modules/video_filter/gaussianblur.c

   1 /*****************************************************************************
   2  * gaussianblur.c : gaussian blur video filter
   3  *****************************************************************************
   4  * Copyright (C) 2000-2007 VLC authors and VideoLAN
   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 it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * 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_memory.h>
  35 #include <vlc_filter.h>
  36 #include <vlc_picture.h>
  37 #include "filter_picture.h"
  38
  39 #include <math.h>                                          /* exp(), sqrt() */
  40
  41 /*****************************************************************************
  42  * Module descriptor
  43  *****************************************************************************/
  44 static int  Create    ( vlc_object_t * );
  45 static void Destroy   ( vlc_object_t * );
  46
  47 #define SIGMA_MIN (0.01)
  48 #define SIGMA_MAX (4096.0)
  49
  50 #define SIGMA_TEXT N_("Gaussian's std deviation")
  51 #define SIGMA_LONGTEXT N_( \
  52     "Gaussian's standard deviation. The blurring will take " \
  53     "into account pixels up to 3*sigma away in any direction.")
  54
  55 #define GAUSSIAN_HELP N_("Add a blurring effect")
  56
  57 #define FILTER_PREFIX "gaussianblur-"
  58
  59 vlc_module_begin ()
  60     set_description( N_("Gaussian blur video filter") )
  61     set_shortname( N_( "Gaussian Blur" ))
  62     set_help(GAUSSIAN_HELP)
  63     set_capability( "video filter", 0 )
  64     set_category( CAT_VIDEO )
  65     set_subcategory( SUBCAT_VIDEO_VFILTER )
  66
  67     add_float_with_range( FILTER_PREFIX "sigma", 2., SIGMA_MIN, SIGMA_MAX,
  68                           SIGMA_TEXT, SIGMA_LONGTEXT,
  69                           false )
  70
  71     set_callbacks( Create, Destroy )
  72 vlc_module_end ()
  73
  74 /*****************************************************************************
  75  * Local prototypes
  76  *****************************************************************************/
  77 static picture_t *Filter( filter_t *, picture_t * );
  78
  79 static const char *const ppsz_filter_options[] = {
  80     "sigma", NULL
  81 };
  82
  83 /* Comment this to use floats instead of integers (faster for bigger sigma
  84  * values)
  85  * For sigma = 2 ints are faster
  86  * For sigma = 4 floats are faster
  87  */
  88 #define DONT_USE_FLOATS
  89
  90 #ifdef DONT_USE_FLOATS
  91 #   define type_t int
  92 #else
  93 #   define type_t float
  94 #endif
  95
  96 struct filter_sys_t
  97 {
  98     double f_sigma;
  99     int i_dim;
 100
 101     type_t *pt_distribution;
 102     type_t *pt_buffer;
 103     type_t *pt_scale;
 104 };
 105
 106 static void gaussianblur_InitDistribution( filter_sys_t *p_sys )
 107 {
 108     double f_sigma = p_sys->f_sigma;
 109     int i_dim = (int)(3.*f_sigma);
 110     type_t *pt_distribution = xmalloc( (2*i_dim+1) * sizeof( type_t ) );
 111
 112     for( int x = -i_dim; x <= i_dim; x++ )
 113     {
 114         const float f_distribution = sqrt( exp(-(x*x)/(f_sigma*f_sigma) ) / (2.*M_PI*f_sigma*f_sigma) );
 115 #ifdef DONT_USE_FLOATS
 116         const float f_factor = 1 << 8;
 117 #else
 118         const float f_factor = 1;
 119 #endif
 120
 121         pt_distribution[i_dim+x] = (type_t)( f_distribution * f_factor );
 122         //printf("%f\n",(float)pt_distribution[i_dim+x]);
 123     }
 124     p_sys->i_dim = i_dim;
 125     p_sys->pt_distribution = pt_distribution;
 126 }
 127
 128 static int Create( vlc_object_t *p_this )
 129 {
 130     filter_t *p_filter = (filter_t *)p_this;
 131
 132     if(   p_filter->fmt_in.video.i_chroma != VLC_CODEC_I420
 133        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_J420
 134        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_YV12
 135
 136        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_I422
 137        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_J422
 138       )
 139     {
 140         /* We only want planar YUV 4:2:0 or 4:2:2 */
 141         msg_Err( p_filter, "Unsupported input chroma (%4.4s)",
 142                  (char*)&(p_filter->fmt_in.video.i_chroma) );
 143         return VLC_EGENERIC;
 144     }
 145
 146     if( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma )
 147     {
 148         msg_Err( p_filter, "Input and output chromas don't match" );
 149         return VLC_EGENERIC;
 150     }
 151
 152     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 153     if( p_filter->p_sys == NULL )
 154         return VLC_ENOMEM;
 155
 156     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
 157                        p_filter->p_cfg );
 158
 159     p_filter->pf_video_filter = Filter;
 160
 161     p_filter->p_sys->f_sigma =
 162         var_CreateGetFloat( p_filter, FILTER_PREFIX "sigma" );
 163     if( p_filter->p_sys->f_sigma <= 0. )
 164     {
 165         msg_Err( p_filter, "sigma must be greater than zero" );
 166         return VLC_EGENERIC;
 167     }
 168     gaussianblur_InitDistribution( p_filter->p_sys );
 169     msg_Dbg( p_filter, "gaussian distribution is %d pixels wide",
 170              p_filter->p_sys->i_dim*2+1 );
 171
 172     p_filter->p_sys->pt_buffer = NULL;
 173     p_filter->p_sys->pt_scale = NULL;
 174
 175     return VLC_SUCCESS;
 176 }
 177
 178 static void Destroy( vlc_object_t *p_this )
 179 {
 180     filter_t *p_filter = (filter_t *)p_this;
 181
 182     free( p_filter->p_sys->pt_distribution );
 183     free( p_filter->p_sys->pt_buffer );
 184     free( p_filter->p_sys->pt_scale );
 185
 186     free( p_filter->p_sys );
 187 }
 188
 189 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 190 {
 191     picture_t *p_outpic;
 192     filter_sys_t *p_sys = p_filter->p_sys;
 193     const int i_dim = p_sys->i_dim;
 194     type_t *pt_buffer;
 195     type_t *pt_scale;
 196     const type_t *pt_distribution = p_sys->pt_distribution;
 197
 198     if( !p_pic ) return NULL;
 199
 200     p_outpic = filter_NewPicture( p_filter );
 201     if( !p_outpic )
 202     {
 203         picture_Release( p_pic );
 204         return NULL;
 205     }
 206     if( !p_sys->pt_buffer )
 207     {
 208         p_sys->pt_buffer = realloc_or_free( p_sys->pt_buffer,
 209                                p_pic->p[Y_PLANE].i_visible_lines *
 210                                p_pic->p[Y_PLANE].i_pitch * sizeof( type_t ) );
 211     }
 212
 213     pt_buffer = p_sys->pt_buffer;
 214     if( !p_sys->pt_scale )
 215     {
 216         const int i_visible_lines = p_pic->p[Y_PLANE].i_visible_lines;
 217         const int i_visible_pitch = p_pic->p[Y_PLANE].i_visible_pitch;
 218         const int i_pitch = p_pic->p[Y_PLANE].i_pitch;
 219
 220         p_sys->pt_scale = xmalloc( i_visible_lines * i_pitch * sizeof( type_t ) );
 221         pt_scale = p_sys->pt_scale;
 222
 223         for( int i_line = 0; i_line < i_visible_lines; i_line++ )
 224         {
 225             for( int i_col = 0; i_col < i_visible_pitch; i_col++ )
 226             {
 227                 type_t t_value = 0;
 228
 229                 for( int y = __MAX( -i_dim, -i_line );
 230                      y <= __MIN( i_dim, i_visible_lines - i_line - 1 );
 231                      y++ )
 232                 {
 233                     for( int x = __MAX( -i_dim, -i_col );
 234                          x <= __MIN( i_dim, i_visible_pitch - i_col + 1 );
 235                          x++ )
 236                     {
 237                         t_value += pt_distribution[y+i_dim] *
 238                                    pt_distribution[x+i_dim];
 239                     }
 240                 }
 241                 pt_scale[i_line*i_pitch+i_col] = t_value;
 242             }
 243         }
 244     }
 245
 246     pt_scale = p_sys->pt_scale;
 247     for( int i_plane = 0 ; i_plane < p_pic->i_planes ; i_plane++ )
 248     {
 249
 250         uint8_t *p_in = p_pic->p[i_plane].p_pixels;
 251         uint8_t *p_out = p_outpic->p[i_plane].p_pixels;
 252
 253         const int i_visible_lines = p_pic->p[i_plane].i_visible_lines;
 254         const int i_visible_pitch = p_pic->p[i_plane].i_visible_pitch;
 255         const int i_in_pitch = p_pic->p[i_plane].i_pitch;
 256
 257         const int x_factor = p_pic->p[Y_PLANE].i_visible_pitch/i_visible_pitch-1;
 258         const int y_factor = p_pic->p[Y_PLANE].i_visible_lines/i_visible_lines-1;
 259
 260         for( int i_line = 0; i_line < i_visible_lines; i_line++ )
 261         {
 262             for( int i_col = 0; i_col < i_visible_pitch; i_col++ )
 263             {
 264                 type_t t_value = 0;
 265                 const int c = i_line*i_in_pitch+i_col;
 266                 for( int x = __MAX( -i_dim, -i_col*(x_factor+1) );
 267                      x <= __MIN( i_dim, (i_visible_pitch - i_col)*(x_factor+1) + 1 );
 268                      x++ )
 269                 {
 270                     t_value += pt_distribution[x+i_dim] *
 271                                p_in[c+(x>>x_factor)];
 272                 }
 273                 pt_buffer[c] = t_value;
 274             }
 275         }
 276         for( int i_line = 0; i_line < i_visible_lines; i_line++ )
 277         {
 278             for( int i_col = 0; i_col < i_visible_pitch; i_col++ )
 279             {
 280                 type_t t_value = 0;
 281                 const int c = i_line*i_in_pitch+i_col;
 282                 for( int y = __MAX( -i_dim, (-i_line)*(y_factor+1) );
 283                      y <= __MIN( i_dim, (i_visible_lines - i_line)*(y_factor+1) - 1 );
 284                      y++ )
 285                 {
 286                     t_value += pt_distribution[y+i_dim] *
 287                                pt_buffer[c+(y>>y_factor)*i_in_pitch];
 288                 }
 289
 290                 const type_t t_scale = pt_scale[(i_line<<y_factor)*(i_in_pitch<<x_factor)+(i_col<<x_factor)];
 291                 p_out[i_line * p_outpic->p[i_plane].i_pitch + i_col] = (uint8_t)(t_value / t_scale); // FIXME wouldn't it be better to round instead of trunc ?
 292             }
 293         }
 294     }
 295
 296     return CopyInfoAndRelease( p_outpic, p_pic );
 297 }