_pitch+x] = 0;
581                             break;
582                         } else goto colorize;
583                     case THETA_X:
584                         if(    p_grad[y*i_src_visible+x] > p_grad[y*i_src_visible+x-1]
585                             && p_grad[y*i_src_visible+x] > p_grad[y*i_src_visible+x+1] )
586                         {
587                             p_outpix[y*i_dst_pitch+x] = 0;
588                             break;
589                         } else goto colorize;
590                 }
591             }
592             else
593             {
594                 colorize:
595                 if( p_filter->p_sys->b_cartoon )
596                 {
597                     if( p_smooth[y*i_src_visible+x] > 0xa0 )
598                         p_outpix[y*i_dst_pitch+x] = (uint8_t)
599                             0xff - ((0xff - p_inpix[y*i_src_pitch+x] )>>2);
600                     else if( p_smooth[y*i_src_visible+x] > 0x70 )
601                         p_outpix[y*i_dst_pitch+x] =(uint8_t)
602                             0xa0 - ((0xa0 - p_inpix[y*i_src_pitch+x] )>>2);
603                     else if( p_smooth[y*i_src_visible+x] > 0x28 )
604                         p_outpix[y*i_dst_pitch+x] =(uint8_t)
605                             0x70 - ((0x70 - p_inpix[y*i_src_pitch+x] )>>2);
606                     else
607                         p_outpix[y*i_dst_pitch+x] =(uint8_t)
608                             0x28 - ((0x28 - p_inpix[y*i_src_pitch+x] )>>2);
609                 }
610             }
611         }
612     }
613 }
614
615 /*****************************************************************************
616  * FilterHough
617  *****************************************************************************/
618 #define p_pre_hough p_filter->p_sys->p_pre_hough
619 static void FilterHough( filter_t *p_filter, picture_t *p_inpic,
620                                              picture_t *p_outpic )
621 {
622     int x, y, i;
623     int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
624     int i_dst_pitch = p_outpic->p[Y_PLANE].i_pitch;
625     int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
626
627     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
628
629     int i_diag = sqrt( i_num_lines * i_num_lines +
630                         i_src_visible * i_src_visible);
631     int i_max, i_phi_max, i_rho, i_rho_max;
632     int i_nb_steps = 90;
633     double d_step = M_PI / i_nb_steps;
634     double d_sin;
635     double d_cos;
636     uint32_t *p_smooth;
637     int *p_hough = malloc( i_diag * i_nb_steps * sizeof(int) );
638     if( ! p_hough ) return;
639     p_smooth = (uint32_t *)malloc( i_num_lines*i_src_visible*sizeof(uint32_t));
640     if( !p_smooth ) return;
641
642     if( ! p_pre_hough )
643     {
644         msg_Dbg(p_filter, "Starting precalculation");
645         p_pre_hough = malloc( i_num_lines*i_src_visible*i_nb_steps*sizeof(int));
646         if( ! p_pre_hough ) return;
647         for( i = 0 ; i < i_nb_steps ; i++)
648         {
649             d_sin = sin(d_step * i);
650             d_cos = cos(d_step * i);
651             for( y = 0 ; y < i_num_lines ; y++ )
652                 for( x = 0 ; x < i_src_visible ; x++ )
653                 {
654                     p_pre_hough[(i*i_num_lines+y)*i_src_visible + x] =
655                         ceil(x*d_sin + y*d_cos);
656                 }
657         }
658         msg_Dbg(p_filter, "Precalculation done");
659     }
660
661     memset( p_hough, 0, 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