git.sesse.net Git - vlc/blob - modules/video_filter/gaussianblur.c

   1 /*****************************************************************************
   2  * gaussianblur.c : gaussian blur video filter
   3  *****************************************************************************
   4  * Copyright (C) 2000-2007 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
  35 #include "vlc_filter.h"
  36 #include "filter_picture.h"
  37
  38 #include <math.h>                                          /* exp(), sqrt() */
  39
  40 /*****************************************************************************
  41  * Module descriptor
  42  *****************************************************************************/
  43 static int  Create    ( vlc_object_t * );
  44 static void Destroy   ( vlc_object_t * );
  45
  46 #define SIGMA_TEXT N_("Gaussian's std deviation")
  47 #define SIGMA_LONGTEXT N_( \
  48     "Gaussian's standard deviation. The bluring will take " \
  49     "into account pixels up to 3*sigma away in any direction.")
  50
  51 #define FILTER_PREFIX "gaussianblur-"
  52
  53 vlc_module_begin ()
  54     set_description( N_("Gaussian blur video filter") )
  55     set_shortname( N_( "Gaussian Blur" ))
  56     set_capability( "video filter2", 0 )
  57     set_category( CAT_VIDEO )
  58     set_subcategory( SUBCAT_VIDEO_VFILTER )
  59
  60     add_float( FILTER_PREFIX "sigma", 2., NULL, SIGMA_TEXT, SIGMA_LONGTEXT,
  61                false )
  62
  63     set_callbacks( Create, Destroy )
  64 vlc_module_end ()
  65
  66 /*****************************************************************************
  67  * Local prototypes
  68  *****************************************************************************/
  69 static picture_t *Filter( filter_t *, picture_t * );
  70
  71 static const char *const ppsz_filter_options[] = {
  72     "sigma", NULL
  73 };
  74
  75 /* Comment this to use floats instead of integers (faster for bigger sigma
  76  * values)
  77  * For sigma = 2 ints are faster
  78  * For sigma = 4 floats are faster
  79  */
  80 #define DONT_USE_FLOATS
  81
  82 #ifdef DONT_USE_FLOATS
  83 #   define type_t int
  84 #else
  85 #   define type_t float
  86 #endif
  87
  88 struct filter_sys_t
  89 {
  90     double f_sigma;
  91     int i_dim;
  92
  93     type_t *pt_distribution;
  94     type_t *pt_buffer;
  95     type_t *pt_scale;
  96 };
  97
  98 static void gaussianblur_InitDistribution( filter_sys_t *p_sys )
  99 {
 100     double f_sigma = p_sys->f_sigma;
 101     int i_dim = (int)(3.*f_sigma);
 102     type_t *pt_distribution = malloc( (2*i_dim+1) * sizeof( type_t ) );
 103     int x;
 104
 105     for( x = -i_dim; x <= i_dim; x++ )
 106     {
 107         const float f_distribution = sqrt( exp(-(x*x)/(f_sigma*f_sigma) ) / (2.*M_PI*f_sigma*f_sigma) );
 108 #ifdef DONT_USE_FLOATS
 109         const float f_factor = 1 << 8;
 110 #else
 111         const float f_factor = 1;
 112 #endif
 113
 114         pt_distribution[i_dim+x] = (type_t)( f_distribution * f_factor );
 115         //printf("%f\n",(float)pt_distribution[i_dim+x]);
 116     }
 117     p_sys->i_dim = i_dim;
 118     p_sys->pt_distribution = pt_distribution;
 119 }
 120
 121 static int Create( vlc_object_t *p_this )
 122 {
 123     filter_t *p_filter = (filter_t *)p_this;
 124
 125     if(   p_filter->fmt_in.video.i_chroma != VLC_CODEC_I420
 126        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_J420
 127        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_YV12
 128
 129        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_I422
 130        && p_filter->fmt_in.video.i_chroma != VLC_CODEC_J422
 131       )
 132     {
 133         /* We only want planar YUV 4:2:0 or 4:2:2 */
 134         msg_Err( p_filter, "Unsupported input chroma (%4s)",
 135                  (char*)&(p_filter->fmt_in.video.i_chroma) );
 136         return VLC_EGENERIC;
 137     }
 138
 139     if( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma )
 140     {
 141         msg_Err( p_filter, "Input and output chromas don't match" );
 142         return VLC_EGENERIC;
 143     }
 144
 145     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 146     if( p_filter->p_sys == NULL )
 147         return VLC_ENOMEM;
 148
 149     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
 150                        p_filter->p_cfg );
 151
 152     p_filter->pf_video_filter = Filter;
 153
 154     p_filter->p_sys->f_sigma =
 155         var_CreateGetFloat( p_filter, FILTER_PREFIX "sigma" );
 156     if( p_filter->p_sys->f_sigma <= 0. )
 157     {
 158         msg_Err( p_filter, "sigma must be positive" );
 159         return VLC_EGENERIC;
 160     }
 161     gaussianblur_InitDistribution( p_filter->p_sys );
 162     msg_Dbg( p_filter, "gaussian distribution is %d pixels wide",
 163              p_filter->p_sys->i_dim*2+1 );
 164
 165     p_filter->p_sys->pt_buffer = NULL;
 166     p_filter->p_sys->pt_scale = NULL;
 167
 168     return VLC_SUCCESS;
 169 }
 170
 171 static void Destroy( vlc_object_t *p_this )
 172 {
 173     filter_t *p_filter = (filter_t *)p_this;
 174
 175     free( p_filter->p_sys->pt_distribution );
 176     free( p_filter->p_sys->pt_buffer );
 177     free( p_filter->p_sys->pt_scale );
 178
 179     free( p_filter->p_sys );
 180 }
 181
 182 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 183 {
 184     picture_t *p_outpic;
 185     filter_sys_t *p_sys = p_filter->p_sys;
 186     int i_plane;
 187     const int i_dim = p_sys->i_dim;
 188     type_t *pt_buffer;
 189     type_t *pt_scale;
 190     const type_t *pt_distribution = p_sys->pt_distribution;
 191
 192     if( !p_pic ) return NULL;
 193
 194     p_outpic = filter_NewPicture( p_filter );
 195     if( !p_outpic )
 196     {
 197         picture_Release( p_pic );
 198         return NULL;
 199     }
 200     if( !p_sys->pt_buffer )
 201     {
 202         p_sys->pt_buffer = realloc( p_sys->pt_buffer,
 203                                     p_pic->p[Y_PLANE].i_visible_lines *
 204                                         p_pic->p[Y_PLANE].i_pitch *
 205                                         sizeof( type_t ) );
 206     }
 207
 208     pt_buffer = p_sys->pt_buffer;
 209     if( !p_sys->pt_scale )
 210     {
 211         const int i_visible_lines = p_pic->p[Y_PLANE].i_visible_lines;
 212         const int i_visible_pitch = p_pic->p[Y_PLANE].i_visible_pitch;
 213         const int i_pitch = p_pic->p[Y_PLANE].i_pitch;
 214         int i_col, i_line;
 215
 216         p_sys->pt_scale = malloc( i_visible_lines * i_pitch * sizeof( type_t ) );
 217         pt_scale = p_sys->pt_scale;
 218
 219         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 220         {
 221             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 222             {
 223                 int x, y;
 224                 type_t t_value = 0;
 225
 226                 for( y = __MAX( -i_dim, -i_line );
 227                      y <= __MIN( i_dim, i_visible_lines - i_line - 1 );
 228                      y++ )
 229                 {
 230                     for( x = __MAX( -i_dim, -i_col );
 231                          x <= __MIN( i_dim, i_visible_pitch - i_col + 1 );
 232                          x++ )
 233                     {
 234                         t_value += pt_distribution[y+i_dim] *
 235                                    pt_distribution[x+i_dim];
 236                     }
 237                 }
 238                 pt_scale[i_line*i_pitch+i_col] = t_value;
 239             }
 240         }
 241     }
 242
 243     pt_scale = p_sys->pt_scale;
 244     for( i_plane = 0 ; i_plane < p_pic->i_planes ; i_plane++ )
 245     {
 246
 247         uint8_t *p_in = p_pic->p[i_plane].p_pixels;
 248         uint8_t *p_out = p_outpic->p[i_plane].p_pixels;
 249
 250         const int i_visible_lines = p_pic->p[i_plane].i_visible_lines;
 251         const int i_visible_pitch = p_pic->p[i_plane].i_visible_pitch;
 252         const int i_pitch = p_pic->p[i_plane].i_pitch;
 253
 254         int i_line, i_col;
 255         const int x_factor = p_pic->p[Y_PLANE].i_visible_pitch/i_visible_pitch-1;
 256         const int y_factor = p_pic->p[Y_PLANE].i_visible_lines/i_visible_lines-1;
 257
 258         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 259         {
 260             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 261             {
 262                 type_t t_value = 0;
 263                 int x;
 264                 const int c = i_line*i_pitch+i_col;
 265                 for( x = __MAX( -i_dim, -i_col*(x_factor+1) );
 266                      x <= __MIN( i_dim, (i_visible_pitch - i_col)*(x_factor+1) + 1 );
 267                      x++ )
 268                 {
 269                     t_value += pt_distribution[x+i_dim] *
 270                                p_in[c+(x>>x_factor)];
 271                 }
 272                 pt_buffer[c] = t_value;
 273             }
 274         }
 275         for( i_line = 0 ; i_line < i_visible_lines ; i_line++ )
 276         {
 277             for( i_col = 0; i_col < i_visible_pitch ; i_col++ )
 278             {
 279                 type_t t_value = 0;
 280                 int y;
 281                 const int c = i_line*i_pitch+i_col;
 282                 for( 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_pitch];
 288                 }
 289
 290                 const type_t t_scale = pt_scale[(i_line<<y_factor)*(i_pitch<<x_factor)+(i_col<<x_factor)];
 291                 p_out[c] = (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 }