Correctly fix the segfault if no mask is provided.
[vlc.git] / modules / video_filter / erase.c
1 /*****************************************************************************
2  * erase.c : logo erase video filter
3  *****************************************************************************
4  * Copyright (C) 2007 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Antoine Cellerier <dionoea -at- videolan -dot- org>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22  *****************************************************************************/
23
24 /*****************************************************************************
25  * Preamble
26  *****************************************************************************/
27
28 #ifdef HAVE_CONFIG_H
29 # include "config.h"
30 #endif
31
32 #include <vlc_common.h>
33 #include <vlc_plugin.h>
34 #include <vlc_sout.h>
35 #include <vlc_image.h>
36
37 #include <vlc_filter.h>
38 #include "filter_picture.h"
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 void FilterErase( filter_t *, picture_t *, picture_t * );
48 static int EraseCallback( vlc_object_t *, char const *,
49                           vlc_value_t, vlc_value_t, void * );
50
51 /*****************************************************************************
52  * Module descriptor
53  *****************************************************************************/
54 #define MASK_TEXT N_("Image mask")
55 #define MASK_LONGTEXT N_("Image mask. Pixels with an alpha value greater than 50% will be erased.")
56
57 #define POSX_TEXT N_("X coordinate")
58 #define POSX_LONGTEXT N_("X coordinate of the mask.")
59 #define POSY_TEXT N_("Y coordinate")
60 #define POSY_LONGTEXT N_("Y coordinate of the mask.")
61
62 #define CFG_PREFIX "erase-"
63
64 vlc_module_begin ()
65     set_description( N_("Erase video filter") )
66     set_shortname( N_( "Erase" ))
67     set_capability( "video filter2", 0 )
68     set_category( CAT_VIDEO )
69     set_subcategory( SUBCAT_VIDEO_VFILTER )
70
71     add_file( CFG_PREFIX "mask", NULL, NULL,
72               MASK_TEXT, MASK_LONGTEXT, false )
73     add_integer( CFG_PREFIX "x", 0, NULL, POSX_TEXT, POSX_LONGTEXT, false )
74     add_integer( CFG_PREFIX "y", 0, NULL, POSY_TEXT, POSY_LONGTEXT, false )
75
76     add_shortcut( "erase" )
77     set_callbacks( Create, Destroy )
78 vlc_module_end ()
79
80 static const char *const ppsz_filter_options[] = {
81     "mask", "x", "y", NULL
82 };
83
84 /*****************************************************************************
85  * filter_sys_t
86  *****************************************************************************/
87 struct filter_sys_t
88 {
89     int i_x;
90     int i_y;
91     picture_t *p_mask;
92     vlc_mutex_t lock;
93 };
94
95 static void LoadMask( filter_t *p_filter, const char *psz_filename )
96 {
97     image_handler_t *p_image;
98     video_format_t fmt_in, fmt_out;
99     picture_t *p_old_mask = p_filter->p_sys->p_mask;
100     memset( &fmt_in, 0, sizeof( video_format_t ) );
101     memset( &fmt_out, 0, sizeof( video_format_t ) );
102     fmt_out.i_chroma = VLC_CODEC_YUVA;
103     p_image = image_HandlerCreate( p_filter );
104     p_filter->p_sys->p_mask =
105         image_ReadUrl( p_image, psz_filename, &fmt_in, &fmt_out );
106     if( p_filter->p_sys->p_mask )
107     {
108         if( p_old_mask )
109             picture_Release( p_old_mask );
110     }
111     else if( p_old_mask )
112     {
113         p_filter->p_sys->p_mask = p_old_mask;
114         msg_Err( p_filter, "Error while loading new mask. Keeping old mask." );
115     }
116     else
117         msg_Err( p_filter, "Error while loading new mask. No mask available." );
118
119     image_HandlerDelete( p_image );
120 }
121
122 /*****************************************************************************
123  * Create
124  *****************************************************************************/
125 static int Create( vlc_object_t *p_this )
126 {
127     filter_t *p_filter = (filter_t *)p_this;
128     filter_sys_t *p_sys;
129     char *psz_filename;
130
131     switch( p_filter->fmt_in.video.i_chroma )
132     {
133         case VLC_CODEC_I420:
134         case VLC_CODEC_J420:
135         case VLC_CODEC_YV12:
136
137         case VLC_CODEC_I422:
138         case VLC_CODEC_J422:
139             break;
140
141         default:
142             msg_Err( p_filter, "Unsupported input chroma (%4s)",
143                      (char*)&(p_filter->fmt_in.video.i_chroma) );
144             return VLC_EGENERIC;
145     }
146
147     /* Allocate structure */
148     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
149     if( p_filter->p_sys == NULL )
150         return VLC_ENOMEM;
151     p_sys = p_filter->p_sys;
152
153     p_filter->pf_video_filter = Filter;
154
155     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
156                        p_filter->p_cfg );
157
158     psz_filename =
159         var_CreateGetNonEmptyStringCommand( p_filter, CFG_PREFIX "mask" );
160
161     if( !psz_filename )
162     {
163         msg_Err( p_filter, "Missing 'mask' option value." );
164         free( p_sys );
165         return VLC_EGENERIC;
166     }
167
168     p_sys->p_mask = NULL;
169     LoadMask( p_filter, psz_filename );
170     free( psz_filename );
171
172     p_sys->i_x = var_CreateGetIntegerCommand( p_filter, CFG_PREFIX "x" );
173     p_sys->i_y = var_CreateGetIntegerCommand( p_filter, CFG_PREFIX "y" );
174
175     vlc_mutex_init( &p_sys->lock );
176     var_AddCallback( p_filter, CFG_PREFIX "x", EraseCallback, p_sys );
177     var_AddCallback( p_filter, CFG_PREFIX "y", EraseCallback, p_sys );
178     var_AddCallback( p_filter, CFG_PREFIX "mask", EraseCallback, p_sys );
179
180     return VLC_SUCCESS;
181 }
182
183 /*****************************************************************************
184  * Destroy
185  *****************************************************************************/
186 static void Destroy( vlc_object_t *p_this )
187 {
188     filter_t *p_filter = (filter_t *)p_this;
189     filter_sys_t *p_sys = p_filter->p_sys;
190     if( p_sys->p_mask )
191         picture_Release( p_sys->p_mask );
192
193     var_DelCallback( p_filter, CFG_PREFIX "x", EraseCallback, p_sys );
194     var_DelCallback( p_filter, CFG_PREFIX "y", EraseCallback, p_sys );
195     var_DelCallback( p_filter, CFG_PREFIX "mask", EraseCallback, p_sys );
196     vlc_mutex_destroy( &p_sys->lock );
197
198     free( p_filter->p_sys );
199 }
200
201 /*****************************************************************************
202  * Filter
203  *****************************************************************************/
204 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
205 {
206     picture_t *p_outpic;
207     filter_sys_t *p_sys = p_filter->p_sys;
208
209     if( !p_pic ) return NULL;
210
211     p_outpic = filter_NewPicture( p_filter );
212     if( !p_outpic )
213     {
214         picture_Release( p_pic );
215         return NULL;
216     }
217
218     /* If the mask is empty: just copy the image */
219     vlc_mutex_lock( &p_sys->lock );
220     if( p_sys->p_mask )
221         FilterErase( p_filter, p_pic, p_outpic );
222     else
223         picture_CopyPixels( p_outpic, p_pic );
224     vlc_mutex_unlock( &p_sys->lock );
225
226     return CopyInfoAndRelease( p_outpic, p_pic );
227 }
228
229 /*****************************************************************************
230  * FilterErase
231  *****************************************************************************/
232 static void FilterErase( filter_t *p_filter, picture_t *p_inpic,
233                                              picture_t *p_outpic )
234 {
235     filter_sys_t *p_sys = p_filter->p_sys;
236
237     const int i_mask_pitch = p_sys->p_mask->A_PITCH;
238     const int i_mask_visible_pitch = p_sys->p_mask->p[A_PLANE].i_visible_pitch;
239     const int i_mask_visible_lines = p_sys->p_mask->p[A_PLANE].i_visible_lines;
240
241     for( int i_plane = 0; i_plane < p_inpic->i_planes; i_plane++ )
242     {
243         const int i_pitch = p_inpic->p[i_plane].i_pitch;
244         const int i_2pitch = i_pitch<<1;
245         const int i_visible_pitch = p_inpic->p[i_plane].i_visible_pitch;
246         const int i_lines = p_inpic->p[i_plane].i_lines;
247         const int i_visible_lines = p_inpic->p[i_plane].i_visible_lines;
248
249         uint8_t *p_inpix = p_inpic->p[i_plane].p_pixels;
250         uint8_t *p_outpix = p_outpic->p[i_plane].p_pixels;
251         uint8_t *p_mask = p_sys->p_mask->A_PIXELS;
252         int i_x = p_sys->i_x, i_y = p_sys->i_y;
253
254         int x, y;
255         int i_height = i_mask_visible_lines;
256         int i_width  = i_mask_visible_pitch;
257
258         const bool b_line_factor = ( i_plane /* U_PLANE or V_PLANE */ &&
259             !( p_inpic->format.i_chroma == VLC_CODEC_I422
260             || p_inpic->format.i_chroma == VLC_CODEC_J422 ) );
261
262         if( i_plane ) /* U_PLANE or V_PLANE */
263         {
264             i_width  >>= 1;
265             i_x      >>= 1;
266         }
267         if( b_line_factor )
268         {
269             i_height >>= 1;
270             i_y      >>= 1;
271         }
272         i_height = __MIN( i_visible_lines - i_y, i_height );
273         i_width  = __MIN( i_visible_pitch - i_x, i_width  );
274
275         /* Copy original pixel buffer */
276         vlc_memcpy( p_outpix, p_inpix, i_pitch * i_lines );
277
278         /* Horizontal linear interpolation of masked areas */
279         p_outpix = p_outpic->p[i_plane].p_pixels + i_y*i_pitch + i_x;
280         for( y = 0; y < i_height;
281              y++, p_mask += i_mask_pitch, p_outpix += i_pitch )
282         {
283             uint8_t prev, next = 0;
284             int prev_x = -1, next_x = -2;
285             int quot = 0;
286
287             /* Find a suitable value for the previous color to use when
288              * interpoling a masked pixel's value */
289             if( i_x )
290             {
291                 /* There are pixels before current position on the same line.
292                  * Use those */
293                 prev = *(p_outpix-1);
294             }
295             else if( y || i_y )
296             {
297                 /* This is the first pixel on a line but there other lines
298                  * above us. Use the pixel right above */
299                 prev = *(p_outpix-i_pitch);
300             }
301             else
302             {
303                 /* We're in the upper left corner. This sucks. We can't use
304                  * any previous value, so we'll use a dummy one. In most
305                  * cases this dummy value will be fixed later on in the
306                  * algorithm */
307                 prev = 0xff;
308             }
309
310             for( x = 0; x < i_width; x++ )
311             {
312                 if( p_mask[i_plane?x<<1:x] > 127 )
313                 {
314                     /* This is a masked pixel */
315                     if( next_x <= prev_x )
316                     {
317                         int x0;
318                         /* Look for the next non masked pixel on the same
319                          * line (inside the mask's bounding box) */
320                         for( x0 = x; x0 < i_width; x0++ )
321                         {
322                             if( p_mask[i_plane?x0<<1:x0] <= 127 )
323                             {
324                                 /* We found an unmasked pixel. Victory! */
325                                 next_x = x0;
326                                 next = p_outpix[x0];
327                                 break;
328                             }
329                         }
330                         if( next_x <= prev_x )
331                         {
332                             /* We didn't find an unmasked pixel yet. Try
333                              * harder */
334                             if( x0 == x ) x0++;
335                             if( x0 < i_visible_pitch )
336                             {
337                                 /* If we didn't find a non masked pixel on the
338                                  * same line inside the mask's bounding box,
339                                  * use the next pixel on the line (except if
340                                  * it doesn't exist) */
341                                 next_x = x0;
342                                 next = p_outpix[x0];
343                             }
344                             else
345                             {
346                                 /* The last pixel on the line is masked,
347                                  * so we'll use the "prev" value. A better
348                                  * approach would be to use unmasked pixels
349                                  * at the end of adjacent lines */
350                                 next_x = x0;
351                                 next = prev;
352                             }
353                         }
354                         if( !( i_x || y || i_y ) )
355                             /* We were unable to find a suitable value for
356                              * the previous color (which means that we are
357                              * on the first line in the upper left corner)
358                              */
359                             prev = next;
360
361                         /* Divide only once instead of next_x-prev_x-1 times */
362                         quot = ((next-prev)<<16)/(next_x-prev_x);
363                     }
364                     /* Interpolate new value, and round correctly */
365                     p_outpix[x] = prev + (((x-prev_x)*quot+(1<<16))>>16);
366                 }
367                 else
368                 {
369                     /* This pixel isn't masked. It's thus suitable as a
370                      * previous color for the next interpolation */
371                     prev = p_outpix[x];
372                     prev_x = x;
373                 }
374             }
375         }
376
377         /* Vertical bluring */
378         p_mask = p_sys->p_mask->A_PIXELS;
379         i_height = b_line_factor ? i_mask_visible_lines>>1
380                                  : i_mask_visible_lines;
381         /* Make sure that we stop at least 2 lines before the picture's end
382          * (since our bluring algorithm uses the 2 next lines) */
383         i_height = __MIN( i_visible_lines - i_y - 2, i_height );
384         /* Make sure that we start at least 2 lines from the top (since our
385          * bluring algorithm uses the 2 previous lines) */
386         y = __MAX(i_y,2);
387         p_outpix = p_outpic->p[i_plane].p_pixels + (i_y+y)*i_pitch + i_x;
388         for( ; y < i_height; y++, p_mask += i_mask_pitch, p_outpix += i_pitch )
389         {
390             for( x = 0; x < i_width; x++ )
391             {
392                 if( p_mask[i_plane?x<<1:x] > 127 )
393                 {
394                     /* Ugly bluring function */
395                     p_outpix[x] =
396                         ( (p_outpix[x-i_2pitch]<<1)       /* 2 */
397                         + (p_outpix[x-i_pitch ]<<2)       /* 4 */
398                         + (p_outpix[x         ]<<2)       /* 4 */
399                         + (p_outpix[x+i_pitch ]<<2)       /* 4 */
400                         + (p_outpix[x+i_2pitch]<<1) )>>4; /* 2 */
401                 }
402             }
403         }
404     }
405 }
406
407 static int EraseCallback( vlc_object_t *p_this, char const *psz_var,
408                           vlc_value_t oldval, vlc_value_t newval, void *p_data )
409 {
410     VLC_UNUSED(oldval);
411     filter_sys_t *p_sys = (filter_sys_t *)p_data;
412
413     if( !strcmp( psz_var, CFG_PREFIX "x" ) )
414     {
415         vlc_mutex_lock( &p_sys->lock );
416         p_sys->i_x = newval.i_int;
417         vlc_mutex_unlock( &p_sys->lock );
418     }
419     else if( !strcmp( psz_var, CFG_PREFIX "y" ) )
420     {
421         vlc_mutex_lock( &p_sys->lock );
422         p_sys->i_y = newval.i_int;
423         vlc_mutex_unlock( &p_sys->lock );
424     }
425     else if( !strcmp( psz_var, CFG_PREFIX "mask" ) )
426     {
427         vlc_mutex_lock( &p_sys->lock );
428         LoadMask( (filter_t*)p_this, newval.psz_string );
429         vlc_mutex_unlock( &p_sys->lock );
430     }
431     else
432     {
433         msg_Warn( p_this, "Unknown callback command." );
434     }
435     return VLC_SUCCESS;
436 }